To provide a biological deodorization method and an apparatus therefor, wherein a deodorizing performance of an odorant gas containing NH3, of a high concentration with a large variation of concentration is easily stabilized with low cost and also a water quantity consumed and a water quantity discharged can be lowered.
The biological deodorization method is composed of a circulation style of nitrification and denitrification method, wherein the odorant gas 1 containing NH3 is contacted 7 with a circulation water 5 in a nitrification step 3 and NH3 contained is absorbed to be biologically nitrification-treated by nitrifying bacteria, and also this nitrification liquid 5 is guided to a denitrification step 4 and the denitrification-treated liquid is again returned 9 as the circulation water 5 to the nitrification step . In this deodorization method, a pH buffer solution is used as the circulation water 5, wherein the pH buffer solution is a phosphate buffer solution or a carbonate buffer solution, and also the said pH buffer solution can be controlled by feeding a reagent such that a pH of the circulation water is in the range of 6.0 and 7.5.
YAMASHITA SHIGEKI
NISHII TAKANORI
