Production of A Bioflocculant by Staphylococcus cohnii ssp. from Palm Oill Mill Effuent (POME)

Abstract

Various kind of inorganic aluminum salts, represented by polyaluminum chloride (PAC), polyacrylamide (PAA) derivatives and so on have been the most widely used for water and wastewater treatment, however, health problems caused by aluminium salts, including Alzheimer’s disease, have been reported recently. Furthermore, they are not easily biodegraded in the natural environment and the monomers derived from them have both neurotoxicity and carcinogenicity. Bioflocculant is a kind of biodegradable macromolecular flocculants secreted by microorganisms. Because of their biodegradability, harmlessness and lack of secondary pollution, bioflocculants have gained much wider attention and research to date. The Staphylococcus cohnii ssp. which is isolated from the POME was found to produce a bioflocculant with high flocculating activity for kaolin suspension. Using optimized culture conditions, a flocculating activity of 70.3% was obtained in 0.4 ml of bioflocculant concentration that was incubated at a temperature of 40°C for 2 days incubation periods. It was found to be effective for flocculation of a kaolin suspension over weakly acidic pH (6-8), divalent and trivalent (Ca2+ and Al3+) enhanced the flocculating activity. This bioflocculant, possesses a good flocculating activity, which can be promoted by the addition of trivalent and bivalent cations in kaolin suspension.