METHOD FOR PREVENTING MALODOR FROM BEING GENERATED IN WASTE WATER TREATMENT

PURPOSE:To prevent malodor from being generated by adding iron based chloride and sulfate, as a flocculant, or adding calcium carbonate compounded slaked lime, as a filter aid, respectively, in a dewatering process. CONSTITUTION:A solution 1 of iron based flocculant comprising iron based chloride and sulfate is mixed at a first mixing tank 2 to effect a reaction. Thereafter, an emulsion 4 of calcium carbonate compounded slaked lime is added to the reaction liquid at a second mixing tank 3 to effect a reaction. And pH is adjusted in a range of about 6-8. By this method, hydrogen sulfide in sludge is reacted with the flocculant 1 so as to be turned to stable solid suspension of hydrogen sulfide, and pH can be maintained in a neutral region. Consequently, ammonia is prevented from being discharged. Further, by being dehydrated by means of a pressure dehydrator 5, the suspension is separated into dehydrated cake and filtrated liquid. At this moment, since malodorous substances have been turned into stable matters, even if they are brought into gas-liquid contact, the malodorous substances are not discharged into the air.