海河流域典型区域重金属沉积物生态风险研究

针对水库重金属污染及其生态效应问题，分析海河流域北部4座典型水库沉积物中6种重金属(As、Cr、Cu、Ni、Pb和Zn)的分布情况，并评价污染物类型的相关性。采用地累积指数法、潜在生态风险指数法和物种敏感性分布法分析4个水库沉积物中重金属的生态风险。结果表明：沙河水库、密云水库和于桥水库的重金属沉积物生态风险等级为优，官厅水库重金属沉积物生态风险等级为良。不同重金属对5%的底栖生物物种的危害质量分数(HC5)不同，由高到低依次为As(0.210 mg/kg)>Ni(0.071 mg/kg)>Cr(0.052 mg/kg)>Zn(0.050 mg/kg)>Cu(0.006 mg/kg)>Pb(0.005 mg/kg)。研究成果有助于了解水库沉积物中重金属的生态风险，为水库生态管理提供依据。

Ecological risk assessment of heavy metals in reservoir sediments of Haihe River basin based on species sensitivity distribution

With the development of industrialization and urbanization,the water environment problems in Haihe River basin are becoming increasingly prominent,and the ecological security of reservoirs is facing threats in Haihe River basin.Sediment is an important index to distinguish HJ2.2mm]water pollution status.The reservoir ecological risk level can be effectively understood through sediment ecological risk assessment.Shahe Reservoir,Miyun Reservoir,Guanting Reservoir and Yuqiao Reservoir are selected as the main research objects because of heavy metal pollution and ecological effects in reservoirs.The data on the mass fraction and toxicology of heavy metals in reservoir sediments were obtained from published articles and journals.Through the analysis of distribution characteristics and correlation analysis,the distribution characteristics and pollution sources of heavy metal sediments were judged.The geological accumulation index and potential ecological risk index were used to evaluate the ecological risk level of heavy metal sediments.Finally,the species sensitivity index was used to evaluate the proportion of potentially harmful species in heavy metal sediments.The distribution characteristics and correlation analysis results show that the distribution of heavy metals in the sediments of the four typical reservoirs are similar to some extent,and the mass fraction of heavy metals are comparable.The distribution of heavy metal deposits in reservoirs of Haihe River basin is similar to some extent,and the mass fraction of heavy metal in sediments may be affected by industrialization.The results of ecological risk analysis showed that As was the most polluted heavy metal in the sediments of the four reservoirs.The ecological risk grade of Shahe Reservoir,Miyun Reservoir and Yuqiao Reservoir is low,but for Guanting Reservoir is medium.Species sensitivity distribution showed that different heavy metals had different mass fraction of harmful mass (HC5) to 5% of benthic species.The average harmful species proportion (PAF) of heavy metals in the sediments of four typical reservoirs from high to low is Zn(97.5%)>Cu(97.1%)>Cr(96.6%)>Zn(92.2%)>Pb (91.8%)>Ni(90.8%).These results indicate that the six heavy metals in sediment may have certain effects on the survival of more than 90% of the benthic organisms in the reservoir.The overall results show that the mass fraction of heavy metals in the sediment a reservoir is relatively low,and the ecological risk level is good,but the impact of heavy metals in the sediment on the benthos of the reservoir cannot be ignored.The research results are helpful to understand the ecological risk of heavy metals in reservoir sediments and provide the basis for reservoir ecological management.