Abstract
This paper examines the method of managing the concentration of residual chlorine for stabilized and safe supply of high quality drinking water. In order to understand the complicated behavior of residual chorine concentration within water supply and distribution systems, simulations using water pipelines information's GIS (Geographic Information System) were conducted to study the behavior and examined for the purpose of reducing residual chlorine through adequate management of residual chlorine concentration.
The east- south water supply main line and its 4 water distribution areas (Nishi-Mizue, Kasai, Koto and Toyozumi) located in eastern Tokyo were used as the model of this study. Residual chlorine concentration simulations were conducted and analyzed with focus on the distance between the water purification plant and the end of the water distribution pipeline network. We compared residual chlorine between the survey date from water distribution areas and the estimated value applied our simulation model. The reduction of residual chlorine in the purification plant was then quantitatively evaluated.
A further scenario involving the installation of the chlorine-injection devices at each water station in the 4 distribution areas was also analyzed. The results revealed the effect of chlorine dosage reduction through adding chlorine, as well as the effect of equalizing the concentration of residual chlorine within the water supply areas.
