PURPOSE: To efficiently remove nitrogen in a short time even when the concentration of organic substance soluble in waste water is low and furthermore to eliminate the need for a precipitation tank.
CONSTITUTION: Waste water is successively passed through a denitrification tank 1 and a nitrification tank 4 and a nitrogen component in waste water is biologically removed. In the method for removing nitrogen in waste water, a polymer carrier 3 inclusively immobilized with denitrification bacteria and a polymer carrier inclusively immobilized with acid forming bacteria are packed in a denitrification tank 1. A polymer carrier 6 inclusively immobilized with nitrification bacteria is fluidized in the nitrification tank 4. A part of treated water discharged from the nitrification tank 4 is circulated to the denitrification tank 1 and also suspended organic substance in waste water is trapped in the gaps of the carrier immobilized with acid forming bacteria and the carrier immobilized with denitrification bacteria in the denitrification tank 1. The suspended organic substance is converted into the soluble organic substance by the function of the acid forming bacteria propagated between these carries. Furthermore nitrogen oxide contained in treated water circulated to the denitrification tank 1 is reudced to gaseous nitrogen by using the soluble organic substance as an organic carbon source.
OTAKE YASUTOMO
SUMINO TATSUO
MORI NAOMICHI
| JPS5929092A | 1984-02-16 | |||
| JPS5775192A | 1982-05-11 |