海绵城市生物滞留带重金属污染特征及风险评价  

Pollution Characteristics and Risk Assessment of Heavy Metals in the Bioretention Systems of Sponge Cities

作　　者：雷晓玲[1,2] 邱丽娜 魏泽军 杨程 何博 LEI Xiao-ling;QIU Li-na;WEI Ze-jun;YANG Cheng;HE Bo(Hehai College,Chongqing Jiaotong University,Chongqing 400074,China;Chongqing Institute of Science and Technology,Chongqing 401123,China)

机构地区：[1]重庆交通大学河海学院,重庆400074 [2]重庆市科学技术研究院,重庆401123

出　　处：《环境科学》2022年第8期4127-4135,共9页Environmental Science

基　　金：重庆市技术创新与应用示范专项重点研发项目(cstc2018jszx-zdyfxmX0010);重庆市技术预见与制度创新项目(cstc2017jsyj-zdcxBX0065);重庆市社会民生科技创新专项项目(cstc2016shmszx30024)。

摘　　要：生物滞留带作为海绵城市重要的净水和渗水措施,在全国海绵城市建设中得到了广泛的应用.为了探明生物滞留带重金属累积、污染和可能存在的环境风险,以全国首批海绵城市建设示范区重庆市悦来新城生物滞留带为研究对象,探讨其重金属含量与空间分布特征,利用污染系数、地质累积指数和潜在生态风险指数进行污染水平和生态环境风险评价.结果表明,悦来新城生物滞留带中除Mn外,Cu、 Zn、 Pb、 Ni和Cd的含量平均值均超出重庆市土壤背景值的4.14、 1.77、 4.98、 1.23和6.51倍.空间分布上,不同功能区域道路旁的生物滞留带重金属含量呈现出较大差异性,工业区道路生物滞留带中Cu、 Zn、 Mn、 Pb、 Ni和Cd的含量均显著高于其他区域生物滞留带中的同种类重金属含量(P<0.05).污染系数和地质累积指数显示重金属的污染水平排序为:Mn<Zn<Ni<Cu<Pb<Cd,其中Cu和Pb为高度污染,Cd为重度污染,且Cd的单个潜在生态危害系数为194.13,处于高度风险,其余重金属均为轻微风险,Cd对综合生态危害指数的污染贡献率为78.73%,其为重金属潜在风险的主要来源.海绵城市生物滞留带长期运行后,因填料内重金属的积累,后期存在一定环境生态风险,需加强运行管理,开展生物滞留设施填料无害化治理研究,防止其成为新型的城市重金属污染源.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(I_(geo)),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 I_(geo) showed that the pollution level of heavy metals was ranked as follows:Mn<Zn<Ni<Cu<Pb<Cd.Among them,Cu and Pb were highly polluted,Cd was severely polluted,and the PERC of Cd was 194.13,which indicated a high risk;the remaining heavy metals were at a minor risk.The pollution contribution of Cd to the composite PERC of all heavy metals was 78.73%,which was the major source of heavy metal potential risk.After the long-term operation of the biofiltration systems in a sponge city,certain environmental and ecological risks may exist later due to the accumulation of filler heavy metals.Hence,it is necessary to strengthen the operation management and carry out research on the non-polluted management of the filler of biofiltration facili

关 键 词：海绵城市 生物滞留带 重金属污染 地质累积指数(I_(geo)) 潜在生态风险指数(PERC) 

分 类 号：X52[环境科学与工程—环境工程] X820.4