Biosurfactant Production using Sequencing Batch Reactor
Biosurfactants produced from Pseudomanas aeruginosa SP 4 which was isolated from a crude oil-contaminated soil were studied by using two identical units of sequencing batch reactors (SBRs). The SBR units having a liquid holding volume of 1,500 ml were operated at a constant temperature of 37°C and aseptic condition. In this study, palm oil was used as a carbon source and fish steaming waste or mineral medium was used as a nutrient source for the growth of Pseudomonas aeruginosa SP 4. At a given of an oil loading rate of 2 kg/m3d, the mineral medium gave the highest reduction of surface tension. With the mineral medium, an oil loading rate of 2 kg/m3d provided the lowest surface tension of 28.1 mN/m, corresponding to a COD reduction of 33% and an oil removal of 94%. From aeration time profile, a minimum surface tension obtained at aeration period of 8-12 h when the SBR units were operated one cycle per day (23 h for aeration, 50 min for sedimentation, 5 min for decanting and 5 min for feeding).