Central Department of Environmental Science, Tribhuvan University
Dairy industries convert raw milk into safe products for human consumption. Cleaning of all pipelines, equipments, machines, Cans; startup, products change, overhead shutdown, pasteurizers and loss in filling operations contribute wastewater generation in dairy industry. So the composition of waste water involves a substantial concentration of fat, milk, protein, lactose, lactic acid, minerals, detergents and sanitizers. The prime objective of this study is to analyze effects of such effluent on stream water discharging directly into it. The study has conducted on a stream which has been receiving dairy effluent from Sita Ram Gokul Milk Industry for years. Water samples at 200 m upstream from discharge point, at discharge point and 200 m downstream were collected in July of 2005, 2007, 2009 and 2011 A.D. All water quality parameters were negatively affected due to discharge of effluent. DO has depleted severely from its original concentration of 6 mg/l to 1 mg/l. BOD values i.e. 214 mg/l to 220 mg/l have in far more elevated level than national standard. COD, Nitrates and phosphates concentration are also in elevated level.