The Effect of Organic Loading Rate on the Performance of Membrane Bioreactor Used for the Treatment of Synthetic Oilfield Wastewater

Oil field wastewater or produced water is a significant waste stream in the oil and gas industries. It contains high concentrations of hydrocarbon constituents and different salts. In this study, amembrane bioreactor (MBR) was used to treat synthetic produced water using consortia of isolated halophilic bacteria from oil-contaminated saline soils at SRT 80 day and TDS 64 g L-1.The MBR was evaluated in terms of biodegradation of hydrocarbons in the synthetic producedwater with various organic loading rates (OLR) (0.3, 0.6, 0.9, 1.2, and 1.7 kg COD m-3 day-1) and membrane performance. With increase in OLR from 0.3 to 1.7 kg COD m-3 day-1, COD and O&Gremoval efficiency increased from 84% and 85% to 91% and 98%, respectively. Also there was nomembrane fouling during 173 days of operation of MBR. This high COD and O&G removal efficiency may be mainly credited to the good capability of the isolated halophilic bacterial culture and the retention of dispersed oily material by membrane. Based on the results, the treated water from MBR is suitable for re-injection and discharge to sea.

کلیدواژه ها:

Produced water ، membrane bioreactor ، organic loading rate ، halophilic bacteria