分流两段式土壤渗滤系统脱氮效果及机理研究

为解决传统土壤渗滤系统占地面积过大的问题，采用多级土壤渗滤系统和地下渗滤系统组合的新型两段式污水处理工艺，研究了在高水力负荷0.3m/d条件下分流比对其脱氮效果的影响，并通过实时定量PCR技术对不同层级的脱氮功能基因数量进行检测，进一步探究该系统中微生物脱氮机理.水质监测结果表明，分流措施可以显著提高两段式土壤渗滤系统在高负荷下的脱氮能力，当分流比为1：2时系统污染物去除能力最佳，对化学需氧量（COD）、总磷（TP）、氨氮（NH₄⁺-N）、总氮（TN）的平均去除率分别达到91.16%、96.91%、72.11%和72.27%.脱氮功能基因丰度分析结果表明，多级土壤渗滤系统中的硝化及厌氧氨氧化和地下渗滤系统中的硝化反硝化的耦合作用是该工艺微生物脱氮的主要途径.

Nitrogen removal performances and mechanisms in a two-stage soil infiltration system by shunt distributing wastewater

In order to solve the problem of large footprints of traditional soil infiltration systems, a two-stage soil infiltration system consisting of a multi-soil-layering (MSL) system and a subsurface wastewater infiltration (SWI) system was developed. The influences of different shunt ratios on nitrogen removal performances were investigated under a high hydraulic loading rate (HLR) of 0.3m/d. And the abundances of nitrogen functional genes in different layers were also analysed by real-time quantitative PCR for further disclosing the nitrogen removal mechanisms. The results showed that the shunt distributing wastewater certainly improved the nitrogen removal under high HLRs. The optimal removal efficiencies of 91.16% for COD, 96.91% for TP, 72.11% for NH₄⁺-N and 72.27% for TN were obtained in the system with shunt ratio of 1:2. Furthermore, the study on nitrogen functional genes indicated that nitrification and anammox in the MSL system coupled with nitrification and denitrification in the SWI system were the main nitrogen removal pathway in the two-stage soil infiltration system.