Development of chlorine dioxide-related by-product models for drinking water treatment

grantor: University of TorontoStatistically-designed factorial experiments were conducted using 'synthetic' waters to examine the effects of various physical/chemical parameters on chlorine dioxide-related disinfection by-product formation. 2-level factorial experiments were then performed on 7 surface waters and a groundwater collected in Ontario to develop statistically-based model equations capable of predicting chlorine dioxide consumption, chlorite and chlorate formation when dosing with chlorine dioxide. These equations were developed in terms of pH, temperature, chlorine dioxide concentration, reaction time and water organic content. Interaction effects involving the aforementioned parameters were also included in the model equations, improving the accuracy of the predictive equations in fitting measured levels as evaluated through internal and external validations. Chlorine-dioxide dose and water organic content were found to be key parameters in developing the predictive equations. Improved correlations between chlorine dioxide consumption, chlorite and chlorate formation with changes in UV$\sb{254}$ were found to exist on a site-and parameter-specific basis.M.A.Sc