武江(乐昌段)水体底泥重金属污染调查

Investigation on Heavy Metal Pollution in the Surface Sediments on Lechang Section of Wujiang River

对武江乐昌段由上游矿山废水排泄沟、中游霜降河和下游武江段3段水道底泥中Pb、Zn、Cu进行测定。结果表明,Pb的质量比为2.54×103mg/kg、1.33×103mg/kg和30.7 mg/kg,Zn的质量比为1.01×103mg/kg、2.48×103mg/kg和156 mg/kg,Cu的质量比为42.9 mg/kg、68.8 mg/kg和69.4 mg/kg。3段支水道底泥污染负荷指数(IPL值)分别是14.0、10.6和1.46,整个区域IPL值为6.19,达到极强度污染程度。Pb、Zn总体污染程度比Cu严重,对武江乐昌段及其下游地区存在潜在生态风险。指出,霜降河和废水排泄沟段底泥不能农用,需特别谨慎地疏浚、转运和处置,而武江段底泥则可农用。

The Pb, Zn and Cu were detected in the surface sediments on upriver of wastewater drainage canal from Lechang mine, the middle river of Shuangjiang stream and downriver of Wujiang river. The results indicated that rates between heavy metal concentration and national control standards for the Pb in sludge were 2.54 × 10^3 mg/kg, 1. 33 × 10^3 mg/kg and 30.7 mg/kg, that for the Zn 1. 01 ×10^3 mg/kg, 2.48 ×10^3 mg/kg and 156 mg/kg,that for the Cu 42.9 mg/kg, 68.8 mg/kg and 69.4 mg/kg. The pollution load index （IpL） of surface sediments on the 3 parts of Wujiang river was 14.0, 10.6 and 1. 46 separately and showed heavy pollution. The sediments on the upriver and Shuangjiang stream could not be directly used for agriculture and should be carefully dredged, transported and treated. The sediments on the downriver of Wujiang river could be used for agriculture. The pollution levels of Pb and Zn were higher than that of Cu and it posed potential ecological risk for the local and downriver areas of Wujiang river.