练江流域(汕头)段底泥污染物分布特征及污染评价

Distribution Characteristics and Pollution Evaluation of Sediment Pollutants in Lianjiang River Basin(Shantou Reaches)

以练江流域(汕头)段为例,采用柱状底泥分层采样器采集底泥分层样品,分上层、中层、下层,检测底泥的pH值、含水率、颗粒组成、有机质、总氮、总磷、镉、铅、锌、铬、铜、镍、汞、砷,并对底泥进行污染评价。结果表明:①底泥中总氮为轻度污染;②总磷重度污染样品占46%、中度污染样品占15%、轻度污染占39%;③有机指数范围为0.002~0.12,属于清洁至较清洁范围,不存在有机质污染;④综合潜在生态危害指数范围为32~625,重危害等级样品占2%、较重危害等级占13%、中等危害等级占26%、低危害等级59%。

Shantou Reaches of Lianjiang River basin was regarded as the research object.The sediment was collected by the cylindrical sediment sampler and the samples were from upper layer,middle layer,and bottom layer.The pH value,moisture content,particle composition,organic matter,total nitrogen,total phosphorus,cadmium,lead,zinc,chromium,copper,nickel,mercury,arsenic of sediment were detected,and the sediment pollution was evaluated.The results showed that:①The total nitrogen in sediment was slightly polluted;②Total phosphorus pollution samples accounted for 46%,medium pollution samples for 15%,light pollution for 39%;③The organic index range is 0.002 to 0.12,belonging to the clean to relatively clean range,and there is no organic pollution;④The comprehensive potential ecological hazard index range is 32 to 625,the samples with heavy ecological hazard degree accounted for 2%,those with heavy ecological hazard degree accounted for 13%,those with medium ecological hazard degree accounted for 26%,and those with low ecological hazard degree accounted for 59%.