SIMULATION OF CHLORINE DECAY IN WATER DISTRIBUTION NETWORKS USING WATERCAD-CASE STUDY

摘要

Deterioration of water quality in distribution networks has a great impact on human health and public acceptance of tap water reaching them. Residual chlorine should be maintained through network pipes to prevent contamination and microbial regrowth. This paper investigates the ability of WaterCAD V8XM to simulate residual chlorine decay through water networks, taking water-age analyses into consideration, and assesses the feasibility of using it as a measuring and controlling tool to estimate . and predict chlorine concentration at different water network points. A study was performed on drinking water network of 6th of October city, where field measurements were done, while data required as program inputs were taken from the daily records of the 6th of October and El-Shaikh Zayed WTPs. The network model was calibrated to minimize error in program results. Errors were evaluated using statistical analyses. The calculated concentrations by the calibrated model were very close to the actual concentrations measured in field at different sampling points for different sampling days. Moreover, WaterCAD showed that for the water network concerned in this study there is high possibility that chlorine concentrations become lower than 0.20 mg/L at network extremities when water-age exceeded 10 hrs, which may call for using re-chlorinating points to raise safety margins.