APPARATUS AND METHOD FOR TREATING WASTE WATER BY USING MICROBE

摘要

PROBLEM TO BE SOLVED: To provide an apparatus and a method for treating waste water by using a microbe, in each of which both of the amount of methanol or the like to be supplied as an electron donor in a denitrification reaction in the conventional method and the amount of waste sludge to be produced can be reduced and the running cost can also be reduced. SOLUTION: The apparatus for treating waste water by using the microbe is provided with: a nitrification tank (1) for converting ammonia nitrogen in waste water into a nitrate ion or a nitrite ion in the presence of an alkali by using aerobic nitrifying bacteria; a denitrification tank (11) for treating the nitrate ion or the nitrite ion with anaerobic denitrifying bacteria in the presence of a hydrogen donor to obtain nitrogen and the treated material; an aeration tank (21) for decomposing the hydrogen donor remaining in the treated material; a solid-liquid separation tank (31) for separating the aerated treated material into sludge and the treated liquid; and a sludge solubilization tank (41) for adding the alkali to the separated sludge to obtain a sludge solution. The obtained sludge solution is added to the nitrification tank or the denitrification tank. COPYRIGHT: (C)2007,JPO&INPIT