石梁河水库表层沉积物重金属含量与污染研究

Contents and Contamination of Heavy Metals in the Surface Sediments of Shilianghe Reservoir

沉积物重金属含量常被作为水环境质量的重要指标之一。本研究通过探讨石梁河水库表层沉积物粒度及重金属含量的分布特征,简要分析了其主要来源,并采用H9kanson潜在生态风险指数法对水库表层沉积物中5种重金属进行生态风险评价。结果表明,石梁河水库表层沉积物的粒度与金属元素的变化规律遵从"粒控效应",库区金属元素的含量数据显示V的浓度最高,而As的浓度最低;用Al校正后发现水库表层重金属元素主要为自然来源,但同时受到人类活动影响;生态风险评价结果显示单一重金属生态风险系数均小于40,所有样点的潜在生态风险指数均小于150,说明水库表层沉积物均处于轻微的生态风险等级,各种重金属元素的生态风险由强到弱顺序为As、Pb、Cu、Cr、Zn。

Heavy metal is often regarded as one of important indicators for water environment quality. Based on analyses of distribution of grain sizes and metal elements concentration in the surface sediments of Shilianghe reservoir, the source was investigated, and risk assessment of five heavy metals was conducted by using method of Hakanson potential ecological risk index. The results showed that relationship between material size and heavy metals followed the regularity of “grain size control”, the concentration of V was the highest and that of As was the lowest. Aluminum-normalized values of heavy metal elements revealed the main source was from nature, meanwhile influenced by human activities. The ecological risk factor for single heavy metal was below 40 and the potential ecological risk index under 150, indicating the risk of heavy metals was minor, and the ecological risk of five heavy metals was in the order： As〉Pb〉Cu〉Cr〉Zn.