ARTIFICIAL WEATHERING REVEALS REDUCED ELEMENTAL LEACHABILITY FROM HARDENED BIOMASS ASH by Erwin Rehl B.Sc., University o f Northern British Columbia (2010) THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF M ASTER OF SCIENCE IN CHEMISTRY UNIVERSITY OF NORTHERN BRITISH COLUMBIA April 2014 © Erwin Rehl, 2014 UMI Number: 1525703 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. Di!ss0?t&iori Publishing UMI 1525703 Published by ProQuest LLC 2014. Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 ABSTRACT Biomass ashes are potential soil amendments that reduce soil acidity and provide plant nutrients, but trace elements in ash may be leached from the solid phase, thereby posing environmental concerns. We determined the leachability o f major and trace elements as influenced by ash pre-treatments, the presence o f soil, and the pH o f the receiving environment. Weathering was simulated by serial batch extraction where pH was uncontrolled, and by single extraction under controlled pH conditions. We found that hardening reduced the solubility o f ash, and reduced the leachability o f Al, Ba, Ca, Cu, Mo, Sr, and V, as determined by ICP-MS. In a separate experiment, extractions o f ash samples showed that when pH was lowered the leachability o f most elements increased while a few decreased. The results o f the weathering experiments support the use o f ash as a soil amendment. TABLE OF CONTENTS ABSTRACT TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES GLOSSARY ACKNOWLEDGMENTS 1.0 INTRODUCTION ii iii v vi viii x 1 1.1. Background 1 1.2. Chemical and Physical Properties o f Biomass Ashes 2 1.3. Use o f Biomass Ash as Soil Amendment 5 1.4. Leaching and W eathering Properties o f Biomass Ash 8 1.5. Problem Formation and Overall Approach 13 1.6. Thesis Project Research Objectives 14 2.0 Characterization and Long Term Weathering o f Bottom Ash 15 2.1. INTRODUCTION 15 2.2. METHODOLOGY 17 2.2.1. Collection o f Bottom Ash from UNBC Gasifier 17 2.2.2. Preparation o f Collected Bottom Ash 17 2.2.3. Preparation o f Hardened Bottom Ash 2.2.4. Collection and Preparation o f Soil 2.2.5. Characterization o f Ash and Soil Samples 17 18 18 2.2.5.1. Electrical Conductivity (EC) and pH 2.2.5.2. Gravimetric Moisture Content 18 19 2.2.5.3. Effective Cation Exchange Capacity (CEC) for Soil 2.2.5.4. Particle-Size Analysis o f Soil 2.2.5.5. Calcium Carbonate Equivalency (CCE) 19 19 20 2.2.5.6. Elemental and Total C/N/S Analysis 2.2.6. Serial Batch Extraction (Long-Term Weathering) 2.2.7. Statistical Analysis o f Serial Batch Extraction 2.2.8. MINTEQ Modelling 2.3. RESULTS 2.3.1. Initial Properties o f Ash and Soil 2.3.2. Serial Batch Extraction 2.3.2.1. Changes in Solid Phase Composition During Long-Term Weathering 2.3.2.2. Aqueous Phase Chemistry During Long-Term Weathering 2.3.3. Geochemical Modelling o f Serial Batch Extraction 21 21 23 23 25 25 31 31 34 40 2.4. DISCUSSION 2.4.1. Initial Characterization and Composition o f Ashes 2.4.2. Simulated Long-Term Weathering o f Ash - Hardened versus Non-Hardened 46 46 47 2.4.3. MINTEQ Analysis o f Serial Batch Extraction - Hardened versus NonHardened 52 iii 2.4.3.1. Changes in Secondary Mineral Formation Over Time 52 2.4.3.2. Changes in Secondary Mineral Formation Between Hardened and NonHardened Ash 2.4.4. Ash as a Soil Amendment 55 2.4.5. Simulated Long-Term Weathering o f Ash-Soil M ixtures 57 2.4.6. Concluding Thoughts 60 3.0 pH Dependent Leaching o f Bottom and Hardened Bottom Ash 54 62 3.1. INTRODUCTION 62 3.2. METHODOLOGY 63 3.2.1. Preparation o f Bottom and Hardened Bottom Ash 63 3.2.2. pH Static Experiment 63 3.3. RESULTS 64 3.3.1. Electrical Conductivity o f Aqueous Extracts 3.3.2. Aqueous Concentration o f M ajor Elements Versus pH 64 65 3.3.3. Aqueous Concentration o f M inor Elements Versus pH 69 3.3.4. Percent Loss for Individual Elements Leached from Ash into the Aqueous Phase 3.3.5. Aqueous Ion Concentrations Compared to Aquatic Criteria 74 3.4. DISCUSSION 3.4.1. pH Static Leaching o f Ash - Hardened Versus Non-Hardened Ash 3.4.2. Implications o f Ash Utilization on Land 3.4.3. Concluding Thoughts 77 79 79 82 83 4.0 CONCLUSION 85 LITERATURE CITED APPENDICES SECTION A 89 97 APPENDICES SECTION B 167 iv LIST OF TABLES Table 1.0 Table 2.0 Table 2.1 Table 2.2 Table 2.3 Table 2.4 Table 2.5 Table 2.6 Table 2.7 Table 2.8 Table 2.9 Table 2.10 Table 3.0 Table 3.1 Table 3.2 Average elemental composition (shown with standard deviation) o f wood fly and bottom ashes and coal fly ashes. Initial (solid phase) properties o f bottom ash (BA), hardened bottom ash (HBA) and soil control prior to serial batch extraction and allowable limits for several monitored elements by Soil Amendment Code o f Practice (SACoP), Alberta, Denmark, Finland and Sweden. Relative enrichment o f elements contained within bottom ash and hardened bottom ash relative to soil control. M ass loss (%) o f individual elements over the 20-cycle serial batch extraction for bottom ash, hardened bottom ash, soil control, 5% bottom ash, and 5% hardened bottom ash, relative to initial masses present in the solid phase within each experimental unit (determined via ICP-OES following HNO 3/HCI digestion). Percent loss o f elements over 20-cycle serial batch extraction relative to initial contents in solid phase as determined by ICP-OES following HNO 3/HCI digestion. Percent loss o f elements over 20-cycle serial batch extraction relative to initial contents in solid phase as determined by ICP-OES following HNO 3/HF/H 2BO 3 digestion. Ratio o f HBA to BA for elemental concentrations in aqueous extracts during days 1, 2, 3, 4, 10 and 20 in the serial batch extraction study; lower values (e.g. < 1) indicate reduced elemental leaching due to HBA treatment. Saturation index for bottom ash leachates during days 1,1 0 and 20 predicting mineral formation from Visual MINTEQ, ver. 3.0. Saturation index for hardened bottom ash leachates during days 1,10 and 20 predicting mineral formation from Visual MINTEQ, ver. 3.0. Saturation index for soil leachates during days 1,10 and 20 predicting mineral formation from Visual MINTEQ, ver. 3.0. Saturation index for 5% bottom ash leachates during days 1,10 and 20 predicting mineral formation from Visual MINTEQ, ver. 3.0. Saturation index for 5% hardened bottom ash leachates during days 1,10 and 20 predicting mineral formation from Visual MINTEQ, ver. 3.0. Percent loss for elements leached from bottom ash based on original solid phase concentrations (from HNO 3/HCI digest) and amount o f ash used during pH static experiment for pH 10 to 4. Percent loss for elements leached from hardened bottom ash based on original solid phase concentrations (from HNO 3/HCI digest) and amount o f ash used during pH static experiment for pH 10 to 4. M aximum concentrations (ppm and ppb as indicated) reached for the major and minor elements from pH static testing compared to allowable limits set by British Columbia Contaminated Sites Regulation (BCCSR). 3 27 30 32 33 33 36 41 42 43 44 45 75 76 78 LIST OF FIGURES Figure 2.0 Figure 2.1 Figure 2.2 Figure 2.3 Figure 2.4 Figure 3.0 Figure 3.1 Figure 3.2 Figure 3.3 Figure 3.4 Figure 3.5 Figure 3.6 Figure 3.7 Figure 3.8 Figure 3.9 Figure 3.10 Figure 3.11 Figure 3.12 Figure 3.13 Serial batch extraction o f bottom ash, hardened bottom ash, soil, and 5% bottom and hardened bottom ash mixed with soil depicting pH values (with standard deviation error bars) over the twenty day timeline. Serial batch extraction o f bottom ash, hardened bottom ash, soil, and 5% bottom and hardened bottom ash mixed with soil depicting electrical conductivity (EC) values over the twenty day timeline. Leachates from serial batch extraction showing bromine, fluorine, nitrite, nitrate and phosphate concentrations (ppm) contained within the extracts from days 1,10 and 20 o f the five treatments (BA, HBA, Soil, 5%BA and 5%HBA). Leachates from serial batch extraction showing chlorine and sulphate concentrations (ppm) contained within the extracts from days 1 , 1 0 and 2 0 o f the five treatments (BA, HBA, Soil, 5%BA and 5%HBA). Leachates from serial batch extraction showing alkalinity as C aC 03 (ppm) contained within the extracts from days 1 , 1 0 and 2 0 o f the five treatments (BA, HBA, Soil, 5%BA and 5%HBA). Electrical conductivity results (mS/cm) for aqueous extracts from bottom and hardened bottom ash ranging from pH 4 to 10 from pH static experiment. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing aluminum, Al, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing calcium, Ca, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing iron, Fe, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing potassium, K, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing magnesium, Mg, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing manganese, Mn, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing sodium, Na, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing phosphorus, P, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing silicon, Si, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing arsenic, As, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing boron, B, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing barium, Ba, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing cadmium, Cd, concentration (mg/L) changes against pH. vi 34 35 38 38 39 65 66 66 66 67 67 67 68 68 68 69 69 70 70 Figure 3.14 Figure 3.15 Figure 3.16 Figure 3.17 Figure 3.18 Figure 3.19 Figure 3.20 Figure 3.21 Figure 3.22 Figure 3.23 Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing cobalt, Co, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing chromium, Cr, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing copper, Cu, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing mercury, Hg, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing molybdenum, Mo, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing nickel, Ni, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing lead, Pb, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing selenium, Se, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing strontium, Sr, concentration (mg/L) changes against pH. Leaching profile for bottom ash (BA) and hardened bottom ash (HBA) showing zinc, Zn, concentration (mg/L) changes against pH. 70 71 71 71 72 72 72 73 73 73 G LO SSA RY A cronym s 5 % Bottom Ash 5% Hardened Bottom Ash Bottom Ash British Columbia British Columbia Contaminated Sites Regulation Calcium Carbonate Equivalency Central Equipment Laboratory Drinking Water Dissolved Organic Carbon Electrical Conductivity Enhanced Forestry Lab Electric Power Research Institute Freshwater Aquatic Life Hardened Bottom Ash Inductively Coupled Plasma Mass Spectroscopy Inductively Coupled Plasma Optical Emissions Spectroscopy Liquid/Solid Ratio Marine Aquatic Life Oven Dry Organic Matter Recycling Regulations (British Columbia) Oxidation Reduction Potential Polycyclic Aromatic Hydrocarbons Quality Assurance / Quality Control Soil Amendment Code o f Practice (British Columbia) University o f Northern British Columbia weight/weight X-Ray Powder Diffraction X-Ray Fluorescence 5%BA 5%HBA BA BC BCCSR CCE CEL DW DOC EC EFL EPRI FAL HBA ICP-MS ICP-OES L/S MAL OD OMRR ORP PAH QA/QC SACoP UNBC w/w XRD XRF E lem ental Symbols an d T h eir Names Symbol Ag Al As B Ba Be Bi Ca Cd Co Cr Cu Fe N am e Silver Aluminum Arsenic Boron Barium Beryllium Bismuth Calcium Cadmium Cobalt Chromium Copper Iron Symbol Hg K Li Mg Mn Mo Na Ni P Pb S Sb Se N ame Mercury Potassium Lithium Magnesium Manganese Molybdenum Sodium Nickel Phosphorus Lead Sulphur Antimony Selenium viii Symbol Si Sn Sr Te Th Ti T1 U V W Y Zn Zr N am e Silicon Tin Strontium Tellurium Thorium Titanium Tantalum Uranium Vanadium Tungsten Yttrium Zinc Zirconium Mineral Formulas Name Amorphous Gibbsite Gibbsite (Soil) Aluminum (III) oxide Basaluminite Aragonite Barite Boehmite Brucite Tricalcium phosphate Calcite (hydrated solid) Calcite Chloropyromorphite(c) Chrysotile Cobalt Ferrite Cupric Ferrite Diaspore Dolomite (disordered) Dolomite (ordered) Fluoroapatite Akaganeite Ferrihydrite Ferrihydrite (aged) Gibbsite (C) Goethite Halloysite Hausmannite Hematite Formula Al(OH)3 (am) Al(OH)3 a 120 3 A1 4(O H ),oS 04 C aC 0 3 B aS 0 4 AIO(OH) Mg(OH)2 Ca3(P 0 4)2 (beta) C aC 0 3*H20 (s) C aC 0 3 Pb5(PH4)3Cl Mg3(Si20 5)(0H )4 CoFe20 4 CuFe20 4 AIO(OH) C aM g(C 03)2 C aM g(C 03)2 FC 0 3 -Apatite Fe(OH)2 7CI0.3 Fe2O 3*0.5(H2O) Fe2O3*0.5(H2O) Al(OH)3 FeO(OH) Al2Si20 5(0 H )4 Mn30 4 Fe20 3 Formula Name Hydroxyapatite Ca5(P 0 4)3(0 H ) Imogolite Al2S i0 3(0 H )4 Al2Si20 5(0 H )4 Kaolinite KFe3(S 0 4)2(0 H )6 K-Jarosite Lepidocrocite FeO(OH) Maghemite Fe20 3 Magnesioferrite MgFe20 4 MnO(OH) Manganite Magnesiochromite MgCr20 4 Manganese hydrogenphosphate M nH P 04 Plumbgummite PbAl3(P 0 4)2(0 H )5-(H20 ) T i0 2 Rutile Clinocervantite Sb20 4 Mg 4Si60 i5 , 6H20 Sepiolite Mg4Si60i5*6H20 Sepiolite (A) SnS04 Tin (I) sulphate F e(P 04)*2(H20 ) Strengite Strontianite S rC 0 3 CuO Tenorite(c) Thorium (IV) hydroxide Th(OH)4 Th02 Thorium (IV) oxide Vaterite C aC 0 3 B aC 0 3 Witherite Yttrium hydroxide Y(OH)3 y p o 4*h 2o Yttrium phosphate Yttrium phosphate ypo4 A C K N O W LED G M EN TS Foremost, I would like to express my sincere gratitude to my supervising professors, Dr. Kerry Reimer and Dr. Michael Rutherford, for their continuous support, patience, motivation, and immense knowledge during my time as a graduate student at UNBC. I would also like to thank my committee members, Dr. Todd W hitcombe and Dr. Steve Helle, and external examiner Dr. W illiam McGill, for their encouraging comments, and feedback on my thesis, and during the oral defence. Many thanks also go out to Dr. Joselito Arocena for providing much needed help during MINTEQ modelling, the engineering staff at the UNBC gasification plant (Doug Carter and Dale Martens) for helping me collect bottom ash samples, and the analytical services provided by the BC M inistry o f Environment (Clive Dawson and Amber Sadowy), and the UNBC Central Equipment Laboratory (Allen Esler and Quangi Wu). Finally, I would like to thank m y family and friends for supporting me throughout my entire undertaking o f this masters. “Keep calm and carry on ” - Winston Churchill 1.0 INTRODUCTION 1.1 Background Combustion o f fossil fuels with the associated greenhouse gas emissions are an increasing environmental concern. Consequently, clean, efficient alternative forms o f energy are in demand. One way to reduce the need for fossil fuel combustion is through the use o f biomass as fuel. Bioenergy refers to processes whereby heat and/or electricity are generated by utilizing biomass (McKendry 2002a,b). Several types o f bioenergy systems exist, which include boilers, pyrolysis systems, and gasifiers. Each o f these thermo-chemical processes utilize biological materials derived from living or recently living organisms (as distinct from coal or petroleum). Plant biomass is the most common fuel used in bioenergy systems, chiefly wood products and wood residues. Gasification is a thermochemical process in which biomass is incinerated with limited amounts o f oxygen to create a combustible gas stream; the gas is then combusted in an oxygen rich environment (McKendry, 2002a). Incineration temperature can reach up to 1200°C, depending on the process (McKendry, 2002b). The generated gas stream can be used as a fuel for energy generation, or to provide feed stocks for chemical synthesis, such as liquid fuels generated using the Fischer-Tropsch process (McKendry, 2002a; Isayama and Saka, 2008; Penniall and Williamson, 2009). The product gas, produced by gasification, is generally 40-50% N 2 , 15-20% H2, 10-15% CO, 10-15% CO 2, and 3-5% CH4 (McKendry, 2002b). The percent range o f the product gases from gasification can be attributed to the use o f different types o f biomass. During the gasification process almost all o f the organic components (e.g. carbon) in the biomass evolve as gas. The leftover residue consists mainly o f inorganic elements and very little carbon, and is known as biomass ash. The ash content o f woody biomass is 1.6% for aspen, 0.69% for birch, 0.48% for douglas-fir, and 0.53% for spruce (Venner et al., 2011). Furthermore, 1 Pitman (2006) also notes that bark typically has more ash content than stem-wood; 6 % and 0.25% respectively. Uses for biomass ash, beyond disposal in landfills, have also been found. These include the incorporation o f fly ash into cement products (Rajamma et al., 2009; Wang et al., 2008) and internal wall partitions (Leiva et al., 2009). Potential utilization o f biomass ash as a soil amendment has also been investigated, but is still an under-researched area. The management and utilization o f biomass ashes depends primarily upon its physical and chemical properties. 1.2 Chemical and Physical Properties of Biomass Ashes Biomass ash can be categorized into two main types, fly ash and bottom ash (Venner et al. 2011; Demeyer et al., 2001; Pitman, 2006). Easily volatilized metallic and non-metallic elements are taken with the gas stream. The formation o f fly ash occurs when some o f these metallic and non-metallic elements condense (Pitman, 2006). Condensation occurs as the volatilized elements reach cooler surfaces, away from the combustion zone (Pitman, 2006). The condensation results in fly ash that generally contains higher concentrations o f so-called “toxic” and “heavy” elements compared to bottom ash. Finally, bottom ash is the residual material that was not converted into the biogas stream (Liao et al., 2007; Augusto et al., 2008; Pitman, 2006). The volatilization o f elements during incineration can occur at different temperatures (Pichtel, 2005). Around 850°C K, Mg, Na, Bi, Cr, Ge, Li, Pb, Sn, Tl, and Zn are volatilized. At I000°C, Al, Be, Cs, Nb, Sb, Sr, Th, Y, and Zr are volatilized, alongside those elements at 850°C (Pichtel, 2005). Pitman (2006) also states that K and S volatilization occurs above 800-900°C and 1000-1200°C respectively. Elements such as Mg, Zn, Mn, P, and Si show very little change in overall concentration (in bottom ash at different burning temperatures) with changes in incineration temperature. Macro-nutrients (e.g. Ca, K, Mg, S, P) contained within the biomass are 2 retained at their highest level in the bottom ash materials when burning temperatures are between 500°C and 800°C (Pitman, 2006). The concentration o f elements contained within bottom ash and fly ash can vary due to elements that become volatilized and condense and those that remain. Furthermore, feedstock can also vary this concentration o f elements (Table 1.0) (Rehl et al., unpublished; Steenari and Lindqvist, 1997; Steenari et al., 1999; Pichtel, 2005; Liao et al., 2007). The typical elemental compositions o f several ashes can be found in Table 1.0. Table 1 . 0 - Average elemental composition (shown with standard deviation) o f wood fly and bottom ashes and coal fly ashes. Parameter Major Elements Al (%) B (ppm) Ba (ppm) Ca (%) Fe (%) K (%) M g(% ) Mn (%) Na (%) P (% ) Si (%) Sr (%) W ood Fly Ashes* Mean SD 2.62 750 1390 17.1 1.44 6.98 3.10 1.09 0.849 0.661 11.9 0.076 2.08 n/a 156 7.7 1.11 5.14 1.11 0.57 0.188 0.123 11.2 n/a Coal Fly Ashesb SD Mean Wood Bottom Ashes0 SD Mean 4.95 367 1198 4.12 3.25 0.274 0.897 0.015 0.570 0.100 4.65 0.056 2.32 n/a 3087 17.0 1.48 5.73 3.08 1.64 1.04 1.12 11.5 0.0371 4.49 333 2070 4.76 3.06 0.172 1.439 0.019 1.11 0.015 9.48 0.033 1.00 n/a 2607 10.5 0.49 3.18 0.88 0.98 0.24 0.49 2.2 n/a Trace Elements As (ppm) Cd (ppm) Co (ppm) Cr (ppm) Cu (ppm) Hg (ppm) Mo (ppm) Ni (ppm) Pb (ppm) Se (ppm) 65 30.0 41.8 46.6 116 24.0 12.9 15.3 5.05 4.31 14.8 25.5 76.4 23.0 22.6 5.5 61.0 13.5 Al 179 49.3 31.9 223 105 26.2 297 357 45 63.3 140 0.148 0.421 0.220 n/a 0.124 0.413 18.4 3.54 14.9 7.50 19.0 20.5 68 81.4 67.3 86.3 134 99.8 819 354 58.0 57.8 470 230 6.4 0.208 2.32 14.2 0.833 3.43 177 2303 2292 3577 3073 155 .Zn(PPm).......... “Compilation from wood fly ash articles (Holmberg et a l, 2000; Steenari et al., 1999; Rehl, unpublished) bCompilation from coal fly ash artilces (Dudas, 1981; Neupane et al., 2012; Talbot, 1978; Theis and Wirth, 1972) “Compilation from wood bottom ash articles (Gori et al., 2011; Steenari et al., 1999; Rehl, unpublished) Oxides o f alkali and alkali earth metals dominate the initial composition o f biomass ash. These oxides are then slowly hydrated and/or carbonated through reactions with air (Demeyer et 3 al., 2001; Pichtel, 2005; Steenari and Lindqvist, 1997). Demeyer et al. (2001) reported that the major compounds found within wood ash are calcite (CaCC^) and lime (CaO). Other constituents included riebeckite ((NaCa) 2(FeMn) 3Fe 2(SiAl)8), portlandite (Ca(OH) 2), calcium silicate (Ca 2Si0 4 ), hydrotalcite (Mg 6A li 2C 0 3 (0 H )i 6*4 H 20 ), and serandite (Na(MnCa)2Si3O g(OH)) (Demeyer et al., 2001). Steenari and Lindqvist (1997) also report the components o f grate fired boiler ashes include calcite, calcium hydroxide, calcium sulphate, and many other calcium, iron, magnesium, and aluminum compounds. Biomass ash has a very high alkalinity, typically ranging from pH 9-13 (Demeyer et al., 2001; Steenari and Lindqvist, 1997; Steenari et al., 1999; Mahmood et al., 2002; Ozolincius et al., 2007a,b). One o f the concerns associated with high pH ash is that it poses risk to ecological receptors (e.g. wildlife), and may create occupational hazards for individuals handling the material (Pitman, 2006). The calcium carbonate equivalence (CCE) has also been reported to be quite high as well, ranging from 50-90% CCE (Demeyer et al., 2001). Calcium carbonate equivalence is a measure o f how close the neutralizing capacity o f a material is compared to calcium carbonate (calcium carbonate has a CCE o f 100%). High calcium carbonate equivalency and pH are the result o f high combustion temperatures. At 1000°C oxides become dominant in ash, o f which calcium oxide (lime) is the major component. Calcium oxide has a CCE greater than 100% resulting in the high CCE observed from analyzed biomass ashes (Demeyer et al., 2001 ). Untreated ash, also termed loose ash, tends to pose several problems in regard to the utilization o f biomass ash. The primary problem is that loose ash is very fine and subject to suspension in air (i.e. is dusty). Consequently, it is hard to handle, or spread evenly, and it poses health risks to operators (Pitman, 2006). Firstly, inhalation o f alkaline ash poses an occupational risk. Secondly, loose ash can have negative effects on ground vegetation such as burning plant 4 tissue (Pitman, 2006; Mahmood et al., 2002). To overcome some o f these problems, the untreated ash can be hardened. Two current techniques are used to produce crushed or granulated ash. Self­ hardened ash is formed through moistening biomass ash to 30-60% (by mass) with water and allowing that to harden for several weeks. The self-hardened ash can then be crushed and sieved (into desired particle size ranges) for better application (Steenari and Lindqvist, 1997; Mahmood et al., 2002; Arvidsson et al., 2002; Jacobson and Gustafsson, 2001; Pitman, 2006; Steenari et al., 1999). Alternatively, granulated ash is produced by mixing ash with water and rolling the ash into balls o f 4-20mm, which are then dried to <5% water content (Pitman, 2006). Upon hardening, the mineralogical properties o f loose ash change. In addition to an increase in carbonates, cement-based minerals such as portlandite (Ca(OH) 2) and ettringite (Ca6Al2(S04)3(0H)i2*26H20) are also formed (Steenari and Lindqvist, 1997). The formation o f calcite, gypsum (C aS 04»2H20 ), allophane (Al2 0 3 Si 0 2 *2 .5 H 20 ), and imogolite (Al2 Si0 3 (0 H)4) were also detected for artificially weathered coal fly ash (Warren and Dudas, 1985). Elemental concentrations are often altered due to the hardening o f ash. For example, hardened ash tends to have lower concentrations o f calcium due to the formation o f hydrates and carbonates (Pitman, 2006). 1.3 Use o f Biom ass Ash as Soil A m endm ent Biomass ash has potential to act as a fertilizer and liming agent for agricultural and forest soils (Ozolincius et al., 2007b; Demeyer et al., 2001; McKendry, 2002b). Plants require N, P, K, Ca, Mg, and S in relatively large concentrations (macro-nutrients) and Fe, Mn, B, Zn, Cu, Cl, Co, Mo, and Ni in small concentrations (micro-nutrients) (Brady and Weil, 2002). M any o f these elements are contained within ash except for nitrogen. Concentration o f nitrogen is often low in woody biomass, and the nitrogen that is present is lost in the gas stream during combustion (Ozolincius et al., 2007b; Demeyer et al., 2001). Chemical and biological assays (bio-assays) are often conducted for specific soil-ash combinations because nutrients present in biomass ash are not necessarily present in forms that are available to plants. For example, iron is one o f the most abundant elements in soils, but under some conditions its bioavailability to plants can be limited. Similarly, phosphorus can convert to non-bioavailable forms upon reacting with soil components (McBride, 1994). Studies that have shown benefits to tree growth using biomass ash as a soil amendment include Ozolincius et al. (2007a), Arvidsson and Lundkvist (2003), Park et al. (2005), and Jacobson and Gustafsson (2001). These studies observed increased growth in plant material treated with bottom ash. Furthermore, the addition o f nitrogen to bottom ash treatments increased growth much more dramatically. Therefore, the addition o f nitrogen fertilizer (commonly ammonium nitrate, NH4NO3) is often incorporated into soil with ash. Compared to non-fertilized stands, a combination o f biomass ash and nitrogen encourages tree growth. Agricultural crop growth also benefits from biomass ash. Increased crop growth has been shown for alfalfa and barley (Meyers and Kopecky, 1998), oats and beans (Krejsl and Scanlon, 1996), and Dallis grass-fescue (Muse and Mitchell, 1995). Patterson et al. (2004) report increased barley biomass and grain yield, and canola seed response to land application o f wood ash in Alberta. These crop studies (including the tree growth studies) report using several tonnes o f ash per hectare. The potential use o f this much ash is desirable, as large amounts are generated from bioenergy plants. Biomass ash has been utilized for other types o f land applications. For instance, the remediation o f highly acidic soils has also been accomplished through the addition o f biomass ashes. Many tropical soils suffer from high acidity resulting in a high concentration o f soluble aluminum and subsequent toxicity to plants. Application o f wood ash has shown to improve 6 tropical soil quality by increasing pH and lowering the solubility o f aluminum resulting in increased growth o f rye grass as well (Nkana et al., 1998). Many jurisdictions have regulations regarding the composition o f ash materials and the quantity applied to land (Chapter 2, Table 2.0). In British Columbia, the land application regulations (Soil Amendment Code o f Practice) state that 11 trace elements (As, Cd, Cr, Co, Cu, Pb, Hg, Mo, Ni, Se and Zn) must be monitored when applications o f wood residue are applied; wood residue includes ash materials (SYLVIS, 2008) (Chapter 2, Table 2.0). Some biomass ashes contain polycyclic aromatic hydrocarbons (PAHs), dioxins and furans that originate from incomplete combustion (Sarenbo, 2009; Pitman 2006). For example, fly ash coming from the incomplete combustion o f wood in boilers may contain as much as 1.4-7.2 mg kg "1 o f PAHs in ash containing roughly 22% carbon (Sarenbo, 2009). Holmberg et al. (2000) stated that if ash carbon content is higher than 5%, then PAH analysis should be performed on ash samples. Several jurisdictions (e.g. Alberta, Sweden) have maximum allowable concentrations o f PAHs in biomass ashes. In Alberta the maximum allowable application rates are 15 tonnes ha "1 o f wood ash to agricultural soils (Alberta Environment, 2002). In British Columbia, the application o f ash materials cannot be performed if the site will become contaminated or exacerbate a contaminated site and the amendment must be applied in such a way to prevent any leachate or runoff from escaping the site (Environmental Management Act, 2007). In South Carolina, an application rate o f up to 22 tonnes ha ’ 1 o f biomass ash is allowed on agricultural lands (Williams, 1997). This requires the application o f biomass ash to be well away from wells, property lines, water ways, schools and hospitals (Williams, 1997). One concern o f ash application to land is the potential uptake o f metals by plants and animals. One study has shown that plant uptake o f non-nutrient metals is minimal in forest berries, mushrooms, and plants (Moilanen et al., 2006). M any species studied by Moilanen et al. (2006) saw decreased metal accumulation over four years compared to the control data. Cadmium was the only metal showing increased accumulation in one species o f mushroom, Russula emetic (Moilanen et al., 2006). 1.4 Leaching and Weathering Properties of Biomass Ash An understanding o f the weathering and subsequent leaching o f metals from biomass ash is critical when considering ash for use as a soil amendment. Possible concerns when applying biomass ash to land is the potential contamination o f water sources (surface or groundwater), and metal ions saturating soil and their leachability. Some o f the methods that identify metal mobility through weathering and leaching include availability testing, serial batch extractions, column leaching, pH static leaching, and the toxicity characteristic leaching procedure (TCLP) (Steenari et al., 1999; Van der Sloot et al., 1996; Wahlstrom, 1996; USEPA Method 1311, 1992). Serial batch extractions or column studies are similar in end result and tend to be the leading weathering tests performed (Chimenos et al., 2000; Dudas, 1981; Gori et al., 2011; Holmberg, et al., 2000; Neupane et al., 2012; Steenari et al., 1999; W arren and Dudas, 1985). Availability testing is used to determine the worst case scenario o f metal leaching from inorganic wastes, providing insight into the total constituents involved in the entire leaching life o f an inorganic waste (Wahlstron, 1996). Availability refers to the total loss o f metals from an inorganic material due to leaching. This test is useful for landfill sites where inorganic wastes, such as biomass ash, may be disposed (Wahlstrom, 1996; Van der Sloot et al., 1996; Lewin 1996). The availability test is a leaching procedure involving the manual alteration o f pH in two leaching cycles, providing a good technique for screening purposes o f total metal mobility from inorganic wastes. 8 Metal mobility depends largely upon pH in aqueous solution. The pH static leaching procedure has been developed to determine the leachability o f metals at specific pH values, creating a leaching profile o f any analyzed element (Van der Sloot et al., 1996). The term “static” is used to indicate that pH was maintained at a specific value throughout the single extraction period. Serial batch extraction is a leaching method involving the equilibration o f a solid waste material with a leaching medium (typically water). After equilibration, the water is extracted and the same amount is added again for another round o f equilibration. This can be done for several cycles to simulate long-term weathering. Normally, liquid to solid (L/S) ratios in batch extractions range from an L/S o f 20-100 (Wahlstrom, 1996). Liquid to solid ratios refer to the amount o f leaching medium used for the solid, by weight. Low L/S ratios more accurately represent rainwater saturation in soils, while high L/S ratios more accurately simulate contact with aqueous environments such as ponds or lakes (EPRI, 1991). Column leaching is another form o f weathering solid waste materials (similar outcome as the serial batch extractions) (Dudas, 1981; EPRI, 1991; Wahlstrom, 1996). In general, column studies involve packing the waste material o f interest within a column and saturating the material with a steady flow o f leaching medium that is run from one end o f the column and collected on the opposite end. Leaching can be studied by batch extractions or column studies; both have advantages and disadvantages (EPRI, 1991). The advantages o f batch extractions include (i) good replication and reproducibility, (ii) control o f master variables (e.g. pH, leaching medium, L/S ratio and ionic strength) are straightforward, (iii) direct evaluation o f geochemical reactions can be studied and (iv) the thermodynamic and kinetic aspects o f the geochemical reactions can be evaluated without hydrodynamic effects (EPRI, 1991). Hydrodynamic effect refers to the interaction between a 9 continuous flowing medium and particles within that medium. Batch extractions are useful weathering experiments that can provide information applicable to the field regardless o f “water flow and other real-world complications related to heterogeneity in physical and chemical properties and in the structure o f the porous medium” (EPRI, 1991, p.3-10). Limitations include the generation o f colloidal materials due to agitation that can influence surface interaction results. In addition, multi-solute chromatographic effects are more difficult to evaluate (EPRI, 1991). In contrast to batch extractions, column studies allow for the evaluation o f geochemical properties in a physical environment and can be representative o f a natural porous medium (EPRI, 1991). Furthermore, column studies allow for the evaluation o f mass transport processes and how water flux and physical attributes o f a porous medium affect the progress o f geochemical reactions (EPRI 1991). The major advantage o f column studies is their use to evaluate “how mass transport, porous media, and degree o f saturation affect the rate and overall manifestation o f geochemical reactions in flow through systems” (EPRI, 1991, p. 4-1). Limitations o f column studies include high variability between studies and replicates; also its time consuming nature. The use o f sieved or homogenized materials is not always directly applicable to the field because the structure o f the natural porous media may have been destroyed (EPRI, 1991). Several studies have employed the use o f batch extractions and column studies to study the leaching phenomena o f ash (Dudas, 1981; Holmberg et al., 2000; Steenari et al., 1999). Using batch extractions and a field study, Holmberg et al. (2000) discovered that granulated wood fly ash, containing 5% carbon and incorporated dolomite, contained some highly mobile elements (a rapid release o f S, Cl, Na, and K was seen). Based on the results o f their study, Holmberg et al. (2 0 0 0 ) concluded their specific fly ash was not suitable for land application (i.e. nutrient recycling, even though elemental levels were within recommendations for ash recycling) without 10 the addition o f dolomite, as the dolomite component (contained within the fly ash) was released very slowly. Another study analyzed wood ashes from several grate-fired boilers through short-term sequential batch extractions (Steenari et al., 1999). Steenari et al. (1999) showed that granulated and lab hardened wood ash significantly reduced calcium leaching compared to untreated wood ash. The slow release o f calcium was attributed to the formation o f calcite. However, potassium release was not slowed by granulation but rather seemed to be controlled by particle size (Steenari et al., 1999). Due to the high pH induced by wood ash, the leaching o f phosphorus and magnesium was low. Through thermodynamic modelling using EQ3NR (Wolery, 1983), Steenari et al. (1999) predicted that once a pH o f 6 is achieved (after significant leaching), only quartz (SiC>2) and aluminum hydroxide (Al(OH)3) would remain in the ash. A long term study o f fly ash from a coal fired power generation plant in Alberta, Canada, used columns to study the mobility o f select metals (Dudas, 1981). Dudas (1981) showed that Ca, B, Sr, and V were preferentially leached. Much o f the Al, Ba, Fe, K, Na, Mn, Pb, and Zn remained contained within the fly ash after leaching. Dudas (1981) concluded that coal fly ash leaching was dominated by the surface adsorbed inorganic salts. Once these salts were leached from the ash, solution concentrations o f other elements were reported at relatively low levels (Dudas, 1981). In a recent weathering experiment, a decrease in the solubility o f Ba, Ca, and Zn was observed in hardened pellet ash compared to loose ash (Rehl et al., unpublished). In contrast an increased solubility o f Cd, Mg, and P was observed in hardened ash compared to loose ash (Rehl et al., unpublished). The pH o f treated ash did not vary considerably in lab-hardened ash treatments compared to those o f non-hardened ash treatments (Rehl et al., unpublished). 11 The chemistry o f mobilized constituents from ash materials will most likely be altered once coming into contact (i.e. react) with soil. In general, the mobility o f ash constituents may be reduced due to various precipitation and sorption mechanisms (Pitman 2006). Pitman (2006) suggested that the leaching o f soluble constituents from wood ash may be attenuated by the soil itself (relating to buffering capacity). Applications o f wood ash on agricultural lands did not contaminate groundwater sources as the soil was able to attenuate many o f the leached elements (Williams, 1997). Kahl et al. (1996) concluded that leached metals from soil receiving low ash application rates ( 6 tonnes h a '1) were minimal. The buffering (i.e. attenuation) capacity o f the soil was overloaded at heavier application rates (20 tonnes h a 1) and a flux o f Ca, Mg, Cl, and SO 4 was found within leachates along with a rise in pH (Kahl et al., 1996). In contrast, trace elements were still attenuated by soil or contained within ash at 20 tonnes ha ' 1 (Kahl et al., 1996). The type o f soil that ash is applied to, can also alter/influence the leachate composition resulting from weathered ash. Small increases in Ca, K, and SO4 were observed in leachates when ash was applied to loamy sands in Maine, USA, as compared to soil controls; trace elemental concentrations were below detection limits (Williams et al., 1996). Increases in Ca, Mg, K, and S 0 4 were observed in leachates from ash applied to drained bogs in Finland (Piirainen, 2001). Leachates coming from ash applications to hapotic podzol soils contained an increased concentration o f Ca, Mg, Al, K, and SO4 compared to that o f soil controls (Saarsalmi et al., 2005). Finally, leachates taken from ash applied to podzolic soils over granite in Sweden contained increased concentrations o f Ca and K over non-treated soils (Fransman and Nihlgard, 1995). In summary, several methods are employed to study the weathering properties o f ash. The most widely used methods include serial batch extractions and column leaching studies (Dudas, 1981; Holmberg et al., 2000; Neupane et al., 2012). Most research investigations on the 12 weathering properties or utilization o f ash have been on ash derived from the combustion o f coal. Not very many studies have investigated biomass ash (Steenari and Lindqvist, 1997; Steenari et al., 1999). Furthermore, ash interaction with soil has been mainly studied using coarse-textured soil (Fransman and Nihlgard, 1995; Piirainen, 2001; Saarsalmi et al., 2005). Not much is known about the interaction between fine-textured soil and ash. 1.5 Problem Formation and Overall Approach It is apparent that biomass ash has the potential to be used as a fertilizer and amendment (i.e. liming agent) for agricultural and forest soils. Benefits include raising the pH and providing plant-essential elements. Biomass ashes tend to differ in their composition depending upon the biomass feedstock and the burning process used. Several gaps in our knowledge exist that need to be addressed. First, (i) many studies focus on fly ash generated from coal combustion or co-generation combustion o f biomass with coal and not on biomass ash (Dudas, 1981; Holmberg et al., 2000; Neupane et al., 2012); the influence o f hardening is not widely studied either (Holmberg et al., 2000; Steenari et al., 1999). Although many studies focus on coal ash, leachate studies using coal ash could be insightful to determine if the major components leached are similar to that o f biomass ash. The study o f biomass ash (specifically bottom ash and lab-hardened bottom ash) would greatly add to this knowledge. Second, (ii) the long-term mobility o f biomass ash components are relatively unknown as few studies have been done in this area (Dudas, 1981; Neupane et al., 2012). Short term studies have shown that many metals o f concern are quite immobile due to the short term increase in pH (Holmberg et al., 2000; Steenari et al., 1999). However, it is unknown how elements may behave if, or when, ash components react for significant periods o f time. Long-term leaching o f biomass ash by serial batch extractions would further advance our knowledge. Third, (iii) the interaction between soil and ash has been studied 13 mainly on coarse soils (Fransman and Nihlgard, 1995; Piirainen, 2001; Saarsalmi et al., 2005). Scandinavian researchers have examined the responses o f forest soils to ash addition for years (Fransman and Nihlgard, 1995; Piirainen, 2001; Saarsalmi et al., 2005). Studying the leachability o f major and minor elements coming from a mix o f fine-textured soils with biomass ash would add to our knowledge. Finally, (iv) leachability o f constituents from biomass ash can be influenced by pH o f the environment and is not widely studied (Dijkstra et al., 2006; Van der Sloot et al., 1996; Whalstrom, 1996). Manipulating the pH o f the environment biomass ash is contained in would identify the characteristic pH profile o f ash. This pH profile would help to understand how leaching changes. 1.6 Thesis Project Research Objectives This project evaluated the potential for UNBC gasifier bottom ash to be used as a soil amendment. This was done by analyzing the long-term weathering o f ash, hardened ash, the interaction o f ash and soil, and how dictating the pH o f the aqueous environment varied the leachability o f major and minor elements in ash and hardened ash. Two research objectives were formulated. Objective 1 To determine leachability o f major and trace elements in both hardened and unhardened bottom ash, with and without the presence o f a fine textured soil. Objective 2 To determine the leachability o f major and minor elements in both hardened and unhardened bottom ash in response to acidification. 14 2.0 Characterization and Long-Term Weathering of Bottom Ash 2.1 INTRODUCTION The combustion o f biomass in thermochemical processes, such as gasification, produces a by-product called biomass ash (McKendry, 2002a,b). This ash is divided into two categories, bottom ash and fly ash. Elements that become volatilized and carried away by the gas stream during biomass incineration are called fly ash once they condense and are caught by filters/precipitators. Bottom ash is usually dominated by the residual inorganic material leftover in the combustion/incineration chamber that did not volatilize (McKendry, 2002a,b). Bottom ash, which is generally produced in greater quantities than fly ash, is commonly landfilled. There is an interest in the utilization o f biomass ash beyond landfilling, such as a component in cement (Rajamma et al., 2009; Wang et al., 2008), internal wall partitions (Leiva et al., 2009), and as a soil amendment (Arvidsson and Lundkvist, 2003; Demeyer et al., 2001; Ozolincius et al., 2007b; Park et al., 2005). The use o f ash as soil amendment has gained most o f the interest. Since many o f the volatile, ‘toxic’, elements often end up in higher concentration in the fly ash, its use as a soil amendment is not as desirable as the use o f bottom ash (Arvidsson and Lundkvist, 2003; Ozolincius et al., 2007a). It is important to know the mineralogical and chemical composition o f bottom ash if it is intended for use as a soil amendment. Bottom ash is a very fine alkaline material (pH 9-13). This alkalinity is mainly due to the presence o f alkali and alkali earth metal oxides (Steenari et al., 1999). The major inorganic elements composing ash are Al, B, Ba, Ca, Fe, K, Mg, Mn, Na, P, Si, and Sr. The remainder o f the ash is comprised mainly o f As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se, and Zn (Gori et al., 2011; Steenari et al., 1999; Rehl et al., unpublished). Application o f ash to soil returns nutrients to soil and can raise the pH o f acidic soils (Nkana et al., 1998). However, excessive rates o f application o f ash to soil could raise the pH to 15 unacceptable levels and overload soil with trace elements o f environmental concern. The mobility o f added trace elements may also pose risks. Application o f loose ash to soil may result in a rapid dissolution o f hydroxides and carbonates from ash (Holmberg et al., 2000; Steenari et al., 1999). A solution to limiting this rapid release is through the hardening o f bottom ash prior to use. Hardening is accomplished by the addition o f water and allowing the ash to react to form new minerals, such as gypsum, portlandite, ettringite, calcite, allophane, imogolite, and riebeckite (Dudas, 1981; Steenari and Lindqvist, 1997). These mineral formations reduce the solubility o f ash and also the leachability o f many elements (Steenari et al., 1999). Simulated weathering o f bottom ash and the resulting leachates are not widely studied. The properties and elemental mobility o f ash have been studied on coal fly ashes (Dudas, 1981; Holmberg et al., 2000; Neupane et al., 2012) and grate-fired boiler ashes (Steenari et al., 1999). Many studies focus on fly ashes and do not examine long-term elemental mobility. Furthermore, the short- and long-term mobility o f ash components are not fully understood when ash is mixed with soil. Suitable methods for studying the long-term weathering o f bottom ash include serial batch extractions and column leaching studies. Even though column studies may be more relevant to the field, the variability in results between experiments (and replicates) makes them unfavourable when studying geochemistry (EPRI, 1991). Generally, serial batch extractions have greater reproducibility and are therefore suggested as the standard leaching procedure for waste materials (EPRI, 1991). Trace elements have leached in minimal amount from ash mixed with coarse-textured soils (Fransman and Nihlgard, 1995; Kahl et al., 1996; Piirainen, 2001; Saarsalmi et al., 2005). Few studies have examined elemental mobility when a fine-textured soil is mixed with ash. In general, it is expected that soil will attenuate the ability for many elements to be leached from ash 16 through precipitation and adsorption reactions (Fransman and Nihlgard, 1995; Piirainen, 2001; Pitman, 2006; Saarsalmi et al., 2005). However, this assumption may not hold for fine-textured soil, or for all ashes. Using a long-term serial batch extraction to simulate bottom ash weathering, this study will determine the leachability o f major and trace elements in both hardened and unhardened bottom ash, with and without the presence o f a fine-textured soil. 2.2 METHODOLOGY 2.2.1 Collection of Bottom Ash from UNBC Gasifier Bottom ash from the UNBC gasifier was collected at a sampling grate port located at the beginning o f the conveyer belt that transported bottom ash away to a collection bin. The feedstock for this gasifier was a mix o f hog fuel, pine, and balsam fir waste (ranging from bark to sawdust). Bottom ash samples were collected 6 times over two months (June 23, June 27, July 6 , July 7, July 11, July 12; all o f 2011). This study focused on the bottom ash; however, some characterization was conducted on fly ash and fly-bottom ash mixes (reported in Appendix A l) 2.2.2 Preparation of Collected Bottom Ash Bottom ash samples were thoroughly mixed together and sieved through a 2mm screen to remove clinker and any rocks that may have originated with the hog fuel. Any char that was removed through sieving was re-collected and re-mixed with bottom ash. In this study, the loose, unhardened bottom ash is henceforth referred to as bottom ash. 2.2.3 Preparation of Hardened Bottom Ash Sieved bottom ash was wetted with double deionized water (40% w/w) and placed on an inert surface in an indoor environment. The wetted bottom ash was formed into flat sheets approximately 2cm in thickness. Sheets were left to harden for a total o f four weeks. Once hardened, the bottom ash was crushed to produce granules < 1 0 mm and was then sieved through a 2mm screen. Only granules <10mm and >2mm were used in the study. Granules <2mm in size 17 were subjected to elemental analysis and were found to have similar composition as the larger granules (Appendix A l). 2.2.4 Collection and Preparation of Soil The soil sample was collected (0-30cm depth) on May 13,2010 from an agricultural field located approximately 10km NW o f Prince George, British Columbia (N54° 04’ 20.156” and W 122° 48’ 01.796”); the property had been cleared o f forest approximately 7 years prior to soil collection. The soil sample collected was from an Ap horizon, a mixture o f A and B horizon materials with some organic material from the original forest organic horizons. Once collected, the soil was air-dried on plastic sheets, sieved through a 4mm screen, homogenized, and stored in a sealed container at 4°C until needed. 2.2.5 Characterization of Ash and Soil Samples 2.2.5.1 Electrical Conductivity (EC) and pH Electrical conductivity (EC) testing was performed by obtaining air-dry equivalent amounts o f sample to make a liquid/solid mass ratio (L/S) o f 5, using deionized water, according to methods performed by Haglund (2008). The analysis was performed in quadruplicate. Samples were transferred into Nalgene centrifuge tubes and an appropriate amount o f double deionized water was added. Samples were capped and shaken on an orbital table shaker (Bamstead LabLine Model 4633) at 280rpm for lhr. After agitation, the samples were vacuum filtered (Whatman No. 41) and EC was promptly obtained using a calibrated YSI Conductivity Instrument. The pH o f loose bottom ash, hardened bottom ash, and soil were determined according to Kalra and Maynard (1991). An amount o f 25.0g (to the nearest O.OOlg) o f air dry sample was mixed with 50.0mL o f double deionized water and stirred every 5min for 30min. After stirring 18 the samples were allowed to settle for 30min; pH readings were promptly taken using a calibrated Thermo Orion 420A+ meter (buffer solutions containing pH 4, 7, and 10 were used). 2.2.5.2 Gravimetric Moisture Content Moisture content o f loose bottom ash, hardened bottom ash, and soil was determined according to Kalra and Maynard (1991). Samples (four replicates) were weighed out to approximately lOg (measured to the nearest 0 . 0 lg) in aluminum weigh boats and placed into a drying oven at 105°C for 24 hours. Gravimetric moisture content was determined by calculating the mass loss o f water relative to the oven-dry (OD) weight o f the solids (i.e. g H 2O g ' 1 OD solids; or g H20 lOOg' 1 OD solids). 2.2.5.3 Effective Cation Exchange Capacity (CEC) for Soil Effective cation exchange capacity (CEC) for soil was determined according to Hendershot and Duquette (1986). Briefly, effective CEC is the sum o f exchangeable cations (Ca, Mg, K, Na, Al, Fe, and Mn) contained within soil. A solution o f BaCl2 is used to displace the cations Ca, Mg, K, Na, Al, Fe, and M n contained within soil, which are then measured in the filtered supernatant by atomic absorption spectroscopy. In a 50mL centrifuge tube, 30.0mL o f 0.1M BaCl2 was added to 1.5g o f air-dry soil (measured to the nearest O.OOlg) and shaken on an end-over-end shaker (15rpm) for 2 hours. The mixture was centrifuged (15min at 700 times gravity) and vacuum filtered with a Whatman No. 41 filter paper. The supernatant was then analyzed by an atomic absorption spectrometer for Ca, Mg, K, Na, Al, Fe, and Mn. Effective CEC was then determined by summing the exchangeable cations, which were determined according to the equations found in Hendershot and Duquette (1986). 2.2.5.4 Particle-Size Analysis of Soil Particle-size analysis o f soil was performed according to Kalra and Maynard (1991). Briefly, the soil was separated into different fraction sizes corresponding to fractions o f sand, silt, 19 and clay as determined by the sedimentation principle based on Stake’s law. Calgon solution (50.0mL) and water (400.OmL) were stirred with soil (50g, measured to the nearest O.OOlg) for 15 minutes, and then transferred to a sedimentation cylinder. The suspension was made up to the 1 L mark, covered, and allowed to stand overnight; a blank consisting o f calgon was also made. The suspension was stirred vigorously using the supplied cylinder plunger and a hydrometer reading was taken 40 seconds after the plunger was removed. Temperature o f the suspension was then recorded at a 5cm depth. Hydrometer and temperature readings were taken again at the end o f two hours (correction factor o f +/- 0.36 graduations to the hydrometer for every +/- 1°C). Hydrometer readings were further adjusted by subtracting the blank readings. Sand, silt, and clay fractions were calculated as a percent o f the original soil amount according to these next equations: silt + clay (%) = (corrected hydrometer reading (at 40s)/sample weight)*100, and clay (%) = (corrected hydrometer reading (at 2 hours)/ sample weight)* 1 0 0 , and sand (%) = 1 0 0 — (Silt% + Clay%). 2.2.5.5 Calcium Carbonate Equivalency (CCE) Calcium carbonate equivalency was determined according to Goh and Mermut (2008). Briefly, a standard curve o f known milligrams o f calcium carbonate (in logarithm) against the pH o f neutralized calcium carbonate was used to compare unknown samples o f ash and soil to calcium carbonate. Standards o f calcium carbonate (CaCC>3) were weighed from 5mg to 500mg (measured to the nearest O.OOlg) and transferred to conical centrifuge tubes. Acetic acid (25.OmL, 0.4M) was then added to each conical tube to neutralize the calcium carbonate. All the samples were quickly hand shaken, vented, and then placed overnight on a horizontal table shaker on low. Once the samples had been shaken they were vented again and given a final degassing for 5 minutes using a sonicator (Branson 1510) and centrifuged (HERMLE Z328) at 1500rpm for 15 minutes. The pH was then promptly taken and used to create the standard curve according to 20 equations used by Goh and Mermut (2008). Analysis o f ash and soil samples would then be analyzed using the same procedure but with 400mg samples (measured to the nearest O.OOlg) and comparing the standard curve for their equivalence to calcium carbonate. 2.2.5.6 Elemental and Total C/N/S Analysis Samples o f the solid phase materials used, including TILL 3 standard, were sent to Victoria, BC, to be analyzed for total elemental content by the BC M inistry o f Environment. Determination o f elemental content was done using an ICP-OES (Teledyne/Leeman Prodigy) following EPA digestion Methods 3051A and 3052 (performed by BC M inistry o f Environment) for Al, Ba, Ca, Fe, K, Mg, Na, P, S, As, B, Bi, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Se, Sr, Zn, Ag, Be, Bi, Li, Sb, Sn, Ti, Tl, U, V, W, Y, and Zr; the BC M inistry o f Environment also ran reagent blanks alongside the elemental analysis for QA/QC. Two digestion methods, HCI/HNO 3 (EPA Method 3051 A) and HNO 3/HF/H 2BO 3 (EPA Method 3052), were performed to determine if there was a difference in the completeness o f the digestion for the requested elements. A TILL 3 standard was included with the solid samples, for QA/QC purposes (CCRMP, 1995). Many o f the elements analyzed were below the allowable 15% relative percent difference (Clark, 2003) o f the TILL 3 Certificate o f Analysis indicating thorough dissolution and analysis o f the solid materials (Appendix A l, Tables A1.12 and A1.13). Total carbon, organic C, inorganic C (determined by difference), and total nitrogen were determined by dry combustion using a Fisons (Carlo Erba) NA-1500 CHS analyzer (Skjemstad and Baldock, 2008). In addition to ICP determination o f sulphur, total sulphur was also determined by dry combustion, using a Leco Truspec CNS analyzer (Leco Corporation, 2008). 2.2.6 Serial Batch Extraction (Long-Term Weathering) The methods for long-term weathering were adapted from Steenari et al. (1999). Four replicates o f bottom ash (BA), hardened bottom ash (HBA), soil, 5%w/w BA with soil (5%BA), 21 and 5%w/w HBA (5% HBA) with soil were prepared in separate 250mL Nalgene centrifuge tubes (mass ratios o f ash and soil done on an equivalent dry weight basis). Reagent grade (i.e. double deionized water) water was used throughout the entire experiment (Clark, 2003); this was water that first went through a reverse osmosis process, and was then passed through a MilliQ machine to achieve an electrical resistance o f 18.2MQ. Double deionized water was then added at an L/S 20 to each sample (e.g. 7.000g o f sample required 140.0mL double deionized water). Samples were capped and shaken on an orbital table shaker (Bamstead Lab-Line Model 4633) for 23 hours at 220rpm. After 23 hours the samples were centrifuged at 24000xg (BECKMAN COULTER Avanti J-E Centrifuge). Vacuum filtration was done using Nalgene filter-ware and 0.45pm filter papers (Whatman No. 41). Double deionized water was then again added to the original treatments at an L/S ratio o f 20 and placed back on the orbital shaker for another 23 hours. Blanks were run simultaneously with the serial batch extraction for QA/QC, and revealed only trace amounts o f the analyzed elements to be present within the aqueous phase o f the blanks (Appendix A l, Table A l.l 1). This cycle was repeated a total o f 20 times. The aqueous extracts were then transferred to labelled conical tubes for analysis. Electrical conductivity (EC) (YSI Conductivity Instrument), oxidation reduction potential (ORP) (Thermo ORION 3 STAR pH Benchtop Meter) and pH (Thermo Orion 420A+ Meter) were promptly obtained. Elemental analysis was performed by the UNBC Central Equipment Laboratory (CEL) using ICP-MS (Agilent Technologies 7500 Series ICP-MS) for Al, Ba, Ca, Fe, K, Mg, Na, P, Si, As, B, Bi, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Se, Sr, Zn, Ag, Be, Bi, Li, Sb, Sn, Ti, Tl, U, V, W, Y and Zr; the analysis encompassed all speciations for each element as a total, unless otherwise stated. For days 1,10 and 20, including the elemental analysis, a full anion scan (B r\ Cl', F', NO 3', N 0 2\ PO 43' and SO42') was performed using ion-chromatography (Waters 1525 Binary HPLC Pump equipped with a Metrohm 833 Suppressor and Waters 432 Conductivity Detector) from modified 22 M etrohm IC Application Note No. S-257, and an alkalinity scan by the BC M inistry o f Environment (Victoria, BC). 2.2.7 Statistical Analysis of Serial Batch Extraction Analysis o f variance (ANOVA) was performed on data generated from the serial batch extraction using the software package CoStat Ver. 6.3111. A one-way completely randomized ANOVA test was performed on data from each o f day 1,10, and 20, followed by (if ANOVA was significant) Tukey’s Honest Significant Difference (HSD) method to compare treatment means. Details o f statistical results are presented in Appendix A3. Tables and figures present means and standard deviations. 2.2.8 MINTEQ Modelling Elemental data, anion data, pH, oxidation reduction potential, and temperature obtained from the different analyses performed on the serial batch extracts were input into MINTEQ modelling to produce a saturation index for minerals (Tables 2.6 to 2.10). Calculated results were obtained from data that contained <20% mass charge imbalance according to Visual MINTEQ v3.0; mass charge imbalance refers to the sum o f the cations and anions entered into MINTEQ modelling. Elements that were undetected were entered at half the value o f their detection limit. Saturation index (SI) is an index value that is used to show whether a particular mineral will dissolve or precipitate in an aqueous solution. SI is calculated by comparing the chemical activities, ion activity product (LAP) and solubility product (Ks), o f dissolved ions for a desired mineral; SI = log(IAP) - log(Ks). A saturation index <0 indicates undersaturation o f a mineral, meaning that if the solid mineral were in contact with the solution, the solid mineral would dissolve. Whereas a value >0 indicates oversaturation o f a mineral, meaning that at the observed ion concentrations, a given mineral would precipitate from solution. A saturation index o f 0 23 indicates that a given mineral in solution would neither precipitate from solution nor dissolve into solution (Meima et al., 2002). 24 2.3 RESULTS 2.3.1 Initial Properties of Ash and Soil The elemental composition o f the un-weathered ash and soil were determined by ICPOES following HCI/HNO3 digestion (Table 2.0). The major constituents o f (herein defined as being greater than lOOOmg kg ' 1 in the solid phase) bottom ash and hardened bottom ash were found to be Al, Ca, Fe, K, Mg, Mn, Na, P, and S (Table 2.0). The trace elements As, B, Ba, Co, Cr, Cu, Mo, Ni, Sr and Zn made up the remainder o f the bottom ash and hardened bottom ash solid phases (Table 2.0). Elements found to be below the detection limits o f the ICP-OES were Ag, Be, Bi, Cd, Hg, Pb, Sb, Se, Tl, U, and Y (Table 2.0). Moisture content for bottom and hardened bottom ash were very low (0.196% and 0.646% respectively); total carbon content was low as well (2.95% and 3.03% respectively) (Table 2.0). The soil used in this study was a siltyclay loam (10.6% sand, 53.5% silt and 35.9% clay) with a cation exchange capacity o f 11.8 cmol+ kg ' 1 (± 0 . 1 cmol+ k g '1). Ash is composed o f a number o f metallic elements, some o f which were measured in this study (Table 2 .0 ), as well as oxygen, hydrogen, carbon and other non-metallic elements that compose silicates, oxides, hydroxides, carbonates, and sulphate minerals (Kirby and Rimstidt, 1993; Meima and Comans, 1999; Meima et al., 2002; Steenari and Lindqvist, 1997). A mass balance is only possible if one considers these other (non-measured) components, in addition to the major inorganic elements reported in this study (Table 2.0). Bottom ash, hardened bottom ash, and soil were digested using two methods (HCI/HNO3 and HNO3/HF/H2BO3; data in Appendix A l). The elements Ag, As, B, Ba, Be, Bi, Cd, Hg, Pb, Sb, Tl, U, and Y were more accurately determined by ICP-OES using the HCI/HNO3 digestion method. ICP-OES analysis o f ash following HNO3/HF/H2BO3 digestion revealed slightly better dissolution for Al, Cr, Cu, Fe, K, Mg, Na, S, Sn, Sr, Ti, V, Zn, and W. The elements Ca, Co, Li, 25 Mn, Mo, Ni, P, and Zr showed no discernible measured difference by ICP-OES from either digestion method. These determinations were based on which method gave higher readings. Since elemental analysis o f ashes found in literature are primarily reported using HCI/HNO3 digestion procedures, this study will also focus on data obtained from ICP-OES following HCI/HNO3 digestion. However, ICP-OES analysis o f ash following HNO3/HF/H2BO3 digestion was also reported in Appendix A l . 26 Table 2 . 0 - Initial (solid phase) properties o f bottom ash (BA), hardened bottom ash (HBA), and soil control p rior to serial batch extraction and m aximum allowable limits (except fo r *, which designates minimum allowable limit) fo r several monitored elements by BC Soil Amendment Code o f Practice (SACoP), Alberta, Denmark, Finland and Sweden**. Parameter HBA BA Soil C o n tro l SD Mean SD pH EC (pS cm '1) 12.28 0.02 11.77 0.02 5.19 9890 60 3093 106 73.0 4.0 Moisture Content (%) 0.196 0.004 0.646 0.042 9.81 0.92 Total N (%) 0.0143 0.001 0.013 0.001 0.131 0.003 Total S (%) Total C (%) (inorganic) 0.032 0.019 0.0267 0.0078 0.0128 0.0004 1.34 0.039 1.57 0.13 <0.05 n/a Total C (%) (organic) 1.60 0.099 1.47 0.274 2.03 0.06 Total C (%) 2.95 0.091 3.03 0.24 2.03 0.06 2.0 29.2 2.3 0.467 0.010 <1.0 n/a <1.0 n/a <1.0 n/a Al (%) 1.70 0.09 1.65 0.04 2.66 0.15 As (ppm) 5.98 0.25 6.94 1.48 6.81 0.35 B (ppm) 140 4 120 7 4.44 1.28 Ba (ppm) 1340 15 1255 57 265 15 Be (ppm) <1.0 n/a <1.0 n/a <1.0 n/a Bi (ppm) <1.0 n/a <1.0 n/a <1.0 n/a CCE (%) 30.5 Mean SA CoP Mean A lb erta SD D en m ark F inland F in lan d Sw eden Agr./For. Agr. For. For. 0.01 Elemental Composition via ICP-OES follow ing HCl/HNO} digestion Ag (ppm) Ca (%) 11.2 0.3 9.98 0.36 0.506 0.009 Cd (ppm) <1.0 n/a <1.0 n/a <1.0 n/a 30 43 20 Co (ppm) 18.2 2.2 16.2 1.1 21.7 1.3 150 Cr (ppm) 37.0 6.7 36.3 3.6 46.7 1.4 1060 27 25 75 46 30 800 8* 6* 12.5* 15 1.5 17.5 30 100 300 300 100 Table 2.0 —Initial (solid phase) properties o f bottom ash (BA), hardened bottom ash (HBA), and soil control prior to serial batch extraction and m aximum allowable limits (continued).___________________________________________________________________________________________________________________________________ Parameter HBA BA Mean SD Mean Mean 0.11 2.92 0.02 n/a <2.0 n/a 0.08 0.418 0.050 0.08 1.63 n/a <2.0 0.09 1.94 Fe (%) 1.54 Hg (ppm) <2.0 K (%) 1.97 Li (ppm) 11.3 0.8 11.9 0.8 25.0 1.0 Mg (%) 1.34 0.04 1.25 0.04 0.695 0.003 Mn (%) 0.658 0.020 0.580 0.024 0.107 0.003 Mo (ppm) 5.85 0.22 5.77 0.27 <1.0 n/a N a (%) 0.425 0.043 0.430 0.026 0.040 0.006 Ni (ppm) 61.0 6.2 55.8 2.4 28.0 0.5 P (%) 0.566 0.014 0.502 0.023 0.116 0.002 Pb (ppm) <2.0 n/a <2.0 n/a 3.88 0.54 0.125 0.004 0.104 0.007 0.012 0.0004 Se (ppm) <10 n/a <10 n/a <10 n/a S (%) Sb (ppm) <4.0 n/a <4.0 n/a <4.0 n/a Sn (ppm) 2.20 0.39 1.36 0.37 <1.0 n/a Sr (ppm) 435 7 403 17 67.4 2.2 Ti (ppm) 843 120 938 58 1546 17 Tl (ppm) <2.0 n/a <2.0 n/a <2.0 n/a U (ppm) <20 n/a <20 n/a <20 n/a V (ppm) 43.3 2.4 47.1 1.9 99.4 2.4 Y (ppm) <2.0 n/a <2.0 n/a <2.0 n/a Z n(ppm ) 148 53 93.7 4.8 144 3 Zr (ppm) 14.5 0.6 14.9 1.2 12.1 3.9 *Minimum allowable **Agriculture (Agr.), Forestry (For.) 28 D enm ark F in lan d Agr./For. 0.2 2.0 1.8 A lberta SACoP SD 17.4 44.2 47.8 Cu (ppm) Soil C o ntrol SD 5 0.8 F in la n d Sw eden M ean SD 600 700 400 1 1 3 (K + P )2* (K+P) 1* 3* 1.5 20 180 30 500 120 100 150 70 (K + P )2* (K+P) 1* 0.7* 100 150 300 14 70 1850 5500 1500 4500 7000 (500*) Some elements were found in greater or lower concentrations in bottom ash and hardened bottom ash than the soil control. Elemental enrichment factors (EF = concentration o f elemental in ash + concentrations in soil) are presented in Table 2.1. Values > 1 indicate that ash contained a higher concentration than soil o f a specific element, whereas values < 1 indicate that the soil sample contained a higher concentration o f a specific element than ash. Elements found to be enriched in soil were total N, Al, Cr, Li, Pb, Ti, and V. Elements found to be enriched in both ashes compared to soil were total C, B, Ba, Ca, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, S, Sn, and Sr. Elements that were found to be approximately the same in both ash and soil (or at very low concentration in both) were Ag, As, Be, Bi, Cd, Co, Hg, Sb, Tl, U, Y, and Zr. Zinc was depleted in hardened bottom ash relative to soil, but was found to be the same for untreated bottom ash and soil. 29 Table 2.1 -R ela tive enrichment o f elements contained within bottom ash and hardened bottom ash relative to soil control. Parameter B A /S o il HBA / Soil Total N 0.11 0.10 Total S 2.53 2.08 Total C (organic) 0.79 0.72 Total C 1.46 1.50 Al 0.64 0.62 As 0.88 1.02 B 31.5 27.0 Ba 5.06 4.73 Ca 22.2 19.7 Co 0.84 0.74 Cr 0.79 0.78 Elemental Content Cu 2.74 2.54 Fe 0.53 0.56 K 4.72 4.64 Li 0.45 0.48 Mg 1.93 1.80 Mn 6.13 5.40 Na 10.7 10.8 Ni 2.18 2.00 P 4.87 4.32 S 10.3 8.59 Sr 6.46 5.98 Ti 0.55 0.61 V 0.44 0.47 Zn 1.03 0.65 1.24 Zr 1.21 *EF could not be calculated fo r Ag, Be, Bi, Cd, Hg, Mo, Pb, Sb, Se, Sn, Tl, U, Y and Total C (inorganic) since data fe ll below analytical detection limits 30 2.3.2 Serial Batch Extraction 2.3.2.1 Changes in Solid Phase Composition During Long-Term Weathering The percent mass loss o f single elements leached from their respective starting material was calculated by determining the mass o f a single element contained within each extraction solution, summing these over the 2 0 extractions, and expressing the results relative to the initial mass o f an element contained within the solid phase o f the starting materials. These results provide an indication o f the potential mobility o f specific elements during weathering. The percent mass loss o f each element from bottom ash, hardened bottom ash, soil control, and ashsoil mixes ranged from < 1% to > 80% (Tables 2.2 to 2.4). Mass losses >10% for individual elements contained in bottom ash and hardened bottom ash were found for B, Ba, Ca, Cr, K, Mo, Na, S, and Sr (Table 2.2 to 2.4). Mass losses >10% for individual elements from soil control were found for B and S (Table 2.2 to 2.4). Mass losses >10% for individual elements from bottom ash mixed with soil were B and S (Table 2.2 to 2.4). Mass losses >10% for individual elements from hardened bottom ash mixed with soil were B, Ca, Mo, Na, S, Sn, and Sr (Table 2.2 to 2.4). 31 Table 2 .2 - Mass loss (%) o f individual elements over the 20-cycle serial batch extraction fo r bottom ash, hardened bottom ash, soil control, 5% bottom ash, and 5% hardened bottom ash, relative to initial masses present in the solid phase within each experimental unit (determined via ICP-OES following H N O fH C l digestion). Parameter (%) BA HBA Soil 5% BA 5%HBA Mean Mean Mean Mean Mean Al 6.88 3.59 0.39 0.83 0.73 As 3.14 2.47 1.56 5.37 5.03 B 54.63 57.57 11.23 28.73 62.72 Ba 15.17 11.07 0.57 1.00 3.66 Ca 27.7 13.3 1.68 17.3 23.2 Co 0.01 0.01 0.87 0.76 0.81 Cr 10.71 10.86 0.38 0.62 1.05 Cu 3.60 0.28 1.26 2.47 2.06 Fe 0.0067 0.0034 0.73 0.59 0.63 K 19.06 22.12 2.16 5.42 8.11 Li 1.70 2.05 0.12 0.09 0.11 Mg 0.44 0.84 0.94 3.12 4.48 Mn 0.005 0.004 1.66 1.51 1.57 Mo 53.98 44.55 n/a n/a 132.38 Na 13.06 14.54 8.18 8.98 16.07 Ni 0.06 0.04 0.60 0.80 0.73 P 0.43 0.48 2.06 6.53 6.16 Pb n/a n/a 2.86 n/a n/a S** 27.0 29.8 87.4 61.1 67.0 Sn 1.02 1.22 n/a n/a 12.64 Sr 23.70 14.38 1.25 7.70 11.20 Ti 0.0052 0.0049 0.23 0.22 0.22 V 8.07 6.50 0.55 1.01 1.02 Zn 0.31 0.29 0.60 0.54 0.56 n/a 0.39 0.52 0.49 Zr n/a *n/a refers to below detection limit **Sulphur mass loss (%) based only on solid phase data (final sulphur content - initial sulphur content) ***Ag, Be, Bi, Cd, Hg, Pb, Sb, Tl, U, and Y were undetected 32 Table 2.3 - Percent loss o f elements over 20-cycle serial batch extraction relative to initial contents in solid phase as determined by ICP-OES following H N O /H C l digestion. BA HBA Soil 5%BA 5%HBA <1% Co, Fe, Mg, Mn, Ni, P, Ti, Zn Co, Cu, Fe, Mn, Ni, P, Ti, Zn Al, Co, Cr, Fe, Li, Ni, Ti, Zn, Zr Al, Co, Fe, Li, Ni, Ti, Zn, Zr 1% to 10% Al, As, Cr, Cu, Li, Sn, V Al, As, Cr, Li, Mg, Sn, V Al, Ba, Co, Cr, Fe, Li, Mg, Ni, Ti, V, Zn, Zr As, Ca, Cu, K, Mn, Na, P, Pb, Sr B n/a n/a n/a S Ag, Be, Bi, Cd, Hg, Mo, Sb, Se, Sn, Tl, U, Y As, Ba, Cu, K, Mg, Mn, Na, P, Sr, V Ca B n/a S n/a Ag, Be, Bi, Cd, Hg, Mo, Pb, Sb, Se, Sn, Tl, U, Y As, Ba, Cr, Cu, K, Mg, Mn, P, V B a,K ,N a Ca, Ba, Na, Sr Ca, S, Sr K, S n/a Mo B, Mo B n/a n/a Ag, Be, Bi, Cd, Ag, Be, Bi, Cd, Hg, Pb, Sb, Se, Hg, Pb, Sb, Se, Tl, U, Y, Zr Tl, U, Y, Zr *Sulphur percent loss was based on solid phase data 11% to 20% 21% to 30% 40% to 50% 50% to 70% >80% Undetected Na, Sn, Sr Ca n/a B, S Mo Ag, Be, Bi, Cd, Hg, Pb, Sb, Se, Tl, U, Y Table 2 .4 - Percent loss o f elements over 20-cycle serial batch extraction relative to initial contents in solid phase as determined by ICP-OES following HNO f H F /H S 0 3 digestion. BA HBA Soil 5%BA 5%HBA <1% Co, Fe, Mg, Mn, Ni, P, Sn, Ti, Zn Co, Cu, Fe, Mg, Mn, Ni, P, Sn, Ti, Zn Al, Ba, Co, Cr, Fe, Li, Na, Ni, Ti, V, Zn, Zr Al, Co, Cr, Fe, Li, Na, Ni, Ti, V, Zn, Zr 1% to 10% Al, Ba, Cr, Cu, K, Li, Na, V, W Ca, Sr S Mo Ag, As, Be, Bi, Cd, Hg, Pb, Se, Tl, U, Y, Zr Al, Ba, Ca, Cr, Li, Na, V, W K, S, Sr Mo n/a Ag, As, Be, Bi, Cd, Hg, Pb, Sb, Se, Tl, U, Y, Zr Al, Ba, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Na, Ni, Sr, Ti, V, W, Zn, Zr Mn, P Cu, K, Mg, Mn, P, Sr, W Ca n/a n/a Ag, As, Be, Bi, Cd, Hg, Mo, Pb, Sb, Se, Sn, Tl, U ,Y Ba, Cu, K, Mg, Mn, P, Sr, W Ca n/a S Ag, As, Be, Bi, Cd, Hg, Mo, Pb, Sb, Se, Sn, Tl, U ,Y 11% to 25% 35% to 50% 50% to 70% Undetected n/a n/a n/a Ag, As, Be, Bi, Cd, Hg, Mo, Pb, Sb, Se, Sn, Tl, U ,Y * Sulphur percent loss was based on solid phase data **Sulphur percent loss fo r soil control and 5%BA were 145% and 89.1% respectively Although Table 2.3 and 2.4 revealed that there was a loss o f elements from the ash, soil control, and ash-soil mixtures, the ash itself was relatively insoluble. This was revealed by comparing the initial mass o f ash in the serial batch extraction to the mass that followed after the serial batch extraction was complete. The mass recoveries at the end o f the study were 99.11% ± 0.05%, 99.34% ± 0.16%, 97.28% ± 0.03%, 97.41% ± 0.03% and 97.43% ± 0.05% for bottom ash, hardened bottom ash, soil, 5% bottom ash, and 5% hardened bottom ash respectively. Some loss can be attributed to trace amounts left on the filter paper. 33 2 .3 .2,2 Aqueous Phase Chemistry During Long-Term Weathering Extracts from bottom ash and hardened bottom ash treatments showed higher pH values than soil and the ash-soil mix extracts (Figure 2.0). Overall, observed pH values declined with time for all treatments except for soil (Figure 2.0). —■— Hardened Bottom Ash - ■X' - 5% Bottom Ash Bottom Ash A — Soil ■*-— 5% Hardened Bottom Ash 13 12 11 10 9 8 7 6 5 4 11— 3 5 7 9 11 13 15 17 19 Timeline (Days) Figure 2 .0 - Serial batch extraction o f bottom ash, hardened bottom ash, soil, and 5% bottom and hardened bottom ash mixed with soil depicting p H values (with standard deviation error bars) over the twenty day timeline; n=4. The electrical conductivity in aqueous extracts was higher from bottom ash and hardened bottom ash treatments than soil and ash-soil mix treatments (Figure 2.1). The high initial electrical conductivity in the aqueous extracts from bottom ash declined rapidly over time. Whereas, the electrical conductivity o f aqueous extracts from hardened bottom ash were below that o f bottom ash, and were relatively unchanged as time progressed (Figure 2.1). Electrical conductivity o f the aqueous extracts from ash-soil mixes neared the measurements taken from soil control extract near the end o f the serial batch extraction (Figure 2.1). 34 6000 Bottom Ash Hardened Bottom Ash — A— Soil —*— 5% Bottom Ash - 5% Hardened Bottom Ash 0 I —1 1 I i— * 3 5 A-#-- * -I- 8 I I- I 7 9 11 13 —j| —| —1|—i 15 17 19 Timeline (Days) Figure 2.1 - Serial batch extraction o f bottom ash, hardened bottom ash, soil, and 5% bottom and hardened bottom ash mixed with soil depicting electrical conductivity (EC) values over the twenty day timeline, n=4. The aqueous concentrations for each element throughout the 20-cycle serial batch extraction are presented within Appendix A2 and only key trends are presented here. The following elemental concentrations for hardened bottom ash are presented relative to bottom ash. Values <1 (Table 2.5) indicate reduced leachability o f an element in the hardened bottom ash treatment relative to bottom ash. Hardening reduced the leachability o f Ba, Ca, Cd, Cu, Fe, Hg, Li, Mg, Mn, Ni, Pb, Sn, Sr, W, and Zn during the first day (Table 2.5). On day 10, hardening exhibited reduced leachability o f Ag, As, B, Ca, Cd, Cu, Ni, P, Pb, Se, Si, Sr, V, and Zn relative to bottom ash. On day 20, hardened bottom ash reduced the leachability o f Al, As, B, Ca, Cu, Fe, Hg, Mn, Na, P, Si, Sr, V, and W (Table 2.5). A few elements (B, Cr, Na, K, P, Se, and Si) also showed enhanced leaching due to hardening o f bottom ash, but only during the initial few days (Table 2.5). 35 Table 2 .5 - Ratio o f HBA to BA fo r elemental concentrations in aqueous extracts during days 1, 2, 3, 4, 10, and 20 in the serial batch extraction study; lower values (e.g. < 1) indicate reduced elemental leaching due to HBA treatment. Parameter Day 1 Day 2 Day 3 Day 4 Day 10 Day 20 HBA/BA HBA/BA HBA/BA HBA/BA HBA/BA HBA/BA Ag 2.75 n/d n/d n/d 0.115 3.51 Al 27.1 0.381 0.128 0.196 1.22 0.446 As n/d 3.62 3.41 1.98 0.831 0.648 B 107 4.32 0.773 0.496 0.879 0.359 Ba 0.018 0.241 0.583 2.12 1.53 1.02 Ca 0.032 0.361 0.619 0.754 0.759 0.686 Cd 0.851 0.281 0.808 0.794 0.212 8.52 Cr 5.14 0.386 0.187 0.284 1.30 0.982 Cu 0.004 0.170 3.07 0.532 0.548 0.689 Fe 0.205 0.198 0.193 0.235 1.30 0.495 Hg 0.654 0.120 0.159 0.307 1.88 0.835 K 1.21 1.23 1.13 1.02 0.960 1.13 Li 0.62 0.99 1.84 1.34 2.22 1.71 Mg 0.499 1.49 2.10 1.64 1.48 1.73 Mn 0.453 0.632 0.592 0.462 1.50 0.472 Mo 1.14 0.243 0.331 0.658 1.41 1.52 Na 1.55 1.07 1.06 0.787 0.973 0.952 Ni 0.226 n/d 1.20 1.29 0.401 n/d P 20.6 4.35 4.18 2.75 0.594 0.907 Pb 0.024 n/d n/d 0.836 0.417 7.90 Sb 8.93 1.21 0.785 0.736 1.25 1.21 Se 2.33 0.243 0.777 n/d 0.777 n/d Si 41.0 5.29 6.00 3.24 0.646 0.850 Sn 0.863 n/d 0.485 0.299 n/d n/d Sr 0.082 0.705 1.21 1.22 0.778 0.839 Ti 1.77 1.69 1.90 1.34 1.07 1.26 V n/d 8.44 3.39 1.54 0.673 0.641 W 0.766 0.153 0.214 0.361 1.71 0.852 0.858 1.09 0.715 0.054 0.805 Zn 0.315 *Be, Bi, Co, Te, Th, Tl, U, Y, and Zr were undetected in the leachate by ICP-MS **n/d (not detected) Anions measured in extracted leachates (days one, ten and twenty) were B r'1, C l'1, F"1, NO 2' 1, N O 3' 1, PO 4'2, and SO 4 '2 (Figures 2.2 and 2.3). Alkalinity (reported as calcium carbonate equivalent; this was different from the measured CCE that was measured for the solid materials) o f extracted leachates was also measured (Figure 2.4). Raw data o f the anion analysis can be found in Appendix A l (Tables A1.6 to A1.10). 36 Anion analysis o f bottom ash and hardened bottom ash extracts showed that aqueous concentrations o f bromine and phosphate were below detection limits o f <0.01 ppm (Figure 2.2). Aqueous chlorine concentrations declined from 7.04 ppm to 0.45 ppm in bottom ash and from 5.30 ppm to 0.03 ppm for hardened bottom ash (Figure 2.3). Aqueous fluorine was only detected for day one and ten for both bottom and hardened bottom ash treatments (Figure 2.2). Aqueous nitrites were only detected for day one for both bottom and hardened bottom ash treatments (Figure 2.2). Aqueous sulphate concentrations and measured alkalinity o f bottom ash and hardened bottom ash extracts decreased during the twenty days for bottom ash (sulphates from 5.26 ppm to 2.41 ppm, and alkalinity from 1617mg L ' 1 to 67.16mg L '1) and hardened bottom ash (sulphates from 47.47 ppm to 0.74 ppm, and alkalinity from 187.0mg L ' 1 to 48.34mg L '1). Bottom ash leachates had the highest measured alkalinity o f all treatments (Figure 2.4). Aqueous bromine concentration was below detection limit (<0.01 ppm) in the soil and ash-soil mix extracts (Figure 2.2). An increase over time o f aqueous chlorine concentration was measured from the ash-soil extracts. Measured aqueous chlorine concentration declined over time in soil control extracts (Figure 2.3). Aqueous fluorine was detected for days one and ten for soil extracts (0.32 ppm and 0.01 ppm respectively, Figure 2.2), but was only detected for day one in both ash-soil extracts (Figure 2.2). Measured values for aqueous nitrite, nitrate, phosphate, sulphate, and alkalinity were found to be declining, as time progressed, in soil and ash-soil mixed treatments (Figures 2.2 to 2.4). 37 .D a y l ‘ D ay' 0 (uidd) uouEiiuaoiicO j/tt < $ in ,D a ,2 ° ^jm r —-- __ T Day 20 Day 1 < CQ O Cl S04 38 1 < 1 " < § *T> ■ Day 10 ■ Day 20 Concentration (ppm) ■ D ayl 5%BA 5%HBA Alkalinity Figure 2.4 - Leachates from serial batch extraction showing alkalinity as CaCO} (ppm) contained within the extracts from days 1, 10 and 20 o f the five treatments (BA, HBA, Soil, 5%BA and 5%HBA). 39 2.3.3 Geochemical Modelling of Serial Batch Extraction Data obtained from the serial batch extraction analyses were entered into MINTEQ modelling to produce a saturation index for minerals (Tables 2.6 to 2.10). Analysis o f the serial batch extraction data by MINTEQ predicted the presence o f secondary minerals due to the oversaturation o f major and minor elements contained within the extracts o f the treatments. Some predicted minerals within the bottom ash and hardened bottom ash treatments were not predicted for the soil control treatment (Tables 2.6 to 2.10). These minerals were primarily calcium carbonate secondary minerals (aragonite, calcite, dolomite, and hydroxyapatite). Hydroxyapatite was also predicted to be present in the aqueous phase o f ash-soil mixes, but not soil (Tables 2.9 and 2.10). MINTEQ predicted that bottom ash and hardened bottom ash treatments contained many o f the same secondary minerals; these minerals were primarily carbonate based (Table 2.6 and 2.7). Gibbsite was predicted to precipitate throughout in the HBA treatment, whereas gibbsite was only predicted to precipitate during the last day in the BA treatment. Hausmannite was only predicted during day ten for the HBA treatment but was prevalent throughout the BA treatment. Kaolinite was only predicted during day twenty, BA treatment, and predicted to precipitate on days ten and twenty for the HBA treatment. The formation o f manganite, strontianite, tenorite, and witherite were predicted in the BA treatment and not the HBA treatment (Table 2.6 and 2.7). 40 Table 2 .6 - Predicted mineral formation based on saturation index fo r bottom ash leachates during days 1,10 and 20. Day One Mineral Day Ten Sat. index Mineral Day Twenty Sat. index Mineral 1.47 Aragonite Sat. index Aragonite 2.91 Aragonite Barite 0.348 Barite -0.877 Barite -0.381 1.15 Brucite 0.312 Brucite -0.903 Brucite -1.21 Ca3(P04)2 (beta) -1.13 Ca3(P04)2 (beta) 0.121 Ca3(P04)2 (beta) -2.08 CaC03xH 20(s) 1.72 CaC03xH20(s) 0.271 CaC03xH 20(s) -0.042 Calcite 3.06 Calcite 1.61 Calcite 1.30 Chrysotile 5.42 Chrysotile 7.86 Chrysotile 6.77 CoFe204(s) 20.1 CoFe204(s) 21.4 CoFe204(s) 22.9 Cupric Ferrite 9.35 Cupric Ferrite 9.50 Cupric Ferrite 11.0 Diaspore -1.17 Diaspore 0.841 Diaspore 1.41 Dolomite (disordered) 1.43 Dolomite (disordered) 0.577 Dolomite (disordered) 0.579 Dolomite (ordered) 1.13 Dolomite (ordered) 1.99 Dolomite (ordered) 1.14 Ettringite -1.87 Ettringite -11.0 Ettringite -12.3 Fluoroapatite 19.7 Fluoroapatite 16.8 Fluoroapatite 9.52 Akaganeite 1.82 Akaganeite 2.64 Akaganeite 3.29 Ferrihydrite 0.243 Ferrihydrite 0.858 Ferrihydrite 1.61 Ferrihydrite (aged) 0.753 Ferrihydrite (aged) 1.37 Ferrihydrite (aged) 2.12 Gibbsite (C) -2.04 Gibbsite (C) Gibbsite (C) 0.544 Goethite 3.00 Goethite 3.61 Goethite 4.34 Gypsum -2.57 Gypsum -3.70 Gypsum -3.54 Hausmannite 4.74 Hausmannite 1.83 Hausmannite 2.25 Hematite 8.39 Hematite 9.62 Hematite 11.1 10.3 Hydroxyapatite 6.55 Kaolinite 0.407 -0.028 Hydroxyapatite 10.1 Hydroxyapatite Kaolinite -10.7 Kaolinite Lepidocrocite 2.19 Lepidocrocite 2.81 Lepidocrocite 3.50 -0.646 Lime -11.1 Lime -14.4 Lime -15.3 Maghemite 0.725 Maghemite 1.97 Maghemite 3.35 Magnesioferrite 7.48 Magnesioferrite 7.50 Magnesioferrite 8.67 Manganite 0.973 Manganite 0.183 Manganite 0.346 Portlandite -1.08 Portlandite -4.33 Portlandite -5.25 Sepiolite -2.97 Sepiolite 3.71 Sepiolite 2.93 Sepiolite (A) -5.87 Sepiolite (A) 0.823 Sepiolite (A) SnS04(s) 16.1 SnS04(s) 19.3 SnS04(s) 20.9 Strontianite -0.564 -0.026 Strontianite 1.20 Strontianite -0.105 Tenorite(c) 0.754 Tenorite(c) -0.334 Tenorite(c) -0.284 Vaterite 2.48 Vaterite 1.04 Vaterite 0.726 Witherite 0.682 Witherite -0.858 Witherite -0.831 41 Table 2.7 - Predicted mineralformation based on saturation index fo r hardened bottom ash leachates during days 1, 10 and 20. Day Twenty Day Ten Day One Sat. index M ineral S a t index Sat. index M ineral Aragonite 1.31 Aragonite 1.20 Aragonite 0.898 CaC03xH 20(s) 0.113 CaC03xH 20(s) 0.007 CaC03xH 20(s) -0.294 Calcite 1.45 Calcite 1.35 Calcite 1.04 Chrysotile 5.02 Chrysotile 6.87 Chrysotile 6.16 CoFe204(s) 21.1 CoFe204(s) 22.3 CoFe204(s) 22.8 Cupric Ferrite 9.04 Cupric Ferrite 10.3 Cupric Ferrite 11.0 Diaspore 1.42 Diaspore 1.25 Diaspore 1.35 M ineral Dolomite (disordered) -0.276 Dolomite (disordered) 0.353 Dolomite (disordered) 0.482 Dolomite (ordered) 0.282 Dolomite (ordered) 0.911 Dolomite (ordered) 1.04 Ettringite -7.37 Ettringite -12.3 Ettringite -16.4 Fluoroapatite 13.6 Fluoroapatite 10.7 Fluoroapatite 8.55 Akagandite 2.59 Akaganeite 3.21 Akaganeite 3.01 Ferrihydrite 0.703 Ferrihydrite 1.30 Ferrihydrite 1.60 Ferrihydrite (aged) 1.21 Ferrihydrite (aged) 1.81 Ferrihydrite (aged) 2.11 Gibbsite (C) 0.549 Gibbsite (C) 0.383 Gibbsite (C) 0.486 Goethite 3.46 Goethite 4.05 Goethite 4.33 Gypsum -2.64 Gypsum -3.71 Gypsum -4.17 Hausmannite -0.014 Hausmannite 0.278 Hausmannite -2.0 Hematite 11.1 Hematite 9.30 Hematite 10.5 Hydroxyapatite 6.43 Hydroxyapatite 6.82 Hydroxyapatite 5.83 Kaolinite 0.374 Kaolinite 0.593 Kaolinite Lepidocrocite -0.002 2.65 Lepidocrocite 3.24 Lepidocrocite 3.48 Lime -16.0 3.32 Lime -14.6 Lime -15.1 Maghemite 1.65 Maghemite 2.84 Maghemite Magnesioferrite 6.41 Magnesioferrite 7.98 Magnesioferrite 8.33 MgCr204(s) 0.086 M gCr204(s) -2.03 MgCr204(s) -2.22 Portlandite -4.57 Portlandite -5.03 Portlandite -5.96 Sepiolite 1.39 Sepiolite 3.22 Sepiolite 2.78 Sepiolite (A) -1.5 Sepiolite (A) 0.330 Sepiolite (A) SnS04(s) 21.2 -0.185 SnS04(s) 20.6 SnS04(s) 20.3 Vaterite 0.881 Vaterite 0.774 Vaterite 0.474 Witherite -1.26 Witherite -0.848 Witherite -0.924 The data from the addition o f ash to soil (5%BA and 5%HBA treatments), as analyzed by MINTEQ, predicted new secondary minerals to form in the aqueous phase, as compared to secondary mineral predictions o f the soil control (Tables 2.8 to 2.10). Chloropyromorphite and hydroxyapatite were predicted to precipitate in the ash-soil mixes but not in the soil control 42 (Tables 2.9 and 2.10). Table 2 .8 - Predicted mineralformation based on saturation index fo r soil leachates during days 1, 10 and 20. Day One M ineral Day Ten Sat. index M ineral Day Twenty Sat. index M ineral Sat. index Akaganeite 7.02 Akaganeite 6.72 Akaganeite 6.14 Al(OH)3 (am) 0.326 Al(OH)3 (am) -0.118 Al(OH)3 (am) -0.645 Al(OH)3 (Soil) 2.84 Al(OH)3 (Soil) 2.40 Al(OH)3 (Soil) 1.87 A1203(s) 2.56 A1203(s) 1.67 A1203(s) 0.638 A14(OH)10SO4(s) 3.46 A14(OH)10SO4(s) 2.29 A14(OH)10SO4(s) -0.387 Boehmite 2.54 Boehmite 2.10 Boehmite 1.57 CoFe204(s) 23.0 CoFe204(s) 20.5 CoFe204(s) 18.9 Cupric Ferrite 13.8 Cupric Ferrite 10.8 Cupric Ferrite 9.16 Diaspore 4.26 Diaspore 3.82 Diaspore 3.29 Ettringite -39.5 Ettringite -51.2 Ettringite -57.2 Ferrihydrite 3.99 Ferrihydrite 3.38 Ferrihydrite 2.97 Ferrihydrite (aged) 4.50 Ferrihydrite (aged) 3.89 Ferrihydrite (aged) 3.48 Gibbsite (C) 3.39 Gibbsite (C) 2.95 Gibbsite (C) 2.42 Goethite 6.75 Goethite 6.14 Goethite 5.70 Gypsum -5.59 Gypsum -7.11 Gypsum -8.08 Halloysite 3.91 Halloysite 1.97 Halloysite 0.586 Hematite 15.9 Hematite 14.7 Hematite 13.8 Imogolite 4.88 Imogolite 3.47 Imogolite 2.24 Kaolinite 6.09 Kaolinite 4.15 Kaolinite 2.74 Lepidocrocite 5.93 Lepidocrocite 5.33 Lepidocrocite 4.86 Lime -24.3 Lime -26.4 Lime -27.0 Maghemite 8.2 Maghemite 7.01 Maghemite 6.07 Magnesioferrite 6.09 Magnesioferrite 2.72 Magnesioferrite 1.38 M nHP04(s) -1.19 M nHP04(s) 0.633 MnHP04(s) 0.087 Plumbgummite 5.14 Plumbgummite 3.58 Plumbgummite 7.07 Portlandite -14.2 Portlandite -16.3 Portlandite -16.9 Rutile 0.784 Rutile 0.919 Rutile 0.743 SnS04(s) 28.8 SnS04(s) 29.3 SnS04(s) 29.1 0.098 Strengite 2.53 Strengite 2.28 Strengite 43 Table 2 .9 - Predicted mineralformation based on saturation indexfo r 5% bottom ash leachates during days 1,10 and 20. Day Ten Day One Mineral Sat. index Mineral Day Twenty Sat. index Mineral Sat index Akaganeite 7.78 Akaganeite 7.96 Akaganeite 7.39 Al(OH)3 (am) -0.168 Al(OH)3 (am) -0.435 Al(OH)3 (am) 0.006 Al(OH)3 (Soil) 2.35 Al(OH)3 (Soil) 2.08 Al(OH)3 (Soil) 2.52 A1203(s) 1.57 Al203(s) 1.03 A1203(s) 1.94 A14(OH)10SO4(s) 0.206 A14(OH)10SO4(s) -3.05 Al4(OH)10SO4(s) -1.14 Boehmite 2.05 Boehmite 1.78 Boehmite 2.23 Calcite -0.973 Calcite -1.46 Calcite -2.97 Chloropyromorphite(c) 0.835 Chloropyromorphite(c) 2.93 Chloropyromorphite(c) 3.44 CoFe204(s) 28.2 CoFe204(s) 28.5 CoFe204(s) 25.3 Cupric Ferrite 18.3 Cupric Ferrite 18.3 Cupric Ferrite 15.7 Diaspore 3.77 Diaspore 3.50 Diaspore 3.94 Ettringite -23.7 Ettringite -30.3 Ettringite -39.6 Fluoroapatite 13.4 Fluoroapatite 6.97 Fluoroapatite -2.96 Ferrihydrite 5.30 Ferrihydrite 5.31 Ferrihydrite 4.56 Ferrihydrite (aged) 5.81 Ferrihydrite (aged) 5.82 Ferrihydrite (aged) 5.07 Gibbsite (C) 2.90 Gibbsite (C) 2.63 Gibbsite (C) 3.07 Goethite 8.06 Goethite 8.07 Goethite 7.29 Gypsum -3.44 Gypsum -5.54 Gypsum -7.05 Halloysite 3.48 Halloysite 2.26 Halloysite 3.03 Hematite 18.5 Hematite 18.5 Hematite 17.0 -0.997 Hydroxyapatite 5.02 Hydroxyapatite 4.74 Hydroxyapatite Imogolite 4.17 Imogolite 3.29 Imogolite 4.11 Kaolinite 5.65 Kaolinite 4.44 Kaolinite 5.19 K-Jarosite 0.142 K-Jarosite -4.75 K-Jarosite -7.24 6.44 Lepidocrocite 7.25 Lepidocrocite 7.26 Lepidocrocite Lime -20.8 Lime -20.8 Lime -22.6 Maghemite 10.8 Maghemite 10.9 Maghemite 9.24 Magnesioferrite 11.6 Magnesioferrite 11.4 Magnesioferrite 8.15 M nHP04(s) 1.83 MnHP04(s) 2.00 MnHP04(s) 1.66 Plumbgummite 4.41 Plumbgummite 3.56 Plumbgummite 6.45 Portlandite -10.8 Portlandite -10.7 Portlandite -12.5 Rutile 0.743 Rutile 0.997 Rutile 0.819 SnS04(s) 27.5 SnS04(s) 25.3 SnS04(s) 25.7 Strengite 1.78 Strengite 1.53 Strengite 2.03 44 Table 2.10-Predicted mineralformation based on saturation index fo r 5% hardened bottom ash leachates during days 1, 10 and 20. Day One Mineral Day Ten Sat. index Mineral Day Twenty Sat. index Mineral Sat. index Akaganeite 7.86 Akaganeite 7.45 1.90 Al(OH)3 (Soil) 2.32 Al(OH)3 (Soil) 2.50 A1203(s) 0.668 A1203(s) 1.50 A1203(s) 1.91 Boehmite 1.60 Boehmite 2.01 Boehmite 2,21 Calcite -0.413 Calcite -2.21 Calcite -3.19 Chloropyromorphite(c) -8.87 Chloropyromorphite(c) 3.88 Chloropyromorphite(c) 3.48 CoFe204(s) 26.4 CoFe204(s) 27.4 CoFe204(s) 25.4 Akaganeite 7.28 Al(OH)3 (Soil) Cupric Ferrite 16.6 Cupric Ferrite 17.5 Cupric Ferrite 15.7 Diaspore 3.32 Diaspore 3.74 Diaspore 3.92 Ettringite -24.0 Ettringite -33.5 Ettringite -38.6 Fluoroapatite 4.12 Fluoroapatite 2.82 Fluoroapatite -4.07 Ferrihydrite 4.71 Ferrihydrite 5.07 Ferrihydrite 4.60 Ferrihydrite (aged) 5.22 Ferrihydrite (aged) 5.58 Ferrihydrite (aged) 5.11 Gibbsite (C) 2.45 Gibbsite (C) 2.87 Gibbsite (C) 3.05 Goethite 7.46 Goethite 7.83 Goethite 7.33 Gypsum -3.27 Gypsum -5.89 Gypsum -6.52 Halloysite 3.12 Hematite 17.1 Halloysite 2.93 Halloysite 2.94 Hematite 17.3 Hematite 18.0 Hydroxyapatite -1.47 Hydroxyapatite 2.38 Hydroxyapatite -1.57 Imogolite 3.44 Imogolite 3.87 Imogolite 4.14 Kaolinite 5.11 Kaolinite 5.12 Kaolinite 5.28 Lepidocrocite 6.65 Lepidocrocite 7.02 Lepidocrocite 6.48 Lime -20.8 Lime -21.6 Lime -22.7 Maghemite 9.65 Maghemite 10.4 Maghemite 9.32 Magnesioferrite 10.7 Magnesioferrite 10.2 Magnesioferrite 8.15 M nHP04(s) -1.07 MnHP04(s) 2.04 M nHP04(s) -0.337 Quartz 1.71 -0.439 Quartz 0.074 Quartz Plumbgummite -2.08 Plumbgummite 5.31 Plumbgummite Portlandite -10.7 Portlandite -11.6 Portlandite -12.7 6.53 Rutile 0.581 Rutile 0.858 Rutile 0.786 SnS04(s) 27.6 SnS04(s) 25.8 SnS04(s) 26.4 Strengite -1.05 Strengite 1.96 Strengite 2.17 45 2.4 DISCUSSION Hardening o f bottom ash was shown to be a means o f improving physical properties and reducing the reactivity o f components contained within gasifier bottom ash. This hardening process altered the mineralogy o f the ash and this study hypothesized that the leachability o f several elements would be altered relative to that o f the loose, untreated, bottom ash. Few studies have examined the long-term weathering o f ashes in the environment; the serial batch extraction was conducted to predict elemental loss from ash materials over the long-term (e.g. if landfilled or stockpiled). These ash materials were also mixed with fme-textured soil, as ash m ay be used as an amendment to improve soil conditions in agricultural or forest applications and relevant studies in the literature have usually focused on ash addition to coarse-textured soils (Fransman and Nihlgard, 1995; Kahl et al., 1996; Piirainen, 2001; Saarsalmi et al., 2005). It was expected that fine-textured soil would alter the mobility o f elements originating from these ash materials. The geochemical model MINTEQ was used to predict the mineralogy o f the ashes, and how mineralogy o f the receiving soil would be influenced by ash additions. However, MINTEQ assumes equilibrium and does not take kinetics into consideration during its calculations. Therefore, a mineral may be predicted to dissolve or precipitate out o f solution, but the time for that to occur is not known. This may take hours or months for the predicted reactions to occur. 2.4.1 Initial Characterization and Composition of Ashes The elemental composition o f the bottom ash used in this study was typical o f other wood-biomass ashes reported in literature (Steenari and Lindqvist, 1997; Steenari et al., 1999; Liao et al., 2007). Bottom ash and hardened bottom ash were found to be primarily composed o f the elements Ca, Fe, K, Al, Mg, Mn, P, Na, Ba, and S (major inorganic elements defined here as being greater than 1000 mg kg ' 1 in the solid phase). The remainder was a composition o f As, B, Co, Cr, Cu, Mo, Ni, Sr, and Zn (Table 2.0). According to the Soil Amendment Code o f Practice 46 (SACoP) there are 11 metals o f concern (Environmental Management Act, 2007), o f which the elements As, Co, Cr, Cu, Mo, Ni, and Zn were found to be contained in ash. The other 4 metals, Cd, Pb, Hg, and Se were below ICP detection limits (Table 2.0). The hardening process did not alter the non-organic elemental composition (Table 2.0), but it was expected that the mineralogical composition changed. In non-hardened bottom ash, the minerals expected to dominate were the oxides o f the major inorganic elements; this is a result o f the burning process (Steenari and Lindqvist, 1997). Calcium makes up a large portion o f these mineralogical components as calcium oxide (CaO) and calcite (CaCOs) (Steenari and Lindqvist, 1997). In hardened ash the formation o f cement-type minerals gypsum, calcite, ettringite, portlandite, and other sulphate bearing minerals was expected to occur (Steenari and Lindqvist, 1997; Demeyer et al., 2 0 0 1 ). 2.4.2 Simulated Long-Term Weathering of Ash - Hardened versus Non-Hardened The batch extraction experiment simulated the long-term weathering o f ash if it were to come into contact with water. In non-hardened ash, the initial leachate composition was dominated by Ca, K, Si, Al, Ba, Na, and S 0 4' 2 (Appendix A2). These high concentrations were accompanied by an elevated electrical conductivity, which is an index o f total dissolved solids (Figure 2.1). The initial elevated concentration o f Ca, K, Al, Ba, Na, and S 0 4‘ rapidly declined over time as highly soluble components were leached from bottom ash (Appendix A2). This rapid decline in concentration was consistent with other leachate studies (Dudas, 1981; Steenari and Karlsson, 1999; Talbot, Anderson and Andren, 1978; Zevenbergen et al., 1998). In comparison, elements and anions leached from other ashes (municipal solid waste incinerator (MSWI) bottom ashes, grate fired boiler ashes, and coal fly ashes) were Ca, K, Si, Al, Na, and S 0 4'2, with some also reporting Fe, Mg, and C l ' 1 to have leached preferentially (Dudas, 1981; Steenari and Karlsson, 1999; Talbot, Anderson and Andren, 1978; Zevenbergen et al., 1998). W ith the 47 exception o f large amounts o f Fe, Mg, and Cl ' 1 leached from several ashes, as reported by other studies, many o f the constituents leached from bottom ash in this study were similar to other studies (Dudas, 1981; Steenari and Karlsson, 1999; Talbot, Anderson and Andren, 1978; Zevenbergen et al., 1998). The hardening process influenced the leachate chemistry during the long-term weathering study, especially during the initial stages o f the experiment. For example, compared to nonhardened ash, the electrical conductivity (Figure 2.1), and aqueous concentrations o f Al, Ba, Ca, Cu, Hg, Sr, and Zn were much lower from hardened bottom ash extracts (Table 2.5). However, some elements exhibited a higher initial aqueous concentration in the hardened ash treatment. These elements were B, Cr, K, Mo, Na, P, Sb, Se, Si, and SO4'2 (Table 2.5, Figure 2.3). As the weathering progressed, the aqueous concentrations o f many elements were similar in the hardened and non-hardened bottom ash treatments (Table 2.5). Observations made from the serial batch extraction were used to explain some o f the leaching characteristics for elements o f agronomic value (Ca, Na, K, and S). The amount o f calcium leached from bottom ash was extensive (Table 2.2 and Figure A2.7). However, hardening reduced the amount o f Ca leached from ash by a significant amount, especially during the initial serial batch extracts (Figure A2.7). Throughout the entire weathering process, the amount o f Ca lost was calculated to be 27% for bottom ash and 17% for hardened bottom ash; these values were similar to the 2% to 19% Ca leached as seen by Steenari et al. (1999) (gratefired boiler bottom ashes). The insoluble nature o f cement based minerals (primarily Ca based) that may have formed during hardening likely contributed to lower Ca dissolution from hardened bottom ash. These formed minerals were likely to be gypsum, portlandite, calcite, calcium silicate, and possibly ettringite (Steenari and Lindqvist, 1997; Demeyer et al., 2001). 48 Sodium and potassium comprised 2% o f the bottom ash solid phase (Table 2.0). The percentage o f Na (13% BA and 15% HBA) and K (19% BA and 23% HBA) leached from the ashes were found to be similar to Steenari et al. (1999) and a little higher than weathered fly ashes found by Neupane et al. (2012). Following hardening, the amount o f Na and K initially leached from bottom ash increased compared to non-hardened ash (Figures A2.14 and A2.19). Higher aqueous concentrations o f N a and K m ay have been due to the soluble hydroxides and sulphate salts o f Na and K that were not as prevalent in non-hardened bottom ash. Sodium and K are in their oxide form, K 2O and Na 2 0 , within bottom ash, and form their hydroxides when exposed to water when ash is hardened (Gori et al., 2011). Due to a high pH environment and the presence o f sulphates within ash (as measured in the aqueous phase; Figure 2.3), hardening may have also resulted in the formation o f N a and K sulphates (Na2SC>4 and K2SO4) (Gori et al., 2011; Ring et al., 2006). The greater amount o f soluble sodium and potassium hydroxides and sulphates likely present in hardened bottom ash would have resulted in a spike in the initial aqueous concentrations o f Na and K compared to bottom ash extracts, as was found in the serial batch extraction analysis (Figures A2.14 and A2.19). Aqueous sulphur was not able to be determined by ICP, but sulphate ions were determined by ion chromatography during days one, ten and twenty o f the serial batch extracts (Figure 2.3). Total sulphur content in bottom ash and hardened bottom ash solid phase was also measured by ICP-OES (Table 2.0). Using the measured sulphur contained in bottom ash and hardened bottom ash, an estimation o f total sulphur loss was determined to be 27% for bottom ash and 30% for hardened bottom ash treatments (Table 2.2). Aqueous extracts from hardened bottom ash were found to contain higher aqueous sulphate concentrations than bottom ash extracts (Figure 2.3). Compared to bottom ash, the increased amount o f sulphate leached from hardened bottom ash may have been due to the dissolution o f gypsum and soluble salts o f 49 Na2SC>4 and K2SO4 that would have formed during hardening compared to non-hardened bottom ash. The formation o f Na2SC>4 and K2SO4 in hardened wood based ashes has also been reported by Ring et al., (2006), along with calcium sulphate (i.e. gypsum) by others (Steenari and Lindqvist, 1997). •y Unlike the dominating ions o f Ca, K, Si, Al, Na, and SO4' in solution, the aqueous concentrations o f environmentally sensitive trace elements and anions were generally low in the non-hardened and hardened bottom ashes. O f the trace elements, aqueous concentrations were greatest for Cr, Cu, Mo, and Hg. High pH o f the aqueous environment (Figure 2.0), low solid phase concentration o f trace elements (Table 2.0), and the adsorption o f trace elements to formed secondary minerals likely attributed to low aqueous concentrations o f the many measured trace elements (Chimenos et al., 2000; W arren and Dudas, 1985; Steenari and Karlsson, 1999; Talbot, Anderson and Andren, 1978; Neupane et al., 2012). As with the major inorganic elements, aqueous concentrations o f trace elements were generally greatest during the initial serial batch extracts. M ost trace elements had very low dissolution and likely persisted within the solid phase, or were adsorbed into the formation o f secondary minerals, and continue to persist in the solid phase (McBride, 1994; Neupane et al., 2012). For example, low zinc leaching (Table 2.5) might be attributed to negatively charged particles present in the aqueous phase during weathering o f bottom ash. Bottom ashes tend to contain Fe-, and Al-hydroxides, and in an alkaline ash-water system, these hydroxides can form soluble species that are negatively charged, which can be incorporated into neoformations (i.e. Al(OH)4', and Fe(OH) 4') (McBride, 1994). Neoformations are the precipitation o f new secondary minerals that form at low temperatures as a result o f various ions weathered from primary minerals (McBride, 1994). These negatively charged species could attract dissolved zinc, as Zn2+, to the surface o f those particles, either through ionexchange, or direct adsorption to the mineral. Other charged ions (i.e. dissolved trace elements in 50 solution) would also tend to co-precipitate in this manner as well. This is likely to have occurred with many o f the trace metals found from weathering bottom and hardened bottom ash (Appendix A2). O f the measured anions, SO 4'2, C l'1, and NO 3 '1 dominated, but decreased over time (Figures 2.2 and 2.3). The trace element and anion concentrations can be put into perspective by comparing them with maximum levels allowable for aquatic systems and drinking water standards. This type o f comparison is also relevant for situations where large quantities o f water in contact with ash m ay make its way into a surface water or ground water. The British Columbia Contaminated Sites Regulation, BCCSR, (Schedule 6 ) contains allowable limits for many o f the trace elements and some major inorganic elements contained within an aqueous system (Chapter 3; Table 3.2). This study was not focused on water quality and its respective limits, nor was there any field experiments performed, and a comparison to water standards is only to put perspective on elemental concentrations found in the extracts during the serial batch extractions. The allowable limits o f Cr, Cu, and Hg for freshwater aquatic life were only exceeded briefly during the first day o f the serial batch extraction for both ashes and fell below allowable limits thereafter. Only aqueous concentrations o f C l 1, NO 3'1, and NO2'1 continually exceeded concentrations set out by BCCSR for aquatic life. Generally, the limits exceeded by ash treatments were short lived as sharp declines in concentration o f the above mentioned (few) elements fell below allowable limits set by the British Columbia Contaminated Sites Regulation (Schedule 6 ). Over the course o f the weathering study, the overall loss o f elements from the solid phase was generally similar in the two ash types (Table 2.2). The weathering experiment resulted in a large percent loss o f some elements (Ca, B, Mo, S, Sr, Ba, K, and Na), while other elements (Fe, Mg, Mn, P, Al, and the rest o f the trace elements) only exhibited slight losses (Table 2.2). 51 Interestingly, even though bottom ash and hardened bottom ash contained high concentrations o f Fe, Mg, Mn, and P, very little loss was observed from these elements (Table 2.2). This observation was also reported in other studies (Steenari and Karlsson, 1999; Talbot, Anderson and Andren, 1978; Zevenbergen et al., 1998). Low leachability o f Fe, Mg, Mn, and P may have been due to high pH conditions and the continual formation o f secondary minerals decreasing solubility as revealed through MINTEQ analysis. 2.4.3 MINTEQ Analysis of Serial Batch Extraction - Hardened versus Non-Hardened Saturation index (SI) is an index value that is used to determine whether a particular mineral is predicted to dissolve or precipitate in water. SI is calculated by comparing the chemical activities, ion activity product (IAP) and solubility product (Ks), o f dissolved ions for a desired mineral; in MINTEQ the calculation for SI = log(LAP) - log(Ks). A saturation index <0 (logLAP < logKs) indicates undersaturation o f a mineral, meaning that it may be dissolved in solution, whereas a value >0 (logLAP > logKs) indicates oversaturation o f a mineral, meaning that the mineral may have precipitated in solution. A saturation index o f 0 indicates that the predicted mineral in solution is in equilibrium. SI values that are at or nearing equilibrium are said to be the main solubility-controlling minerals in an aqueous solution (Meima et al., 2002). 2.4.3.1 Changes in Secondary Mineral Formation Over Time Analysis o f the data from the serial batch extraction by MINTEQ revealed a few notable changes in the formation o f secondary minerals between hardened and non-hardened bottom ash. In bottom ash, barite, brucite, calcite (hydrate), strontianite, tenorite, and witherite were predicted to be become thermodynamically unstable (i.e. SI < 0) as time progressed, indicating their potential dissolution. Disapore, gibbsite, and sepiolite were predicted minerals in a bottom ash/water mixture that started thermodynamically unstable (i.e. undersaturated) but were predicted to become stable (i.e. saturated over time). However, in hardened bottom ash calcite 52 (hydrate) was predicted to be thermodynamically unstable indicating dissolution. Dolomite (disordered) and kaolinite began thermodynamically unstable but were predicted to become stable. Looking at the SI o f several key elements (Ca, Fe, Mn, and P) that were prominent within the predicted secondary mineral formation o f both bottom ash and hardened bottom ash we can obtain further insight into the leaching observations made from the serial batch extraction. O f the predicted mineral formations containing Ca (aragonite, calcium phosphate, calcite, dolomite, fluoroapatite, hydroxyapatite, and vaterite), their SI values were decreasing over time, which could potentially indicate dissolution o f Ca for bottom ash and hardened bottom ash (Table 2.6 and 2.7). More specifically, possible solubility-controlling minerals for Ca dissolution from bottom ash may be from calcite-type minerals (aragonite, calcite-hydrate, and vaterite), apatite, and dolomite at high pH, as many o f these predicted minerals were nearing equilibrium as time progressed (Table 2.6). Compared to non-hardened bottom ash, calcite is likely more dominant in the solid phase o f hardened bottom ash, and was found to be the primary solubility-controlling mineral for Ca dissolution as calcite, calcite-hydrate, aragonite, and vaterite (all calcite-type minerals); these calcite minerals were much closer to equilibrium, over time, compared to that o f non-hardened bottom ash (Table 2.7). Other possible solubility-controlling minerals in an ashwater system that have been reported in literature have been portlandite (Ca(OH) 2), lime (CaO), and possibly gypsum (CaS 0 4 ) (Meima and Comans, 1997 and 1998). As with Ca, other solubility-controlling minerals for Mg (brucite), Fe (ferrihydrite), P (Ca 3(P 0 4)2), and potentially Mn (manganite) were determined by modelling for bottom ash (Table 2.6). Potential solubility controlling minerals predicted for hardened bottom ash for Fe and Mn were ferrihydrite and hausmannite (Table 2.7). 53 O f the predicted mineral formations containing Fe from both ash treatments (cobalt ferrite, cupric ferrite, akaganeite, ferrihydrite, goethite, hematite, lepidocrocite, and maghemite), their SI values were increasing over time, which could potentially indicate a greater likelihood o f mineral formation that would keep Fe dissolution low (Table 2.6 and 2.7); as was observed for Fe leaching during the serial batch extraction. O f Mn and P, predicted minerals containing these elements showed slowly declining SI values over time, however these SI values were very high compared to other predicted minerals; this could potentially indicate very slow Mn and P dissolution. In addition, as P was leached from ash, secondary minerals o f P can form as Al, Fe, and Ca phosphates when they react together with any o f these major inorganic elements in solution and are sparingly soluble (namely apatite, fluoroapatite, and hydroxyapatite; Table 2.6 and 2.7) (McBride, 1994). 2.4.3.2 Changes in Secondary Minerals Between Hardened and Non-Hardened Ash M ore secondary minerals were predicted to form in an aqueous environment containing bottom ash, which may be due to the greater influx o f dissolved ions in solution from bottom ash compared to hardened bottom ash. The greater influx o f ions in solution was observed from the measured electrical conductivity measurement taken from bottom ash extracts (Figure 2.1). More ions in solution would result in a greater amount o f predicted secondary minerals to precipitate. Differences that were predicted were the formation o f barite, brucite, calcium phosphate, manganite, strontianite, tenorite, and witherite in bottom ash compared to hardened bottom ash. These were Mg, Ba, Ca, Mn, Sr, and Cu based minerals, and their predicted mineralogy m ay be due to a higher aqueous concentration o f these elements leached from bottom ash compared to hardened bottom ash. 54 2.4.4 Ash as a Soil Amendment The high pH o f bottom ash makes it ideal for use as a soil amendment to ameliorate acidic forest or agricultural soils. The calcium carbonate equivalency o f bottom ash and hardened bottom ash were 30.5% and 29.2% respectively (Table 2.0). Bottom ash also has other properties beyond that o f a simple liming agent such as an agricultural limestone, which is a liming agent that contains other added plant nutrients. In addition to a high concentration o f calcium, bottom ash and hardened bottom ash are relatively high in other plant macro-nutrients such as Fe, K, Mg, Mn, P, Na, and S (Table 2.0). Only N is lacking in significant concentrations. M any o f these major inorganic elements (primarily macro-nutrients, Ca, K, Na, and S) were readily leached from bottom ash (Table 2.2). This could be advantageous if the ash was intended for use as a soil amendment. In general, hardening produced a slower release o f nutrients as compared to untreated ash (Figure 2.1 and Table 2.5); this may be desirable in some conditions where salinity o f the receiving soil may be o f concern. Some other concerns with bottom ash may be from elevated trace elements and the presence o f products from incomplete combustion (e.g. PAHs). However, products o f incomplete combustion were not studied in this experiment, but a sample collected at UNBC containing low carbon ash (collected July 13, 2012) contained negligible PAHs, dioxins, and furans (unpublished data). It is likely that the same inference could be made about the bottom ash used in this study. Bottom ash intended for use as a soil amendment must meet certain compositional criteria as many jurisdictions have maximum allowable concentrations for environmentally sensitive elements. For example, within western Canada (British Columbia and Alberta) the BC Soil Amendment Code o f Practice (SACoP), and Alberta Environment have maximum allowable elemental limits for chemical constituents (Table 2.0). Guidelines also exist in the European countries o f Denmark, Finland, and Sweden (Table 2.0). 55 The BC SACoP requires a waste material be measured for its As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se, and Zn content, while Alberta Environment (regarding ash as a liming agent) only requires a waste material’s content o f B, Cd, and Zn to be determined. Both bottom ash and hardened bottom ash used in this study did not exceed any trace element limits as set out by the SACoP. However, B concentrations in bottom ash (140 mg k g 1) and hardened bottom ash (120 mg k g '1) did not meet the Alberta Environment criteria o f 43 mg kg ' 1 (dry weight). Furthermore, Ni (61 ppm for BA, and 56ppm for HBA) exceeded the maximum allowable limit for Denmark (30ppm allowable), and Zn (148ppm for BA, and 94ppm for HBA) did not meet the minimum limit for Sweden (500ppm minimum) in forestry applications (Table 2.0). It is probable that bottom ash in its hardened state would make a good soil amendment or liming agent. Hardening o f bottom ash was shown to significantly reduce the electrical conductivity o f an aqueous solution in contact with ash (i.e. lower concentration o f ions released into the aqueous phase), likely due to newly formed secondary minerals that slowly release their respective elements. Another concern with use o f biomass ashes as a soil amendment is its reactivity based on measured electrical conductivity o f an aqueous solution in contact with ash, as defined by Haglund (2008). Haglimd (2008) indicated that recycling ash to forest floors (not applicable to agricultural land) can be separated into three categories based on reactivity; A (<2800 mS m '1), B (2800 - 3200 mS m '1) and C (3200 - 3600 mS m '1) (C being the most reactive). Their recommended rates for a, one-time, 10 year application include 2-3 ton ha ' 1 (A), 1-2 ton ha ' 1 (B), and <1 ton ha ' 1 (C). According to numbers given by Haglund (2008), BA (989 mS m '1) and HBA (309 m S m '1) fell within category A, and both ashes would be appropriate for recycling to forest floors, based on reactivity (Table 2.0). 56 2.4.5 Simulated Long-Term Weathering of Ash-Soil Mixtures Ash components can undergo a number o f reactions upon addition to soil. These include adsorption o f leached ash constituents to the soil profile (Fransman and Nihlgard, 1995; Pitman, 2006; Ring, 2006), and the binding o f leached elements, such as Ca, to organically bound P in soils (Jacobson et al., 2004). In general, these reactions are expected to reduce the solution concentrations o f elements present compared to ash-only mixtures, but may not always be the case. The addition o f ash to soil may also increase concentrations o f aqueous species relative to the untreated soil such as Ca, Mg, P, and K (Fransman and Nihlgard, 1995; Jacobson et al., 2004). Few studies in literature report on the influence o f ash addition to fme-textured soils, or changes which m ay occur over the long-term. The purpose o f the long-term weathering experiment with ash and soil was designed to determine how major and minor elemental leaching may be altered when ash was mixed with soil. Hardened and non-hardened bottom ashes in this study were added to a fme-textured soil, typical o f many soils found in north-central British Columbia. It was expected that a fine-textured soil would behave similar to coarse-textured soils that have had ash applications (Fransman and Nihlgard, 1995; Kahl et al., 1996; Piirainen, 2001; Saarsalmi et al., 2005). That is, the fme-textured soil would reduce the concentration o f elements released from ash into an aqueous system. In general, the leachability o f ash was reduced when mixed with soil, after the initial dissolution o f the more soluble constituents contained within ash. In addition to any possible dilution effects, the reduced leaching o f many elements, both major and minor, may have been due to three mechanisms. First, secondary mineral formation (i.e. precipitation reactions) as a result o f ions in solution likely reduced aqueous phase concentrations (MINTEQ predictions). Second, soil attenuated the ability for many elements to be leached likely through adsorption reactions, which was commonly reported in field studies looking at ash application to coarse-textured soils (Fransman and Nihlgard, 1995; Kahl et al., 1996; Piirainen, 2001; Saarsalmi et al., 2005). Third, secondary minerals were likely causing absorption and adsorption o f many minor elements. Ash addition to soil resulted in a long-term elevation o f pH relative to the non-treated soil (Figure 2.0). Both, bottom ash and hardened bottom ash were observed to have similar leaching characteristics when applied to soil. Electrical conductivity o f solution extracts were initially high, but decreased as soluble constituents were leached from the ash, as was found in the ashonly treatment (Figure 2.1). Initially, some major inorganic elements (Al, Ca, K, Mg, Na, P, Si, Sr, and S 0 4‘ ) and environmentally sensitive elements (As, Cr, Hg, and Mo) were measured to have elevated aqueous concentrations compared to the soil control, but decreased after several leaching cycles. The ability for soil to reduce the aqueous concentration o f elements, from the leached bottom ash, was observed by ICP analysis o f the ash-soil extracts (Appendix A2) and overall lowering electrical conductivity measurements that converged with soil control measurements (Figure 2.1). Some elements (As, Mg, and P) were found to have increased aqueous concentrations relative to both control soil and the ash-only treatments, even after several leaching cycles. This increased solubility o f As, Mg, and P was likely due to the lower pH o f the ash-soil mixtures, relative to ash-only (Figure 2.0). This is significant, especially for P, as it is often the most limiting nutrient in many ecosystems (McBride, 1994). The availability o f ash-derived P increased as pH decreased to neutral values (Figure A2.21). It is likely that P is present as apatites in ash (Yusihami and Gilkes, 2012), which have very low solubility at high pH, but increase in solubility as the environment becomes neutral to acidic (McBride, 1994). Although soluble As concentrations increased in ash treatments, the aqueous concentrations were still well below Canadian guidelines for aquatic systems and drinking water. The slight increase o f arsenic 58 leached from ash-soil mixes was probably attributed to the lower pH environment and lack o f iron dissolution (Figure 2.0 and Figure A2.2). Chapter 3 reveals how neutral pH can cause enhanced As solubility from pH 5 to 7.5 in bottom ash. Together, the lack o f iron leaching and lower pH increased arsenic solubility in ash-soil mixes, as secondary minerals can form with arsenic and iron (Theis and Wirth, 1977). The formation o f iron secondary minerals at very high pH would explain the low solubility o f arsenic in ash-only treatments (Tables 2.6 to 2.10) (Chapter 3). In contrast, iron solubility was slightly hindered at pH 5 to 7 (Chapter 3). Incidentally, arsenic had highest solubility at this pH (approx. pH 6 - 8 ) during the serial batch extraction o f soil-ash mixes (Figure A2.2). Generally, soil reduced the ability for minor elements (Co, Cu, Pb, Zn, Cd, Ni, and Se), major inorganic elements (Al, K, Mg, Na, Si, and Sr), and the anion SO 4 '2 in ash-soil treatments to be leached from ash after several leaching cycles, eventually showing that aqueous concentrations in ash-soil mixes were similar to soil control (Appendix A2). The formation o f secondary minerals from ions in solution, and the soxption influence o f soil and secondary minerals likely attributed to the low aqueous concentration o f the many trace elements seen in the treatments containing ash and soil (Appendix A2). Neupane et al. (2012) also revealed that the slow but persistent dissolution o f elements through weathering (even at low concentrations) may be due to the adsorption o f these elements to formed secondary minerals. Therefore, the probable adsorption by soil particles and secondary mineral formation (from saturated major inorganic elements) was likely the reason for the low aqueous concentration o f the trace elements. 59 2.4.6 Concluding Thoughts Bottom ash and hardened bottom ash were primarily composed o f Ca, Fe, K, Al, Mg, Mn, P, Na, Ba, and S, with the remainder being composed o f B, Sr, As, Co, Cr, Cu, Mo, Ni, and Zn. Long-term weathering revealed that Ca, K, Si, Al, Ba, Na, and SO4' dominated the bottom ash leachate, and was accompanied by a high electrical conductivity. Initial elevated aqueous concentrations rapidly declined as highly soluble components were leached from ash. Hardening influenced the initial stages o f weathering by reducing electrical conductivity o f the aqueous mixture and aqueous concentrations o f Al, Ba, Ca, Cu, Hg, Sr, and Zn. However, hardening also increased initial aqueous concentrations o f B, Cr, K, Mo, Na, P, Sb, Se, Si, and SO4' . As weathering progressed, aqueous concentrations o f leached elements were similar in hardened versus non-hardened bottom ash indicating that hardening had a greater influence during the initial stages o f weathering. Trace elements had minimal aqueous concentration, from both ashes, because o f a high pH environment and likely adsorption to secondary minerals. Comparison o f aqueous concentrations to aquatic criteria (only for perspective) revealed that Cr, Cu, and Hg initially exceeded some aquatic limits, but concentrations then declined quickly. Only aqueous concentrations o f C l 1, NO 3'1, and NO2'1 in bottom ash and hardened bottom ash leachate exceeded select aquatic criteria over the long-term. The addition o f ash to soil (both hardened and non-hardened additions) and subsequent weathering revealed an initial elevation o f aqueous As, Al, Ca, Cr, Hg, K, Mg, Mo, Na, P, Si, Sr, and SO4'2 compared to the soil-only treatment. All aqueous concentrations from ash-soil mixes that were elevated compared to the soil-only were eventually similar to soil-only aqueous concentrations over time except As, Mg, P, and Ca. The elevated aqueous concentration o f As, Mg, and P may have been due to a lower pH environment compared to ash-only; aqueous As concentrations were still well below limits for aquatic life criteria. As a soil amendment the high pH and low reactivity o f both bottom ash and hardened 60 bottom ash were ideal, and its composition did not exceed any allowable limits set out by SACoP. However, the solubility o f components in ash may alter if the pH o f the surrounding environment were to become acidic. 61 3.0 pH Dependent Leaching of Bottom and Hardened Bottom Ash 3.1 INTRODUCTION The common management practice for ash produced through thermochemical processes is landfilling. Since ash is very alkaline in nature, natural weathering would allow for the pH to gradually decline as the ash reacts within the environment; this provides a steady release o f the elements that make up ash. Generally, trace elements are also locked within the ash due to the high pH o f ash (Chapter 2). However, this release o f elements may be changed if the pH were to decrease, as the dissolution o f constituents could be influenced by a more acidic environment. Factors that may lower the pH in environments where ash is stockpiled or stored include acid rain, carbon dioxide contact, and/or acid producing reactions from waste material or organic matter (Fallman and Aurell, 1996). Carbonic acid can be generated from carbon dioxide during the decomposition o f organic matter in landfills. This carbonic acid could result in acidic leachates that m ay come into contact with ash, and in turn influence the composition o f ash leachates. Additionally, ash may be used to neutralize acidic mine tailings, but there is a risk that the lowered pH, o f the neutralized ash, may release ash components (i.e. metals) into the environment. Acidity is not the only factor to influence the constituents released from ash but is a primary concern when disposing o f ash (Dijkstra et al., 2006; Meima and Comans, 1997,1998, 1999, and 2002). Other factors include contact time, temperature, mineralogy, redox potential, the amount o f liquid to solid contact, and biological activity (Dijkstra et al., 2006; Van der Sloot et al., 1996; Whalstrom, 1996). A better understanding o f elemental release from ash may require that some o f these factors be controlled during weathering experiments. pH is a key factor that dictates the release o f elements during long-term weathering (Dijkstra et al., 2006; Van der Sloot et al., 1996; Vitkova et al., 2009; Whalstrom, 1996). 62 The leaching behaviour o f ashes can be further characterized, apart from sequential batch extraction or column studies, by determining elemental mobility through pH dependency o f single batch extracts, known as pH static experimentation (Dijkstra et al., 2006; Whalstrom, 1996). As pH is lowered many o f the constituents that make up ash will likely vary in their solubility (Dijkstra et al., 2006; Van der Sloot et al., 1996; Whalstrom, 1996; Meima and Comans, 2002). To gain a more thorough understanding o f the leaching behaviour o f bottom and hardened bottom ash (in addition to the discoveries made through serial batch extractions in Chapter 2), pH was altered to determine the changes in aqueous phase concentrations o f major (Al, Ca, Fe, K, Mg, Mn, Na, P, and Si) and minor elements (As, B, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se, Sr, and Zn) as determined by ICP-MS (major and minor elements as defined in Chapter 2). 3.2 METHODOLOGY 3.2.1 Preparation of Bottom and Hardened Bottom Ash Bottom ash and hardened bottom ash used in the pH static experiment were the same as those used in Chapter 2. All preparations and analyses o f the solid phase were described in Chapter 2. # 3.2.2 pH Static Experiment Bottom ash and hardened bottom ash were subjected to the pH static method following the protocol o f Van der Sloot et al. (1996) and W ahlstrom (1996). Nalgene centrifuge tubes would degrade rapidly therefore 400mL glass beakers were used; they were acid washed and rinsed with double deionized water after each run. Bottom ash (20.Og OD equivalent, measured to the nearest 0.000 lg) was added to a 400mL glass beaker, to which was also added lOOmL o f double deionized water (L/S 5). Polyether ether ketone, PEEK, stir bars were used to suspend the ash. Nitric acid (1M) was then used to acidify the ash-water mixture and pH was monitored by an 63 electronic pH meter (Thermo Orion 420A+ Meter). The pH was held at pH 10 for 24 hours. Blanks were run without ash in 400mL glass beakers; these contained lOOmL o f double deionized water, 1M nitric acid and PEEK stir bar. After 24 hours, all the samples were vacuum filtered through 0.45pm W hatman filter papers using Nalgene filter-ware. Blanks were run simultaneously with the pH static experiment for QA/QC, and revealed only trace amounts o f the analyzed elements to be present within the aqueous phase o f the blanks (Appendix B2, Table B2.4). The aqueous extract was then analyzed for electrical conductivity (YSI Conductivity Instrument) and oxidation reduction potential (Thermo ORION 3 STAR pH Benchtop Meter). The entire procedure was repeated in quadruplicate for pH 9, 8 , 7, 6 , 5, and 4 for both bottom and hardened bottom ash. Although target pH was closely achieved for pH 10 to 4 for each sample, the actual pH o f the ash-water mixture would vary slightly, but would always be close to the target pH. Elemental analysis o f the extracts was performed by the UNBC Central Equipment Laboratory (CEL) using ICP-MS (Agilent Technologies 7500 Series ICP-MS) for Al, Ba, Ca, Fe, K, Mg, Na, P, Si, As, B, Bi, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Se, Sr, Zn, Ag, Be, Bi, Li, Sb, Sn, Ti, Tl, U, V, W, Y, and Zr; the analysis encompassed all speciations for each element as a total. 3.3 RESULTS 3.3.1 Electrical Conductivity of Aqueous Extracts Electrical conductivity increased as pH was lowered (Figure 3.0). At pH 4 to 7 aqueous extracts from bottom ash had a lower electrical conductivity than extracts from hardened bottom ash. But, at pH 7 to 10, aqueous extracts from bottom ash had a higher electrical conductivity than those from hardened bottom ash (Figure 3.0). During the pH static experiment, ionic 64 strength was not controlled; rather only a titration o f the material was performed using 1M nitric acid. —♦ —Bottom Ash 40 m E —• —Hardened Bottom Ash 35 ~30 c* 1 25 o 4 20 15 10 w 5 3 4 5 6 7 8 9 10 11 pH Figure 3 .0 - Electrical conductivity results (mS cm'1) fo r aqueous extracts from bottom and hardened bottom ash ranging from p H 4 to 10 from p H static experiment; n=4. 3.3.2 Aqueous Concentration of Major Elements Versus pH Most o f the major inorganic elements exhibited an increase in aqueous concentration as pH declined. Major inorganic elements that displayed increasing concentrations as pH declined (from 10 to 4) were Ca, Mg, Mn, and Si (Figures 3.2, 3.5, 3.6, and 3.9). Sodium and K showed increases in aqueous concentration as pH declined for bottom ash extracts, but not as prominent as the previous mentioned elements (Figures 3.4 and 3.7). However, acidification o f hardened bottom ash produced little change in aqueous concentrations o f Na and K as pH declined (Figures 3.7 and 3.4). Additionally, compared to bottom ash leachates, leachates from hardened bottom ash were found to contain higher aqueous concentrations o f Na and K from pH 10 to about pH 7 (Figures 3.7 and 3.4). Iron had low leaching as pH varied, and overall a slightly increased concentration as pH decreased (Figure 3.3). Phosphorus was found to have increased aqueous concentrations as pH declined from pH 8 to 6, and then a rapid decline in concentration as pH dropped from pH 6 to 4 (Figure 3.8). Overall, hardening reduced the aqueous concentrations o f Ca, Fe, Mn, and P, but increased the aqueous concentration o f Na and K. 65 120.0 •HBA •BA 100.0 80.0 A1 60.0 (mg L*1) 40.0 20.0 H 0.0 3.00 4.00 5.00 6.00 10.00 11.00 Figure 3.1 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing aluminum, Al, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 10000 9000 8000 7000 6000 Ca 5000 (mg L 1) 4000 3000 2000 1000 0 3.00 4.00 5.00 7.00 6.00 8.00 9.00 10.00 PH Figure 3.2 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing calcium, Ca, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 1.20 - Fe , 0.60 (n»g L ') 0.20 - Figure 3.3- Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing iron, Fe, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 66 11.00 K 4UU (mg L-1) 300 200 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 PH Figure 3 .4 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing potassium, K, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 1000 900 700 Mg (mg L 1) 100 3.00 pH Figure 3.5 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing magnesium, Mg, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 140 •BA HBA 120 100 M n 80 (mg L-') go 40 20 0 9.00 3.00 10.00 Figure 3 .6 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing manganese, Mn, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 67 11.00 Na (mg L 1) 10.00 11.00 Figure 3 .7 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing sodium, Na, concentration (mg/L) changes against p H (standard deviation error bars); n=4. (m gL 1) 15 Figure 3.8 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing phosphorus, P, concentration (mg/L) changes against p H (standard deviation error bars); n -4 . (mg L 1) 200 - 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 Figure 3.9 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing silicon, Si, concentration (mg/L) changes against pH (standard deviation error bars); n=4. 68 11.00 3.3.3 Aqueous Concentration of Minor Elements Versus pH The minor elements that displayed increasing aqueous concentrations as pH was decreased (from 10 to 4) were B, Ba, Cd, Co, Cu, Ni, Sr, and Zn (Figures 3.11, 3.12, 3.13, 3.14, 3.16,3.19, 3.22, and 3.23). The minor elements that displayed decreased concentrations as pH declined (from 10 to 4) were Cr, Hg, Mo, and Pb (Figures 3.15, 3.17,3.18, and 3.20). Selenium concentrations stayed relatively constant as pH was varied (Figure 3.21). Aqueous concentrations o f As showed enhanced leaching around neutral pH (pH 7 to 5) for both ash treatments (Figure 3.10). Due to hardening, aqueous concentrations o f As, Cd, Co, Hg, Ni, and Pb were reduced compared to leachates from non-hardened bottom ash. 0.10 - (mg L 1) 0.06 0.04 0.02 - 11.00 Figure 3.10- Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing arsenic, As, concentration (mg/L) changes against p H (standard deviation error bars); n=4. B (mg L '1) Figure 3.11 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing boron, B, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 69 9 BA HBA 8 7 6 Ba 5 (mg L 1) 4 3 2 1 0 4.00 3.00 5.00 6.00 7.00 8.00 9.00 11.00 10.00 PH Figure 3.12 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing barium, Ba, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 0.0025 •BA •HBA 0.0020 Cd 0.0015 i (“ 8 L ‘ ! ) 0.0010 0.0005 0.0000 9.00 3.00 10.00 11.00 Figure 3.13 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing cadmium, Cd, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 30 BA ■HBA 25 20 Co (mg L ‘) 15 10 05 00 9.00 3.00 10.00 Figure 3.14 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing cobalt, Co, concentration (mg/L) changes against pH (standard deviation error ___ bars); n=4. 70 11.00 (mg L-*) 0.08 0.06 0.04 0.02 0.00 Figure 3.15 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing chromium, Cr, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 0 .70 •HBA BA 0 ,60 0 .50 C u 0 40 (mg L '1) o, 30 0 ,20 H 0 . 10 0 ,00 10.00 3.00 11.00 Figure 3.16 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing copper, Cu, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 0.0006 - 4- BA •HBA 0.0005 0.0004 Hg 0.0003 (mg L ') 0.0002 0.0001 0.0000 10.00 3.00 11.00 Figure 3.17 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing mercury, Hg, concentration (mg/L) changes against pH (standard deviation error bars); n=4. 71 0.30 i 0.25 0.20 Mo 0.15 (mg L 1) 0.10 0.05 H 0.00 3.00 10.00 11.00 Figure 3.18 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing molybdenum, Mo, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 3.5 •BA ■HBA 3.0 -\ 2.5 2.0 Ni ( m g L 1) i .5 1.0 0.5 0.0 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 Figure 3.19 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing nickel, Ni, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 0.018 t ■BA HBA 0.016 0.014 0.012 Pb 0.010 (mg L '1) 0.008 0.006 H 0.004 0.002 0.000 3.00 4.00 5.00 7.00 6.00 8.00 9.00 10.00 pH Figure 3.20 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing lead, Pb, concentration (mg/L) changes against pH (standard deviation error bars); n=4. 72 11.00 Se 008 (mg L 1) 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 Figure 3.21 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing selenium, Se, concentration (mg/L) changes against p H (standard deviation error bars); n=4. Sr (mg L ‘) Figure 3.22 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing strontium, Sr, concentration (mg/L) changes against p H (standard deviation error bars); n-4. •HBA ■BA Zn (mg L ') 9.00 3.00 10.00 Figure 3.23 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing zinc, Zn, concentration (mg/L) changes against pH (standard deviation error bars); n=4. 73 11.00 3.3.4 Percent Loss for Individual Elements Leached from Ash into the Aqueous Phase Percent loss for the elements was calculated by determining the total amount present in the aqueous phase (i.e. ICP data o f the aqueous phase and the total volume used during extraction) and dividing that by the total amount available in the solid material (i.e. ICP data o f the solid phase and total solid material used during extraction). A sample calculation can be found in the Appendix B2. The maximum percent loss for many o f the major inorganic elements contained in BA or HBA normally occurred at the lowest pH (Table 3.0 and 3.1). Maximum leaching for Al, B, Ba, Ca, Fe, K (in BA), Mg, Mn, Na (in BA), and Sr in BA and HBA occurred at pH 4. Similarly, minimum leaching o f these mentioned elements occurred at highest pH (pH 10). Maximum leaching for K (in HBA) and Na (in HBA) did not change drastically as pH was altered (Table 3.0 and Table 3.1). Finally, the amount o f P leached was at a maximum at pH 6 for both BA and HBA, whereas a minimum was observed at high pH (Table 3.0 and 3.1). Similar to the major inorganic elements leached, the maximum percent loss o f many o f the minor elements leached from BA and HBA also occurred at the lowest pH (Table 3.0 and 3.1). Maximum leaching for Cd, Co, Cu, Ni, and Zn occurred at approximately pH 4 (Table 3.0 and 3.1). M aximum leaching for Cr, Hg, and Mo occurred at high pH for both BA and HBA (approximately pH 9 to 10) (Table 3.0 and 3.1). Lead leaching was at a maximum approximately pH 7 for BA (Table 3.0) and pH 10 for HBA (Table 3.1). Arsenic leaching was at a maximum at pH 6 for both BA and HBA (Table 3.0 and 3.1). 74 Table 3 .0 - Percent loss fo r elements leachedfrom bottom ash based on original solid phase concentrations (from H N O /H C l digest) and amount o f ash used during p H static experiment fo r p H 10 to 4. pH 9 pH8 pH 7 pH 5 pH 10 pH 6 Mean Mean SD SD Mean SD Mean SD Mean SD Mean SD 0.14 0.27 0.20 0.32 0.33 0.12 0.27 0.15 0.43 0.33 0.14 0.15 Ag (% )•* 0.28 0.002 0.001 0.004 0.05 0.06 0.22 0.002 0.005 0.001 0.006 0.001 A1 (%) 1.71 7.81 1.41 9.86 0.19 0.13 1.16 0.50 0.16 18.3 2.8 4.30 As (%) 4.9 93.4 17.7 9.5 30.7 2.2 41.3 55.6 3.6 5.4 8.8 73.8 B (%) 0.64 0.04 0.06 0.70 0.72 0.99 1.46 0.15 Ba (%) 0.69 0.01 0.03 0.15 47.0 7.1 2.4 24.3 6.6 33.2 1.2 35.3 1.7 68.1 1.8 80.3 Ca (%) n/a n/a n/a 0.60 0.30 0.76 0.69 0.17 1.31 0.17 Cd (%)** n/a 0.35 n/a 0.09 2.03 0.95 2.20 1.37 7.28 1.21 7.41 1.92 Co (%) n/a 0.06 0.49 0.86 2.04 n/a n/a 0.59 n/a n/a 0.15 0.10 Cr (%) 2.12 0.60 0.39 0.19 0.70 0.44 0.04 0.13 0.62 0.24 0.50 0.06 0.68 0.18 Cu (%) 0.029 0.016 0.001 0.012 0.008 0.025 0.013 0.012 0.012 0.002 0.0117 0.0005 Fe (%) 0.07 0.24 0.04 0.28 0.35 0.02 0.33 0.06 0.05 0.15 0.13 0.03 Hg (%)** 0.7 17.5 21.4 12.0 0.9 14.0 0.6 14.3 1.2 1.5 20.0 1.8 K (%) 1.49 0.59 0.29 0.49 4.43 1.16 8.29 0.84 Li (%) 0.31 2.33 1.28 7.63 0.56 9.25 7.2 35.1 54.1 4.1 61.2 0.63 3.22 18.0 12.6 3.3 Mg (%) 0.001 0.05 0.64 0.002 0.04 0.40 1.51 0.93 5.36 1.11 6.43 1.37 Mn (%) 2.1 29.3 33.7 1.9 29.4 22.5 1.1 3.0 19.7 10.9 5.16 3.92 Mo (%) 1.85 12.2 0.6 13.1 0.9 22.9 24.5 2.7 7.89 3.2 33.1 2.5 N a (%) 0.78 5.90 3.78 11.6 7.1 0.02 0.01 0.50 27.9 3.3 40.2 7.7 Ni (%) 0.004 0.04 0.03 0.68 3.86 2.19 0.02 0.02 0.09 0.13 1.00 1.00 P (% ) 3.70 9.37 4.14 0.36 4.85 2.64 8.18 3.85 0.55 4.64 1.42 Pb (%)** 6.25 1.64 0.49 3.23 0.78 5.97 1.91 7.92 2.81 6.24 2.06 Sb (%)** 0.59 3.93 4.19 8.39 0.22 2.23 7.40 3.64 4.32 0.49 5.15 0.18 Sn (%) 3.06 1.51 23.2 23.9 1.1 31.1 4.2 4.0 2.2 Sr (%) 15.0 5.6 0.9 45.3 49.3 0.002 0.001 0.003 0.001 0.004 Ti (%) n/a n/a 0.001 0.001 0.003 0.001 0.003 0.24 0.79 0.61 0.12 0.41 0.22 n/a 0.08 T1 (%)** 0.73 0.16 n/a 0.23 0.03 0.11 0.01 0.003 0.02 0.07 0.02 0.03 0.05 0.03 0.01 0.00 U (%)** 0.34 0.81 1.61 0.34 0.05 0.53 0.05 0.57 1.96 0.15 0.68 0.20 V (%) 0.02 0.08 0.04 0.18 0.07 0.02 0.11 0.03 0.17 0.05 0.65 0.36 Y (%)** 0.07 0.14 0.06 0.01 0.01 0.94 3.8 0.07 0.01 0.05 1.63 10.0 Zn (%) 0.01 0.00 0.01 0.00 0.01 0.001 0.00 n/a n/a 0.01 0.00 Zr (%) 0.01 *n/a designation is given fo r undetected, **Estimation based on detection limit, ***Be and Bi were undetected Parameter 75 pH 4 M ean 0.33 3.58 0.97 107 2.01 89.3 3.61 13.2 1.28 9.65 0.049 0.17 31.7 12.5 70.8 16.9 n/a 38.1 44.5 0.29 2.51 6.22 1.99 60.9 0.011 n/a 0.01 0.18 48.3 36.1 0.02 SD 0.19 3.48 0.49 2 0.38 2.5 0.68 1.8 0.94 4.26 0.028 0.07 3.5 1.1 2.1 3.6 n/a 3.3 1.5 0.15 0.13 3.33 0.27 2.8 0.006 n/a 0.01 0.04 22.4 3.4 0.01 Table 3.1 - Percent loss fo r elements leachedfrom hardened bottom ash based on original solid phase concentrations (from HNO3/HCI digest) and amount o f ash used during p H static experiment fo r p H 10 to 4. pH 9 pH 7 pH 6 pH 10 pH8 pH 5 SD Mean SD Mean SD Mean Mean SD Mean SD Mean 0.04 n/a n/a Ag (%)*• 0.11 n/a n/a n/a n/a n/a n/a n/a 0.001 0.0008 0.0005 0.0007 0.0002 A1 (%) 0.001 0.003 0.003 0.0021 0.0002 0.01 0.47 3.06 As (%) 0.11 0.25 1.01 0.14 2.97 0.17 0.68 0.96 0.15 11.4 59.4 4.1 77.5 17.4 2.9 29.1 42.3 5.0 103 8.6 B (%) 0.04 0.58 0.09 0.07 2.60 1.24 Ba (%) 0.32 0.54 1.98 0.37 2.46 19.6 6.3 5.2 71.7 Ca (%) 11.7 2.5 27.2 5.5 45.2 8.3 91.0 n/a n/a n/a n/a n/a Cd (%)** n/a n/a n/a n/a n/a 0.85 n/a 0.14 0.41 0.22 Co (%) n/a n/a 0.18 0.66 1.03 n/a 0.18 0.74 1.05 0.48 0.20 Cr (%) 2.04 0.63 1.33 1.06 1.19 0.21 0.46 0.09 0.005 0.01 0.09 0.03 0.11 Cu (%) 0.12 0.01 0.08 0.03 0.30 0.002 0.0002 0.0019 0.0004 0.003 0.003 0.002 0.0002 0.0026 Fe (%) 0.0027 0.0003 0.04 0.02 0.13 0.10 0.05 0.08 0.02 0.14 Hg (%)** 0.18 0.05 0.08 1.4 20.4 21.4 K (%) 1.0 18.7 19.0 0.9 1.5 1.7 21.1 16.1 1.40 3.49 4.42 0.58 6.11 Li (%) 0.24 2.35 0.93 0.82 7.03 0.80 49.7 2.04 2.44 16.0 10.7 27.71 6.50 36.9 3.1 4.3 61.9 Mg (%) 0.06 0.12 0.66 1.97 Mn (%) 0.00 0.00 0.18 0.27 1.10 0.97 4.22 1.2 23.0 1.9 25.1 1.7 6.28 Mo (%) 19.6 25.4 1.0 4.53 0.85 21.4 4.7 29.1 17.2 1.4 25.9 3.7 3.4 N a (%) 25.3 4.8 23.2 Ni (%) 0.09 0.05 1.58 2.18 9.69 2.05 21.8 4.2 32.1 3.31 2.18 0.01 0.03 0.03 0.01 0.59 0.09 1.16 0.34 P (% ) 0.01 0.08 0.25 0.04 0.75 0.17 0.14 0.22 0.60 0.92 0.67 0.56 0.52 Pb (%)** 0.08 0.34 3.20 1.51 1.28 7.77 1.60 4.63 0.99 8.11 4.61 Sb (%)** 0.72 0.95 0.10 0.84 0.41 Sn (%) 1.74 0.13 1.06 0.08 1.05 0.15 1.07 2.2 16.9 4.1 3.2 Sr (%) 11.1 21.5 3.5 30.0 43.6 4.7 51.3 Ti (%) 0.0010 0.0009 0.0006 0.0003 0.0007 0.0003 0.0027 0.0029 0.0013 0.0006 0.0015 n/a n/a 0.65 n/a n/a 0.23 0.10 n/a 0.39 n/a T1 (%)** n/a 0.02 0.02 0.02 0.05 n/a 0.05 0.02 0.13 0.05 U (%)** n/a n/a 0.09 0.42 0.34 0.05 0.60 0.10 0.31 0.48 0.06 0.13 0.11 V (%) n/a n/a n/a n/a n/a n/a 0.20 0.15 0.15 0.04 1.53 Y (%)** 0.00 0.03 0.01 0.01 0.10 0.03 1.54 0.03 0.03 0.89 12.6 Zn (%) *n/a designation is given fo r undetected, **Estimation based on detection limit, * * *Be, Bi, and Zr were undetected Parameter 76 SD n/a 0.01 0.34 6 0.17 3.8 0.14 1.06 0.09 0.10 0.0005 0.02 1.0 0.49 4.8 1.18 0.25 1.0 3.2 0.14 0.04 0.38 0.28 3.2 0.0007 n/a n/a 0.03 1.11 5.4 pH 4 M ean 0.37 3.86 0.46 119 2.83 94.6 2.65 5.60 1.80 7.04 0.017 n/a 27.7 10.1 67.4 12.8 n/a 31.1 39.1 0.30 0.60 3.75 0.83 63.9 0.004 n/a 0.01 0.06 49.4 45.7 SD 0.17 1.88 0.08 7 0.33 2.7 0.39 1.32 1.04 1.97 0.006 n/a 2.0 1.0 1.2 2.0 n/a 2.7 1.7 0.21 0.16 1.12 0.16 4.6 0.003 n/a 0.01 0.01 17.2 9.8 3.3.5 Aqueous Ion Concentrations Compared to Aquatic Criteria The British Columbia Contaminated Sites Regulation (BCCSR) has maximum allowable limits set for the aqueous concentrations o f major inorganic elements Al, Fe, Mg, Mn, and Na for different water types (Freshwater Aquatic Life, Marine Water Aquatic Life, and Drinking Water); (Table 3.2). M inor elements monitored are those o f As, B, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se and Zn (Table 3.2). The values presented in Table 3.2 are intended to put the maximum concentrations reached during the pH static experiment into perspective as these extracts were never intended for drinking water (Table 3.2). Both bottom ash and hardened bottom ash treatments exceeded the limits o f Al, Mg, and M n for safe drinking water. Bottom ash and hardened bottom ash treatments exceeded the allowable Al limit at pH 4 (Table 3.2). The safe limit for Mg was exceeded below pH 9 for both ashes. At pH 8 and lower, M n limits were exceeded for both ashes (Table 3.2). Bottom ash exceeded the safe drinking water limits o f As (1 16ppb at pH 6 ), Cr (120ppb at pH 10), Mo (280ppb at pH 8 ), Pb (1 lppb at pH 8 ), and Se (13ppb at pH4), whereas hardened bottom ash exceeded the safe drinking water limits o f As (27ppb at pH 7), Cr (130ppb at pH 10), and Se (1 lppb at pH 4). The BCCSR also has allowable limits for elemental concentration for freshwater aquatic life (FAL) and marine aquatic life (MAL). The 50ppb limit for As was exceeded between pH 7 and 5 for the bottom as?treatm ent, but never exceeded 27ppb for hardened bottom ash at any pH range (Table 3.2). Cadmium limits o f O.lppb were exceeded by the bottom ash treatment below pH 9, whereas the hardened bottom ash treatment exceeded O.lppb below pH 6 . Cobalt limits (40ppb) were exceeded below pH 8.5 (maximum 222ppb at pH 4) and below pH 5 (maximum 8 6 ppb at pH 4) for bottom ash and hardened bottom ash respectively (Table 3.2). Chromium limits (lOppb) were also exceeded below pH 5 and at pH 10 for both ashes. Copper limits 77 (20ppb) were exceeded below pH 5 for both ash treatments. Nickel limits were also exceeded below pH 8.5 for both ash treatments reaching maximum concentrations o f 251 Oppb (bottom ash treatment) and 2080ppb (hardened bottom ash treatment) at pH 4. Aqueous concentrations o f Se only exceeded the lOppb limit below pH 5, reaching 13ppb (bottom ash treatment at pH 4) and 1 lppb (hardened bottom ash treatment at pH 4). Aqueous concentrations o f Zn exceeded the BCCSR limit (75ppb) at levels below pH 7, where a maximum o f 4930ppb (bottom ash treatment at pH 4) and 4080ppb (hardened bottom ash treatment at pH 4) were reached (Table 3.2). Table 3.2 - Maximum aqueous concentrations (ppm and ppb as indicated) reached fo r the major and minor elements from p H static testing (ppm or ppb at determined p H in brackets) compared to aquatic criteria set by British Columbia Contaminated Sites Regulation (BCCSR). Parameter BA HBA BCCSR FAL MAL DW Al (ppm) 55.76 (pH4) 60.68 (pH4) 9.5 B (ppm) 13.81 (pH4) 13.61 (pH4) 50 Ba (ppm) 2.5 (pH4) 3.4 (pH4) 10 Fe (ppm) 0.69 (pH4) 0.27 (pH4) Mg (ppm) 804 (pH4) 881 (pH4) 100 Mn (ppm) 103 (pH4) 71 (pH4) 0.55 Na (ppm) 150 (pH4) 162 (pH8) 200 As (ppb) 116 (pH6) 27 (pH7) 50 125 10 Cd (ppb) 1.7 (pH4) 1.3 (pH4) 0.1 0.1 5 Co (ppb) 222 (pH4) 86 (pH4) 40 Cr (ppb) 120 (pHIO) 130 (pH 10) 10 50 50 20 5 6.5 Cu (ppb) 300 (pH4) 420 (pH4) 20 Hg (ppb) 0.51 (pH9) 0.32 (pHIO) 1 1 1000 Mo (ppb) 280 (pH8) 220 (pH8) 10000 250 Ni (ppb) 2510 (pH4) 2080 (pH4) 83 Pb (ppb) 11 (pH8) 2 (pH 10) 40 20 10 Se (ppb) 13 (pH4) 11 (pH4) 10 540 10 75 100 4930 (pH4) 4080 (pH4) Z n (PPb) .. *Freshwater Aquatic Life (FAL), Marine Water Aquatic Life (MAL), Drinking Water (DW) **Aqueous concentrations were shown as a comparison to BCCSR guidelines to provide perspective on maximum observed concentrations 78 3.4 DISCUSSION As found from the long-term weathering o f bottom ash, at high pH, leachates were generally dominated by Ca, K, Si, Al, Ba, Na, and SO 4'2 while aqueous trace metal content was minimal (Chapter 2). The low aqueous concentrations o f trace metals were mainly due to the high pH o f the resulting ash-water mixtures. However, the dissolution o f minerals from biomass ash can be affected by acidic environments (Dijkstra et al., 2006). As pH is altered many o f the constituents (i.e. elemental constituents) that make up ash will exhibit altered solubility; most o f which have shown increased mobility at the acidic range (Dijkstra et al., 2006; Vitkova et al., 2009). Acidification during a single batch extraction (i.e. pH static experiment) can be used to study the leaching behaviour o f bottom and hardened bottom ash. In this study, pH was altered to determine its effect on the concentrations o f elements within the aqueous phase. 3.4.1 pH Static Leaching of Ash - Hardened versus Non-Hardened Ash To acidify the ash-water mixture 1M nitric acid was used to bring the pH o f the ash-water mixture to a specific set point; this required constant addition o f acid over a 24hr period as the pH o f the ash-water mixture would continually rise. The constant addition o f acid to maintain a stable pH indicated a high buffering capacity for bottom ash and hardened bottom ash. The high buffering capacity may be due to the presence o f hydroxides and carbonates in both hardened and unhardened bottom ash (Dijkstra et al., 2006). It has been reported that Ca, Mg, and Si bearing minerals control the high buffering capacity o f bottom ash (Johnson et al., 1995; Yan et al., 1998). In this study, bottom ash and hardened bottom ash buffering capacities were likely controlled by minerals containing Ca, Mg, K, and N a as these elements showed the highest aqueous concentration at all pH values (Figures 3.2, 3.5, 3.4, 3.7, 3.9, and 3 .6 ). As pH declined, the aqueous concentrations o f Ca, Mg, K, Na, Si, and Mn increased, and were accompanied by a high electrical conductivity (Figure 3.0). The high aqueous concentrations o f these elements in 79 bottom ash leachates were consistent with other static leaching studies (Dijkstra et al., 2006; M eima and Comans 1997,1998, and 1999) Hardening influenced the leaching o f elements from bottom ash during acidification. Hardening reduced the aqueous concentrations o f Ca, Fe, Mn, and P as compared to non­ hardened ash. In addition, compared to non-hardened bottom ash, the electrical conductivity o f the aqueous mixture containing hardened bottom ash was also found to be lower (Figure 3.0). However, below pH 7, the electrical conductivity was observed to have increased over non­ hardened bottom ash-water mixtures. At pH 4, electrical conductivity o f hardened and non­ hardened ash-water mixtures was the same (Figure 3.0). Some elements exhibited a higher aqueous concentration due to hardening; these elements were K and N a (Figures 3.4 and 3.7). High K and Na aqueous concentrations were observed at high pH, but as pH was reduced (below pH 6 ), K and Na aqueous concentrations were similar to non-hardened bottom ash. This increase in aqueous K and Na concentration from hardened bottom ash may have been due to K- and Na-chlorides/sulphates present in hardened ash (Meima and Comans, 1997). These salts are highly soluble and would account for the increased aqueous concentration o f K and Na at higher pH (Figures 3.4 and 3.7). Hardening also reduced the ability o f some trace metals to be leached from bottom ash (As, Cd, Co, Hg, Ni, and Pb). W ith a concern for these trace elements becoming mobile in ash when acidified and in contact with water, a reduction in dissolution due to hardening is beneficial. Generally, hardening influenced leaching at higher pH (Figure 3.0); but, as pH declined, hardened ash was found to show similar leaching as unhardened bottom ash. Overall, the elements that exhibited an increase in aqueous concentration as a result o f acidification were As, B, Ca, Cd, Co, Cu, Mg, Mn, Ni, Si, Sr, and Zn; these were primarily major inorganic elements. Other elements that exhibited a decline in concentration were Cr, Hg, Mo, and Pb for both bottom ash and hardened bottom ash. 80 The pH-leaching profiles o f many elements were similar to findings from other studies (Comans and Middelburg, 1987; Dijkstra et al., 2006; Johnson et al., 1995; M eima and Comans 1997,1998, and 1999; Quina et al., 2009). A few elements, Ca, K, Na, and Mg can be discussed as to their solubility-controlling minerals found in bottom ashes. At high pH (approximately pH 12 to 10), the solubility-controlling minerals for Ca and Mg are likely portlandite and brucite (Johnson et al., 1995; Meima and Comans, 1997). Portlandite forms as a result o f hydrolysis from CaO present in ash (Meima and Comans, 1997). Brucite was also predicted to be the main solubility-controlling mineral for Mg during the weathering o f bottom ash (Chapter 2). Below pH 12, portlandite dissolves and gypsum is likely the solubility-controlling mineral for Ca dissolution in bottom ashes (Dijkstra et al., 2006; Meima and Comans, 1997). Potassium and Na leaching may be due to soluble salts o f K- and Na-chlorides/sulphates present in bottom ashes (Meima and Comans, 1997). Regardless o f pH (even though slight aqueous concentration increases were seen), Na and K were relatively insensitive to the influence o f pH (Table 3.0 and 3.1). These were similar to findings by Quina et al. (2009), and may have been be due to K- and Na-chloride/sulphate salts, o f which hardened bottom ash may have had more of. Similar to the major inorganic elements, some leached trace elements were found to increase in aqueous concentration as pH declined; these trace elements were As, Cd, Co, Cu, Ni, and Zn. Some trace elements (Cr, Hg, Mo, and Pb) decreased in aqueous concentration as pH declined. However, trace metal leaching from both ashes was still relatively low compared to the major inorganic elements and only exceeded limits for MAL and FAL aqueous systems when the system became quite acidic (i.e. pH 5 or 4) (Table 3.2). Further data on aqueous concentrations as a result o f pH change can be found in Figures 3.1 to 3.23. The allowable limits that were exceeded by trace elements are discussed a little later (Section 3.4.2). Low trace metal leaching may have been due to adsorption to secondary minerals or due to low solubility. Declining 81 aqueous concentrations for Cr, Hg, Mo, and Pb upon acidification may have been due to the presence and/or formation o f Fe- and Al-oxides/hydroxides in ash-water systems. For example, Mo and Pb are easily bound to hydrous ferric oxides and aluminum hydroxides (Meima and Comans, 1998 and 1999). As pH was reduced, Fe and Al aqueous concentrations slightly increased (Figures 3.1 and 3.5), which may have caused a greater likelihood for secondary minerals to form. If there was an increased formation o f Fe and Al secondary minerals at lower pH, then that would allow for even more adsorption o f aqueous Mo and Pb, and in effect lower their aqueous concentration, as was seen (Figures 3.19 and 3.21). As with the adsorption o f Mo and Pb ions in solution to Fe- and Al-oxides/hydroxides, Cr and Hg ions in solution m ay have undergone the same adsorption as well, as their pH-leaching profiles were similar to Mo and Pb (Figures 3.18 and 3.20). Increasing aqueous concentrations for As, Cd, Co, Cu, and Zn as pH declined may have been due to general acidification allowing for greater dissolution o f minerals at lower pH, but at higher pH their low dissolution may have been in part due to the surface complexation to calcite. For example, Cd, Zn, and Co have a great affinity towards calcite; that is they are readily adsorbed to the surface o f calcite (Comans and Middelburg, 1987). Since calcite commonly forms at high pH in ash-water systems (Steenari and Karlsson, 1999) (Chapter 2; Table 2.8 and 2.9), the aqueous concentrations o f As, Cd, Co, Cu, and Zn would likely be much lower at higher pH than lower pH due to adsorption to calcite. At lower pH, calcite formation would not be as prominent, allowing for greater As, Cd, Co, Cu, and Zn aqueous concentrations. 3.4.2 Implications of Ash Utilization on Land The results o f this pH static study have implications for storage o f ash or utilization o f ash as a soil amendment to acidic environments. Ash is normally alkaline and many constituents were relatively immobile under high pH conditions. However, as pH declined the aqueous 82 concentrations o f major inorganic elements B, Ca, Mg, Mn, Si, and Sr, and minor elements As, Cd, Co, Cu, Ni, and Zn increased in aqueous concentration for both ashes. Even though the aqueous concentrations o f many elements increased as pH declined, their aqueous concentrations did not exceed most aquatic criteria until pH 4 (Table 3.2). The British Columbia Contaminated Sites Regulation (Schedule 6 ) has set maximum allowable limits on several elemental concentrations within aqueous systems (See Table 3.2). The focus o f this study was to determine how elemental leachability changes due to acidification o f bottom ash and hardened bottom ash. The comparison o f elemental concentrations contained within the extracts to BCCSR limits were only used to provide perspective to the aqueous concentrations. The aqueous concentrations o f many trace elements stayed well below allowable limits (set by BCCSR) for freshwater aquatic life at neutral to high pH (Figures 3.1 to 3.23). It was only at low pH (approximately below pH 5) that the aqueous concentrations o f most elements o f concern exceeded allowable criteria (Table 3.2). 3.4.3 C oncluding T houghts Bottom ash and hardened bottom ash had a very high buffering capacity, which was likely controlled by minerals containing Ca, Mg, K, and N a as these elements dominated the aqueous concentration at all pH ranges. The acidification o f bottom ash and hardened bottom ash resulted in the increased aqueous concentrations o f As, B, Ba, Ca, Cd, Co, Cu, Mg, Mn, Ni, Si, Sr, and Zn, whereas a decrease in aqueous concentration was seen for Cr, Hg, Mo, and Pb. Hardening o f bottom ash had the greatest influence at high pH, where Ca, Fe, Mn, and P exhibited reduced aqueous concentrations along with lower electrical conductivity. However, hardening also increased the aqueous concentrations o f Na and K, which may have likely been due to Na- and K- sulphates/chlorides present as a result o f hardening. Below pH 5, hardened ash showed little difference in leachate composition (o f major inorganic elements leached) and electrical 83 conductivity, indicating similar dissolution o f minerals as non-hardened bottom ash. Similar to the major inorganic elements leached, the trace metals As, Cd, Co, Hg, Ni, and Pb showed much lower leachability from hardened bottom ash compared to bottom ash. The low aqueous concentrations o f As, Cd, Co, Cu, and Zn at high pH, and increasing aqueous concentration as pH declined, was likely in part due to the adsorption o f these trace metals to calcite forming at high pH. Additionally, the declining aqueous concentration o f Cr, Hg, Mo, and Pb as pH declined was likely due to trace metal adsorption to Fe- and Aloxides/hydroxides. At high pH, the aqueous concentration o f very few trace metals exceed allowable limits set by BCCSR, but many o f the allowable limits were exceeded as the acidity o f the ash-water mixture fell below pH 5. In a landfill situation, monitoring leachate and the surrounding aqueous environment for pH decreases would be important as the aqueous concentrations o f trace metals may start to exceed allowable limits. 84 4.0 CONCLUSION Biomass ash may be used as a soil amendment to raise soil pH, and supply essential plant nutrients to agricultural crops or to forest tree species. However, there are concerns about the mobility o f environmentally-sensitive constituents (i.e. trace elements) originating from ash. Few studies have investigated the long-term mobility o f ash components. In addition, little is known about how ash constituents may interact with fme-textured soils, which are common in northcentral British Columbia. Untreated ash is in some cases quite reactive, and the fine-texture o f biomass ash makes it dusty and prone to air transport when handled or applied to land. Hardening is one way ash can be made less reactive and easier to handle. The overall goal o f this study was to determine the suitability o f UNBC gasifier bottom ash as a soil amendment, that is to simulate the long-term leachability o f constituents contained within biomass bottom ash as influenced by a hardening process, and when this ash interacts with soil. The results o f the study are also relevant to situations where biomass ash is landfilled or stockpiled, since leachates originating from ash would likely come in to contact with soil if they migrate downwards from a landfill or storage site. This work had two objectives. First, to determine the leachability o f major and trace elements in both hardened and non-hardened bottom ash, with and without the presence o f a fmetextured soil. Second, to determine the leachability o f major and minor elements in both hardened and non-hardened bottom ash in response to acidification. To address the first objective, the solid phases o f bottom ash, hardened bottom ash, and the soil were analyzed by ICP-OES (following microwave acid digestion) to determine elemental content while pH was measured to determine alkalinity, and electrical conductivity (EC) was measured to determine salinity (Chapter 2). Five treatments (bottom ash, hardened bottom ash, soil control, and two ash-soil mixes) were then artificially weathered through 2 0 -day serial batch extractions (Chapter 2). The extracts from the 20-day serial batch extractions were analyzed by 85 ICP-MS for elemental content, pH for alkalinity, EC for salinity, and anions were analyzed by ion-chromatography. The residual solid phase was also analyzed by ICP-OES to determine final elemental content. MINTEQ was used to predict saturated minerals that might be present within the aqueous phase o f weathered ash treatments (Chapter 2). The second objective was addressed by the acidification o f bottom ash and hardened bottom ash in single batch extractions. Elemental analysis o f the collected extracts was then performed by ICP-MS (Chapter 3). Bottom ash and hardened bottom ash were primarily composed o f Ca, Fe, K, Al, Mg, Mn, P, Na, and S, with the remainder being composed o f B, Ba, Sr, As, Co, Cr, Cu, Mo, Ni, and Zn. Weathering o f bottom ash revealed that the leachate was dominated by Ca, K, Si, Al, Ba, Na, and S 0 4‘2, which was also accompanied by a high electrical conductivity. Hardening primarily influenced the elemental leachability from bottom ash during the initial stages o f weathering by reducing the aqueous electrical conductivity, and aqueous concentrations o f Al, Ba, Ca, Cu, Hg, Sr, and Zn. However, due to hardening, B, Cr, K, Mo, Na, P, Sb, Se, Si, and SO4'2 exhibited an increase in initial aqueous concentration. Trace metal leaching resulting from both ashes was minimal, and was likely due to the high pH and the adsorption o f trace metals to secondary minerals. The high pH o f bottom ash and hardened bottom ash make it ideal for use as a soil amendment to ameliorate acidic forest or agricultural soils. Simulated long-term weathering o f ash-soil mixtures revealed that when mixed with soil, bottom ash and hardened bottom ash leachability does not vary much. Largely, the leachate composition o f ash-soil mixtures was not that different from the soil-only leachates. The long­ term weathering experiment showed that solution concentrations o f major inorganic elements in ash-soil mixtures were generally lower than those from ash-only treatments, but some o f the minor elements (As, Cr, Hg, and Mo) exhibited higher solution concentrations in ash-soil mixtures compared to soil-only treatment, but did not exceed any allowable aquatic limits. 86 Compared to the high pH o f ash-only mixtures, the neutral pH environment o f the ash-soil mixtures in water likely attributed to the increased aqueous concentrations o f As, Cr, Hg, and Mo. Generally, due to the sorptive properties o f soil, many o f the trace metals originating from ash were likely adsorbed to minerals present within soil. As a soil amendment, the elemental composition o f bottom ash did not exceed sensitive trace metal content by SACoP, but did exceed the B limit for Alberta and the Ni limit for Denmark. As the normal pH o f ash-water mixtures is high, acidification o f bottom ash and hardened bottom ash was found to alter the solubility o f constituents contained in ash (Chapter 3). Such a situation may arise if ash were stored or added to highly acidic environments. Declining pH increased the aqueous concentrations o f Ca, Mg, Mn, and Si, and minor elements As, B, Ba, Cd, Co, Cu, Ni, Sr, and Zn. Aqueous concentrations o f Hg, Mo, Ni, and Pb were found to decrease as pH declined. The elements As and P were found to have increased aqueous concentrations at neutral pH. Hardening lowered leachability o f the minor elements As, Cd, Co, Hg, Ni, and Pb, and major inorganic elements Ca, Fe, Mn, and P. Trace metals tend to have lowered mobility at higher pH, but as pH lowered many o f the trace metals tend to increase in aqueous concentration and exceed allowable aquatic criteria. If landfilled, ash would have to be carefully monitored to make sure that the pH o f the leachate does not drop much below pH 5. Overall, there is potential for the use o f UNBC gasifier bottom ash as a soil amendment. The high pH o f both hardened and non-hardened bottom ash would make it a good liming agent. No solid phase limits were exceeded according to the SACoP. As a result o f hardening, electrical conductivity and the release o f constituents were lowered during simulated weathering. The mobility o f trace metals was minimal, and the addition o f ash to soil showed little influence on the resulting leachate chemistry as compared to extracts obtained from soil-only. 87 Further investigation into different application rates o f ash to soil are important, as higher concentrations o f ash may overload the buffering capacity o f soil, and leachability o f ash-soil mixes are likely to alter (especially those o f trace elements o f concern). Investigation o f ash to soil mixes would inevitably lead to field studies involving ash applications in soil regarding forestry or agriculture. 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Journal o f Geochemical Exploration. 1998. 62, 293-298. 95 APPENDICES TABLE OF CONTENTS Appendix A1 Appendix A2 Appendix A3 Appendix B1 Appendix B2 Solid Phase and Aqueous Phase Data Serial Batch Extraction Graphs from ICP-MS Data ANOVA Statistics Between Ash Types Using CoStat Ver. 6.3111 pH Static Leachate Graphs Mass loss (%) o f Individual Elements from Ash During pH Static Experimentation for HNO 3/HF/H 2BO 3 Digestion 96 97 111 130 167 172 APPENDIX A1 Solid Phase and Aqueous Phase Data Table A 1 .0 - Selected properties o f non-weathered solid phase BA/FA mix, FA, TILL3 (reference material) and leftover HBA fro m sieving (HBA powder), where elemental content (except fo r C, N and S via dry combustion) was measured by ICP-OES follow ing concentrated HCI/HNO 3 digestion; n=4. Parameter BA/FA Mix FA Mean Mean SD TIL L 3 SD Mean HBA P ow der SD Mean SD Moisture Content (%) 0.152 0.015 1.37 0.08 0.995 0.019 0.726 0.033 Total N (%) 0.0190 0.0008 0.170 0.005 n/a n/a 0.0159 0.0013 n/a n/a 0.07 2.13 0.07 0.52 n/a 0.0836 n/a n/a n/a 4.50 0.0171 1.75 0.09 Total S (%) Total C (inorganic) 1.43 Total C (organic) 2.60 0.13 9.67 0.655 0.940 0.091 1.81 0.18 Total C (%) 4.03 0.11 14.2 0.4 1.02 0.09 3.56 0.16 CCE (%) 29.4 0.8 n/a n/a n/a n/a 30.1 1.0 Ag (ppm) <1.0 n/a <1.0 n/a <1.0 n/a <1.0 n/a A1 (%) 1.84 0.06 1.14 0.04 1.40 0.06 1.74 0.02 As (ppm) 7.04 1.04 4.65 0.94 86.9 1.0 7.35 0.42 B (ppm) 149 2 366 7 8.07 0.93 144 7 Ba (ppm) 1233 18 2053 15 57.7 3.3 1391 31 Be (ppm) <1.0 n/a <1.0 n/a <1.0 n/a <1.0 n/a Bi (ppm) <1.0 n/a <1.0 n/a <1.0 n/a <1.0 n/a Elemental Content via ICP-OES follow ing HCI/HNO3 digestion Ca (%) 11.7 0.5 24.8 0.6 0.725 0.028 11.2 0.4 Cd (ppm) 6.18 0.29 119 3 <1.0 n/a <1.0 n/a Co (ppm) 14.0 0.2 7.78 0.36 30.9 5.8 15.0 0.5 Cr (ppm) 36.2 1.2 30.2 2.0 75.5 2.1 40.8 1.6 Cu (ppm) 52.5 1.3 140 4 19.0 0.9 49.3 1.7 97 Table A 1.0- Selected properties o f non-weathered solid phase BA/FA mix, FA, TILL3 (reference material) and leftover HBA from sieving (HBA powder), where elemental content (except fo r C, N and S via dry combustion) was measured by ICP-OES following concentrated HCI/HNO3 digestion (continued). Parameter FA BA/FA Mix Mean SD TILL 3 Mean SD Mean HBA Powder SD Mean SD 2.06 0.05 1.56 0.03 nidi <2.0 n/a <2.0 n/a Fe (%) 1.62 0.08 0.973 0.050 Hg (ppm) <2.0 n/a <2.0 K (%) 2.26 0.02 5.77 0.12 0.192 0.010 2.08 0.09 Li (ppm) 18.4 0.8 231 6 28.4 0.7 12.0 0.3 Mg (%) 1.48 0.06 3.10 0.07 0.644 0.011 1.34 0.04 Mn (%) 0.739 0.029 1.63 0.04 0.034 0.001 0.660 0.024 Mo (ppm) 6.01 0.09 12.5 0.1 <1.0 n/a 6.17 0.18 N a (%) 0.464 0.009 0.263 0.006 0.048 0.002 0.447 0.017 Ni (ppm) 54.8 2.3 91.2 13.8 33.6 0.6 63.0 2.6 P (%) 0.560 0.016 1.32 0.03 0.051 0.002 0.591 0.027 Pb (ppm) 2.26 0.18 43.2 0.5 13.0 0.4 <2.0 n/a S(% ) 0.113 0.013 0.104 0.007 0.015 0.001 0.132 0.006 Sb (ppm) <4.0 n/a <4.0 n/a <4.0 n/a <4.0 n/a Sn (ppm) 7.36 0.10 54.5 2.9 <1.0 n/a 2.45 0.51 Sr (ppm) 412 6 706 13 46.1 3.7 446 8 Ti (ppm) 947 70 321 22 1344 43 1019 67 T1 (ppm) U (ppm) <2.0 n/a <2.0 n/a <2.0 n/a <2.0 n/a <20 n/a <20 n/a <20 n/a <20 n/a V (ppm) 42.6 0.7 15.0 0.4 53.3 1.5 46.8 1.3 Y (ppm) <2.0 n/a <2.0 n/a <2.0 n/a <2.0 n/a Zn (ppm) 769 26 5505 122 51.3 2.2 115 8 16.4 15.4 1.5 9.24 2.30 1.1 14.9 Zr (ppm) 0.5 *A sample o f bottom andfly ash mix was collectedfrom the active collection bin and a separate sample ofpure fly ash on June 27, 2011 98 Table A I .I - Selected properties o f weathered solid-phase bottom ash, hardened bottom ash, soil, 5%BA and 5%HBA, where elemental content (except fo r C, N and S via dry combustion) was measured by ICP-OESfollowing concentrated HCI/HN0 3 digestion; n=4. Parameter BA (Batch E xtraction) HBA (Batch E xtraction) Mean Mean SD Soil (B atch Extraction) SD Mean SD 5% B A (B atch E xtraction) 5% H B A (B atch E x trac tio n ) Mean Mean SD SD Total N (%) 0.0131 0.000004 0.0124 0.0032 0.132 0.002 0.112 0.002 0.116 0.001 Total S (%) n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a Total C (inorganic) 1.16 0.08 1.40 0.03 n/a n/a n/a n/a n/a n/a Total C (organic) 1.92 0.18 1.73 0.17 n/a n/a n/a n/a n/a n/a Total C (%) 3.07 0.16 3.13 0.17 2.13 0.03 1.97 0.07 2.04 0.04 <1.0 n/a <1.0 n/a <1.0 n/a <1.0 n/a <1.0 n/a A1 (%) 1.81 0.04 1.63 0.04 2.39 0.44 3.16 0.17 3.15 0.55 As (ppm) 5.78 1.94 6.21 1.42 6.29 0.48 7.03 0.93 6.88 0.56 B (ppm) 63.1 1.9 52.7 1.8 3.03 2.59 8.81 0.64 6.46 1.05 Elemental Content via ICP-OES following HCI/HNO3 digestion Ag (ppm) Ba (ppm) 1352 34 1169 10 252.8 32.5 393 12 345 12 Be (ppm) <1.0 n/a <1.0 n/a <1.0 n/a <1.0 n/a <1.0 n/a Bi (ppm) <1.0 n/a <1.0 n/a <1.0 n/a <1.0 n/a <1.0 n/a Ca (%) 8.44 0.07 8.55 0.10 0.542 0.022 0.942 0.010 0.960 0.121 Cd (ppm) <1.0 n/a <1.0 n/a <1.0 n/a 1.20 n/a <1.0 n/a Co (ppm) 25.6 3.5 20.9 0.4 22.8 0.7 23.6 0.1 23.1 0.6 Cr (ppm) 35.0 1.7 31.1 1.7 43.8 4.1 53.1 2.1 49.2 1.8 Cu (ppm) 59.7 6.5 50.0 4.7 18.4 0.6 20.4 0.3 20.0 0.2 Fe (%) 1.79 0.15 1.64 0.09 2.96 0.07 3.09 0.08 3.37 0.58 Hg (ppm) <2.0 n/a <2.0 n/a <2.0 n/a <2.0 n/a <2.0 n/a K (%) 1.66 0.01 1.40 0.04 0.345 0.112 0.610 0.053 0.501 0.055 Li (ppm) 12.9 0.6 11.1 0.6 23.7 2.4 29.7 1.6 27.5 1.1 99 Table A l l - Selected properties o f weathered solid-phase bottom ash, hardened bottom ash, soil, 5%BA and 5%HBA, where elemental content (except fo r C, N and S via dry combustion) was measured by ICP-OESfollowing concentrated HCl/HNQ3 digestion (continued)._______________________________________________ 5%BA (Batch Soil (Batch 5%HBA (Batch HBA (Batch BA (Batch Extraction) Extraction) Extraction) Extraction) Parameter Extraction) Mean SD Mean SD Mean SD Mean SD M ean SD M g(% ) 1.45 0.01 1.25 0.02 0.698 0.009 0.782 0.023 0.826 0.125 Mn (%) 0.714 0.004 0.581 0.008 0.111 0.006 0.142 0.002 0.149 0.025 Mo (ppm) 2.98 0.27 2.72 0.19 <1.0 n/a <1.0 n/a <1.0 n/a Na (%) 0.442 0.015 0.374 0.006 0.042 0.009 0.081 0.006 0.066 0.008 Ni (ppm) 98.8 51.8 55.5 1.0 28.5 0.8 31.7 0.7 30.9 0.7 P (% ) 0.509 0.011 0.441 0.012 0.105 0.002 0.128 0.001 0.127 0.002 n/a 4.62 0.80 3.68 0.38 3.79 0.23 0.001 0.011 0.001 0.010 0.001 0.011 0.0003 Pb (ppm) <2.0 n/a <2.0 S (%) 0.034 0.002 0.031 Sb (ppm) <4.0 n/a <4.0 n/a <4.0 n/a <4.0 n/a <4.0 n/a Sn (ppm) 2.46 0.86 0.880 0.277 <1.0 n/a <1.0 n/a <1.0 n/a Sr (ppm) 383 2 355 4 61.3 7.6 92.0 1.4 82.1 2.3 Ti (ppm) 1003 28 943 30 1419 150 1501 131 1603 44 T1 (ppm) <2.0 n/a <2.0 n/a <2.0 n/a <2.0 n/a <2.0 n/a U (ppm) <20 n/a <20 n/a <20 n/a <20 n/a <20 n/a V (ppm) 47.1 3.2 44.3 2.1 92.3 8.2 107 3 101 3 Y (ppm) <2.0 n/a <2.0 n/a <2.0 n/a <2.0 n/a <2.0 n/a Zn (ppm) 100 17 79.1 2.5 126 1 141 3 141 2 Zr (ppm) 15.9 0.9 16.1 1.2 8.70 5.75 18.6 0.9 12.5 4.0 100 Table A 1.2 —Selected properties o f non-weathered solid phase bottom ash, hardened bottom ash, fly ash, soil control, leftover HBA from sieving (HBA powder), BA/FA mix and TILL 3 (reference material), determined by ICP-OES following concentrated HN0y'HF/H2B 0 3 digestion; n 4 . HBA Parameter Powder HBA FA Soil Control BA/FA Mix BA TILL 3 Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD Elemental Content Ag (ppm) <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 Al (%) 4.66 0.13 4.88 0.11 1.35 0.02 7.29 0.16 4.50 0.03 4.56 0.10 6.65 0.11 As (ppm) <12 <12 <12 <12 <12 <12 <12 <12 <12 <12 <12 <12 <12 <12 Ba (ppm) 1949 29 1789 54 2500 128 756 13 1964 34 1701 51 447 4 Be (ppm) <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 Bi (ppm) <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 Ca (%) 13.8 0.3 12.3 0.4 29.9 0.2 0.966 0.023 13.9 0.6 14.2 0.5 1.92 0.03 Cd (ppm) <3.0 <3.0 <3.0 <3.0 103 1 <3.0 <3.0 <3.0 <3.0 6.13 0.22 <3.0 <3.0 Co (ppm) 22.2 1.6 20.1 1.2 8.12 0.50 27.5 1.5 18.6 0.4 17.0 0.5 32.5 5.2 Cr (ppm) 63.8 7.5 62.1 10.9 36.0 2.0 63.5 3.3 67.5 5.5 54.2 3.7 97.8 3.9 Cu (ppm) 66.2 0.8 64.7 4.0 152 4 22.1 0.4 66.5 2.0 71.1 2.1 22.2 0.6 Fe (%) 2.51 0.08 2.66 0.14 1.25 0.05 3.71 0.08 2.50 0.04 2.51 0.06 2.90 0.02 Hg (ppm) <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 K (%) 3.65 0.10 3.54 0.04 5.32 0.09 1.62 0.04 3.49 0.04 3.68 0.09 2.18 0.03 Li (ppm) 13.0 0.3 13.0 0.5 121 1 25.4 0.4 12.6 0.2 16.3 0.3 24.5 0.7 M g(% ) 1.83 0.03 1.74 0.06 3.63 0.03 0.975 0.024 1.84 0.04 1.95 0.05 1.09 0.02 Mn (%) 0.770 0.017 0.683 0.027 1.79 0.02 0.124 0.006 0.787 0.032 0.848 0.023 0.0518 0.0008 Mo (ppm) 5.35 1.25 6.24 0.35 12.8 0.2 <3.0 <3.0 6.49 0.45 6.07 0.21 <3.0 <3.0 N a (%) 1.42 0.06 1.54 0.04 0.299 0.008 1.70 0.04 1.37 0.02 1.42 0.03 2.03 0.03 Ni (ppm) 72.9 11.0 71.0 6.6 95.3 6.2 31.8 0.4 74.4 4.4 62.9 1.9 40.1 0.3 P (% ) P b(ppm ) 0.568 0.023 0.505 0.017 1.16 0.01 0.124 0.002 0.570 0.024 0.525 0.015 0.0529 0.0004 <6.0 <6.0 <6.0 <6.0 41.7 0.4 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 16.9 1.2 S (%) 0.166 0.029 0.171 0.010 2.74 0.01 0.0105 0.0084 0.240 0.011 0.385 0.018 0.00306 0.00427 <12 <12 <12 <12 <12 <12 <12 <12 <12 <12 <12 <12 <12 <12 Sb (ppm) 101 Table A 1.2 - Selected properties o f non-weathered solid phase bottom ash, hardened bottom ash, fly ash, soil control, leftover HBA from sieving (HBA powder), BA/FA mix and TILL 3 (reference material), determined by ICP-OES following concentrated H N 0/H F /H 2 B 0 3 digestion (continued)._______ HBA Powder Parameter HBA FA Soil Control BA/FA Mix TILL 3 BA Mean SD Mean SD Mean SD 0.04 7.80 0.82 69.7 1.1 <3.0 8 479 14 639 12 208 2215 55 2301 69 385 26 T1 (ppm) <6.0 <6.0 <6.0 <6.0 <6.0 U (ppm) <60 <60 <60 <60 <60 V (ppm) 64.6 1.6 68.7 1.6 17.2 0.3 <6.0 Mean SD Sn (ppm) 9.00 Sr (ppm) 519 Ti (ppm) Mean SD Mean SD Mean <3.0 10.3 0.9 16.0 0.4 <3.0 <3.0 5 515 16 457 16 273 3 5250 143 2203 17 2089 64 2690 39 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <60 <60 <60 <60 <60 <60 <60 <60 <60 115 2 65.6 1.0 61.6 1.4 67.3 1.0 17.0 2.5 109 12 92.0 5.0 167 58 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 W (ppm) 142 22 110 7 63.7 3.2 Y (ppm) <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 SD Zn (ppm) 117 15 102 11 5386 35 134 2 109 6 554 19 53 1 Zr (ppm) 56.1 3.1 56.1 2.9 19.2 5.5 98.1 12.1 54.7 2.5 54.1 2.3 129 14 102 Table A 1.3 - Selected properties o f weathered solid phase bottom ash, hardened bottom ash, soil, 5%BA and 5%HBA, determined by ICP-OES following concentrated HNOfHF/H 2BO 3 digestion; n=4. 5%HBA BA (Batch HBA (Batch Soil (Batch 5%BA (Batch (Batch Parameter Extraction) Extraction) Extraction) Extraction) Extraction) Mean Mean SD SD Mean SD Mean SD Mean SD Elemental Content Ag (ppm) <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 7.10 0.11 <12 <12 A1 (%) 4.76 0.12 4.68 0.10 7.43 0.03 7.31 0.07 As (ppm) <12 <12 <12 <12 <12 <12 <12 <12 Ba (ppm) 1830 75 1582 57 761 10 827 22 806 19 Be (ppm) <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 Bi (ppm) <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 Ca (%) 9.89 0.24 10.2 0.4 1.01 0.04 1.40 0.04 1.30 0.03 Cd (ppm) <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 Co (ppm) 26.8 2.6 23.6 1.0 28.0 0.5 27.9 0.4 26.8 0.7 Cr (ppm) 57.7 5.5 53.1 6.8 63.1 2.4 63.8 0.2 60.4 0.5 Cu (ppm) 73.2 7.8 63.2 6.5 22.6 0.3 24.0 0.2 23.6 0.4 Fe (%) 2.67 0.17 2.59 0.17 3.75 0.02 3.69 0.04 3.57 0.04 Hg (ppm) <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 K (% ) 3.46 0.09 3.21 0.10 1.67 0.03 1.74 0.02 1.69 0.05 0.1 Li (ppm) 13.2 0.5 13.6 1.8 25.5 0.3 24.7 24.4 0.3 Mg (%) 1.87 0.04 1.70 0.08 1.00 0.01 1.01 0.02 0.968 0.012 Mn (%) 0.778 0.018 0.660 0.024 0.129 0.004 0.159 0.005 0.146 0.002 Mo (ppm) 3.12 <3.0 3.06 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 Na (%) 1.39 0.03 1.39 0.03 1.73 0.02 1.72 0.03 1.67 0.04 Ni (ppm) 86.8 26.7 61.2 3.0 31.7 0.2 33.4 0.6 31.9 0.6 P (%) 0.587 0.020 0.510 0.017 0.123 0.001 0.138 0.003 0.133 0.001 Pb (ppm) S (%) <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 0.0608 0.0061 0.0428 0.0068 0.0152 0.0045 0.0152 0.0058 0.0105 0.0015 103 Table A l.3 - Selected properties o f weathered solid phase bottom ash, hardened bottom ash, soil, 5%BA and 5%HBA, determined by ICP-OESfollowing concentrated H N 0fH F /H 2B 0 3 (contimied)._____________________________________ Parameter BA (B atch E xtraction) HBA (B atch E xtraction) Soil (B atch E xtraction) 5% BA (B atch Extraction) 5% H B A (B atch E xtraction) Mean SD Mean SD Mean SD Mean SD M ean SD Sb (ppm) <12 <12 <12 <12 <12 <12 <12 <12 <12 <12 Sn (ppm) 8.90 0.20 7.01 0.45 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 Sr (ppm) 442 22 413 17 210 2 220 3 212 4 Ti (ppm) 2272 109 2260 78 5149 42 5056 78 4987 92 T1 (ppm) <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 U (ppm) <60 <60 <60 <60 <60 <60 <60 <60 <60 <60 V (ppm) 63.1 2.2 62.8 3.9 114 0 110 1 108 1 W (ppm) 198 26 153 10 44.6 3.4 48.3 4.8 46.1 5.6 Y (ppm) <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 <6.0 Zn (ppm) 133 27 104 6 142 1 143 4 134 2 Zr (ppm) 56.7 3.6 55.0 1.2 91.0 4.3 91.4 1.3 86.0 1.5 104 Table A1.5 - Total loss o f individual elements (%) from original concentration amounts as calculatedfrom ICP solid phase analysis (HNO 3/HF/H 2BO 3 digestion) and ICP aqueous phase analysis. Parameter (%) BA HBA Soil 5% BA 5% HBA Mean Mean Mean Mean Mean Ag n/a n/a n/a n/a n/a A1 2.52 1.21 0.14 0.30 0.27 As n/a n/a n/a n/a n/a Ba 10.43 7.76 0.20 0.39 1.41 Be n/a n/a n/a n/a n/a Bi n/a n/a n/a n/a n/a Ca 22.57 10.76 0.88 11.03 14.57 Cd n/a n/a n/a n/a n/a Co 0.01 0.01 0.69 0.60 0.64 Cr 6.22 6.35 0.28 0.45 0.77 Cu 2.60 0.19 0.99 1.93 1.61 Fe 0.0041 0.0021 0.57 0.46 0.49 Hg n/a n/a n/a n/a n/a K 10.30 12.12 0.56 1.54 2.30 Li 1.48 1.87 0.12 0.09 0.11 Mg 0.32 0.60 0.67 2.23 3.20 Mn 0.00401 0.00313 1.44 1.31 1.35 Mo 58.98 41.18 n/a n/a n/a Na 3.92 4.06 0.19 0.30 0.53 Ni 0.05 0.04 0.53 0.70 0.64 P 0.43 0.48 1.93 6.19 5.83 Pb n/a n/a n/a n/a n/a s** 36.5 25.1 145 89.1 61.1 Sb n/a n/a n/a n/a n/a Sn 0.25 0.21 n/a n/a n/a Sr 19.90 12.10 0.40 2.89 4.16 Ti 0.00198 0.00200 0.07 0.07 0.07 Tl n/a n/a n/a n/a n/a U n/a n/a n/a n/a n/a V 5.41 4.45 0.47 0.86 0.88 W Y 7.01 8.30 0.08 3.08 5.42 n/a n/a n/a n/a n/a Zn 0.39 0.27 0.65 0.58 0.60 n/a 0.05 0.07 0.06 n/a Zr *n/a refers to below detection limit **Percent loss based on solid phase data 105 Table A 1.6-A nion concentration o f bottom ash leachates from serial batch extraction during days one, ten and twenty; n=4. Parameter Day 1 Day 10 Mean Br (ppm) SD Mean <0.01 n/a Day 20 Mean SD <0.01 n/a SD <0.01 n/a Cl (ppm) 7.04 0.28 1.80 1.20 0.45 0.95 F (ppm) 0.49 0.02 0.02 0.00 <0.01 n/a N 0 2 (ppm) 1.13 0.02 <0.01 n/a <0.01 n/a N 03 (ppm) 3.55 0.09 0.44 0.27 0.32 0.11 P 0 4 (ppm) <0.01 n/a <0.01 n/a <0.01 n/a S 0 4 (ppm) 5.36 0.67 1.39 0.12 2.41 0.10 Alkalinity (mg L ) *Alkalinity as CaCOs 1617 60 133.0 38.0 67.16 2.01 Table A 1.7 -A nion concentration o f hardened bottom ash leachates from serial batch extraction during days one, ten and twenty; n=4. Parameter Day 10 Day 1 SD Mean Mean Day 20 Mean SD SD Br (ppm) <0.01 n/a <0.01 n/a <0.01 n/a Cl (ppm) 5.30 1.16 2.37 0.06 0.03 0.03 F (ppm) 0.39 0.00 0.01 0.00 <0.01 n/a N 0 2 (ppm) 1.11 0.01 <0.01 n/a <0.01 n/a N 0 3 (ppm) 2.96 0.08 2.21 3.11 3.27 5.54 P 0 4 (ppm) <0.01 n/a <0.01 n/a <0.01 n/a S 04 (ppm) 47.47 2.88 1.51 0.10 0.74 0.04 Alkalinity (mg L ) *Alkalinity as CaCOj 187.0 17.9 77.88 5.99 48.34 4.00 Table A l. 8 -A nion concentration o f soil leachates from serial batch extraction during days one, ten and twenty; n=4. Parameter Day 1 Day 20 Day 10 SD Mean Mean Mean SD SD Br (ppm) <0.01 n/a <0.01 n/a <0.01 n/a Cl (ppm) 1.17 1.28 2.36 0.08 0.57 1.04 F (ppm) 0.32 0.01 0.01 0.00 <0.01 n/a N 0 2 (ppm) 0.99 0.01 <0.01 n/a <0.01 n/a N 03 (ppm) 5.15 0.27 0.50 0.08 0.54 0.35 P 0 4 (ppm) <0.01 n/a 1.07 0.01 0.89 0.01 S 0 4 (ppm) 0.24 0.03 0.03 0.01 <0.01 n/a Alkalinity (mg L ) *Alkalinity as CaCOs 2.73 1.87 0.39 0.35 1.27 n/a 106 Table A l. 9 -A nion concentration o f soil with 5% bottom ash leachates from serial batch extraction during days one, ten and twenty; n=4. Parameter Day 1 Day 10 Mean SD Mean Day 20 SD Mean SD Br (ppm) <0.01 n/a <0.01 n/a <0.01 n/a Cl (ppm) 0.36 0.02 1.87 1.23 2.09 0.08 F (ppm) 0.46 0.01 <0.01 n/a <0.01 n/a N 0 2 (ppm) 1.07 0.01 0.81 0.01 0.92 0.01 N 03 (ppm) 5.32 0.03 0.31 0.17 0.33 0.02 P 0 4 (ppm) 1.38 0.08 1.38 0.06 1.13 0.04 S 0 4 (ppm) 5.80 0.40 0.07 0.02 <0.01 n/a Alkalinity (mg L ) *AHcalinity as CaCO j 31.34 1.84 12.63 3.82 5.47 0.77 Table A L I O - Anion concentration o f soil with 5% hardened bottom ash leachates from serial batch exi during days one, ten and twenty; n=4. Parameter Day 20 Day 10 Day 1 Mean SD Mean SD Mean SD Br (ppm) <0.01 n/a <0.01 n/a <0.01 n/a Cl (ppm) 0.54 0.46 2.41 0.16 2.14 0.07 F (ppm) 0.40 0.01 <0.01 n/a <0.01 n/a N 0 2 (ppm) 1.11 0.03 0.80 0.01 0.94 0.02 N 03 (ppm) 5.02 0.25 0.41 0.03 0.30 0.08 P 0 4 (ppm) <0.01 n/a 1.53 0.13 1.18 0.11 S 04 (ppm) 4.41 0.33 0.05 0.00 0.02 n/a 3.35 4.41 0.60 Alkalinity (mg L ) mAlkalinity as CaCOj 69.46 1.67 8.16 107 Table A l . l l - Total elemental content present within the aqueous phase o f the blank samples run during serial batch extraction. Parameter Serial Batch Extraction Blanks Mean SD Ag (ppm) 2.64E-03 3.08E-03 A1 (ppm) 8.23E-04 2.24E-04 As (ppm) 1.26E-05 1.06E-05 B (ppm) 1.06E-03 1.16E-03 Ba (ppm) 4.29E-04 5.32E-04 Be (ppb) < 1.0 n/a Bi (ppm) 6.19E-06 8.07E-07 Ca (ppm) 4.70E-02 1.96E-02 Cd (ppm) 1.57E-05 7.20E-06 Co (ppb) < 0.1 n/a Cr(ppb) < 0.1 n/a Cu (ppm) 1.71E-04 5.16E-05 Fe (ppm) 5.10E-04 7.64E-04 Hg (ppm) 2.29E-06 2.04E-05 K (ppm) 1.03E-02 7.66E-03 Li (ppm) 1.25E-04 4.92E-05 Mg (ppm) 1.18E-03 9.03E-04 Mn (ppm) 1.57E-04 1.65E-04 Mo (ppm) 3.87E-05 3.12E-05 Na (ppm) 8.09E-03 1.40E-02 Ni (ppm) 9.46E-04 1.54E-03 P (ppm) 3.33E-03 1.86E-03 Pb (ppm) 1.55E-05 6.47E-06 Sb (ppm) 2.81E-06 1.81E-06 Se (ppm) 9.39E-05 5.29E-06 Si (ppb) < 1.0 n/a Sn (ppb) < 0.1 n/a Sr (ppm) 6.32E-05 2.16E-05 Te (ppb) < 0.1 n/a Th (ppm) 9.65E-06 4.89E-06 Ti (ppb) < 0.1 n/a T1 (ppm) 1.51E-05 7.69E-06 U (ppm) 1.13E-05 3.36E-06 V (ppm) 6.59E-05 8.20E-06 W (ppm) 4.07E-05 2.03E-05 Y (ppb) < 0.1 n/a Zn (ppm) 2.94E-04 2.23E-04 Z r (PPb) < 0.1 n/a 108 Table A 1 .1 2 - Relative percent difference, RPD, calculation fo r TILL 3 standard as determined by ICP-OES following HCI/HN03 digestion. TILL 3 (As Measured by TILL 3** R P D (% ) Parameter EPA Method 3051A) Mean A g(ppm ) <1.0 A1 (%) 1.40 As (ppm) 86.9 B (ppm) 8.07 Ba (ppm) 1.2 15.1 57.7 49.2 15.9 Be (ppm) <1.0 <2.0 Bi (ppm) <1.0 Ca (%) 0.725 Cd (ppm) <1.0 <0.35 Co (ppm) 30.9 14.8 70.5 Cr (ppm) 75.5 Cu (ppm) 19.0 16.5 14.1 Fe (%) 2.06 2.1 2.1 Hg (ppm) <2.0 K (% ) 0.192 0.0964 66.3 Li (ppm) 28.4 Mg (%) 0.644 0.7445 14.5 Mn (%) 0.034 0.0317 5.8 Mo (ppm) <1.0 6 Na (%) 0.048 0.0427 11.5 Ni (ppm) 33.6 26.5 23.5 P (% ) 0.051 0.0457 10.5 Pb (ppm) 13.0 23 55.9 S(% ) 0.015 Sb (ppm) <4.0 Sn (ppm) <1.0 Sr (ppm) 46.1 Ti (ppm) 1344 T1 (ppm) <2.0 U (ppm) <20 V (ppm) 53.3 66.1 21.5 Y (ppm) <2.0 Zn (ppm) 51.3 42.7 18.3 15.4 Zr (ppm) *EPA Method 3051A follows HC1/HN03 digestion, and a relative percent difference, RPD, within 15% is considered good **TILL 3 values obtained from TILL Certificate of Analysis, Single source data by EPA 3051 digestion 109 Table A 1 .1 3 - Relative percent difference, RPD, calculation fo r TILL 3 standard as determined by ICP-OES following HN03/HF/H2B03 digestion. Parameter T IL L 3 (As M easured by EPA M ethod 3052) RPD (% ) TIL L 3** Mean Ag (ppm) <3.0 A1 (%) 6.65 As (ppm) <12 87 Ba (ppm) 447 489 Be (ppm) <3.0 2 Bi (ppm) <3.0 <5 Ca (%) 1.92 Cd (ppm) <3.0 Co (ppm) 32.5 15 73.6 Cr (ppm) 97.8 123 22.8 8.9 Cu (ppm) 22.2 22 0.9 Fe (%) 2.90 2.78 4.1 Hg (ppm) < 6.0 K (%) 2.18 Li (ppm) 24.5 21 15.4 Mg (%) 1.09 Mn (%) 0.0518 0.052 0.4 Mo (ppm) <3.0 2 Na (%) 2.03 Ni (ppm) 40.1 39 2.8 0.0529 0.049 7.7 42.4 P (% ) 16.9 26 0.00306 <0.05 Sb (ppm) <12 0.9 Sn (ppm) <3.0 Sr (ppm) 273 300 9.5 Ti (ppm) 2690 2910 7.9 T1 (ppm) < 6.0 Pb (ppm) S (%) U (ppm) <60 2.1 V (ppm) 67.3 62 W (ppm) 167 <1 Y (ppm) < 6.0 17 Zn (ppm) 53 56 8.2 6.4 230 56.2 129 Zr (ppm) ♦EPA Method 3052 follows H N03/HF/H2B03 digestion, and a relative percent difference, RPD, within 15% is considered good **TILL 3 values obtained from TILL Certificate o f Analysis, Summary o f “total” elements in TILL series 110 APPENDIX A2 Serial Batch Extraction Graphs from ICP-MS Data; n=4 0.025 •Hardened Bottom Ash •5% Bottom Ash —♦ Bottom Ash ■■"it Soil *5% Hardened Bottom Ash 0.02 - 0.015 Ag (mg L-') 0.01 0.005 9 11 13 Timeline (Days) Figure A2.0 - Aqueous concentrations (with standard deviation error bars) fo r A g (silver) during serial batch extraction. Hardened Bottom Ash 5% Bottom Ash ■Bottom Ash •Soil •5% Hardened Bottom Ash (mg L 1) » 3 5 7 9 11 13 15 Timeline (Days) Figure A2.1 - Aqueous concentrations (with standard deviation error bars) fo r A l (aluminum) during serial batch extraction. Ill 0.0025 ♦ Bottom Ash Soil *5% Hardened Bottom Ash B Hardened Bottom Ash X 5% Bottom Ash 0.0015 (mg I / 1) 0.00 - 0.0005 9 11 13 15 17 19 Timeline (Days) Figure A2.2 - Aqueous concentrations (with standard deviation error bars) fo r As (arsenic) during serial batch extraction. 1.2 i Bottom Ash Soil 5% Hardened Bottom Ash •Hardened Bottom Ash •5% Bottom Ash B (mg I / ') 0.6 Timeline (Days) Figure A2.3 - Aqueous concentrations (with standard deviation error bars) fo r B (boron) ______________ during serial batch extraction.___________________________ 112 Hardened Bottom Ash 5% Bottom Ash Bottom Ash * Soil M* 5% Hardened Bottom Ash Ba ( m g L 1) 2 M 9 11 *— * * 1 tt « 13 Timeline (Days) Figure A2.4 - Aqueous concentrations (with standard deviation error bars) fo r Ba (barium) during serial batch extraction. 0.00014 ! 0.00012 B Hardened Bottom Ash 5% Bottom Ash •Bottom Ash •Soil —# —5% Hardened Bottom Ash 0.0001 Be 0.00008 (mg L 1) 0.00006 0.00004 0.00002 3 5 7 9 11 13 Timeline (Days) Figure A2.5 - Aqueous concentrations (with standard deviation error bars) fo r Be (beryllium) during serial batch extraction. 113 0.00002 Bottom Ash —A—Soil 5% Hardened Bottom Ash 0.000018 •Hardened Bottom Ash •5% Bottom Ash 0.000016 0.000014 H 0.000012 Bi (mg I/*) 0.00001 0.000008 0.000006 0.000004 0.000002 9 11 13 Timeline (Days) Figure A2.6 - Aqueous concentrations (with standard deviation error bars) fo r Bi (bismuth) during serial batch extraction. 600 •■♦“ Bottom Ash •Soil •5% Hardened Bottom Ash "W Hardened Bottom Ash K 5% Bottom Ash 500 400 Ca (mg I /')3 0 0 9 11 13 15 17 Timeline (Days) Figure A2 . 7 - Aqueous concentrations (with standard deviation error bars) fo r Ca (calcium) during serial batch extraction.____________________ 114 19 0.00012 0 .0 0 0 1 ♦ ' Bottom Ash -nfc—Soil W 5% Hardened Bottom Ash •Hardened Bottom Ash •5% Bottom Ash - 0.00008 Cd (mg L-') 0.00006 0.00004 0.00002 9 11 13 Timeline (Days) Figure A2.8 - Aqueous concentrations (with standard deviation error bars) fo r Cd (cadmium) during serial batch extraction. Bottom Ash Soil 5% Hardened Bottom Ash 0.0012 •Hardened Bottom Ash •5% Bottom Ash 0.001 0.0008 Co (mg L-')0.0006 + f 0.0004 0.0002 9 11 13 Timeline (Days) Figure A2.9 - Aqueous concentrations (with standard deviation error bars) fo r Co (cobalt) during serial batch extraction. 115 0.12 i —^-Bottom Ash •Hardened Bottom Ash •5% Bottom Ash - < i 1 Soil • " # “ 5% Hardened Bottom Ash 0.08 Cr (mg L-»)0.06 0.04 - 0.02 9 11 13 Timeline (Days) Figure A 2.10 - Aqueous concentrations (with standard deviation error bars) fo r Cr (chromium) during serial batch extraction. ___ Hardened Bottom Ash 5% Bottom Ash ♦ Bottom Ash 0.09 - 5% Hardened Bottom Ash 0.07 - Cu (mg L 1) 0.05 3 5 7 9 11 13 Timeline (Days) Figure A 2 .ll - Aqueous concentrations (with standard deviation error bars) fo r Cu ___________________ (copper) during serial batch extraction._____________________ 116 Hardened Bottom Ash 5% Bottom Ash ♦ Bottom Ash * Soil HE—5% Hardened Bottom 1.2 i Fe (mg L*1) 0.6 • 9 11 13 Timeline (Days) Figure A 2.12 - Aqueous concentrations (with standard deviation error bars) fo r Fe (iron) during serial batch extraction.__________________________ Hardened Bottom Ash 5% Bottom Ash ■Bottom Ash •Soil 5% Hardened Bottom Ash 0.003 i 0.0025 0.002 Hg (mg L-'X).0015 0.001 0.0005 m ■»" m M i m m 0 it ir 9 11 13 15 17 IS Timeline (Days) Figure A 2.13 - Aqueous concentrations (with standard deviation error bars) fo r Hg (mercury) during serial batch extraction.___________________ 117 ♦ Bottom Ash ■"i r "Soil #"■ 5% Hardened Bottom Ash Hardened Bottom Ash 5% Bottom Ash (mg I / 1) 3 5 7 9 11 13 15 Timeline (Days) Figure A 2.14 - Aqueous concentrations (with standard deviation error bars) fo r K (potassium) during serial batch extraction. ________________ 0.0025 Hardened Bottom Ash 5% Bottom Ash ■Bottom Ash ■Soil ■5% Hardened Bottom Ash 0.0015 (mg I / 1) 0.0005 9 11 13 Timeline (Days) Figure A 2.15 - Aqueous concentrations (with standard deviation error bars) fo r Li (lithium) during serial batch extraction.___________________ 118 Bottom Ash —* - S o il Hardened Bottom Ash 5% Bottom Ash —# —5% H ardened Bottom Ash (mg L 1) 9 11 13 Timeline (Days) Figure A2.16 - Aqueous concentrations (with standard deviation error bars) fo r M g (magnesium) during serial batch extraction. 0.12 0.1 Bottom Ash Soil 5% Ha dened Bottom Ash •Hardened Bottom Ash •5% Bottom Ash - 0.08 Mn (mg L-'xi.oe 0.04 0.02 9 11 13 Timeline (Days) Figure A2.17 - Aqueous concentrations (with standard deviation error bars) fo r Mn (manganese) during serial batch extraction.___________________ 119 Bottom Ash it Soil —W—5% Hardened Bottom Ash Hardened Bottom Ash 5% Bottom Ash 0.06 0.05 Mo (mg L 1) 0.04 0.03 0.02 0.01 3 5 7 9 11 13 Timeline (Days) Figure A 2.18- Aqueous concentrations (with standard deviation error bars) fo r Mo (molybdenum) during serial batch extraction.________________ Hardened Bottom Ash 5% Bottom Ash » Bottom Ash A Soil Na (mg L '1) 8 # "»i I M i 3 5 7 m 9 11 13 15 17 19 Timeline (Days) Figure A2.19 - Aqueous concentrations (with standard deviation error bars) fo r Na (sodium) during serial batch extraction.______________________ 120 •Bottom Ash •Hardened Bottom Ash •5% Bottom Ash -Hr-Soil 0.0018 ' *-#—5% Hardened Bottom Ash 0.00 6 0.0014 0.0012 Ni (mg I / 1) 0.001 0.0008 0.0006 0.0004 0.0002 9 11 13 15 Timeline (Days) Figure A2.20 - Aqueous concentrations (with standard deviation error bars) fo r Ni (nickel) ____________________ during serial batch extraction.__________________________ 0.45 - •Bottom Ash -* -* S o il )* 5% Hardened Bottom Ash Hardened Bottom Ash 5% Bottom Ash P 0.25 (mg L-') 0.05 ' 9 11 13 Timeline (Days) Figure A2.21 - Aqueous concentrations (with standard deviation error bars) fo r P __________ (phosphorus) during serial batch extraction._________________ 121 0.0016 -I '♦ Bottom Ash Hardened Bottom Ash 5% Bottom Ash •— ir-Soil 0 0014 - 5% Hardened Bottom Ash 0.0012 0.001 Pb (mg I / 1) 0.0008 0.0006 0.0004 0.0002 0 1 6 16 Timeline (Days) Figure A2.22 - Aqueous concentrations (with standard deviation error bars) fo r Pb (lead) during serial batch extraction. -0 0.006 i Hardened Bottom Ash '5% Bottom Ash ■""^■ "Bottom Ash -A -S o il HC 5% Hardened Bottom Ash 0.005 - 0.004 0.002 - 0.001 Timeline (Days) Figure A2.23 - Aqueous concentrations (with standard deviation error bars) fo r Sb ___________________(antimony) during serial batch extraction.__________________ 122 0.0012 ■♦"■Bottom Ash B Hardened Bottom Ash )< 5% Bottom Ash — ir* Soil —# —5% Hardened Bottom Ash 0.001 0.0008 (mg L"1) 0.0006 0.0004 0.0002 0 3 7 5 9 11 13 15 17 19 Timeline (Days) Figure A2.24 -Aqueous concentrations (with standard deviation error bars) fo r S e (selenium) during serial batch extraction. » 18 B 1Hardened Bottom Ash Bottom Ash Soil 5% Hardened Bottom As] 5% Bottom Ash 16 14 12 6 4 2 0 1 3 5 7 9 11 13 15 17 19 Timeline (Days) Figure A2.25 - Aqueous concentrations (with standard deviation error bars) fo r Si (silicon) ____________________________ during serial batch extraction.____________________________ 123 0.0005 0.00045 - ♦ Bottom Ash -rip—Soil 5% Hardened Bottom Ash Hardened Bottom Ash 5% Bottom Ash 0.0004 0.00035 0.0003 - Sn (mg L-‘) 0.00025 0.0002 0.000 5 0.000 0.00005 3 5 7 9 11 13 15 17 Timeline (Days) Figure A2.26 - Aqueous concentrations (with standard deviation error bars) fo r Sn (tin) _______________ during serial batch extraction. Hardened Bottom Ash 5% Bottom Ash —♦ —Bottom Ash —♦ —Soil 5% Hardened Bottom Ash Sr (“ gLt 9 11 13 mM 1 i 15 17 i Timeline (Days) Figure A2.27 - Aqueous concentrations (with standard deviation error bars) fo r Sr (strontium) during serial batch extraction.__________________ 124 i 19 I 0.00006 ♦ Bottom Ash it So — 5°A Hardened Bottom Ash Hardened Bottom Ash 5% Bottom Ash 0.00005 - 0.00004 Te (mg L'*)0.00003 0.00002 0.00001 9 11 13 Timeline (Days) Figure A2.28 - Aqueous concentrations (with standard deviation error bars) fo r Te (tellurium) during serial batch extraction. 0.00006 i Hardened Bottom Ash 5% Bottom Ash ■Bottom Ash •Soil 5% Hardened Bottom Ash 0.00005 0.00004 Th (mg L-‘) 0.00003 0.00002 0.00001 3 5 7 9 11 13 15 Timeline (Days) Figure A2.29 - Aqueous concentrations (with standard deviation error bars) fo r Th (thorium) during serial batch extraction.___________________ 125 0.025 •■♦■-Bottom Ash -ilr-S oil —* —5% Hardened Bottom Ash •Hardened Bottom Ash •5% Bottom Ash 0.02 0.015 Ti (mg L->) 0.01 - 0.005 : 9 11 13 Timeline (Days) Figure A2.30 - Aqueous concentrations (with standard deviation error bars) fo r Ti (titanium) during serial batch extraction. 0.00009 0.00008 B Hardened Bottom Ash )( 5% Bottom Ash Bottom Ash Soil ■5% Hardened Bottom Ash 0.00007 0.00006 Tl 0.00005 (mg L 1) 0.00004 0.00003 0.00002 - 0.00001 - 9 11 13 Timeline (Days) Figure A2.31 - Aqueous concentrations (with standard deviation error bars) fo r Tl (tantalum) during serial batch extraction.__________________ 126 0.00035 0.0003 Bottom Ash Soil 5% Hardened Bottom Ash •Hardened Bottom Ash •5% Bottom Ash 0.00025 U 0.0002 (mg L>) 0.00015 - 0.0001 0.00005 • 9 11 13 Timeline (Days) Figure A2.32 - Aqueous concentrations (with standard deviation error bars) fo r U (uranium) during serial batch extraction. 0.025 -i Bottom Ash Soil 5% Hardened Bottom Ash Hardened Bottom Ash 5% Bottom Ash 0.02 0.015 V (mg L 1) 0.01 - 0.005 - 9 I "1 * )( * ”■ & '6 A 11 13 a "■» j . H .....i> 15 t i 17 1 Timeline (Days) Figure A2.33 - Aqueous concentrations (with standard deviation error bars) fo r V (vanadium) during serial batch extraction.__________________ 127 0.12 i •Bottom Ash •Soil •5% Hardened Bottom Ash •Hardened Bottom Ash •5% Bottom Ash 0.08 W (mg L-')o.06 0.04 ■ 0.02 # 9 11 i i M tt 1 13 Timeline (Days) Figure A2.34 - Aqueous concentrations (with standard deviation error bars) fo r W (tungsten) during serial batch extraction. Hardened Bottom Ash 5% Bottom Ash ♦ Bottom Ash —# - S o il *' 5% Hardened Bottom Ash 0.00016 0.00014 0.00012 0.0001 (mg LM 0.00008 0.00006 0.00004 0.00002 1 6 11 16 Timeline (Days) Figure A2.35 -Aqueous concentrations (with standard deviation error bars) fo r Y (yttrium) during serial batch extraction.___________________________ 128 0.009 i •Bottom Ash Soil •5% Hardened Bottom Ash •Hardened Bottom Ash *5% Bottom Ash ■■'i r '" Zn 0.005 (mg L 1) 0.004 0.001 - 1 3 5 7 9 11 13 15 17 19 Timeline (Days) Figure A2.36 - Aqueous concentrations (with standard deviation error bars) fo r Z n (zinc) during serial batch extraction. 0.0006 •Hardened Bottom Ash •5% Bottom Ash •Bottom Ash •Soil ""Bit' 5% Hardened Bottom Ash 0.0005 0.0004 Zr (mg L->) 0.0003 0.0002 0.0001 3 5 7 9 11 13 15 Timeline (Days) Figure A2.37 - Aqueous concentrations (with standard deviation error bars) fo r Zr (zirconium) during serial batch extraction._________ 129 APPENDIX A3 ANOVA Statistics Between Ash Types Using CoStat Ver. 6.3111 Analysis of Variance Table for Ag - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 0.28882954371 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.80999225449 MSD 0.05 = 1.17347543668 Rank Mean Name 1 SBAl 2 SHBA1 3 SOILl 4 HBA1 5 BA1 Mean 0.6265225 0.6056525 0.2125425 0.1515675 0.0807225 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for Ag - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 20.8732008105 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 6.8858028569 MSD 0.05 = 9.97579973099 Rank Mean Name 1 BA10 2 SHBA10 3 SBA10 4 HBA10 5 SOIL10 Mean 6.203 1.00925 0.868125 0.52265 0.36175 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for Ag - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 15.2876072883 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 5.89291012927 MSD 0.05 = 8.53734742397 Rank Mean Name 1 SHBA20 Mean 4.938175 n Non-significant ranges 4 a 130 2 SOIL20 3 HBA20 4 SBA20 5 BA20 0.74275 0.2841 0.2225 0.125075 4 a 4 a 4 a 4 a Analysis of Variance Table for A1 - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 75482.6543333 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 414.079414651 MSD 0.05 = 599.897121531 Rank Mean Name 1 HBA1 2, SBA1 3 SOIL1 4 SHBA1 5 BAl Mean 4987.25 67 9.4 5 296.425 213.8 183.225 n Non-significant ranges 4 a 4 b 4 b 4 b 4 b Analysis of Variance Table for A1 - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 5579.4435 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 112.578511182 MSD 0.05 = 163.098001047 Rank Mean Name 1 HBA10 2 BAl0 3 SBA10 4 SHBA10 5 SOIL10 Mean 1239.5 1021.55 629.575 513.925 235.325 n Non-significant ranges 4 a 4 b 4 c 4 c 4 d Analysis of Variance Table for A1 - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 2970.17883333 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 82.1393682544 MSD 0.05 = 118.999324373 Rank Mean Name Mean n Non-significant ranges 131 1 2 3 4 5 BA20 HBA20 SBA20 SHBA20 SOIL20 1489.5 666.025 350.9 305.475 147.825 4a 4 b 4 c 4 c 4 d Analysis of Variance Table for As - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 0.01204918029 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.16543934813 MSD 0.05 = 0.23968008363 Rank Mean Name SBA1 SHBA1 SOILl HBA1 BAl Mean 2.8685 1.327 0.301525 0.19218 0.1 n Non-significant ranges 4 a 4 b 4 c 4 c 4 c Analysis of Variance Table for As - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00728789183 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.12866517588 MSD 0.05 = 0.18640353981 Rank Mean Name 1 SHBA10 2 SBA10 3 BAl 0 4 HBA10 5 SOIL10 Mean 1.04795 0.945 0.472425 0.38925 0.32275 n Non-significant Non ranges 4 a 4 a 4 b 4 b 4 b Analysis of Variance Table for As - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 0.002694154 83 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.07822964049 MSD 0.05 = 0.11333511034 Rank Mean Name Mean n Non-significant ranges 132 1 SBA20 2 BA20 3 SHBA20 4 HBA20 5 SOIL20 0.6668 0.656075 0.629725 0.421275 0.2098 4 a 4 a 4 a 4 b 4 c Analysis of Variance Table for B - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 1508.28393852 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 58.5331116541 MSD 0.05 = 84.7997846624 Rank Mean Name 1 HBA1 2 SBA1 3 SHBAl 4 BAl 5 SOIL1 Mean 1032.9 163.525 14 9.85 9.68475 6.6365 n Non-■significant ranges 4 a 4 b 4 b 4 c 4 c Analysis of Variance Table for B - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 93.3327421745 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 14.5605262567 MSD 0.05 = 21.0945472784 Rank Mean Name 1 BA10 2 HBA10 3 SBA10 4 SHBAl0 5 SOIL10 Mean 167.825 147.225 2.2055 1.80725 0.895675 n Non-■significant ranges 4 a 4 a 4 b 4 b 4 b Analysis of Variance Table for B - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 9.17715836383 Degrees of Freedom: 15 Keep If: n Me a ns = 5 LSD 0 . 0 5 = 4 . 5 6 5 7 7 1 4 9 0 3 8 MSD 0 . 0 5 = 6 . 6 1 4 6 5 6 7 0 0 4 7 133 Rank Mean Name 1 BA20 2 HBA20 3 SBA20 4 SHBA20 5 SOIL20 Mean 84.8075 30.2225 2.289 1.59885 0.183125 n Non-significant ranges 4 a 4 b 4 c 4 c 4 c Analysis of Variance Table for Ba - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 6857.74157565 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 124.810354454 MSD 0.05 = 180.818871271 Rank Mean Name 1 BAl 2 HBA1 3 SHBAl 4 SBA1 5 SOIL1 Mean 34 91 60.77 35.0975 22.4 925 9.56375 n Non-•significant ranges 4 a 4 b 4 b 4 b 4 b Analysis of Variance Table for Ba —Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 122.42030785 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 16.6758044058 MSD 0.05 = 24.159054298 Rank Mean Name 1 HBA10 2 BA10 3 SBA10 4 SHBAl0 5 SOIL10 Mean 366.375 241.8 7.9215 6.919 4.17125 n Non- significant ranges 4 a 4 b 4 c 4 c c 4 Analysis of Variance Table for Ba - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 72.2003056333 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 12.806474141 MSD 0.05 = 18.5533660992 134 Rank Mean Name 1 HBA20 2 BA20 3 SHBA20 4 SBA20 5 SOIL20 Mean 399.925 389.675 5.7125 5.46325 2.99825 n Non-significant ranges 4 a 4 a 4 b 4 b 4 b Analysis of Variance Table for Be - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 5.8858805e-5 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.01156287363 MSD 0.05 = 0.01675170115 Rank Mean Name 1 BAl 2 HBA1 3 SOIL1 4 SHBAl 5 SBA1 Mean 0.1 0 .1 0.1 0.1 0.0914225 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for Be - Day Ten N/A Analysis of Variance Table for Be - Day Twenty N/A Analysis of Variance Table for Bi - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 1.63049678e-6 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.00192450938 MSD 0.05 = 0.00278813096 Rank Mean Name 1 HBA1 2 SHBAl 3 SBA1 4 SOIL1 5 BAl Mean 0.01 0.01 0.01 0.0081965 0.00777175 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for Bi - Day Ten N/A 135 Analysis of Variance Table for Bi - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 3.261458e-7 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 8.60728045e-4 MSD 0.05 = 0.00124697886 Rank Mean Name 1 HBA20 2 SOIL20 3 SHBA20 4 SBA20 5 BA20 Mean 0.01 0.01 0.01 0.01 0.0093615 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for Ca - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 317222355.583 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 26843.6737423 MSD 0.05 = 38889.7444295 Rank Mean Name 1 BAl 2 SHBAl 3 HBA1 4 SBA1 5 SOIL1 Mean 502335 20075 16085 13337.5 1175.75 n Non-significant ranges 4 a 4 b 4 b 4 b 4 b Analysis of Variance Table for Ca - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 5955377.28867 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 3678.02518824 MSD 0.05 = 5328.53516808 Rank Mean Name 1 BA10 2 HBA10 3 SBA10 4 SHBAl0 Mean 32231.5 24634 4858 2918 n Non-significant ranges 4 a 4 b 4 c 4 c 136 5 SOILlO 270.35 4 c Analysis of Variance Table for Ca - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 276863.194667 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 793.035578519 MSD 0.05 = 1148.90947 Rank Mean Name 1 BA20 2 HBA20 3 SBA20 4 SHBA20 5 SOIL20 Mean 22107.5 15197.5 1964.5 1655.25 168.05 n Non-significant ranges 4 a 4 b 4 c 4 c d 4 Analysis of Variance Table for Cd - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 1 .11170333e-4 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.01589112017 MSD 0.05 = 0.02302224383 Rank Mean Name 1 BAl 2 HBA1 3 SOIL1 4 SBA1 5 SHBAl Mean 0.0474175 0.04033 0.03269 0.0279905 0.0237225 n Non-significant ranges 4 a 4 ab 4 ab 4 ab 4 b Analysis of Variance Table for Cd - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 5.88336075e-5 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.01156039833 MSD 0.05 = 0.01674811506 Rank Mean Name 1 SHBAl0 2 SOILlO 3 SBA10 Mean 0.019885 0.0185425 0.016835 n Non-significant ranges 4 a 4 a 4 a 137 4 BA10 5 HBAIO 0.0148275 0.0081125 4 a 4 a Analysis of Variance Table for Cd - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 2.46003389e-4 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.02363908182 MSD 0.05 = 0.03424709521 Rank Mean Name 1 HBA20 2 SOIL20 3 SBA20 4 SHBA20 5 BA20 Mean 0.027115 0.01755 0.01337 0.01085675 0.00960675 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for Co - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 0.002014385 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.06764431423 MSD 0.05 = 0.09799962992 Rank Mean Name 1 SBA1 2 SOIL1 3 SHBAl 4 BAl 5 HBAl Mean 0.6219 0.454125 0.258025 0 .1 0 .1 n Non-significant ranges 4 a 4 b 4 c 4 d 4 d Analysis of Variance Table for Co - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00487985517 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.10528427845 MSD 0.05 = 0.15253048896 Rank Mean Name 1 SOILlO 2 SHBAl0 Mean 0.646475 0.4625 n Non-significant ranges 4 a 4 b 138 3 SBA10 4 BAl0 5 HBA10 0.432 0.1 0.1 4 b 4 c 4 c Analysis of Variance Table for Co - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 0.002282275 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.07200191469 MSD 0.05 = 0.10431269906 Rank Mean Name 1 SHBA20 2 SOIL20 3 SBA20 4 BA20 5 HBA20 Mean 0.40245 0.353925 0.316825 0.1 0.1 n Non-significant ranges 4 a 4 a 4 a 4 b 4 b Analysis of Variance Table for Cr - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 0.6367483645 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 1.20266307725 MSD 0.05 = 1.74235688298 Rank Mean Name 1 HBAl 2 BAl 3 SBA1 4 SHBAl 5 SOIL1 Mean 95.8275 18.93 9.4125 8.507 0.532625 n Non-significant ranges 4 a 4 b 4 c 4 c 4 d Analysis of Variance Table for Cr - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00808707167 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.13553632469 MSD 0.05 = 0.19635810951 Rank Mean Name 1 HBA10 Mean 4.46975 n Non-significant ranges 4 a 139 2 3 4 5 BA10 SHBAIO SBA10 SOILIO 3.47975 0.5633 0.553325 0.417525 4 4 4 4 b c c c Analysis of Variance Table for Cr - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00599537 033 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.11669925034 MSD 0.05 = 0.16906791762 Rank Mean Name 1 BA20 2 HBA20 3 SHBA20 4 SBA20 5 SOIL20 Mean 4.165 4.0745 0.429125 0.4052 0.311475 n Non-significant ranges 4 a 4 a 4 b 4 b 4 b Analysis of Variance Table for Cu - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 554 3.52919716 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 112.215598093 MSD 0.05 = 162.572231086 Rank Mean Name 1 BA1 2 SBA1 3 SHBA1 4 SOIL1 5 HBA1 Mean 92.419375 6.46475 2.42875 1.1992 0.3397 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for Cu - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00842361183 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.13832772421 MSD 0.05 = 0.20040214665 Rank Mean Name Mean n Non-significant ranges 140 1 SBA10 2 SHBAIO 3 SOILIO 4 BAIO 5 HBAIO 1.00785 0.902125 0.50625 0.4209 0.21305 4 a 4 a 4 b 4 b 4 c Analysis of Variance Table for Cu - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00762651833 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.13162040361 MSD 0.05 = 0.1906849229 Mean Rank Mean Name 1 SBA20 2 SHBA20 3 SOIL20 4 BA20 5 HBA20 0.60825 0.489225 0.25015 0.124025 0.1088 n Non-significant ranges 4 a 4 a 4 b 4 b 4 b Analysis of Variance Table for Fe - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 1101.27818319 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 50.0159562872 MSD 0.05 = 72.4605646785 Rank Mean Name 1 SOIL1 2 SBA1 3 SHBAl 4 BA1 5 HBA1 Mean 465.7 415.575 182.2 4 .489 0.9023 n Non-significant ranges 4 a 4 a 4 b 4 c 4 c Analysis of Variance Table for Fe - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 6608.09258095 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 122.517497751 MSD 0.05 = 177.497097508 Rank Mean Name Mean n Non-significant ranges 141 1 SOILIO 2 SHBA10 3 SBA10 4 HBA10 5 BA10 616.15 431.95 390.4 1.2915 1.0161 4 a 4 b 4 b 4 c c 4 Analysis of Variance Table for Fe - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 1708.03888787 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 62.2886525335 MSD 0.05 = 90.2406206075 Rank Mean Name 1 SHBA20 2 SOIL20 3 SBA20 4 BA20 5 HBA20 Mean 398 .3 394.075 326.125 2.11825 1.06405 n Non-significant ranges 4 a 4 a 4 a 4 b 4 b Analysis of Variance Table for Hg - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00894083926 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.14251126745 MSD 0.05 = 0.20646305058 Rank Mean Name 1 BA1 2 HBA1 3 SBAl 4 SHBA1 5 SOILl Mean 2.307 1.5205 0.411425 0.1651575 0.01 n Non-significant ranges 4 a 4 b 4 c d 4 d 4 Analysis of Variance Table for Hg - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 0.0018053241 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.0640379836 MSD 0.05 = 0.09277496217 142 Rank Mean Name 1 HBA10 2 BA10 3 SHBA10 4 SOILIO 5 SBA10 Mean 0.341975 0.188425 0.01087 0.01 0.0090175 n Non-significant ranges 4 a 4 b 4 c 4 c 4 c Analysis of Variance Table for Hg - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00120661167 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.05235327072 MSD 0.05 = 0.07584674653 Rank Mean Name 1 BA20 2 HBA20 3 SOIL20 4 SHBA20 5 SBA20 Mean 0.496375 0.416775 0.01 0.01 0.01 n Non-■significant ranges 4 a 4 b 4 c 4 c 4 c Analysis of Variance Table for K - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 6229973.00796 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 3761.86443886 MSD 0.05 = 5449.99719526 Rank Mean Name 1 HBA1 2 BAl 3 SHBA1 4 SBA1 5 SOIL1 Mean 121655.1 101942.6 4821.4875 3665.1 1001.775 n Non- significant ranges 4 a 4 b 4 c 4 c 4 c Analysis of Variance Table for K - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 10885.8376667 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 157.250120077 MSD 0.05 = 227.815947996 143 Rank Mean Name 1 BA10 2 HBA10 3 SHBA10 4 SBA10 5 SOIL10 Mean 5039 4781.75 532.025 471.475 230.1 n Non-significant ranges 4 a 4 b 4 c 4 c 4 d Analysis of Variance Table for K - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 9254.56275792 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 144.989987137 MSD 0.05 = 210.054093145 Rank Mean Name 1 HBA20 2 BA20 3 SHBA20 4 SBA20 5 SOIL20 Mean 3774.1125 3367.0375 334.1625 304.11875 115.1875 n Non-significant ranges 4 a 4 b 4 c 4 cd 4 d Analysis of Variance Table for Li - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00708396938 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.12685231476 MSD 0.05 = 0.18377715915 Rank Mean Name 1 BA1 2 HBA1 3 SHBA1 4 SBA1 5 SOIL1 Mean 2.3505 1.43325 0 .1 0.1 0.0951325 n Non-significant ranges 4 a 4 b 4 c 4 c 4 c Analysis of Variance Table for Li - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00231544983 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.07252333164 144 MSD 0.05 = 0.10506810133 Rank Mean Name 1 HBA10 2 BA10 3 SOIL10 4 SHBA10 5 SBA10 Mean 0.447575 0.217 0.1 0.1 0.1 n Non-significant ranges 4 a 4 b 4 c 4 c 4 c Analysis of Variance Table for Li - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00521787924 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.10886971115 MSD 0.05 = 0.15772488085 Rank Mean Name 1 HBA20 2 BA20 3 SOIL20 4 SBA20 5 SHBA20 Mean 0.829375 0.45435 0.1651325 0.148225 0.0848075 n Non-significant ranges 4 a 4 b c 4 4 c 4 c Analysis of Variance Table for Mg - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 12728.5950117 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 170.039685579 MSD 0.05 = 246.344817722 Rank Mean Name 1 SHBA1 2 SBA1 3 SOIL1 4 BA1 5 HBA1 Mean 6143.75 2887.75 753.325 34.8425 17.31 n Non-significant ranges 4 a 4 b 4 c d 4 d 4 Analysis of Variance Table for Mg - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 1302.42116667 Degrees of Freedom: 15 Keep If: n Means = 5 145 LSD 0.05 = 54.3920943789 MSD 0.05 = 78.8004901897 Rank Mean Name 1 SBA10 2 SHBA10 3 HBA10 4 SOIL10 5 BA10 Mean 458.425 355.075 192.125 151.075 130.425 n Non-significant ranges 4 a 4 b 4 c 4 c 4 c Analysis of Variance Table for Mg - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 1231.03316667 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 52.8804248714 MSD 0.05 = 76.6104605622 Rank Mean Name 1 HBA20 2 BA20 3 SHBA20 4 SBA20 5 SOIL20 Mean 598.65 348.225 249.85 234.25 125.2 n Non-significant ranges 4 a 4 b 4 c 4 c 4 d Analysis of Variance Table for Mn - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 22.0142052023 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 7.07150029931 MSD 0.05 = 10.2448287076 Rank Mean Name 1 SBAl 2 SOIL1 3 SHBA1 4 BAl 5 HBA1 Mean 50.1125 38.2875 23.2675 0.356475 0.143475 n Non-significant ranges 4 a 4 b 4 c 4 d 4 d Analysis of Variance Table for Mn - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 58.2584875825 Degrees of Freedom: 15 Keep If: 146 n Means = 5 LSD 0.05 = 11.5037560088 MSD 0.05 = 16.6660545593 Rank Mean Name SOILIO SHBA10 SBA10 HBA10 BA10 Mean n Non-significant ranges 63.9375 59.3925 59.1825 0.438025 0.30815 b b Analysis of Variance Table for Mn - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 23.552555057 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 7.31440616397 MSD 0.05 = 10.5967383266 Rank Mean Name 1 SHBA20 2 SBA2 0 3 SOIL20 4 BA20 5 HBA20 Mean 48.3075 42.5575 35.3275 0.877625 0.430575 n Non-significant ranges 4 a 4 ab 4 b 4 c 4 c Analysis of Variance Table for Mo - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 4.4 9338302733 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 3.19482282969 MSD 0.05 = 4.62849625343 Rank Mean Name 1 HBA1 2 BA1 3 SBAl 4 SHBA1 5 SOIL1 Mean 71.38 63.44 8.9725 7.3025 0.23945 n Non-significant ranges 4 a 4 b 4 c 4 c 4 d Analysis of Variance Table for Mo - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00202547238 Degrees of Freedom: 15 Keep If: 147 n Means = 5 LSD 0.05 = 0.06783021934 MSD 0.05 = 0.09826895975 Rank Mean Name 1 HBA10 2 BA10 3 SBA10 4 SHBA10 5 SOIL10 Mean 1.9505 1.4105 0.338425 0.270025 0.1012125 n Non-significant ranges 4 a 4 b 4 c 4 c 4 d Analysis of Variance Table for Mo - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 0.006167 03509 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.11835817739 MSD 0.05 = 0.17147128646 Mean Rank Mean Name 1 HBA20 2 BA20 3 SBA20 4 SHBA20 5 SOIL20 2.448 1.6035 0.1651 0.150375 0.071965 n Non-significant ranges 4 a 4 b c 4 c 4 c 4 Analysis of Variance Table for Na - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 51045.16 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 340.515859244 MSD 0.05 = 493.321997106 Rank Mean Name 1 HBA1 2 BA1 3 SHBA1 4 SBA1 5 SOILl Mean 13260 8668.75 1677 .5 1482 451.65 n Non-significant ranges 4 a 4 b 4 c c 4 4 d Analysis of Variance Table for Na - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 4999.75939833 Degrees of Freedom: 15 148 Keep If: n Means = 5 LSD 0.05 = 106.569913096 MSD 0.05 = 154.393050815 Rank Mean Name 1 BA10 2 HBA10 3 SOILIO 4 SHBA10 5 SBA10 Mean 1051.95 1017.85 115.925 103.1175 83.13 n Non-significant ranges 4 a 4 a 4 b 4 b 4 b Analysis of Variance Table for Na - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 106.297871667 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 15.5389741213 MSD 0.05 = 22.5120726051 Rank Mean Name 1 BA20 2 HBA20 3 SHBA20 4 SBA20 5 SOIL20 Mean 679.975 647.375 87.84 87.7375 35.29 n Non-significant ranges 4 a 4 b 4 c 4 c 4 d Analysis of Variance Table for Ni - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 0.0528988789 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.34664368507 MSD 0.05 = 0.5021996784 Rank Mean Name 1 SBA1 2 SHBA1 3 SOIL1 4 BA1 5 HBA1 Mean 2.4345 1.31295 0.835975 0.28325 0.06498 n Non-significant ranges 4 a 4 b 4 b 4 c 4 c Analysis of Variance Table for Ni - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 0.0031115302 6 149 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.08407116648 MSD 0.05 = 0.12179801504 Rank Mean Name 1 SBA10 2 SOILIO 3 SHBA10 4 BA10 5 HBA10 Mean 0.437775 0.360775 0.349525 0.1157475 0.088195 n Non-significant ranges 4 a 4 a 4 a 4 b 4 b Analysis of Variance Table for Ni - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00327378808 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.086235352 MSD 0.05 = 0.12493337657 Rank Mean Name 1 SBA20 2 SHBA20 3 SOIL20 4 BA20 5 HBA20 Mean 0.276925 0.273925 0.236625 0.147515 0.1 n Non-significant ranges 4 a 4 a 4 ab 4 be c 4 Analysis of Variance Table for P - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 341.4508428 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 27.8499329172 MSD 0.05 = 40.3475613632 Rank Mean Name 1 SBA1 2 SHBA1 3 HBA1 4 SOIL1 5 BA1 Mean 368.95 148.675 74.8675 61.23 0.3335 n Non-significant ranges 4 a 4 b c 4 4 c 4 d Analysis of Variance Table for P - Day Ten Test: Tukey's HSD Significance Level: 0.05 150 Variance: 3557.03804333 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 89.8885373967 MSD 0.05 = 130.225925112 Rank Mean Name 1 SHBA10 2 SBA10 3 SOIL10 4 BA10 5 HBA10 Mean 293.9 242.175 118.1325 105.8 63.6375 n Non-significant ranges 4 a 4 ab 4 be 4 c 4 c Analysis of Variance Table for P - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 259.38515 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 24.2735118182 MSD 0.05 = 35.1662250137 Rank Mean Name 1 SHBA20 2 SBA20 3 SOIL20 4 BA20 5 HBA20 Mean 184.45 171.225 37.1325 36.86 34.9875 n Non-significant ranges 4 a 4 a 4 b 4 b 4 b Analysis of Variance Table for Pb - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 0.01757667902 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.199815176 MSD 0.05 = 0.28948202852 Rank Mean Name 1 BAl 2 SOILl 3 SBA1 4 SHBA1 5 HBAl Mean 1.30316675 0.28393325 0.24551675 0.12688675 0.03109 n Non-significant ranges 4 a 4 b 4 b 4 b 4 b Analysis of Variance Table for Pb - Day Ten Test: Tukey's HSD 151 Significance Level: 0.05 Variance: 0.0194144822 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.21000177472 MSD 0.05 = 0.30423985283 Rank Mean Name 1 SOILIO 2 SHBA10 3 SBA10 4 BA10 5 HBA10 Mean 0.3551 0.23368333333 0.22135833333 0.19131666667 0.04638333333 n Non-significant ranges 4 a 4 ab 4 ab 4 ab 4 b Analysis of Variance Table for Pb - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 0.11413857271 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.50918579288 MSD 0.05 = 0.73768238813 Rank Mean Name 1 HBA20 2 SOIL20 3 SBA20 4 SHBA20 5 BA20 Mean 0.3972625 0.3167415 0.27156675 0.27083325 0.05700825 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for Sb - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 0.03505279641 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.28217685849 MSD 0.05 = 0.40880343041 Rank Mean Name 1 HBA1 2 SBAl 3 SHBA1 4 BA1 5 SOILl Mean 4.425 1.3815 1.351 0.4 9305 0.027785 n Non-significant ranges 4 a 4 b 4 b 4 c 4 d 152 Analysis of Variance Table for Sb - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 7.75841938e-4 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.04198041087 MSD 0.05 = 0.06081907661 Rank Mean Name 1 HBA10 2 BA10 3 SBA10 4 SHBA10 5 SOIL10 Mean 0.84575 0.693875 0.15155 0.108615 0.0133275 n Non-significant ranges 4 a 4 b 4 c 4 c 4 d Analysis of Variance Table for Sb - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 5.64556738e-4 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.03581078627 MSD 0.05 = 0.05188083938 Rank Mean Name 1 HBA20 2 BA20 3 SBA20 4 SHBA20 5 SOIL20 Mean 1.08025 0.898025 0.0442975 0.04177 0.01088775 n Non-significant ranges 4 a 4 b 4 c 4 c c 4 Analysis of Variance Table for Se - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 0.0039749445 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.09502231209 MSD 0.05 = 0.13766347587 Rank Mean Name 1 HBA1 2 BA1 3 SBA1 4 SHBA1 Mean 0.96985 0.400825 0.29545 0.1108 n Non-significant ranges 4 a 4 b 4 b 4 c 153 5 S0IL1 0.1 4 c Analysis of Variance Table for Se - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00105478353 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.04894876387 MSD 0.05 = 0.07091447078 Rank Mean Name 1 SHBA10 2 SOIL10 3 BA10 4 HBA10 5 SBA10 Mean 0.130715 0.0962575 0.09214 0.088965 0.0821425 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for Se - Day Twenty N/A Analysis of Variance Table for Si - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 536712.246 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 1104.15695196 MSD 0.05 = 1599.64623636 Rank Mean Name 1 HBA1 2 SHBA1 3 SBA1 4 SOIL1 5 BA1 Mean 11338.75 3165.75 2469.75 1103.25 283.75 n Non-significant ranges 4 a 4 b 4 be 4 cd 4 d Analysis of Variance Table for Si - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 86987.421 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 444.516909696 MSD 0.05 = 643.993410837 Rank Mean Name Mean n Non-significant ranges 154 1 BA10 2 HBA10 3 SHBA10 4 SBA10 5 SOILIO 15987.5 10311.5 1224 966.175 328.175 4 a 4 b 4 c 4 cd 4 d Analysis of Variance Table for Si - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 27127.6106667 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 248.236609476 MSD 0.05 = 359.632529931 Mean Rank Mean Name 1 BA20 2 HBA20 3 SHBA20 4 SBA20 5 SOIL20 6312.75 5365.75 996.6 863.6 231.1 n Non-significant ranges 4 a 4 b 4 c 4 c 4 d Analysis of Variance Table for Sn - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 1. 49117372e-4 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.0184045066 MSD 0.05 = 0.0266635098 Rank Mean Name 1 SOIL1 2 SHBA1 3 SBA1 4 BA1 5 HBA1 Mean 0.1 0.1 0.1 0.084635 0.0698575 n Non-significant ranges 4 a 4 a 4 a 4 ab 4 b Analysis of Variance Table for Sn - Day Ten N/A Analysis of Variance Table for Sn - Day Twenty N/A Analysis of Variance Table for Sr - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 388.313575 Degrees of Freedom: 15 Keep If: 155 n Means = 5 LSD 0.05 = 29.6996509706 MSD 0.05 = 43.0273384702 Rank Mean Name 1 BAl 2 HBA1 3 SHBAl 4 SBA1 5 SOILl Mean 1566.75 127.2 101.9875 59.1325 10.9625 n Non-significant ranges 4 a 4 b 4 be 4 c 4 d Analysis of Variance Table for Sr - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 27.0283649167 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 7.83555829113 MSD 0.05 = 11.351756929 Mean Rank Mean Name 1 BAl 0 2 HBA10 3 SBA10 4 SHBAl0 5 SOIL10 179.4 139.175 16.665 10.5685 1.97125 n Non-significant ranges 4 a 4 b 4 c cd 4 4 d Analysis of Variance Table for Sr -D ay Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 3.66521691667 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 2.88542572941 MSD 0.05 = 4.18025752602 Rank Mean Name 1 BA20 2 HBA20 3 SBA20 4 SHBA20 5 SOIL20 Mean 94.015 79.1225 7.5565 6.8335 1.66975 n Non-significant ranges 4 a 4 b 4 c 4 c d 4 Analysis of Variance Table for Te - Day One N/A Analysis of Variance Table for Te - Day Ten N/A 156 Analysis of Variance Table for Te - Day Twenty N/A Analysis of Variance Table for Th - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 1.84826932e-6 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.00204900343 MSD 0.05 = 0.00296849159 Rank Mean Name 1 SBA1 2 BAl 3 HBA1 4 SOILl 5 SHBAl Mean 0.0168475 0.01 0.01 0.008106 0.00795275 n Non-significant ranges 4 a 4 b 4 b 4 b 4 b Analysis of Variance Table for Th - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 1.345354e-5 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.00552813125 MSD 0.05 = 0.0080088744 Rank Mean Name 1 SOIL10 2 HBA10 3 BA10 4 SBA10 5 SHBA10 Mean 0.0120115 0.01 0.00915775 0.0090465 0.00800825 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for Th - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 9.4656005e-7 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.00146633819 MSD 0.05 = 0.00212435592 Rank Mean Name Mean n Non-significant ranges 1 BA20 0.01 4 a 157 2 HBA20 3 SOIL20 4 SHBA20 5 SBA20 0.01 0.01 0.01 0.00891225 4 a 4 a 4a 4 a Analysis of Variance Table for Ti - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 0.41977617335 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.9764925877 MSD 0.05 = 1.41469262135 Rank Mean Name 1 SBAl 2 SOILl 3 SHBAl 4 HBA1 5 BAl Mean 9.11575 6.99325 4.3805 0.1781525 0.10079 n Non-significant ranges 4 a 4 b 4 c 4 d 4 d Analysis of Variance Table for Ti - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 1.3978179249 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 1.78190834442 MSD 0.05 = 2.58153786164 Rank Mean Name 1 SOIL10 2 SHBAl0 3 SBAl0 4 HBA10 5 BA10 Mean 9.54275 8.281 7.57225 0.13633 0.1149925 n Non-significant ranges 4 a 4 a 4 a 4 b 4 b Analysis of Variance Table for Ti - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 0.50706037716 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 1.07322281491 MSD 0.05 = 1.55483043746 Rank Mean Name Mean n Non-significant ranges 158 1 SHBA20 2 SBA20 3 SOIL20 4 HBA20 5 BA20 7.02225 6.3635 6.36225 0.09658 0.0719 4 a 4 a 4 a 4 b 4 b Analysis of Variance Table for TI - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 8.413202e-7 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.00138242226 MSD 0.05 = 0.00200278281 Rank Mean Name 1 BAl 2 SOILl 3 SHBAl 4 SBAl 5 HBAl Mean 0.01 0.01 0.01 0.01 0.0089745 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for TI - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 1.02245e-7 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 4.81926823e-4 MSD 0.05 = 6.98190983e-4 Rank Mean Name 1 HBAl0 2 SOIL10 3 SHBAl0 4 SBAl0 5 BA10 Mean 0.01 0.01 0.01 0.01 0.0096425 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for TI - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 9.9502605e-7 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.00150340948 MSD 0.05 = 0.00217806292 Rank Mean Name Mean n Non-significant ranges 159 1 HBA20 2 SOIL20 3 SHBA20 4 SBA20 5 BA20 0.01 0.01 0.01 0.01 0.00888475 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for U - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 3.68876758e-4 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.02894680965 MSD 0.05 = 0.04193666039 Rank Mean Name 1 SHBAl 2 SBAl 3 SOILl 4 BAl 5 HBAl Mean 0.26195 0.150175 0.0277225 0.01 0.01 n Non--significant ranges 4 a 4 b 4 c 4 c 4 c Analysis of Variance Table for U - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 2.1445495e-5 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.00697956083 MSD 0.05 = 0.01011163149 Rank Mean Name 1 SBAl0 2 SHBAl0 3 SOIL10 4 BA10 5 HBA10 Mean 0.0337675 0.02229 0.0194375 0.0120375 0.01 n Non-■significant ranges 4 a 4 b 4 be 4 c 4 c Analysis of Variance Table for U - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 1.67183338e-6 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.00194875192 MSD 0.05 = 0.00282325231 160 Rank Mean Name 1 SHBA20 2 BA20 3 HBA20 4 SOIL20 5 SBA20 Mean 0.010308 0.01 0.01 0.009407 0.00926475 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for V - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 2.15880398333 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 2.21445400505 MSD 0.05 = 3.20818793784 Rank Mean Name 1 HBAl 2 SBAl 3 SHBAl 4 SOILl 5 BAl Mean 15.8975 3.146 1.42275 1.176 0.1 n Non-significant ranges 4 a 4 b 4 b 4 b 4 b Analysis of Variance Table for V - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 0.06817981667 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.39353917736 MSD 0.05 = 0.5701394741 Rank Mean Name 1 BAl0 2 HBA10 3 SHBAl0 4 SBA10 5 SOILl0 Mean 11.6075 7.79575 2.96925 2.86325 1.797 n Non-significant ranges 4 a 4 b 4 c 4 c 4 d Analysis of Variance Table for V - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 0.0318911545 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.26915049302 MSD 0.05 = 0.38993149697 161 Rank Mean Name 1 BA20 2 HBA20 3 SHBA20 4 SBA20 5 SOIL20 Mean 6.82 4.36225 2.14125 2.06925 1.069925 n Non-significant ranges 4 a 4 b 4 c 4 c 4 d Analysis of Variance Table for W - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 13.9044952248 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 5.62001756004 MSD 0.05 = 8.14199459798 Rank Mean Name 1 BAl 2 HBAl 3 SBAl 4 SHBAl 5 SOILl Mean 99.4875 76.1525 20.7575 9.44425 0.08681 n Non-significant ranges 4 a 4 b 4 c 4 d 4 e Analysis of Variance Table for W - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 2.61047817733 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 2.43511845686 MSD 0.05 = 3.52787533302 Rank Mean Name 1 HBA10 2 BA10 3 SHBAl0 4 SBA10 5 SOIL10 Mean 16.3375 9.76625 1.1336 1.06975 0.1 n Non-significant ranges 4 a 4 b 4 c 4 c 4 c Analysis of Variance Table for W - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 1.45763403184 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 1.81963511251 162 MSD 0.05 = 2.6361944777 Rank Mean Name 1 BA20 2 HBA20 3 SHBA20 4 SBA20 5 SOIL20 Mean 26.525 22.6325 0.392525 0.3877 0.0923775 n Non-significant ranges 4 a 4 b 4 c 4 c 4 c Analysis of Variance Table for Y - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 1.65936185e-4 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.01941469666 MSD 0.05 = 0.02812702161 Rank Mean Name 1 SOILl 2 SBAl 3 BAl 4 HBAl 5 SHBAl Mean 0.128475 0.10171 0.1 0.1 0.0766225 n Non-significant ranges 4 a 4 ab 4 b 4 b 4 b Analysis of Variance Table for Y - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 1.12180465e-4 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.01596315302 MSD 0.05 = 0.02312660135 Rank Mean Name 1 BA10 2 HBAl0 3 SHBAl0 4 SOIL10 5 SBA10 Mean 0.1 0.1 0.070535 0.06253 0.0547025 n Non-significant ranges 4 a 4 a 4 b 4 b 4 b Analysis of Variance Table for Y - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 1.1887704e-4 Degrees of Freedom: 15 Keep If: n Means = 5 163 LSD 0..05 = 0.01643270468 MSD 0,.05 = 0.02380686382 Rank Mean Name 1 BA20 2 HBA20 3 SOIL20 4 SBA20 5 SHBA20 Mean 0.1 0.1 0.1 0.1 0.06347 n Non-significant ranges 4 a 4 a 4 a 4 a 4 b Analysis of Variance Table for Zn - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 0.63933985183 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 1.20510793743 MSD 0.05 = 1.74589887161 Rank Mean Name 1 BAl 2 SOILl 3 SHBAl 4 SBAl 5 HBAl Mean 6.7665 3.64225 2.88925 2.73575 0.351425 n Non--significant ranges 4 a 4 b 4 b 4 b 4 c Analysis of Variance Table for Zn - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 0.10199204333 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.481330304 MSD 0.05 = 0.69732677757 Rank Mean Name 1 SOIL10 2 SBAl0 3 SHBAl0 4 BAl0 5 HBA10 Mean 2.19025 1.7975 1.61375 0.6949 0.58065 n Non--significant ranges 4 a 4 a 4 a 4 b 4 b Analysis of Variance Table for Zn - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 0.04911719633 Degrees of Freedom: 15 Keep If: 164 n Means = 5 LSD 0.05 = 0.33402336227 MSD 0.05 = 0.48391599886 Rank Mean Name 1 SOIL20 2 SHBA20 3 SBA20 4 HBA20 5 BA20 Mean 1.71125 1.67425 1.64425 0.695025 0.597875 n Non-significant ranges 4 a 4 a 4 a 4 b 4 b Analysis of Variance Table for Zr - Day One Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00170163833 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.06217183549 MSD 0.05 = 0.09007138203 Rank Mean Name 1 SBA1 2 SOIL1 3 SHBAl 4 BA1 5 HBA1 Mean 0.635075 0.352325 0.2916 0.1 0 .1 n Non-significant ranges 4 a 4 b 4 b 4 c 4 c Analysis of Variance Table for Zr - Day Ten Test: Tukey's HSD Significance Level: 0.05 Variance: 0.00146885583 Degrees of Freedom: 15 Keep If: n Means = 5 LSD 0.05 = 0.05776298726 MSD 0.05 = 0.08368406775 Rank Mean Name 1 SHBAl0 2 SBA10 3 SOIL10 4 BA10 5 HBA10 Mean 0.179825 0.13745 0.1269 0.1 0.1 n Non-significant ranges 4 a 4 a 4 a 4 a 4 a Analysis of Variance Table for Zr - Day Twenty Test: Tukey's HSD Significance Level: 0.05 Variance: 1.39734032e-4 Degrees of Freedom: 15 165 Keep If: n Means = 5 LSD 0.05 = 0.01781603896 MSD 0.05 = 0.02581096792 Rank Mean Name 1 BA20 2 HBA20 3 SHBA20 4 SBA20 5 SOIL20 Mean 0.1 0.1 0.084425 0.0768175 0.071985 n Non-significant ranges 4 a 4 a 4 ab 4 ab 4 b 166 APPENDIX B1 pH Static Leachate Graphs; n=4. 0.00050 -I 0.00045 0.00040 0.00035 H 0.00030 Ag .0.00025 A (mg L‘ ) 0 00020 .BA •HBA T • 0.00015 A 0.00010 ■ 0.00005 4 0.00000 3.00 4.00 5.00 6.00 8.00 9.00 10.00 11.00 Figure B 1 .0 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing silver, Ag, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 0.0035 •BA HBA 0.0030 0.0025 0.0020 Be (mg L-1) 0.0015 0.0010 0.0005 0.0000 10.00 3.00 11.00 Figure B l . l - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing beryllium, Be, concentration (mg/L) changes against p H (standard deviation error bars); n=4. ____________ i 0 ■BA •HBA 6.00 7.00 9 8 Bi (mg I / 1) .7 ^ 6 .5 4 • ,3 - .2 1 ^ 0 3.00 4.00 5.00 8.00 9.00 10.00 pH Figure B1.2 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing bismuth, Bi, concentration (mg/L) changes against pH (standard deviation error bars); n=4. ___________________ 167 11.00 (mg L-') pH Figure B1.3 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing lithium, Li, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 0.025 -| •HBA ..♦ ...BA 0.020 - Sb (mg L ‘) 0.015 - 0.010 0.005 4 0.000 3.00 4.00 5.00 7.00 6.00 1.00 9.00 10.00 pH Figure B1.4 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing antimony, Sb, concentration (mg/L) changes against p H (standard deviation error bars); n=4. (mg L') pH Figure B1.5 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing tin, Sn, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 168 11.00 0.0007 -I 0.0006 0.0005 0.0004 Te (mg I / 1) 0.0003 0.0002 -I 0.0001 0.0000 3.00 10.00 11.00 Figure B 1 .6 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing tellurium, Te, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 1.0 i •BA •HBA 0.9 0.8 -| 0.7 0.6 H Th 0.5 (mg L 1) 0.4 0.3 0.2 0.1 0.0 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 pH Figure B1.7 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing thorium, Th, concentration (mg/L) changes against p H (standard deviation error bars); n -4 . 0.014 i •HBA 0.012 0.010 0.008 Ti (mg L 1) 0.006 0.004 0.002 0.000 3.00 11.00 Figure B1.8 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing titanium, Ti, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 169 0.0025 0.0020 - TI (mg L 1) 0.00 5 0.0010 0.0005 0.0000 Figure B1.9 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing tantalum, TI, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 0.0025 0.0020 0.0015 (mg L-1) Q0Q10 0.0005 0.0000 Figure B1.10 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing uranium, U, concentration (mg/L) changes against p H (standard deviation error bars); n=4. HBA (mg L 1) 0.060 - 0.000 Figure B l .l l - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing vanadium, V, concentration (mg/L) changes against pH (standard deviation error bars); n-4. 170 0.45 •BA •HBA 0.40 0.35 0.30 W 0.25 (mg L '1) 0.20 0.15 0.10 0.05 0.00 3.00 10.00 11.00 Figure B1.12 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing tungsten, W, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 0.07 •BA •HBA 6.00 7.00 0.06 0.05 Y 0.04 - (mg L-') o.03 0.02 H 0.01 0.00 3.00 4.00 5.00 8.00 9.00 10.00 11.00 PH _ _ Figure B1.13 - Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing yittrium, Y, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 0.00040 H 0.00035 0.00030 Z r 0.00025 (mg L '1) 0.00020 0.00015 0.00010 0.00005 0.00000 3.00 11.00 Figure B1.14- Leaching profile fo r bottom ash (BA) and hardened bottom ash (HBA) showing zirconium, Zr, concentration (mg/L) changes against p H (standard deviation error bars); n=4. 171 APPENDIX B2 Mass loss (%) of Indivdiual Elements from Ash During pH Static Experimentation for HNO3/HF/H2BO3 Digestion Table B2.0 - Percentage o f elements leached from bottom ash based based on original solid phase concentrations (from HNO 3/HF/H 2BO 3 digest) and amount o f ash used during p H static experiment fo r p H 10 to 7. Parameter (Bottom Ash) Ag (%)** Al (%) As (%)** Ba (%) Be (%)** Bi (%)** Ca (%) Cd (%)** Co (%) Cr (%) Cu (%) Fe (%) Hg (%)** pH 10 pH 9 Mean SD Mean 0.09 0.09 0.05 0.0009 0.08 0.10 1.15 0.19 0.13 0.04 0.44 0.47 n/a n/a n/a n/a n/a n/a 27.03 19.81 5.34 n/a n/a n/a 0.07 n/a n/a 1.19 1.23 0.50 0.28 0.32 0.03 0.010 0.000 0.007 0.09 0.12 0.02 7.57 6.46 0.49 K (% ) 0.25 1.29 Li (%) 0.51 0.46 0.41 6.80 Mg (%) 0.04 0.001 0.001 Mn (%) 31.97 24.59 2.33 Mo (%) 2.37 3.66 0.56 N a (%) 0.66 0.01 0.01 Ni (%) 0.04 0.02 0.00 P (% ) 1.62 2.08 0.12 Pb (%)** 1.08 0.55 0.16 Sb (%)** 0.55 0.75 0.05 Sn (%) 19.51 12.61 4.72 Sr (%) 0.0004 n/a n/a Ti (%) 0.08 0.26 0.20 TI (%)** 0.0036 0.01 0.0010 U (%)** 0.54 0.23 0.23 V (% ) 1.82 1.07 W (%) 0.47 0.02 0.03 0.01 Y (%)** 0.08 0.08 0.01 Zn (%) 0.0019 0.0020 0.0002 Zr (%) *n/a designation is given fo r undetected **Estimation based on original detection limit pH 7 pH8 SD 0.05 0.0005 0.50 0.01 n/a n/a 0.99 n/a 0.05 0.35 0.09 0.005 0.01 0.30 0.27 2.37 0.03 1.21 0.19 0.42 0.02 0.88 0.20 0.37 0.72 0.0004 0.04 0.01 0.04 0.17 0.01 0.01 0.0006 172 Mean 0.14 0.0016 1.70 0.48 n/a n/a 28.71 0.20 1.67 n/a 0.45 0.02 0.11 7.73 2.02 13.25 0.55 36.81 3.92 4.93 0.09 2.73 1.31 1.81 20.04 0.0008 0.24 0.02 0.36 1.57 0.04 0.09 0.0018 SD 0.07 0.0007 0.16 0.03 n/a n/a 1.41 0.10 0.78 n/a 0.14 0.01 0.02 0.39 0.42 5.29 0.34 2.04 0.28 3.16 0.03 1.23 0.26 1.03 0.91 0.0005 0.14 0.01 0.03 0.26 0.01 0.01 0.0010 Mean 0.11 0.0018 7.78 0.49 n/a n/a 38.26 0.25 1.81 0.28 0.50 0.02 0.08 9.48 3.85 25.78 1.29 32.13 6.88 9.69 0.68 3.12 1.99 2.05 26.09 0.0012 0.07 0.04 1.08 1.02 0.06 0.18 0.0026 SD 0.05 0.0004 1.41 0.02 n/a n/a 5.79 0.12 1.13 0.34 0.17 0.01 0.02 0.67 1.11 9.23 0.79 3.28 0.95 5.97 0.13 1.28 0.64 0.89 3.49 0.0003 0.05 0.01 0.38 0.26 0.01 0.07 0.0005 Table B2.1 - Percentage o f elements leachedfrom bottom ash based based on original solid phase concentrations (from HNO 3/HF/H2BO} digest) and amount o f ash used during pH static experimentfo r p H 6 to 4. Parameter pH 6 pH 5 (Bottom Ash) Mean SD Mean Ag (%)** 0.05 0.11 0.11 A1 (%) 0.0021 0.0005 0.02 18.25 2.80 9.82 As (%)** 0.10 Ba (%) 0.68 1.00 Be (%)** n/a n/a n/a Bi (%)** n/a n/a n/a 55.39 1.44 Ca (%) 65.33 0.23 0.06 0.44 Cd (%)** 5.98 1.00 6.09 Co (%) Cr (%) n/a n/a 0.09 0.36 Cu (%) 0.04 0.49 0.001 0.0072 Fe (%) 0.008 0.04 0.05 0.01 Hg (%)** 0.83 10.82 11.58 K (%) 6.64 7.21 Li (%) 1.01 3.01 44.96 Mg (%) 39.73 4.58 0.95 Mn (%) 5.50 21.51 11.93 Mo (%) 5.63 9.92 0.74 7.35 Na (%) Ni (%) 23.33 2.73 33.66 3.85 1.00 2.18 P (% ) 1.38 Pb (%)** 0.18 1.55 2.64 2.08 Sb (%)** 0.94 1.06 1.26 Sn (%) 0.12 Sr (%) 38.02 3.33 41.35 0.0016 Ti (%) 0.0010 0.0004 n/a n/a 0.08 TI (%)** 0.01 U (%)** 0.02 0.0029 1.32 0.46 0.10 V (% ) 0.32 0.10 W (%) 0.16 Y (%)** 0.06 0.22 0.02 Zn (%) 2.05 1.18 12.60 n/a 0.0021 Zr (%) n/a *n/a designation is given fo r undetected **Estimation based on original detection limit pH 4 SD 0.04 0.02 4.29 0.10 n/a n/a 1.98 0.06 1.58 0.06 0.13 0.0003 0.01 0.99 0.73 2.44 1.17 4.28 0.80 6.45 0.99 0.47 0.69 0.04 1.87 0.0010 0.03 0.0001 0.13 0.08 0.12 4.83 0.0012 173 Mean 0.11 1.31 0.96 1.39 n/a n/a 72.64 1.20 10.84 0.75 6.96 0.03 0.06 17.15 10.87 52.02 14.48 n/a 11.42 37.24 0.29 0.84 2.07 0.49 51.15 0.0042 n/a 0.0046 0.12 0.01 16.09 45.33 0.0053 SD 0.06 1.27 0.49 0.26 n/a n/a 2.00 0.23 1.52 0.55 3.07 0.02 0.02 1.91 0.94 1.55 3.06 n/a 1.00 1.28 0.15 0.04 1.11 0.07 2.32 0.0022 n/a 0.0030 0.03 0.00 7.47 4.21 0.0030 Table B2.2 - Percentage o f elements leachedfrom hardened bottom ash based based on original solid phase concentrations (from HNO3/HF/H 2BO 3 digest) and amount o f ash used during pH static experiment fo r p H 10 to 7. Parameter (Hardened Bottom Ash) Ag (%)** A1 (%) As (%)*• Ba (%) Be (%)** Bi (%)** Ca (%) Cd (%)** Co (%) C r(% ) Cu (%) Fe (%) Hg (%)** pH8 pH 7 pH 10 pH 9 Mean Mean SD Mean SD n/a 0.0003 0.55 0.41 n/a n/a 15.88 n/a n/a 0.78 0.06 0.0012 0.04 10.23 2.14 11.52 0.05 21.24 5.98 1.24 0.03 0.25 1.07 0.17 14.23 0.0002 n/a 0.01 0.29 0.81 n/a 0.02 n/a n/a 0.0002 0.29 0.07 n/a n/a 5.10 n/a n/a 0.61 0.00 0.0001 0.01 0.78 1.28 7.73 0.10 1.77 1.32 1.72 0.03 0.06 0.50 0.02 3.45 0.0001 n/a 0.01 0.06 0.46 n/a 0.01 n/a n/a 0.0002 1.17 0.38 n/a n/a 22.05 n/a 0.15 0.62 0.06 0.0012 0.03 10.39 3.17 19.95 0.15 23.50 7.07 2.60 0.08 0.22 1.54 0.18 18.12 0.0003 0.08 0.02 0.23 0.37 n/a 0.02 n/a n/a 0.0001 0.17 0.05 n/a n/a 4.46 n/a 0.11 0.70 0.01 0.0002 0.02 0.51 0.85 4.68 0.23 0.89 1.34 1.72 0.01 0.05 0.43 0.01 2.90 0.0001 0.03 0.01 0.04 0.19 n/a 0.01 n/a SD 0.04 0.01 0.0004 0.0002 0.17 0.13 0.03 0.22 n/a n/a nidi n/a 9.50 2.00 n/a n/a n/a n/a 1.19 0.37 0.00 0.08 0.0017 0.0002 0.06 0.01 8.84 0.57 K (%) 0.73 0.22 Li (%) 1.47 1.76 Mg (%) 0.00 0.00 Mn (%) 18.11 1.12 Mo (%) 4.81 0.38 Na (%) 0.07 0.04 Ni (%) 0.01 0.01 P (% ) 0.01 0.31 Pb (%)** 0.53 0.11 Sb (%)** 0.30 0.02 Sn (%) 9.34 1.84 Sr (%) 0.0004 0.0004 Ti (%) n/a n/a TI (%)** n/a n/a U (%)** 0.04 0.33 V (% ) 1.01 0.06 W (%) n/a n/a Y (%)** 0.002 0.03 Zn (%) n/a n/a Zr (%) *n/a designation is given fo r undetected **Estimation based on original detection limit 174 Mean nidi 0.0010 3.43 1.39 n/a n/a 36.60 n/a 0.53 0.28 0.06 0.0019 0.03 11.19 4.03 26.59 0.94 23.21 7.22 7.62 0.58 0.19 2.59 0.15 25.27 0.0011 n/a 0.04 0.41 0.31 0.07 0.10 n/a SD n/a 0.0011 0.20 1.83 n/a nidi 4.25 n/a 0.33 0.12 0.02 0.0018 0.01 0.83 0.53 2.26 0.56 1.61 1.02 1.61 0.09 0.07 0.33 0.07 2.71 0.0012 n/a 0.01 0.07 0.10 0.05 0.03 n/a Table B2.3 - Percentage o f elements leached from hardened bottom ash based based on original solid phase concentrations (from H N 0fH F/H 2B 0 3 digest) and amount o f ash used during pH static experimentfo r p H 6 to 4. Parameter (Hardened Bottom Ash) pH 6 Mean SD n/a n/a Ag (%)** A1 (%) 0.0007 0.0001 3.53 0.79 As (%)** 0.87 0.26 Ba (%) n/a Be (%)** n/a Bi (%)** n/a n/a Ca (%) 58.11 6.74 n/a n/a Cd (%)** 0.14 0.18 Co (%) Cr (%) 0.43 0.12 0.02 Cu (%) 0.08 0.0012 0.0001 Fe (%) 0.05 0.02 Hg (%)** 11.71 0.91 K (% ) Li (%) 5.56 0.75 3.12 Mg (%) 35.77 Mn (%) 1.68 0.83 Mo (%) 5.80 4.19 0.96 Na (%) 8.12 17.13 3.33 Ni (%) 0.24 1.15 P (% ) Pb (%)** 0.20 0.03 0.24 Sb (%)** 2.70 Sn (%) 0.18 0.03 3.93 Sr (%) 36.71 0.0005 0.0002 Ti (%) 0.22 0.13 TI (%)** 0.02 0.02 U (%)** 0.21 0.09 V (% ) 0.02 W (%) 0.03 Y (%)** 0.05 0.01 0.82 Zn (%) 1.42 n/a Zr (%) n/a *n/a designation is given fo r undetected **Estimation based on original detection limit pH 5 pH 4 Mean SD n/a 0.0045 1.11 1.73 n/a n/a 73.68 0.28 0.83 0.27 0.21 0.0016 0.03 11.59 6.40 44.56 3.59 0.79 6.49 25.20 0.34 0.17 1.54 0.19 43.13 0.0006 n/a n/a 0.08 0.02 0.51 11.59 n/a n/a 0.0040 0.39 0.12 n/a n/a 3.11 0.05 0.85 0.06 0.07 0.0003 0.01 0.57 0.44 3.42 1.01 0.23 0.27 2.50 0.14 0.01 0.13 0.05 2.70 0.0003 n/a n/a 0.02 0.00 0.37 5.01 n/a 175 Mean 0.12 1.30 0.54 1.98 1.50 n/a 76.62 0.88 4.50 1.05 4.81 0.0106 n/a 15.19 9.18 48.51 10.91 n/a 8.68 30.72 0.29 0.20 1.25 0.14 53.74 0.0016 n/a 0.00 0.04 0.01 16.47 42.11 n/a SD 0.06 0.63 0.10 0.23 0.62 n/a 2.18 0.13 1.06 0.61 1.34 0.0039 n/a 1.07 0.92 0.85 1.66 n/a 0.75 1.33 0.20 0.05 0.37 0.03 3.85 0.0011 n/a 0.00 0.01 0.00 5.74 9.05 n/a Table B2.4 - Total elemental content present within the aqueous phase o f the blank samples run during pH static experiment. Parameter pH Static Experiment Blanks SD Mean Ag (ppb) <0.1 n/a A1 (ppm) 3.90E-02 3.03E-02 As (ppb) <0.1 n/a B (ppm) 8.76E-01 2.51E-01 Ba (ppm) 3.43E-03 1.62E-03 Be (ppb) <1.0 n/a B i(ppb) <0.1 n/a Ca (ppm) 1.75E+01 2.83E+00 Cd (ppb) <0.1 n/a Co (ppb) <0.1 n/a Cr (ppb) <1.0 n/a Cu (ppm) 1.63E-02 1.37E-02 Fe (ppm) 1.56E-01 1.90E-01 Hg (ppb) <0.1 n/a K (ppm) 1.53E+00 1.57E-01 Li(ppb) <1.0 n/a Mg (ppm) 2.95E+00 3.56E-02 Mn (ppb) <1.0 n/a Mo (ppm) 3.28E-03 2.22E-03 N a (ppb) <10.0 n/a Ni (ppm) 2.12E-03 1.58E-03 P (ppm) 1.85E+00 1.15E-01 Pb (ppm) 3.62E-03 3.82E-03 Sb (ppb) <0.1 n/a Se(ppb) <1.0 n/a Si (ppb) <100. n/a Sn (ppm) 6.84E-03 7.70E-03 Sr (ppm) 5.51E-02 2.27E-02 Te (ppb) <0.1 n/a Th (ppb) <0.1 n/a Ti (ppm) 1.36E-03 8.67E-04 TI (ppb) <0.1 n/a U (ppb) <0.1 n/a V (ppm) 1.18E-03 3.74E-04 W (ppm) 1.59E-03 1.22E-03 Y (ppb) <0.1 n/a Zn (ppm) 4.51E-02 9.72E-03 Zr (ppb) <0.1 n/a 176 Sample Percent Loss Calculation for Individual Elements Leached from Ash into the Aqueous Phase (Section 3.3.4); sample calculation for Ca percent loss using one replicate and ICP data following HNO3/HCI digestion for solid phase. Ca co n ten t in solid phase = 1 1 22 4 5 m # k g ' 1 A m ount o f BA (OD eq u iva len t ) u sed in sin g le extra c tio n = 20.0554 g = 0.0200554& # Total A vailable Ca = 112 2 4 5 m # k g ' 1 * 0 .0 2 0 0 5 5 4 k g = 2 2 5 1 m # A queous Ca concentration = 3 6 5 0 m # L '1 Total aqueous volum e = 0.1213L Total Ca co n ten t in aqueous solu tio n = 3 6 5 0 m g L '1 * 0.1213 L = 4 43m # Total Ca co n ten t in aqueous so lu tio n 443m g Ca P ercent Loss = - — —— .--------------- :------ — —-— = r r r = 19.7% Total A vailable Ca co n ten t in solid phase 2251m g 177