Patent KR-20030087673-A (KR)
Title: Organic Acid Producing Facility for Advanced Biological Nutrient Removal, and Facility and Method of Hybrid of Sludge & Nutrient Removal (HSNR) by the OAPF
Inventor: AHN JAE HWAN
IPC: C02F11/18
Filed: 2002-05-09
Abstract: PURPOSE: Provided is an organic acid producing facility provided to a sludge thickener of a sewage treatment system for producing organic acid, thereby reducing sludge production by oxidizing waste sludge in a sludge thickener using the organic acid and removing nitrogen at low cost by using the organic acid as carbon source, and further provided are an advanced sewage treatment method using the same apparatus. CONSTITUTION: The organic acid producing apparatus comprises a reaction tank which is sealed and stores excess sludge passing out a sludge thickener, a heater for heating the reaction tank to a predetermined temperature, an oxygen supply unit for supplying oxygen to the reaction tank for oxidizing the sludge in the reaction tank, a cooling unit for producing organic acid from the waste sludge by cooling inside of the reaction tank. The advanced sewage treatment apparatus comprises a sludge thickener(11), an organic acid producing facility(12) storing thickened sludge and thermally oxidizing the sludge at high temperature and high pressure therein, thereby producing organic acid, an anaerobic tank(17) for receiving decant water of a sedimentation tank and sludge returned from a settling tank, and releasing phosphorous in the sludge using organic material in inflow sewage, a denitrification tank(19) for receiving phosphorous-released sludge from the anaerobic tank(17) and decant water from the organic acid producing facility(12) and reducing nitrate in the sludge returned from an aeration tank using the organic acid in the decant water from the facility(12), and the aeration tank(21) for nitrifying the mixed sludge from the denitrification tank(19) and producing nitrate-rich sludge, in which a part of the sludge is returned to the anaerobic tank(17) and the other part of the sludge is returned to the sludge thickener(11). The method comprises the steps of transporting thickened sludge to a thermal oxidizing tank; oxidizing the thickened sludge at a predetermined temperature and pressure while supplying oxygen to the thermal oxidizing tank and mixing the sludge; transporting organic acid produced by the thermal oxidizing tank to a storage tank; transporting decant water of the organic acid to a denitrification tank; releasing phosphorous in sludge which is returned from a settling tank using organic material in decant water of a sedimentation tank; reducing nitrate to nitrogen gas using the organic acid after receiving the decant water of the storage tank, phosphorous-released sludge from an anaerobic tank and nitrified sludge from an aeration tank in the denitrification tank, and transporting reduced sludge to the aeration tank; and eliminating organic material from mixed sludge introduced into the aeration tank, nitrifying the mixed sludge introduced into the aeration tank and returning the nitrified mixed sludge to the denitrification tank, and solid/liquid separating in the settling tank and returning a part of the sludge to the anaerobic tank and the other part of the sludge to a sludge thickener.