山林地表慢渗系统处理农村生活污水厂尾水研究

利用山区污水处理厂周边森林植被构建慢速渗滤污水处理系统,用来处理山区农村生活污水厂尾水。结果表明,慢渗系统能够深度净化污水尾水,对COD_(Cr)、NH_3-N、NO_3-N、TN、TP的平均去除率分别为23.8%、40.2%、14.3%、11.3%和23.6%。并且土层越深,COD_(Cr)、TN、TP浓度越低,相应的去除率越高,而NO_3-N、TN去除率则呈降低趋势;山体坡度越大,COD_(Cr)、氨氮浓度有升高趋势,硝态氮、TN、TP有降低趋势;而坡长越大,COD_(Cr)、NH_3-N、NO_3-N、TN浓度有降低趋势,TP有升高趋势。此外,植被类型对水样化学性质有一定影响,竹林更利于COD_(Cr)、NH_3-N、TP浓度的降低,针阔混交林更利于NO_3-N、TN浓度的降低。

Study of the Treatment of Tail Water from Rural Domestic Wastewater Treatment Plants by Forest Surface Infiltration System

In this study, a slow infiltration sewage treatment system was constructed by using the surrounding forest vegetation in mountain to treat tail water from rural domestic wastewater treatment plants. The result showed that the slow infiltration system could deeply purify the tail water, and the average removal rate of CODcr, ammonia nitrogen (NH3-N), nitrate nitrogen (NO3-N), total nitrogen (TN) and total phosphorus (TP) was 23.8%, 40.2%, 14.3%, 11.3% and 23.6% respectively. When the soil layer was deeper, the concentrations of CODCr, TN and TP were lower and the corresponding removal rates were higher, but the removal rate of NO3-N and TN showed a decreased trend. When the slope of mountain increased, the concentrations of CODcr and NH3-N increased, but those of NO3-N, TN and TP decreased. Moreover, as the slope length increased, the concentrations of CODcr, NH3-N, NO3-N and TN decreased, but that of TP increased. Additionally, vegetation types had certain effects on the chemical properties of water samples. Bamboo forest was more conducive to the concentration reduction of CODcr, NH3-N and TP, while mixed coniferous and broad-leaved forests were more conducive to the concentration reduction of NO3-N and TN.