Patent ID: 7879229
Filing Date: 2011-02-01
Classification: B01D,C02F

Abstract:
1. A wastewater treatment plant having, (a) two or more membrane tanks, each membrane tank having an inlet and a mixed liquor outlet; (b) a train of cassettes of membrane modules located in each membrane tank, the membrane modules each having a feed side in communication with the inlet and the mixed liquor outlet, and a permeate side in communication with a permeate outlet port and a source of suction; and, (c) a recycle conduit in communication with the mixed liquor outlet of each membrane tank and a region upstream of the membrane tank inlets, wherein each train has a train permeate header in communication with the permeate outlet port of each module, and the train headers are attached to a common plant permeate header which is in turn connected to a plurality of parallel permeate pumps downstream of the common plant permeate header, the plurality of parallel permeate pumps connected by their inlets to the plant permeate header and by their outlets to a common permeate pipe, wherein each train header has an isolation valve and each permeate pump may be separately turned on or off; and wherein permeate may be diverted from the common permeate pipe to a backwash circuit, the backwash circuit comprising a backwash tank in communication with the common permeate pipe, at least one backwash pump downstream of the backwash tank, and a backwash manifold downstream of the backwash pump and in communication with a train backwash header of each module.