Electronic Thesis and Dissertation Repository

Degree

Doctor of Philosophy

Program

Civil and Environmental Engineering

Supervisor

Dr. Ernest Yanful

Abstract

Water resources around the world are under increasing pressure from the rapidly growing demands of rising population and industrialization. Furthermore, changes in global weather patterns are expected to intensify its current and future stresses. In the present study, knowledge and perceptions towards wastewater reclamation for potable and non-potable uses were investigated by the used of an on-line survey distributed amongst the university community at Western university. Subsequent statistical analysis of the results was performed using IBM-SPSS software. Survey results show that member of the university community are more likely to accept reclaimed wastewater for applications that do not involve drinking or close personal contact. However, acceptability improves when benefits to the environment are extensive, it is safe for humans, the source of reclaimed water is perceived as cleaner than municipal wastewater, and the reclaimed wastewater is put back into natural systems with long retention times such as aquifers. Knowledge of the urban water cycle and water resources in Canada is moderate among the university community and the Gamma measure of association shows that there is a moderate (0.303) positive relationship between “water knowledge” and “close contact acceptability”. The majority of the university community (75.8 %) thinks that reclaiming water to provide an alternate source of water in southwestern Ontario is a good idea, but there are still concerns with the presence of chemicals such as pharmaceuticals from reclaimed water and the long-term effects on human health from exposure to these contaminants.

Additionally, the suitability of the predominant soils of southwestern Ontario for Soil Aquifer Treatment (SAT) of secondary effluents and combine sewers overflows (CSOs) was investigated by the use of a laboratory scale SAT system operated at three hydraulic retention times. Samples were analyzed for dissolved nitrate, sulphate and phosphate ions, ammonia nitrogen, total nitrogen, total coliforms, E. coli, dissolved organic carbon (DOC), dissolved oxygen and biological oxygen demand (BOD5). Results show that prevalent soils of southwestern Ontario have the ability to further polish secondary effluents in terms of organic matter, E.coli and total coliforms. However, issues with the persistence of nitrates affects its suitability for potable aquifer recharge. Quality of CSOs was slightly improved, however sustainable SAT for non-potable or potable aquifer recharge is not achievable due to low removal of biological contamination, potential for high nitrate concentrations in the effluent and media clogging.


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