图们江中游表层沉积物的重金属污染特征与生态风险评价

Pollution characteristics and its ecological risk assessment of heavy metals in the surface sediments from middle reaches of Tumen River

采用电感耦合等离子体质谱法（ICP-MS）测定了图们江中游表层沉积物中As、Cd、Cr、Co、Cu、Ni、Pb、Zn的含量,并对其生态风险进行了评价.研究表明：表层沉积物中8种重金属的浓度在0.48~241.81mg/kg之间,平均浓度的高低顺序为As、Pb、Zn、Cu、Ni、Cr、Co、Cd;8个采样点中,白龙（T5）、日光（T6）、图们公园（T7）3处采样点的污染较为严重;地积累指数（Igeo）评价结果显示,污染程度的高低顺序为Pb、Cd、Cu、As、Ni、Co、Zn、Cr,其中Pb和Cd呈中度污染,As和Cu呈偏中度污染;生态风险系数（Eir）评价结果显示,8种重金属元素的潜在生态风险指数（RI）在215.6~349.3之间,其高低顺序依次为Cd、Pb、As、Cu、Ni、Co、Cr、Zn,其中Cd呈强生态风险,除图们下游（T8）采样点是中等潜在生态风险外,T1-T7采样点都属于强生态风险.

The contents of As, Cd, Cr, Co, Cu, Ni, Pb and Zn in surface sediments from middle reaches of Tumen River are detected by Inductively Coupled Plasma Mass-Spectrometry （ICP-MS）. The ecological risks of each heavy metals are evaluated. The mean concentration of 8 heavy metals is between from 0. 48-241. 81 mg/kg. The levels of heavy metals in surface sediments followed the order, As, Pb, Zn, Cu, Ni, Cr, Co, Cd. Among 8 sampling points, the White Dragon（T5）, the Daylight （T6） and the Tumen Park （T7） are more seriously contaminated. Ph and Cd are moderately polluted, As and Cu are partial moderately polluted by geo-accumulation index （Igeo）, the pollution extent of heavy metals followed the order, Pb, Cd, Cu, As, Ni, Co, Zn, Cr. Cd is highly risk by the potential ecological risk factors （E~）, the possible ecological risk index is Cd, Pb, As, Cu, Ni, Co, Cr and Zn. The possible ecological risk indexes （RI） of 8 heavy metals at all sampling points are 215.6-349.3. The heavy metals in the surface sediments from middle reaches of Tumen River is high ecological risk among the sampling point （T1-T7）, however, the lower reaches of Tumen （T8） is moderate potential ecological risk.