万峰湖水体和沉积物中汞的污染现状及风险评价

摘要

pollution status and spatial distribution of mercury in the water and sediment at the Wan-feng Lake were analyzed in this paper. The single-factor index method was adopted to evaluate the mercury pollution degree in water ,and the geo-accumulation index and the potential ecological risk index were applied to assess the pollution degree and the ecological risk of mercury in sediments. The results showed that,in 11 sampling spots,mercury in water ranged from ND-0. 034μg·L-1 and the average content was 0 . 014 μg · L-1 which conformed to the national surface water quality Ⅲclass standard. Mercury in sediments ranged from 0. 039-0. 358 mg·kg-1 and the average content was 0. 169 mg·kg-1 . Along the sampling route,from Sanjiankou to Hongcun Dock,mercury con-tent in water had the same distribution trend with that of in sediment. The single-factor index meth-od showed that the level of mercury in water of Wanfeng Lake was very low ,and the geo-accumula-tion index and the potential ecological risk index showed that in sediments,mercury pollution was not found in 82% of surveyed sediments,and ecological risk in 45% was in a low level.%分析了万峰湖水体和沉积物中汞的污染现状以及汞含量分布状况，分别采用单因子污染指数法表征了水体中汞污染程度，地累积指数法和潜在生态危害指数法评价了沉积物中汞污染程度和潜在生态风险。结果表明，11个采样点水中汞含量为ND~0.034μg/L，平均值0.014μg/L，均符合国家地表水质量Ⅲ类标准；沉积物中汞含量为0.039~0.358 mg/kg，平均值0.169 mg/kg。从三江口—红村码头水和沉积物中汞含量均呈现波状起伏分布，分布趋势较一致。单因子评价法显示研究区水体中无汞污染，地累积指数法和潜在生态危害指数法显示所测样点沉积物中有82%无汞污染，45%生态风险很低。