生物接触氧化法-人工湿地处理常低温生活污水

BCO-constructed wetland treatment of domestic sewage under normal and low temperatures

采用生物接触氧化法(BCO)-人工湿地组合工艺处理常低温生活污水,当BCO的气水比为7∶1、回流比为100%、人工湿地的水力停留时间(HRT)为9 h,人工湿地的水力负荷(HLR)为3. 65 m3/(m2/d)时,在常温下(22~27℃),组合工艺出水COD、NH_4^+—N、TN和PO_4^(3-)—P分别为14. 60、1. 40、12. 70和0. 43 mg/L,出水满足《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级A标准;而低温下(7~12℃),组合工艺出水COD、NH_4^+—N、TN和PO_4^(3-)—P分别为29. 60、9. 90、19. 90和0. 88 mg/L。保持气水比和回流比不变,控制低温下BCO的HRT为12 h,人工湿地的HLR为2. 74 m3/(m2/d)时,组合工艺出水COD、NH_4^+—N、TN和PO_4^(3-)—P为18. 40、6. 17、14. 17和0. 66 mg/L,去除率分别为90. 60%、87. 80%、75. 40%和85. 30%。结果表明:常、低温下该组合工艺均能够实现污染物的良好去除,为实际工程应用提供参考。

The combined process of BCO -constructed wetland was applied to treat domestic sewage under normal and low temperatures.When the ratio of air to water was 7:1,the ratio of reflux was 100%, the hydraulic retention time (HRT)was 9h and the hydraulic load rate (HLR)of constructed wetland was 3.65m3/(m2/d),the combined process effluent concentrations of COD,NH4^+-N、TN and PO4^3--P were 14.60,1.40,12.70and 0.43mg/L respectively at normal temperature (22-27℃),which could meet the first class A standards of "Discharge standard of pollutants for municipal wastewater treatment plant"(GB 18918-2002)of China.At low temperature (7-12℃),the combined process effluent concentrations of COD,NH4-N,TN and PO4^3--P were 29.60,9.90,19.90 and 0.88mg/L respectively. When the ratio of air to water and reflux remained unchanged,the HRT of BCO at 12h and the HLR of constructed wetland of 2.74m^3/(m^2/d),the combined process effluent concentrations of COD,NH4^+- N,TN and PO4^3--P were 18.40,6.17,14.17and 0.66mg/L,the corresponding removal rates were 90.60%,87.80%,75.40%and 85.30%.The results showed that the combined process could achieve a good removal of pollutants under normal and low temperatures,which provided a theoretical basis for practical engineering applications.