CHLORINATION OF POLLUTED WATER

Abstract

The Hindon and Ganga rivers are two major rivers of northern India. The Ganga is not only sacred to Hindus but is also a lifeline to millions of Indians who live along its course and depend on it for their daily needs. The Hindon is a tributary of the Yamuna River, which in turn is a major tributary of the Ganga. Both Ganga and Yamuna are used as a major water source for agricultural, domestic and industrial uses. The Ganges basin has a population of 400 million people and is the most heavily populated basin in the world. Nearly 57 million people depend on the Yamuna waters. The waters of these rivers are polluted due to discharge of untreated domestic and industrial- effluents. Untreated sewage, industrial effluents from paper mills, sugar mills, distilleries, slaughterhouses, dye and chemical industries, along with agricultural runoff and religious offerings cause pollution in these rivers. This results in a high rate of illness among people using the river water on a daily basis. The incidence of water-borne and enteric diseases — such as gastrointestinal disease, cholera, dysentery, hepatitis A and typhoid -among people who use the river's waters for bathing, washing dishes and brushing teeth is high, at an estimated 66% per year. Disinfection is an important step in the treatment of water used for drinking and domestic purposes. Chlorination is widely used tomake drinking water safe for use. Though chlorination has aided in the control of many water-borne diseases, it poses a health risk in that chlorination of polluted water can result in the formation of halogenated disinfection by-products which are harmful. Many disinfection by-products are proven human carcinogens. Very few studies have been carried out to observe the effects of chlorination on the waters of the major rivers in India. The objective of the present work was to disinfect water samples from Hindon river and Upper Ganga Canal. Trihalomethanes were identified and quantified and were correlated with some of the commonly estimated water quality parameters like BUD, COD, TOC and UV absorbance.