Optimal Design of a Booster Chlorination System for a Drinking Water Distribution Network Using EPANET and PSO

摘要

In booster chlorination, the chlorine is reapplied at strategic locations to achieve the uniform chlorine concentration within the water distribution network. The only source chlorination provides uneven residual chlorine at various locations in the network covering large area. The critical nodes are identified by developing response coefficient matrix using EPANET. EPANET is used to simulate the flow hydraulics and residual chlorine in the network. It uses first order reaction kinetics to simulate the chlorine decay. At selected locations chlorine mass rate range provides solution space for particles in PSO. The objective is to minimize the total mass rate of chlorine application in the network. The minimum residual chlorine and its maximum values are maintained by introducing penalty terms. Distribution network of Vadodara City area of India is selected for the application of model. The junction nodes of network feeding micro network to consumer end are monitored for residual chlorine. Maximum two booster stations are proposed to be selected and the coupled model is used to find their locations and mass rate of chlorine injection in conjunction with the source chlorination mass rate. The residual chlorine concentrations are obtained for optimum solution and results are compared with that obtained for conventional source chlorination. It is observed that reduction of more than 30% is achieved in booster chlorination strategy as obtained by optimization model. The suggested strategy also results in uniform distribution over conventional approach. The reduction in chlorine in the network also helps reducing disinfection by products.