府河-白洋淀沉积物中重金属污染特征及潜在风险评价

沉积物重金属污染是水环境污染评价的重要内容,重金属含量水平常被作为水环境质量的重要指标之一。为了掌握华北平原的府河和白洋淀中沉积物重金属的污染水平,研究了19个沉积物样品和3个土壤样品中7种重金属的污染特征,利用地积累指数法、潜在生态危害指数法及生物效应浓度法评估了重金属的环境风险,并初步分析了污染来源。结果表明,府河和白洋淀沉积物受多种重金属复合污染,其中Zn、Pb、Cu和Cd污染较为严重,府河沉积物的潜在生态环境危害强于白洋淀。相关分析显示府河和白洋淀重金属污染具有相似污染源,保定市工业废水、生活污水及府河沿岸金属冶炼企业很可能是白洋淀地区重金属的主要来源。从城市环境管理、生态环境修复、宣传教育等方面提出白洋淀区域重金属污染控制对策与建议,为白洋淀区域生态环境保护提供科技支撑。

Pollution Characteristic and Potential Risk Assessment of Heavy Metals in Surface Sediment from Fuhe River and Baiyangdian Lake,North China

Contamination of heavy metals in sediment is an essential component of environmental pollution assessment.It is also regarded as very important parameters reflecting water environmental quality.Pollution characteristics of heavy metals（Zn,Pb,Cu,Ni,Cd,Cr and As） in nineteen surface sediments and three soils from Fuhe River and Baiyangdian Lake,North China,were investigated.The potential environmental risk assessments were conducted systematically by using the Index of Geoaccumulation（Igeo）,the Potential Ecological Risk Index（RI） and Sediment Quality Guidelines（SQGs）,respectively.The potential sources of heavy metals in sediments were examined.The results showed that average concentrations of Zn,Cu,Pb and Cd in sediments from Fuhe River were 1 147.1,190.5,109.7 mg·kg-1 and 3.3 mg·kg-1,respectively,whereas these in sediment from Baiyangdian Lake were 269.4,31.3,16.3 mg·kg-1 and 0.3 mg·kg-1.The concentrations of heavy metals（Zn,Cu,Pb and Cd） in sediments from Fuhe River were higher than those of Baiyangdian Lake.The heavy metal contamination of Zn,Pb,Cu and Cd in surface sediment from Fuhe River was serious.Potential ecological risk assessments indicated that the potential risk of sediment from Fuhe River was larger than that of Baiyangdian Lake.The heavy metals in sediment sample from S3 indicated the highest total toxic units（20.93） among all the sample sites.Correlation analysis suggested that heavy metals in sediments from Fuhe River and Baiyangdian Lake might come from similar sources,which were possibly from industrial and domestic sewage discharge and the smaller metal refinery plants along the bank of Fuhe River.In view of the potential ecological risk of heavy metals in sediments from Fuhe and Baiyangdian Lake,control strategies and suggestion were provided,based on city environmental management,ecological restoration,environmental education and communication.