Start Up and Commissioning Of a Membrane Bioreactor Plant Treating a High TDS Refinery Wastewater

Biological treatment of refinery wastewater is a common practice around the world. However, the situation at the Bahrain Petroleum Company (BAPCO, closed) Refinery, in Awali, Bahrain, presents several unique features, which make biological treatment of this wastewater challenging. These include stringent discharge limits, especially for nitrogen and phosphorus, along with high salinity (Total Dissolved Solids concentration of approximately 27,000 mg/l) and high temperature (up to 48°C). Moreover the management of the spent caustic was needed. An extensive study was conducted to confirm that the pre-identified technology of membrane bioreactor (MBR) was able to achieve the needed effluent quality. Based on this study, a MBR process was designed and built. This paper provides description of the rationales for the treatment technology selection, an overview of the full-scale wastewater treatment plant (WWTP), startup and commissioning challenges during acclimation of biomass to high TDS and nitrogen removal and results of the performance test.