抄録
In order to establish a methodology for the optimization of a water treatment process in terms of its total toxicity reduction, we proposed a simple method for describing changes in the concentrations of a toxic chemical and of its derivatives, and changes in the total toxicity derived from these chemicals. Dichlorvos (DDVP), an organophosphate, was selected as a model chemical, and the toxicity of the treated water was evaluated by the growth inhibition of cultured human cells. In a series of experiments, although original DDVP was rapidly degraded, its oxidation intermediate (DDVP' and DDVP'') was produced and strongly affected the total toxicity of the treated water. Changes in the concentrations of these chemicals and the total toxicity were well described by a simple numerical model. By using this model, we predicted the effects of ozone concentration, pH, and ozonation time on the total toxicity reduction during ozonation of DDVP at the level of the environmental standard. Such a methodology proposed in this work would be useful for choosing an better treatment process and also in optimizing the running conditions.
