信江流域底泥重金属溯源与评价

The Tracing and Evaluation of Heavy Metals in Sediment of Xinjiang River Basin

目前江西省信江流域(鹰潭段冶炼区)支流的底泥重金属底数不明,给地方生态风险评价及污染治理带来不确定性.为解决该区域在环境管理中的不足,该文构建了污染物工业排放耦合系数fCCPE指标,用以评估污染物排放的底泥压力并佐证了底泥重金属的来源,结合传统的地累积指数及潜在生态风险指数评估了金属冶炼区周边灌溉水底泥的重金属污染程度.研究结果显示:在冶炼区周边底泥中各种金属fCCPE>1,这表明冶炼厂周边的底泥重金属主要来源于铜冶炼活动;在各村镇底泥中Cu含量由大到小依次为长塘村(421.91 mg·kg^(-1))>邱家村(164.07 mg·kg^(-1))>江南村(134.76 mg·kg^(-1))>黄坑村(101.23 mg·kg^(-1))>龙石村(40.11 mg·kg^(-1))>版上村(14.59 mg·kg^(-1)).在各村镇底泥中Cu和Pb比的fCCPE值由大到小依次为邱家村(8.13)>长塘村(7.94)>江南村(3.69)>黄坑村(3.50)>龙石村(3.12)>版上村(0.68).地累积指数表明金属冶炼区在周边底泥中Cd处于轻度污染;在灌溉水底泥中重金属Cr、Mn、Ni、Cu、Zn、As、Cd和Pb生态危害系数(Ei,r)平均值分别为0.55、0.67、3.53、35.12、1.45、11.17、313.87和4.49.综合潜在生态风险指数(RI)为370.85,生态危害程度强.建议对风险超标的底泥及时进行管控和治理.

The profiles of heavy metals in branch sediment around the Xinjiang river basin′s tributaries(Yingtan smelting area)in Jiangxi are unknown still,which brings rather confusion on assessing the ecological risk and controlling the pollution.To make up the deficiencies of the management,index of pollutant emission coupling coefficient f CCPE is created,which can be used to reflect the environmental pressure from the industrial emissions,along with the traditionally indexes both geo-accumulation(I geo)and ecological risk are taken to evaluate the pollutant levels.The findings reveal that indexes f CCPE coefficient>1 is mainly located in the smelting area,indicating that heavy metals in the sediment around the smelting plant are affected by industrial activities.The levels of sediment′s Cu of the villages are listed as follow:Changtang(421.91 mg·kg^(-1)),Qiujia(164.07 mg·kg^(-1)),Jiangnan(134.76 mg·kg^(-1)),Huangkeng(101.23 mg·kg^(-1)),Longshi(40.11 mg·kg^(-1))and Banshang(0.68 mg·kg^(-1)).Index I geo shows that the sediment Cd around the smelting area is slightly polluted,and the average values of the potential ecological hazard coefficients(E i,r)of the heavy metals Cr,Mn,Ni,Cu,Zn,As,Cd and Pb in the irrigation sediment are 0.55,0.67,3.53,35.12,1.45,11.17 and 313.87,respectively,with the whole ecological risk index 370.85 that is a strong ecological hazard level.It is suggested that the sediment with excessive risk should be controlled and treated in a timely manner.