WASTEWATER TREATMENT METHODS USING ANAEROBIC CONDITION AND TWO STAGE ALTERING-INTERMITTENT AERATING CONDITION

摘要

PURPOSE: A sewage and wastewater treatment method using anaerobic and two stage alternate intermittent aeration is provided, which can treat nutrient salt contained in sewage and waster water continuously by keeping anaerobic-anoxic-aerobic condition in an anaerobic and two stage alternate intermittent aeration tank made in a single reaction tank. The system can solve problems of effluent ammonia nitrogen that is not oxidized at anoxic tank of the existing process. CONSTITUTION: The method is as follows: (i) feed sewage and wastewater to a treatment tank that is comparted into one anaerobic tank (11) and two alternate intermittent aeration tanks (13,16); (ii) agitate at the anaerobic tank (11) by keeping the dissolved oxygen at 0.5 mg per liter and potential difference at lower than -100mV for 1-2 hours for releasing phosphorus; (iii) conduct alternate aeration and agitation by keeping dissolved oxygen at more than 2.0 mg per liter in case of continuous aeration and at less than 0.5 mg per liter in case of aeration stopped and the potential difference at higher than 0 mV in case of continuous aeration and at 0-100 mV in case of aeration stopped for 2-4 hours for aerobic and anoxic conditions respectively, the time interval being 30-90 min. for inducing nitrification, denitrification, excess intake of phosphorus and induce increasing of settling of facultative microorganism; (iv) separate solid liquid of facultative microorganism, a part of which being recycled to treatment tank for keeping concentration of microorganism, the residue sludge being discharged; and (v) keeping the retention time at 10-30 days and the concentration of microorganism at 2000-4000 mg per liter.