粪便污水与城市污水同步脱氮的优化控制

Characteristics of nitrogen removal by consolidated treatment of nightsoil sewage and municipal wastewater

采用倒置A2/O工艺,以实际粪便污水与城市污水同步脱氮为目标进行试验。试验条件下得到,混合污水同步脱氮的临界氨氮污泥负荷为0.019 8 kg.kg-1.d-1;水力停留时间是混合污水脱氮的限制因素;污泥回流比对硝化和反硝化影响最弱;水温28～35℃时,混合污水同步脱氮最佳工况氨氮污泥负荷为0.018 kg.kg-1.d-1、水力停留时间为8 h、溶解氧浓度为2.0 mg.L-1、污泥回流比为80%、混合液回流比为150%、泥龄为20 d。此时,NH4+-N和TN去除率分别为97.0%～99.4%和61.4%～68.7%,出水可达标排放。

With inverted A2/O process, We tried to remove the nitrogen from the actual fecal sewage and urban sewage simultaneously. Under optimal experimental conditions, nitrogen load for simultaneous removal of the critical mixture from the sewage sludge is 0.019 8 kg.kg^-1.d^-1. Hydraulic retention time is the controlling factor for mixed sewage removal. Sludge recycle ratio affects the nitrification and denitrification is weakest. In the water temperature of 28--35 ℃, the best condition for synchronized denitrification from the mixture of sewage nitrogen is as follow： Ammonia sludge load 0.018 kg.kg^-1.d^-1; HRT, 8 h; dissolved oxygen, 2.0 rag-L^-1; returned sludge ratio, 80%; return ratio of mixed liquor, 150%; sludge retention time, 20 d. In this condition, ammonia and nitrogen removal rate are 97.0%-99.4% and 61.4%-68.7 %, respectively. The discharged effluent could be fully treated and reached the standard.