Analysis On Commission And Operation Of Combined ABR -High Rate Tricking Filter Processes For Wastewater Treatment

The paper analyses the commission and operation of combined anaerobic baffled reactor (ABR)-aeration-high rate trickling filter processes used for a municipal wastewater treatment plant in the north of China. The plant had run since May, 2006. After commission for 3 months, effluent reached Grade 2 of"Discharge standard of pollutants for municipal wastewater treatment plant"(GB18918-2002). PhaseⅠproject check was up to grade. No waste sludge was discharged during continuous operation for 6 months. The practical operation shows that the combined processes have many advantages under the normal inffluent condations, such as stable treatment performance, good effluent quality, low civil engineering cost, low operation cost, good tolerance for shock loading, a little sludge production etc. They have good treatment effect for low strength wastewater as well. The processes are cost-effective for municipal wastewater treatment plant in small town.The performance of the wastewater treatment plant was not perfect during October and November, and laboratory test was carried out. Elastic filler biological contact oxidation method was used to treat wastewater from the plant. The test was divided into 2 phases. In the first phase, it was difficult to reach effluent standard during hydraulic residence time ranged from 1h to 4h. By investigation, it was found that much river water of alkaline soil from agricultural drainage trench flowed into wastewater pipelines by mistake, and changed quality of the wastewater, and biodegradability was very bad(BOD5/CODcr<0.15～0.1). The test was turned to the second phase after adjusting pipelines. Influent accorded with characteristics of representative municipal wastewater at the time. During hydraulic residence time ranged from 1h to 4h, CODcr fell from 120～150mg/L to 70mg/L or so, BOD5 from 40～60mg/L to10～20mg/L,ammonia nitrogen from 30～40mg/L to 20mg/L below. Under the existing conditions, it is suggested that aeration tank should be modified to elastic filler biological contact oxidation tank according to the experiment results. It would have a rather big reinforcement effect for the treatment system of the plant.