Development of modified natural zeolites and study of phosphate removal from aqueous solutions

Lake eutrophication has been an issue in many countries including Canada. Controlling and reducing the level of phosphorus, which is available as a form of phosphate in water, have been studied to manage the lake eutrophication. Natural zeolite-based adsorbents are one of the best candidates for water treatment due to its wide availability, cost-effectiveness, and superior characteristics as an ion exchanger. In this study, the concept of struvite crystallization was employed to develop magnesium-ammonium-modified zeolites (MNZ). Their removal capacity of phosphate was tested with comparison of magnesium-modified zeolites (MZ) based on the design of experiments (DOE) and response surface methodology (RSM). According to RSM, MNZ was found to be more effective in removing phosphates from aqueous solutions up to 92% of removal since MZ was effective up to 46% of removal. Contact time and zeolite dosage were found to be the significant parameters on phosphate removal.