WASTE-WATER TREATMENT APPARATUS AND METHOD USING MEMBRANE BIO-REACTOR WITH COMPATIBLE ANOXIC/ANAEROBIC ZONE

摘要

An apparatus and a method for wastewater treatment using a membrane bioreactor with a compatible anaerobic/anoxic zone are provided to effectively eliminate nutrients such as nitrogen, phosphorous and the like contained in the influent by properly supplying return sludge into a reactor according to load fluctuations of influent. An apparatus for wastewater treatment using a membrane bioreactor with a compatible anaerobic/anoxic zone is a combination of a pre-denitrifying tank, a first anaerobic-anoxic compatible tank, a second anaerobic-anoxic compatible tank, and a membrane bioreactor, wherein the pre-denitrifying tank functions to remove nitrite nitrogen and nitrate nitrogen contained in influent and sludge returned from the membrane bioreactor, wherein the first anaerobic-anoxic compatible tank functions as an anoxic tank while the second anaerobic-anoxic compatible tank functions as an anaerobic tank when the influent has a nitrogen concentration higher than a phosphorous concentration, and the first and second anaerobic-anoxic compatible tanks function as an anaerobic tank when the influent has the phosphorous concentration higher than the nitrogen concentration; and the membrane bioreactor conducts a function of converting organic nitrogen and ammonia nitrogen into nitrite nitrogen and nitrate nitrogen, digesting phosphorous released by phosphorous-accumulating microorganisms, and returning the produced nitrite nitrogen and nitrate nitrogen to any one of the pre-denitrifying tank, the first anaerobic-anoxic compatible tank, and the second anaerobic-anoxic compatible tank.