滦河口沉积物重金属分布及生态风险评价

对2013年滦河口近岸海域33个表层沉积物重金属(Cu、Pb、Zn、Cr、Cd和Hg)分析,研究了重金属的分布特征和污染状况。结果表明,重金属高值区主要分布在砂质粉砂和粉砂质砂等细粒沉积物覆盖的河口和南部区域,明显受粒径制约,与2007年相比,2013年的重金属含量要高得多,高值区中心更加靠近河口位置。富集因子结果表明,Cu、Zn和Cr主要来源于岩石的自然风化与侵蚀过程,Cd和Hg既有来自岩石的自然风化与侵蚀过程,也有一部分受人为影响,Pb主要受人为活动影响。河流输入和沿岸排放是重金属的主要来源,潜在生态风险评价结果显示,重金属总体污染程度和生态风险程度均较低。

DISTRIBUTION OF HEAVY METALS IN SURFACE SEDIMENTS OF THE LUANHE RIVER ESTUARY AND ECOLOGICAL RISK ASSESSMENT

Thirty-three surface sediment samples from the Luanhe River Estuary have been analyzed for heavy metals of Cu, Pb, Zn, Cr, Cd and Hg in order to reveal their spatial distribution and make evaluation of contamination. Higher heavy metal concentrations are found at the river mouth and southern areas covered by sandy silt or clayey silt. Compared with the data collected in 2007, the high value heavy metals zones of 2013 become closer to the estuary. The study of enrichment factors indicates that Cu, Zn and Cr, which are mainly derived from the natural weathering of rocks, are not enriched and Cd and Hg are partly enriched in minor to moderate amount under the influence of both the natural and the anthropogenic sources. Pb was mainly derived from the anthropogenic sources. Fluvial input and coastal discharge are the primarily sources of these heavy metals. Risk assessment shows a low degree of contamination and ecological risk in the region.