The optimization of chlorine dose in water treatment process in order to reduce the formation of disinfection by-products

The main threat to human health is associated with organic compounds, which are found in the natural water ecosystem. The law relating to drinking water quality protects consumers' health. Thus, the need to remove disinfection by-products (DBP) precursors requires the application of high-efficient water treatment processes. Usually, chlorine is used to disinfection, and then, haloforms are generated. Well-calibrated model, estimating the concentration of DBP in treated water, can be a useful tool for predicting the quantity of trihalomethanes in water in the distribution network. Such a model makes it also possible to identify the critical control points in the monitoring process. This paper presents the statistical analysis of chloroform formation in treated water, based on laboratory tests. The chloroform concentration is expressed as a function of factors, which determine kinetics of the chemical reaction of organic compounds with chlorine. Two new variables-the ratio of total organic carbon and chloroform and the ratio of chlorine consumption and chlorine dose, both obtained after 1 h of the reaction-were taken into account. From the function predicting the chloroform concentration, one can determine the optimal dose of chlorine in the disinfection of water in dynamic operational conditions.