Investigation of the efficiency of dairy wastewater treatment using lipid-degrading bacterial strains

Abstract

Dairy industry is considered as the largest producer of wastewater in the food industry in many countries. Dairy wastewater contains high concentrations of nutrients, organic and inorganic constituent. Therefore, discharging untreated/partially treated dairy wastewater causes serious environmental problems. Biological treatment methods show the highest efficiency for treating dairy wastewater. Aim of the present study was to identify indigenous bacteria capable of degrading dairy wastewater efficiently. Bacterial isolates were tested individually and in combinations using synthetic wastewater medium, incubated at 30 °C, for 2 days and Chemical Oxygen Demand (COD), pH, free fatty acid content, cell growth rate and the lipase activity were obtained at 6 hr time intervals for 36 hours. All the tested bacteria along with the consortium exhibited lipid degradation as well as removal of organic matter. Pseudomonas aeruginosa showed the highest activity in lipid degradation and COD reduction to 250mgO2/ltr at 12 hours.