Investigation of membrane-aerated biofilm reactor (MABR) for the treatment of crude oil wastewater from offshore oil platforms

Abstract

Membrane-aerated biofilm reactor (MABR) was designed to treat oilfield produced wastewater from offshore oil platform. The effects of suspended solids (SS) of influent, intra-membrane air pressure, and feed flow velocity on chemical oxygen demand (COD), oil, and ammonia nitrogen (NH4+-N) removals were investigated through a 160-d process study. The results indicate: (a) high influent SS resulted in the formation of a barrier layer containing insoluble SS on the outside surface of biofilm which significantly reduced the mass transfer of NH4+-N and organic substrates from wastewater to the biofilm; (b) under the condition of feed flow velocity of 0.01 m/s, with the increase in intra-membrane air pressure, the oxygen permeate flux of hollow fiber membrane was enhanced and NH4+-N removal efficiency at 0.12 MPa was up to 95%; (c) under the condition of intra-membrane air pressure of 0.08 MPa, with the increase in flow velocity, the performance of MABR was significantly enhanced, the best removal efficiencies of COD, oil, and NH4+-N reached 60.3, 80, and 95%, respectively, at the feed flow velocity of 0.05 m/s.