Feasibility study on petrochemical wastewater treatment and reuse using a novel submerged membrane distillation bioreactor

Treatment of wastewater from a petrochemical industry has been investigated using a novel submerged membrane distillation bioreactor (MDBR). A bench scale MDBR system with flat sheet membranes was used in the study. The testing system ran continuously (24-h) over 105 days. Membrane cleaning was conducted when the permeate flux decreased to less than 5.5 L/m(2) h. The results showed that MDBR product quality consistently met the requirements of NEWater of Singapore except for a slightly higher total organic carbon (TOC). The membranes were found to be thermally stable, and good separation characteristics were maintained throughout the whole period of the investigation. A permeate flux of 5.5-8.6 L/m(2) h for more than a month without membrane cleaning was achieved despite variations in the feed wastewater. The flux decline was mainly due to inorganic fouling of the membranes. Membrane permeability could be recovered by chemical cleaning. It was concluded that it was feasible to treat and reuse the wastewater using submersed MDBR technology. (C) 2010 Elsevier B.V. All rights reserved.