3种乡镇生活污水处理工艺的对比分析

Comprehensive analysis of 3 kinds of processes for township domestic sewage treatment

以四川省3座乡镇生活污水处理厂为例,基于2023年2~12月的运行数据,分析了BOD5、COD、NH3-N、TN、TP、色度和悬浮物的进出水浓度,讨论了A^(2)/O、A^(2)/O+MBBR和生物转盘工艺的运行和净化效果。结果表明,研究期间3种工艺的出水浓度均能满足GB 18918—2002《城镇污水处理厂污染排放标准》一级A标准;A^(2)/O+MBBR工艺强化了反硝化和硝化过程,进而显著提升了对生活污水的脱氮效果,而A^(2)/O工艺和生物转盘工艺对TN的平均去除率仅为63.21%和48.85%;3种工艺中,污染指标的去除率从高到低顺序为A^(2)/O+MBBR工艺、A^(2)/O工艺和生物转盘工艺;生物转盘工艺的吨水投资及运行费用均最低,其次为A^(2)/O+MBBR和A^(2)/O工艺。综合去除效果和投资及运行成本,A^(2)/O+MBBR工艺可认为是处理乡镇生活污水的优势工艺。

Taking 3 township domestic sewage treatment plants in Sichuan province as examples,the colority and the concentrations of BOD5,COD,NH3-N,TN,TP and SS in the influent and effluent water were analyzed based on the operating data during February to December 2023.The operation and purification effect of A^(2)/O,A^(2)O+MBBR and biological rotating disc process were discussed.The results showed that,the effluent pollutants concentrations of the three processes during the study period could all meet the requirement of level A grade 1 in GB 18918—2002 Discharge standard of pollutants for municipal wastewater treatment plant.The A^(2)/O+MBBR process strengthened the denitrification and nitrification process,and thus significantly improved the denitrification effect of the municipal wastewater,while the average TN removal rates by A^(2)/O process and biological rotating disc process were only 63.21%and 48.85%respectively;the pollutants removal rates by the above three kinds of processes followed the descending order of A^(2)/O+MBBR,A^(2)/O and biological rotating disc process.biological rotating disc process has the lowest investment and operating costs,followed by A^(2)/O+MBBR and A^(2)/O processes.Combining the pollutants removal effect,investment and operation cost,A^(2)/O+MBBR process is considered as the dominant process of township domestic sewage treatment.