MIXED LIQUOR FILTERABILITY TREATMENT IN A MEMBRANE BIOREACTOR

摘要

A membrane bioreactor (MB R) (10) uses a process and apparatus for dosing flux enhancing chemicals (FEC) to respond to temporary periods of operation that cause or are likely to cause membrane fouling. An FEC dosing device (32) is provided in communication with a channel (20) separating a process tank (12) and the membrane filtration system (14) of an MBR. A mixer (36) in the channel (20) rapidly mixes dosed FEC with mixed liquor (18) flowing into the membrane tank. The dosing device (32) is connected to sensors (40 42) sensing conditions in the channel or the membrane filtration system (14) or both. FEC is added to the mixed liquor (18) flowing into the membrane filtration system (14) considering conditions in the mixed liquor (18) flowing to the membrane unit or membrane operating parameters or both. The FEC dosage may be in the range of 0.05 to 10 mg/g MLSS. The process may include steps of initiating dosing adjusting the dosing concentration and terminating dosing.