武汉城市湖泊汞的迁移与富集

对武汉远郊、城乡结合部和市区3种环境中6个湖泊的水、界面水、沉积物和生物(鱼)进行调查采样,用离心机离心出沉积物中的孔隙水,用原子荧光光谱仪进行汞含量测定。以土壤—水—界面水—孔隙水—沉积物—生物为轴线,探讨了汞在研究区土壤—沉积物系统、湖水—沉积物系统和湖水—界面水—孔隙水系统中的分配以及湖泊鲢鱼肉中汞与沉积物和水中汞的关系。建立了武汉城市湖泊汞的迁移、富集理想模式:湖泊水汞经悬浮物吸附沉淀而富集于沉积物中,沉积物中汞经化学转化传输给孔隙水;存在于悬浮物中的界面水汞,经解吸附后向湖水扩散而产生二次污染。湖水汞被鱼吸收而产生生物富集。从而得出湖水—界面水—孔隙水—沉积物、湖水—鱼的两种富集机制。

Migration and enrichment of mercury from urban lakes in Wuhan

Samples of water,interface water,sediments and fish were collected from six lakes in urban,suburban and countryside regions of Wuhan.Pore water in sediments was extracted by use of a centrifugal separator.The concentration of mercury was measured by use of an atomic fluorescence spectroscopy.According to the sequence of soil-water-interface water-pore water-sediment-organism,the distribution of mercury in the soil-sediment system,the lake water-sediment system and the lake water-interface water-pore water system was studied.And the relationship between the distribution of mercury in water,sediments and fish of Wuhan urban lakes was also studied.As a result,an ideal migration and enrichment model of mercury in lakes of Wuhan was established,that is,mercury in lake water was adsorbed by suspended solids and then deposited and accumulated in sediments.Mercury in sediments was transformed into pore water by chemical change,while mercury in interface water can enter into lake water and produces secondary pollution by desorption and diffusion.The mercury in water was adsorbed by fish and accumulated.These are the two enriched mechanisms of mercury in lakes,i.e.lake water-interface water-pore water-sediments and lake water-fish.