JPS5681195A - Denitrification process of sewage - Google Patents

Abstract

PURPOSE: To decontaminate a sewage in a simple installation without necessity of methanol addition, by dividing one reaction vessel to an aerobic reaction zone and an anaerobic reaction zone, reducing BOD of and nitrificating-denitrificating the sewage in said zones, and returning a sludge from a precipitation vessel to the reaction vessel.

CONSTITUTION: A primary treated water solution 80 is charged in a reaction vessel 71, where the solution is reduced of its BOD value and nitrificated by the operation of a rotary disc 77 at the upper aerobic oxidizing zone 78. Then a sludge split from the disc 77, a sludge returned from a precipitation vessel 73, and the nitric and nitrous nitrogen generated by the nitrification are contacted together in a lower anaerobic denitrification zone 79 of the vessel 71, so that denitrification is carried out using as an organic carbon source the sludges themselves and organics in the solution to be treated. The operation of the aerobic and anaerobic reactions is repeated in each reaction chamber 76, to facilitate the denitrification. The mixture of the solution and the sludge discharged from the vessel 71 is treated in a second aeration vessel 72 and carried to the precipitation vessel 73. In the vessel 73, the sludge separated from the solution is returned to the vessel 71. The returned sludge cntains a lot of denitrificating bacteria, and acts as a main component for the denitrification.

COPYRIGHT: (C)1981,JPO&Japio