Clean drinking water is essential for all life on Earth. Over 400, 000 people die annually from lack of clean drinking water, and the demand on water is predicted to increase in all sectors. The demand for safe drinking water presents an ongoing challenge for new water purification techniques. Since the 1950s, natural zeolite has been investigated as a means of water purification due to its stable, crystalline, porous structure and cation exchange capacities. Recent publications have indicated that natural zeolite modified with metal cations provides a stable treatment media for the elimination of E. coli bacteria in drinking water. In this series of analysis, Canadian natural zeolite from the Bromley River Valley, Kamloops BC, was modified with zinc and copper sulphates to create three novel water treatment options. Treatment of E. coli contaminated water was most effective with zinc modified zeolite, which also significantly lowered the pH in comparison to the copper and copper/zinc modified zeolite. Of the three zeolites, all released too much copper and zinc into solution that may be linked to the low cation exchange capacity (CEC) of the Canadian zeolite. E. coli colony forming units were reduced; however, they were not sufficient to meet drinking water standards. Future studies will focus on optimizing the ratio of modified zeolite needed to treat a given amount of pathogen in solution.
I evaluated how intra- and inter-specific competition affects the development of eleven wood attributes of trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) over 34 years. My analysis was conducted in a mixedwood trial site in Northern British Columbia, Canada, that included treatments consisting of 0, 1000, 2000, 5000, and 10000 stems per hectare of aspen. Competition was found to negatively influence wood attribute development in aspen and positively impact spruce (at low levels of competition). Plot level competition indices were the best predictor of variation in aspen wood attributes, while stand level competition (population density) best explained the majority of spruce wood attributes. Maintaining aspen at lower densities in intimate mixture can have a positive effect on spruce wood quality, while incurring relatively small reductions in spruce volume production and also retaining the ecological benefits associated with managing for mixed stands.
