Abstract：
As an important water purification and seepage measure for sponge cities, biofiltration systems have been widely used in their construction in China. In order to identify the heavy metal accumulation, pollution, and its potential environmental risk in the biofiltration systems, this study examined the heavy metal contents and spatial distribution characteristics by taking the biofiltration systems of Yuelai new town, Chongqing, the first demonstration area of sponge city construction in China, as the research object, and conducted a risk evaluation of the pollution level and ecological environment in this new town using the contamination factor (CF), geo-accumulation Index (Igeo), and potential ecological risk coefficient (PERC). The results showed that, except for Mn, the average contents of Cu, Zn, Pb, Ni, and Cd in the biofiltration systems of Yuelai new town were 4.14, 1.77, 4.98, 1.23, and 6.51 times higher than the soil background values of Chongqing. In terms of spatial distribution, the contents of heavy metals in biofiltration systems along the roads in different functional areas showed great differences. The contents of Cu, Zn, Mn, Pb, Ni, and Cd in the industrial area were significantly higher than those of the same types of heavy metals in the biofiltration systems in other areas (P<0.05). The CF and Igeo showed that the pollution level of heavy metals was ranked as follows:Mn
摘要：
作为海绵城市重要的净水和防渗措施,生物过滤系统在我国的建设中得到了广泛的应用。为了识别重金属的积累，污染,以及其在生物过滤系统中的潜在环境风险，本研究采用悦来新城的生物过滤系统，考察了重金属含量和空间分布特征，重庆,中国首个海绵城市建设示范区,作为研究对象,并利用污染因子(CF)对该新城的污染水平和生态环境进行了风险评价,地质积累指数(Igeo)，和潜在生态风险系数(PERC)。结果表明,除了锰，铜的平均含量，Zn,Pb,Ni,岳来新城生物过滤系统中Cd和Cd分别比重庆土壤背景值高4.14、1.77、4.98、1.23和6.51倍。在空间分布方面,不同功能区道路生物过滤系统中重金属含量差异较大。Cu的含量,Zn,Mn,Pb,Ni,工业区域的Cd和Cd含量明显高于其他区域的生物过滤系统中相同类型的重金属（P<0.05）。CF和Igeo表明重金属的污染水平如下：Mn
