Biodegradation of Effluents from Dairy Plant by Bacterial Isolates

Abstract

<em>Micro flora of the effluents from a dairy factory in Tehran(Pegah</em> <em>Dairy Processing Plant) were isolated and screened for their ability to reduce the organic matter content and COD of the effluents. 10 bacteria were selected due to reduction in COD content from the 4th to 6th day of incubation at 30 °C and pH =11. Highest COD reduction were obtained by two isolates, BP₃ and BP₄, 70.7 % and 69.5 %,, respectively (The initial COD concentration was 3000 mg/l and reduced to 880 and 920 mg/l).After optimization of the condition for test organisms, big reductions in COD, carbohydrate, fat and protein content of the effluents were observed by BP₃ up to 84.70 %, 98 %, 45.30 % and 53 %, respectively .The mixture of BP₃ and BP₄ did not show the good results as the BP₃ alone .Therefore, BP₃ has been selected as the most efficient microorganism for the system.The</em><em>overall</em><em>efficiency of the system will</em><em>be increased if it is added to</em><em>anaerobic activated</em><em>sludge tank.</em>