Biodegradation of dairy effluent by using microbial isolates obtained from activated sludge

Water resources are of significant importance to human beings. The present investigation was carried out for biodegradation of dairy effluent by using selected aerobic microbial isolates and a model having layers of sawdust and activated charcoal as filtering media. Yeast isolates (DSI1) and two bacterial isolates (DSI2 and DSI3) were obtained from the dairy sludge. A mixed culture (DSI4) was prepared by taking 1:1, DSI1 and DSI3 to treat the effluent and check its efficiency. After aeration period of 48 h, mixed culture of dairy sludge isolates proved to be most efficient in treatment of effluent. DSI2 showed least reduction in chemical oxygen demand. After aeration, the reduction efficiency of DSI4 was highest by 47.52% in biological oxygen demand in comparison with other isolates. DSI3 was second most effective in reduction of water parameters mainly electrical conductivity, totals solids, chemical oxygen demand and biological oxygen demand.