多级土壤渗漏系统处理农村生活污水

构建了多级土壤渗漏系统（MSL）以处理农村生活污水,主要研究了MSL的挂膜启动特征,进水水力负荷对MSL处理生活污水性能的影响,以及MSL运行过程中生物膜的特征.实验结果表明,采用连续进水的方式挂膜28d后,挂膜成功,MSL对生活污水中COD,氨氮,TN,TP的去除率分别达到84.5%,74.7%,66.7%,76.4%.MSL运行过程中,表现出对进水水力负荷变化较强的适应性,水力负荷为400L/（m²·d）时,生活污水中COD,氨氮,TN,TP的平均去除率分别达到93.4%,94.9%,80.4%,94.7%,系统出水水质能够满足城镇污水处理厂污染物排放标准（GB18918-2002）一级A标准.MSL对有机物和氮磷的去除途径结果表明,微生物降解和转化作用对污水中COD,氨氮,TN的去除贡献率最大,Fe³⁺与PO₄^3-的化学沉淀作用则是TP去除的主要途径.实时荧光定量PCR技术检测结果显示,生物膜中硝化功能菌占总菌群的35.5%.

Multi soil layering filter and its performance in rural domestic sewage treatment

The MSL was constructed to treat rural domestic wastewater. Biofilm colonization, effects of hydraulic loading rate (HLR) on the treatment of domestic wastewater by the MSL, and biofilm characteristics during the working process of the MSL were investigated. The biofilm colonization was success after 28d of influent by "continuous manner", and at this moment, removal efficiencies of COD, ammonia, TN and TP reached 84.5%, 74.7%, 66.7%, and 76.4%, respectively. During the treatment process of the domestic wastewater, the MSL exhibited a strong adaptability on the variation of HLR. The average removal efficiencies of COD, ammonia, TN, TP reached 93.4%, 94.9%, 80.4%, and 94.7%, respectively, which meet to the 1A discharge standard of the Discharge standard of pollutants for municipal wastewater treatment plant (GB 18918-2002), when the HLR was adjusted to 400L/(m²·d). Pathways of the removal of COD, ammonia, TN and TP by the MSL showed that the biological decomposition and biotransformation processes of microorganisms were the most important pathway for the removal of COD, ammonia, and TN, while TP was mainly removed by the chemical reaction with iron irons. q-PCR showed that the nitrifying bacteria in the biofilm were about 35.5% of the total flora.