Reducing COD Level on Oily Effluent by Utilizing Biosurfactant-Producing Bacteria

Two bacteria isolated from crude oil contaminated soil, Pantoea agglomerans and Planococcus citreus, produced biosurfactants utilizing 1.5 % of kerosene and olive oil as the sole carbon sources, respectively. The bacteria and the biosurfactants produced were introduced to oily effluent, arising from margarine and soap industry. Emulsification activities were determined by increases in the absorbance of the oil-in-water emulsions at 610 nm, whereas the water-in-oil emulsions were expressed as the height (cm) of the emulsion layers formed. The 72 h incubation experiment resulted in a COD (Chemical Oxygen Demand) reduction of 76 % with Planococcus citreus strain and 70 % with Pantoea agglomerans.The COD reduction with bacterial biosurfactants was over 50 % in 24 h of incubation. The COD reduction showed that these strains and the surfactants produced could be used in bioremediation processes