Abstract: A waste water treatment process for biologically removing phosphates incorporates a membrane filter. The process includes three zones, an anaerobic zone, an anoxic zone and an aerobic zone containing an anaerobic, anoxic and aerobic mixed liquor. Water to be treated flows first into the anaerobic zone. Anaerobic mixed liquor flows to the anoxic zone. Anoxic mixed liquor flows both back to the anaerobic zone and to the aerobic zone. The aerobic mixed liquor flows to the anoxic zone and also contacts the feed side of a membrane filter. The membrane filter treats the aerobic mixed liquor to produce a treated effluent lean in phosphorous, nitrogen, BOD OR COD, suspended solids and organisms at a permeate side of the membrane filter and a liquid rich in rejected solids and organisms. Some or all of the material rejected by the membrane filter is removed from the process either directly or by returning the material rejected by the membrane filter to the anoxic or aerobic zones and wasting aerobic sludge.

Abstract: A waste water treatment process for biologically removing phosphates incorporates a membrane filter. The process includes three zones, an anaerobic zone, an anoxic zone and an aerobic zone containing an anaerobic, anoxic and aerobic mixed liquor. Water to be treated flows first into the anaerobic zone. Anaerobic mixed liquor flows to the anoxic zone. Anoxic mixed liquor flows both back to the anaerobic zone and to the aerobic zone. The aerobic mixed liquor flows to the anoxic zone and also contacts the feed side of a membrane filter. The membrane filter treats the aerobic mixed liquor to produce a treated effluent lean in phosphorous, nitrogen, BOD OR COD, suspended solids and organisms at a permeate side of the membrane filter and a liquid rich in rejected solids and organisms. Some or all of the material rejected by the membrane filter is removed from the process either directly or by returning the material rejected by the membrane filter to the anoxic or aerobic zones and wasting aerobic sludge.

Abstract: A waste water treatment process for biologically removing phosphates incorporates a membrane filter. The process includes three zones, an anaerobic zone, an anoxic zone and an aerobic zone containing an anaerobic, anoxic and aerobic mixed liquor. Water to be treated flows first into the anaerobic zone. Anaerobic mixed liquor flows to the anoxic zone. Anoxic mixed liquor flows both back to the anaerobic zone and to the aerobic zone. The aerobic mixed liquor flows to the anoxic zone and also contacts the feed side of a membrane filter. The membrane filter treats the aerobic mixed liquor to produce a treated effluent lean in phosphorous, nitrogen, COD, suspended solids and organisms at a permeate side of the membrane filter and a liquid rich in rejected solids and organisms. Some or all of the material rejected by the membrane filter is removed from the process either directly or by returning the material rejected by the membrane filter to the anoxic or aerobic zones and wasting aerobic sludge.