赣江南昌段表层水和底泥中重金属污染状况及其风险评价

摘要

为揭示鄱阳湖流域中赣江南昌段表层水和底泥重金属空间分布及污染特征,采用潜在生态危害指数法、地累积指数法对重金属进行风险评价.结果表明:赣江表层水中重金属质量浓度均远低于《地表水环境质量标准GB3838—2002》的一级标准限值.赣江南昌段底泥中重金属w(Cu)、w(Pb)、w(Cd)、w(Zn)、w(Cr)、w(As)的平均值分别为 29.509、22.372、2.341、22.092、20.203、11.671 mg/kg.整个赣江南昌段的RI平均值为 144.21,总生态风险水平属于很高,其中八一大桥 2 个断面RI分别为 169.89 和 192.38,已成为潜在生态高风险区域,根据地累积指数法评价得出赣江重金属污染程度表现为Cu>Cd>Pb>As>Cr>Zn,其中 Cu、Cd是主要污染物,相关部门应采取紧急措施,加强对赣江环境管理和污染治理力度.%To reveal the spatial distribution of heavy metal pollution and sediment characteristics in the surface water of Poyang Lake basin in the Nanchang section of Ganjiang River,the experimental study was carried out for the risk assessment of heavy metals by using the potential ecological risk index and geo-accumulation index.The results show that the heavy metal concentration in surface water of Ganjiang River is far lower than"surface water environmental quality standard GB3838—2002".The average contents of the heavy metal in the sediment of Nanchang section of Ganjiang River,such as w(Cu),w(Pb),w(Cd),w(Zn),w(Cr),w(As), were 29.509、22.372、2.341、22.092、20.203、11.671 mg/kg.The RI average value in the Nanchang section of Ganjiang River is 144.21,the total ecological risk level is very high.The RI value of 2 sections of the Bayi Bridge are 169.89 and 192.38,which has become a high potential ecological risk area.According to the evaluation index of geo-accumulation,the heavy metal pollution in the Ganjiang river takes the form of Cu>Cd>Pb>As>Cr>Zn,among which Cu and Cd are the main pollutants.