Development and microbial community analysis of a biological treatment process for edible oil effluent

Abstract

Globally, wastewaters emanating from edible oil manufacturers contain high organic (BOD & COD) and phosphate loads and known for creating shock-loading problems for the receiving wastewater treatment installations. Discharge of poor quality final effluents also negatively impact on and cause eutrophication of natural water sources such as rivers and dams. In South Africa, a large concentration ofthe edible industries are localized in the Pietermaritzburg region of Kwa-Zulu Natal and have been regularly associated with discharge of poor quality final effluent that did not subscribe to municipal regulation standards. Current treatment of choice for wastewater's in the edible oil industry have been limited primarily to dissolved air flotation combined with the use of chemical coagulants or physical separation of oil and grease via a gravity fat trap and subsequent pH correction. These physico-chemical methods have achieved limited success and the emulsified grease tends to clog sewer pipes and pumps producing poor quality effluents. Therefore, the aim of the current research was to develop suitable treatment technology focussing on adapting activated sludge process to remediate edible oil effluents and determine the microbial community of the process using novel molecular techniques.