Patent ID: 8795527

Claim:
A filtration system comprising: a plurality of vessels, at least one of the vessels containing at least one first filtration element comprising a chosen one of an ultrafiltration membrane and a microfiltration membrane, the first filtration element being in series with at least one second filtration element comprising a chosen one of a reverse osmosis membrane and a nanofiltration membrane, the vessel comprising: an inlet port for providing a liquid feed to the filtration elements; at least one outlet port for directing a permeate produced by the elements from the vessel; at least one outlet port for directing a concentrate produced by the elements from the vessel; and a backwash port for receiving permeate from at least one other of the plurality of the vessels, the permeate received from the at least one other vessel being directed simultaneously to the at least one first filtration element and to the at least one second filtration element, and wherein the vessel is configured to concurrently direct the permeate received from the at least one other vessel to the at least one first filtration element in a reverse flow direction and to the at least one second filtration element in a forward flow direction.