横沙岛潮滩沉积物中重金属的空间分布与累积

SPATIAL DISTRIBUTION AND ACCUMULATION OF HEAVY METALS IN INTERTIDAL SEDIMENTS OF HENGSHA ISLAND

长期以来,长江流域的工农业及城市生活排污一直没有得到有效的控制,这必将对下游河口地区的生态环境造成直接或潜在的威胁。因此,针对横沙岛目前的潮滩环境进行研究,并就潮滩质量和发展趋势进行评价非常必要。通过对横沙岛潮滩表层沉积物中重金属元素空间分布与累积的统计学分析,得知横沙岛潮滩环境总体比较清洁,但多年来受城市工业废水和生活污水排放,以及城市汽车尾气和工业粉尘干湿沉降的影响,局部地区表现出较严峻的污染形势,Cu、Zn、Cr、Pb的最高浓度分别达到背景值的2.34、4.24、2.74和1.63倍。通过对潮滩表层沉积物粒度和有机质含量的分析,指出水动力条件、潮滩生物活化作用是影响重金属空间分布和累积的主要因素。

For a long period, the industrial and city sewage were over-discharged along the Yangtze River, which would no doubt have harmful effect in estuary environment either directly or indirectly. So it is very necessary to study tidal flat environment of Hengsha, and to qualitatively assess the environment. Based on heavy metal analysis in intertidal sediment samples in Hengsha, spatial distribution and accumulation of heavy metals were concluded. Up to now, the tidal environment of Hengsha is relatively clean, but there is still severe pollution trend at some places, owning to the city sewage discharge, and the wet and dry depositions of automobile tail gas and industrial dust. The concentration of Cu, Zn, Cr, Pb were the highest among heavy metals and even reached 2.34, 4.24, 2.74, 1.63 times to sediment background. Through correlation analysis on sediment granularity and organic component With heavy metals, factors which control the heavy metals include effect of water dynami＇c action and activating effects of tidal flat livlngs.