An Overview of the Design Principles of Drinking Water Chlorination

The goal of drinking water chlorination is the inactivation of pathogenic organisms in water. It offers the advantage of producing residuals useful for the preservation of water quality in a distribution system. Basic key chlorination concepts include chlorine demand/decay, chlorine residuals, and CT disinfection. The application of these concepts required a good understanding of the hydraulic condition of the system. Important consideration is the determination of initial required chlorine dose. A demonstration model using a public school water supply scheme with an overhead tank is done. This incorporates the kinematic of Contact Time (CT) disinfection, and the application of a demand model for the determination of initial chlorine concentration/dose required. Optimal application of chlorine will prevent incidences of either an over-dose or under-doze which highlight the importance of this study. Keywords— chlorine demand, CT Disinfection, initial chlorine concentration, log removal value, residual concentration