【摘要】 为了解阿哈水库水体中重金属的污染现状,选取了4个典型点位进行夏、冬两季采样分析,研究了上覆水体及沉积物孔隙水中Co、Ni、Cu、Zn、As、Cr及Pb 7种重金属的时空分布规律及其界面扩散通量。结果表明:阿哈水库上覆水体中溶解性重金属的均值含量符合我国《地表水环境质量标准》（GB 3838—2002）Ⅰ类标准与《生活饮用水卫生标准》（GB 5749—2006）,未受到重金属污染。夏季分层期,底层水缺氧导致水体As、Co、Cr含量增高,而冬季混合期重金属的垂向变化较小。沉积物孔隙水中重金属浓度均值高于上覆水,且Co与Ni、As呈显著正相关,其在水库中的迁移转化过程受铁锰循环的共同影响; Cu、Zn与Pb存在正相关关系,具有相似的污染来源。分析沉积物-水界面重金属扩散通量显示,Zn保持负扩散,表明沉积物对Zn具有很好的净化吸附效果;而Co、Ni、As、Pb保持正扩散,特别是夏季As的扩散通量达2.07μg·cm^-2·a^-1,对上覆水体可能产生较大的释放风险。研究证实,近十年来阿哈水库水体重金属的污染控制取得了显著的效果。更多还原

【Abstract】 Distribution characteristics and interfacial diffusion fluxes of seven heavy metals（ Co,Ni,Cu,Zn,As,Cr,and Pb） were examined in the overlying water and sediment porewater from four sampling sites from Aha Reservoir in summer and winter,to understand the pollution status of dissolved heavy metals in the water body. Results showed that the average concentrations of dissolved heavy metals in the overlying water from Aha reservoir were lower than the standard of Grade I of Environmental Quality Standard for Surface Water（ GB 3838-2002） and the Sanitary Standard for Drinking Water（ GB 5749-2006） in China. Concentrations of As,Co and Cr in the bottom water increased during the anoxic period in summer,and the vertical changes of all heavy metals during the mixed season in winter were not significant. The mean concentrations of heavy metals in pore water were significantly higher than that in overlying water. There were significant positive correlations among Co,Ni and As,indicating their migration and transformation processes being affected by the iron-manganese cycle in Aha Reservoir. Concentrations of Cu,Zn and Pb had a positive correlation with the same pollution source. Results from the analysis of the diffusion fluxes of heavy metals at the sediment-water interface（ SWI） showed that Zn remained negative diffusion,which indicated that sediment had a good adsorption effect on Zn. Co,Ni,As and Pb showed positive values at the SWI. The concentration of As reached 2.07 μg·cm^-2·a^-1 in summer,which may impose a greater release risk on the overlying water. Our results demonstrated that the pollution control of heavy metals had achieved remarkable results in the past decade in Aha Reservoir.更多还原