滏阳河表层沉积物重金属污染现状分析及风险评价

Pollution analysis and ecological risk assessment of heavy metals in surface sediments of Fuyang River

针对海河流域重金属污染严重问题,选择海河南系滏阳河作为研究对象,研究表层沉积物中6种重金属元素(Cr、Ni、Cu、Zn、Cd和Pb)含量空间分布特征,采用富集系数(EF)和相关性探讨其来源,并利用地积累指数和潜在生态危害指数评价重金属生态风险.结果表明,滏阳河表层沉积物存在重金属污染问题,Cr、Ni、Cu、Zn、Cd和Pb平均含量分别高达142 mg·kg-1、38.2 mg·kg-1、96.2 mg·kg-1、573 mg·kg-1、0.730mg·kg-1和89.2 mg·kg-1,各元素分别超标河北省环境背景值的1.1倍、0.2倍、3.4倍、6.3倍、7.1倍和3.1倍;沉积物中Ni无重金属富集,其它元素在整个河段上存在不同程度的富集,且Cu、Zn、Cd、Pb 4种重金属元素受人为排放源影响较大.沉积物中重金属污染处于强风险等级,Cd污染达到重风险等级,其它元素处于低风险等级.滏阳河表层沉积物重金属污染主要存在于城市近郊河段以及受污染支流汇入河段.

In order to find out serious heavy metals pollution problems in the Haihe River Basin, six types of heavy metals such as Cr, Ni, Cu, Zn, Cdand Pb in the surface sediments in Fuyang River were analyzed to demonstrate the spatial characteristics and the sources by enrichment factor, andcorrelation analysis and the potential ecological risk evaluation were conducted by geo-accumulation index and potential ecological risk index. Results showthat the sediments of Fuyang River were polluted by heavy metals. The contents of Cr, Ni, Cu, Zn, Cd and Pb were 142 mg·kg-1, 38.2 mg·kg-1, 96.2mg·kg-1, 573 mg·kg-1, 0.730 mg·kg-1 and 89.2 mg·kg-1, respectively. Compared to the background of soil in the Hebei Province, Cr, Ni, Cu, Zn,Cd and Pb exceeded 1.1, 0.2, 3.4, 6.3, 7.1 and 3.1 times of the standard values. Moreover, Ni was not accumulated and the others heavy metals wereexisted accumulations in the surface sediments. Heavy metals overall were in high level of ecological risk and Cu, Zn, Cd and Pb were seriously influencedby anthropogenic sources. Cd pollution was the most serious, reaching the highest level of risk, but the other elements in the low risk level. In summary,heavy metals pollution were caused by the influences of urban rivers and polluted tributaries of Fuyang River.