Treatment Efficiency Enhancement of Dairy Effluent by Bioaugmentation Using Bacterial Species

Abstract

Dairy wastewater mainly contains biodegradable pollutants and generally treated by using biological processes. Bacterial species plays vital role in reducing nutrients and organic waste concentration from dairy effluent to permissible limit. Activated sludge process is most commonly used for biological treatment but it has few treatment problems that lower down its efficiency, which can be increased by bioaugmentation of specific bacterial species and growing them by providing favorable environmental conditions within the system. Studies are carried out in search of bacterial species which can effectively remove particular pollutant from wastewater. Lot of researches emphasizes the importance of various bacterial species in treatment of wastewater emerging from different categories of industries. Efficiency of conventional activated sludge process can be increased by adding specific kind of bacterial species. The present study was carried out to test efficiency of lipase producing bacteria like bacillus subtilis and pseudomonas aeruginosa for the treatment of dairy wastewater. A lab scale model of aeration tank with the provision of diffused aeration was developed. Study was carried out to test the performance of reactor inoculated with pure culture of individual bacterial species in removal of different parameter including Turbidity, BOD and COD. Treatment efficiency in terms of COD removal for individual species of bacteria was studied for the period of 14 days. The Pseudomonas aeruginosa offered highest COD removal efficiency for dairy wastewater, which was 84.2%.