CHLORINATION OF TREATED SEWAGE

Abstract

To prevent the pollution of the river Ganga and to improve the water quality, an Action Plan , popularly known as the Ganga Action Plan (GAP) was formulated on the basis of a comprehensive survey of the Ganga Basin carried out by Central Pollution Control Board in 1984. Ganga Action Plan was launched in June, 1985. After completion of first phase of GAP, necessary action is to be carried out to reduce bacterial pollution of the river by way of disinfection of effluents as the entire sketch of Ganga is contaminated with bacteria of faecal origin. In this perspective, sewage treatment plant Kankhal of capacity 18 MLD (commissioned in 1995) is taken as the case study. Waste water being pumped into sewage treatment plant rages from 30-35 MLD. Therefore, has become necessary to by pass raw sewage, mix it with treated effluent. This mixed sewage is used for irrigation purpose also. To improve the hygienic quality in the sewage farm and river water quality a need has been felt to disinfect mixed sewage. The objective of the project is to disinfection of mixed sewage with chlorine. An attempt has been made to determine the chlorine dose and contact time required to bring down the pathogenic indicator organism within permissible limit as per Central Pollution Control Board (CPCB) standard.