Patent ID: 7718065

Claim:
A method for treating an influent stream comprising a digestible waste, the method comprising: filtering a mixed liquor in the membrane bioreactor, wherein the mixed liquor is contacted with outer surfaces of a plurality of porous hollow fiber membranes, and wherein a permeate is removed from lumens of the membranes; removing biological solids from the membrane bioreactor by recycling a substrate containing biological solids to an offline treatment vessel via a recycle loop, whereby a preselected concentration of biological solids is maintained within the membrane bioreactor; digesting biological solids in the offline treatment vessel; and conducting an effluent stream from the offline treatment vessel to the membrane bioreactor, wherein the effluent stream comprises at least a portion of the mixed liquor, wherein the step of removing biological solids further comprises the step of passing the substrate containing biological solids through a hydrocyclone, whereby inert solids are removed, wherein the hydrocyclone is part of the recycle loop.