The First Two Years of Full-Scale Anaerobic Membrane Bioreactor (AnMBR) Operation Treating High-Strength Industrial Wastewater

Abstract

The anaerobic membrane bioreactor (AnMBR) incorporates anaerobic digestion and membrane filtration in one process to form an innovative technology for treating high-strength industrial wastewater. The first AnMBR installation in North America, also known as the largest AnMBR installation in the world, was built at Ken's Foods in Massachusetts, USA. Ken's Foods existing anaerobic process was upgraded to AnMBR in July 2008 to treat raw wastewater from the production of salad dressings and barbeque sauces. The system was converted to AnMBR due to lack of space, positive economics, and the ability to provide additional capacity for flow and organic load beyond the original anaerobic system design parameters. This AnMBR system has a design influent flow rate of 475 m3/d with 39,000 mg/l COD, 18,000 mg/l BOD, and 12,000 mg/l TSS. The AnMBR system consistently produces a high quality effluent with non-detectable TSS concentrations and average COD and BOD concentrations of 210 and 20 mg/l, with removals of 99.4 and 99.9 percent, respectively. The AnMBR system provides superior performance and a very low rate of membrane fouling with the aid of biogas scour across the membrane surface. The first 20 months of AnMBR operating expenses were reduced by 50 compared to the prior 12-month fiscal period due to increased system capacity, ability to treat wastewater with higher biomass, and elimination of the need to dewater and dispose of dewatered solids.