Minimizing Drinking Water Contaminants - Natural, Anthropogenic & By-products of Treatment

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The ULTIMATE GOAL of much of my research is to facilitate the provision of safe drinking water to all, particularly in regards to minimizing chemical contaminants that are of potential human health concern. Even at trace levels, several contaminants in drinking water have known or suspected human health effects. Nitrosamines, for example, can exert carcinogenic effects at ng/L (parts-per-trillion) concentrations and can be present either in the raw water or are formed as by-products of disinfection. Certain pharmaceuticals can also find their way into our drinking water treatment plant intakes, usually as a result of upstream wastewater discharges (especially in heavily urbanized areas). They are not readily removed by conventional treatment processes, and while their direct effects are thought to be minimal some of them can be transformed during treatment into the nitrosamines mentioned above. In addition, some trace contaminants such as the compound known as `mutagen X', although discovered as a chlorination by-product more than 20 years ago, is currently being re-examined for its potential health impacts and treatability.*******The proposed research program's MAIN OBJECTIVE is to discover and report on factors which improve the removal of trace contaminants from water and/or minimize by-products formed from the disinfection or oxidative treatment of water when using conventional and/or innovative treatment processes. SECONDARY OBJECTIVES include considerations of treatment process efficiencies such that, for example, protocols for solar treatment may be developed for use in remote locations in North America or in developing nations.*******The SCIENTIFIC APPROACH of the research is to characterize and quantify contaminant destruction and by-product formation resulting primarily from UV-based and solar-based irradiation and advanced oxidation, to compare with the results from chlorination and chloramination. Some of this work employs novel, solar-sensitive photocatalytic materials that have been developed during recent collaborative projects. Some testing also employs newly available toxicological tests, also made possible through recent collaborations.*******This work is UNIQUE AND SIGNIFICANT in that it involves: (i) the examination of emerging contaminants of potential human health concern, (ii) the investigation of conventional and innovative treatment processes (e.g. advanced oxidation, photocatalysis) as a means to remove them (iii) significant direct participation of end users, allowing the information obtained to be more directly applied by Canadian municipalities, consultants, regulatory personnel and researchers than might otherwise be possible. With substantial reductions being contemplated for regulated levels of many by-products, results of this research will also be essential in regulatory negotiation and compliance.***