玄武湖上覆水间隙水和沉积物中的重金属分布研究

为了研究湖泊中重金属的分布情况及其潜在迁移趋势,以南京市玄武湖为对象,分析了该湖上覆水、间隙水和沉积物中的Fe,Mn,Ba,Zn,Ni和Cd等重金属的含量。结果表明,上覆水和间隙水中的金属浓度呈相同的分布顺序:Fe>Mn>Cd>Ba>Zn>Ni;而沉积物则具有不同的分布顺序:Fe>Mn>Ba>Zn>Ni>Cd。同种重金属在三者间的分布顺序为:沉积物>间隙水>上覆水,表明了该湖中的重金属有从沉积物向上覆水扩散的趋势。统计分析结果表明,上覆水、间隙水和沉积物中的金属浓度之间没有发现明显的相关性;但多数金属与Fe、Mn存在明显的浓度相关性,表明了Fe和Mn在湖泊系统的金属地球化学循环过程中起重要作用。

Trace Metal Levels in Overlying Water, Pore Water and Sediment of Xuanwu Lake, Nanjing

Total concentration of heavy metals such as Fe, Mn, Ba, Zn, Ni and Cd were determined in overlying water, pore water and bottom sediments of Xuanwu Lake, Nanjing to investigate metal levels and distribution in integrated lake system. Results showed that the amount of metal in overlying water and pore water presented the same concentration order while different orders were found for the sediment. For each metal, sediments presented the highest concentration, then followed by pore water and overlying water, which indicated the mobile trends of metals were from sediments to overlying water. Statistic analysis results showed that no significant general correlations were found among overlying water, pore water and sediments, but significant correlations were found between some metals concentration and Fe (or/and Mn) concentration, which indicated that Fe and Mn play important roles in geochemical recycles of metals in lake system.