Pentair’s decades of experience with membrane technology have led to highly reliable AnMBR designs. Submerged membrane units have been abandoned in favor of external installation, making it easy to inspect, clean, and maintain the membranes. The bioreactor thus never needs to be opened, which goes a long way in solving odor issues. X-Flow tubular membranes are used for the solids-liquid separation step, providing an effluent without TSS and retaining all of the biomass inside the bioreactor.
In July 2017, Deschutes initiated a pilot study to verify that Pentair’s AnMBR technology is capable of handling the levels of COD and TSS created by spent hops and yeast residuals. The pilot also served to identify the organic loading rate, the MLSS concentration, and ideal sludge retention time to minimize the footprint without sacrificing effluent quality and membrane performance. Before designing the ideal full-scale system for the Deschutes Brewery, the team had to determine the membrane flux rate, crossflow velocity, filtration cycle, backwash interval, and chemical cleaning frequency.