Full-Scale Applications of the Anaerobic Membrane Bioreactor Process for Treatment of Stillage from Alcohol Production in Japan

Kubota Corporation has constructed five full-scale anaerobic membrane bioreactor (AnMBR) systems in Japan for treatment of stillage from shochu alcohol production. These systems were commissioned from 2006 to 2008. The AnMBR process has been demonstrated to have numerous process advantages over more conventional technologies, such as superior effluent quality, and ability to handle high concentrations of COD, TSS, and FOG, while attaining high organic loading rates (10 to 15 kgCOD/m3·d).AnMBR installations typically operate at 55 °C, which provides additional benefits of higher bacterial kinetic rates and less sludge production. The flat sheet Kubota membranes ensure no biomass is lost to the effluent. COD, BOD, TSS, and FOG removals are typically over 98 percent in the AnMBR process. Despite the very high strength of alcohol stillages, the pairing of the AnMBR with an aerobic MBR (designed for biological nutrient removal), provides a twostage process that can produce an effluent with less than 10 mg/l TSS and BOD, and very low total nitrogen (TN) and total phosphorus (TP) concentrations.