METHOD FOR SIMULTANEOUSLY REMOVING PHENOL, AMMONIACAL NITROGEN AND NITRATE NITROGEN IN WASTE WATER

摘要

PROBLEM TO BE SOLVED: To provide a technique by which the phenol, ammoniacal nitrogen and nitrate nitrogen contained in the waste water discharged from the petroleum refining, heavy oil reforming, thermal cracking, etc. ;SOLUTION: The raw water contg. phenol, ammoniacal nitrogen and nitrate nitrogen is treated by a biological circulation-type nitrating and denitrifying method. In this case, the water to be treated is passed successively through a denitrification tank 1 packed with a suspended filter medium 3 on which phenol-resistant bacteria are immobilized and acclimatized and the nitration tank 2 packed with the suspended filter medium 4 on which nitrating bacteria are immobilized and acclimatized and treated, a part of of the water at the outlet of the nitration tank 2 is obtained as the treated water, a part of the treated water at the outlet of the tank 2 is circulated to a treated water tank 6 through a water dividing tank 5, the raw water and the circulating water are mixed and treated in the denitrification tank 1, and the water is controlled to pH6.5 to 9.0 and the weight ratio of the chemical oxygen demand to nitrate nitrogen to 2 to 10.;COPYRIGHT: (C)1998,JPO