NITRIFICATION AND DENITRIFICATION APPARATUS BY BIOFILM FILTRATION METHOD

摘要

PROBLEM TO BE SOLVED: To reduce consumption of hydrogen donator by microbial aspiration and to prevent the hydrogen donator from streaming ununiformly and its injection pipe from clogging by providing fixed bed filter media on a lower part of a filter and fluidized bed carriers on an upper part of the filter and leading raw water in upward stream from the lower part of the filer in a nitrification denitrification apparatus by a biofilm filtration method. ;SOLUTION: The body of a cylindrical filter 2 is filled with non-fluidized bed filter media 4 on the lower part and with fluidized bed carriers 3 on the upper part, wherein porous ceramics having specific gravity of 2.4 and average particle size of 4mm is used for the non-fluidized bed filter media 4 and polypropylene having specific gravity of 1.05, adjusted by addition of talc, and average particle size of 3mm is used for the fluidized bed carriers 3. While a raw water inlet pipe 1 is connected to the bottom face of the filter 2, a hydrogen donator-injecting pipe 11 is connected to right above the bed of the non-fluidized bed filter media 4 and the raw water is allowed to pass through the non-fluidized bed filter media 4 and the fluidized bed carriers 3 from the lower part of the filter 2. Thereby the raw water is nitrified and denitrified to be treated water and allowed to pass through a treated water outlet pipe 5 and to discharge to a treated-water storage tank 6.;COPYRIGHT: (C)1998,JPO