PURPOSE: To eliminate generation of N2 which may be the cause for floating of activated sludge, and reduce the NO3-N content in the treated water, by providing an NH3 form N removal process by cation exchanger just before the aeration tank, in a waste water treating plant.
CONSTITUTION: When treating waste water 1 by a known activated sludge method consisting of primary treatment sedimentation pond 2, secondary treatment aeration tank 3, sedimentation pond 4, etc., by providing a treating apparatus 8 using cation exchange resin before the aeration tank 3, the NH3-N source is captured and eliminated with ion exchanger. As a result, floatation of activated sludge in the sedimentation pond 4 derived from generation of NO3-N due to oxidation of NH3-N or generation of N2 due to reduction of NO3-N may be prevented, and, at the same time, the source of eutrophication (NO3-N) which may be the cause for red tide may be reduced.
TAKAHASHI SANKICHI
ISHIBASHI HITOSHI
ODAWARA YOUJI
KUBOTA SHIYOUJI
