根据上海市土壤层的特点,设计了不同结构的生态浅层渗滤中试系统,测定其对路面径流的长期净化效果及净化机制.研究结果表明:不同结构的人工模拟渗滤系统对径流污染物均具有较好的净化效果,并表现出良好的耐冲击负荷能力.COD的去除率大多都在60％～80％；NH3-N出水浓度多数在1.3 mg/L以下,去除率基本在50％～70％；NO2--N去除率大多都在80％～90％,出水浓度基本在0.1 mg/L以下；下设有原状土垫层的渗滤系统对NO3--N去除效果明显好于无原状土垫层的渗滤系统.除部分重金属、COD和NO2- -N外,经渗滤后的径流出水浓度大大低于上海地区浅层地下水的背景值.硝化和反硝化作用是系统去除氮的主要途径；土壤的吸附与沉淀作用是渗滤系统去除有机物和重金属的重要途径.%According to the soil horizon characteristics of Shanghai City, a bio-filtration pilot experiment system with different structures was designed and its long-term treatment effect on the runoff and the mechanism of the treatment were studied The results showed that the different artificial bio-filtration system could purify stormwater runoff efficiently and the systems had strong resistance to shock load The COD removal rate was about 60%~80%. The effluent concentration of NO2--N and NH3-N were below 0.1 mg/L and 1. 3 mg/L, with the removal rate about 80%~90% and 50% ~70% respectively. In the bio-filtration system with native soil at the bottom layer, the effluent NO3--N concentration was obviously lower than that of the bio-filtration system with construction wastes at the bottom layer. Except for some heavy metals, COD and NO2--N most pollutants concentrations in effluent after filtration were much lower than their background values for subsurface water in Shanghai. The main removal mechanism for nitrogen was biological nitrogen removal through nitrification and de- nitrification. Organic matter and heavy metals in the runoff were mainly removed by fixation processes in the soil such as adsorption and chemical precipitation.
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