Filter membranes in systems for drinking water, tertiary water treatment and combined sewage overflow, MBR and MBT are efficiently cleaned without use of air scour. In one system the membranes, preferably flat plate membranes, are cleaned by mechanically driven wipers that can clean the surfaces of two adjacent membranes simultaneously. Another system uses water jets to clean the membrane surfaces.

The invention discloses an automatic off-line gas-water combined-washing membrane bioreactor, comprising a PLC automation control cabinet, a MBR reactor, a MBR membrane assembly, a rotating hood, an annular guide rail, a lifting device, a washing pipe network, an external interface, a gas washing pipe, a water washing pipe, a gas pump and a water pump, wherein the gas pump, the water pump and the three-way change valve are all connected with the PLC automation control cabinet, the washing pipe network is provided with several nozzles. The present invention adopts a full PLC automation control system, the PLC automation control cabinet controls a pressure washing pump (gas pump and water pump), and gas or water is injected into the washing pipe network by flexibly adjusting the three-way change valve, so that the operation is simple, the cleaning is complete, and the manual operation load is reduced.

The invention discloses an automatic off-line gas-water combined-washing membrane bioreactor, comprising a PLC automation control cabinet, a MBR reactor, a MBR membrane assembly, a rotating hood, an annular guide rail, a lifting device, a washing pipe network, an external interface, a gas washing pipe, a water washing pipe, a gas pump and a water pump, wherein the gas pump, the water pump and the three-way change valve are all connected with the PLC automation control cabinet, the washing pipe network is provided with several nozzles. The present invention adopts a full PLC automation control system, the PLC automation control cabinet controls a pressure washing pump (gas pump and water pump), and gas or water is injected into the washing pipe network by flexibly adjusting the three-way change valve, so that the operation is simple, the cleaning is complete, and the manual operation load is reduced.

A water treatment system includes a source of inlet water, a prefiltration unit, a feeder, a pump, and a membrane element. The prefiltration unit is in fluid communication with the source and provides a prefiltered water to a prefiltered water line. The feeder is in fluid communication with the prefiltered water line and is positioned downstream of the prefiltration unit. The feeder is designed to deliver a chemical additive to the prefiltered water. The pump is in fluid communication with the prefiltered water line and a permeate flush line, and the pump is designed to increase a flow rate of water in a membrane feed line. The membrane element includes an inlet that is in fluid communication with the pump via the membrane feed line. The membrane element produces a permeate imparted with a first concentration of solutes and a retentate imparted with a second concentration of solutes.