中文摘要：

对广东云浮黄铁矿Tl污染区地表溪流水和沉积物中Tl、Cd、Cr、Pb、Ni、As、Cu、Zn的分布特征进行了调查和分析,并采用沉积物基准法、Hakanson潜在生态指数法等方法评估了重金属的环境风险.结果表明,矿区溪流各采样点水体中Tl的含量为0.19～65.25μg/L,均高于国家地表水质量标准（0.1μg/L）;沉积物中Tl、Zn、As、Cd、Pb含量分别为5.89～63.0 mg/kg、1 215～5 754 mg/kg、208.4～1 327 mg/kg、4.20～17.5 mg/kg、282～13 770 mg/kg.这些重金属含量全部高于LEL（最低效应水平）,其中Pb、As、Zn含量全部高于SEL（严重效应水平）,其它元素则大部分或部分高于SEL水平.对比沉积物质量基准（SQGs）,矿区溪流表层沉积物中的重金属含量处于中度以上污染水平,将会对水域生物产生较为严重的影响.以广东省土壤背景值作为参考标准进行分析,发现各样品点的表层沉积物均呈现出强至极强的生态风险,生态风险由强至弱的顺序依次为Tl〉Cd〉As〉Pb〉Cr〉Ni〉Zn〉Cu.沉积物中剧毒元素Tl、Cd累积较为严重,矿区沉积物是以Tl为主的生态风险,因此Tl与Cd应成为下一步重点防控的元素.

英文摘要：

Distribution of Thallium（Tl）,Cadmium（Cd）,Chromium（Cr）,Lead（Pb）,Nickel（Ni）,Arsenic（As）,Copper（Cu）,Zinc（Zn） in water and sediments of Yunfu pyrite mine area was studied.The environmental risk assessment was conducted systematically using Sediment Quality Guidelines（SQGs） and Hakanson potential ecological risk index.The results indicated that concentration range of Tl in stream water was 0.19-65.25 μg/L,which is higher than the environmental quality standards for surface water.Concentration ranges of Tl,Zn,As,Cd,Pb in sediments were 5.89-63.0 mg/kg,1 215-5 754 mg/kg,208.4-1 327 mg/kg,4.20-17.5 mg/kg,282-13 770 mg/kg.According to Sediments Quality Guidelines,sediments was moderately to severe level of pollution since concentrations of Tl,Cd,Cr,Pb,Ni,As,Cu,Zn were much higher than LEL（lowest effect level） values,and the concentrations of Pb,As,Zn were higher than SEL（severe effect level） values,the others were partly higher than SEL values,which may result in severe negative biota effects in the watersheds.Compared to soil background values of Guangdong province,the metals in stream sediment showed strong to severe strong ecological risk,and the ecological risk of heavy metals in the descending order of Tl,Cd,As,Pb,Cr,Ni,Zn and Cu.Besides,the sediments were severe contained by toxic element thallium and cadmium.Besides,the mainly ecological risk of heavy metal is thallium.More emphasis should be placed on thallium and cadmium control and disposal in future.