江苏海岸带的重金属特征及生态风险分析

通过测定水体和沉积物重金属含量,分析了江苏海岸带的重金属水平。结果表明,江苏沿海水体中Hg、Pb超过标准值,沉积物中Cd样品超过背景值。重金属元素与有机质、铝元素的关系显示:Cu、Zn、Hg和有机质的相关性较好,表明该地区的Cu、Zn、Hg有人为污染成分;Cr和铝元素的相关性较好,说明Cr主要是陆地碎屑成分。重金属潜在生态风险分析显示:江苏海岸带的生态风险程度以启东最低,其他地区较高,其中灌云沿海最高。粒度分析显示:重金属元素与粘粒有较好的正相关性,而与砂粒呈负相关性。

Heavy Metals in Littoral Zone of Jiangsu Province and an Ecological Risk Evaluation of Heavy Metals to This Zone

Heavy metals in the littoral zone have an adverse effect on the aquatic organisms.In this study,7 metals(copper,lead,zinc,chromium,cadmium,mercury,and arsenic) in seawater and sediments of 6 areas in littoral zone of Jiangsu Province were monitored.The effects of organic matter in sediment,and grain size of sediment on the metal concentration in the sediment were analyzed.Then an ecological risk evaluation for this littoral zone was given.The results show Mercury and lead in seawater have exceeded the national environment standard for seawater.Cadmium in sediments has increased during these years.Correlation analysis of heavy metals and organic matter shows that the correlative coefficients of copper,zinc and mercury are higher than other metals,suggesting anthropogenic sources are the main cause for copper,zinc and mercury content increases in the sediment.Evaluation on the potential ecological risk of heavy metals based on Ecological Risk Index from Hakanson shows that Qidong area is the lowest degree of the ecological risk,the Guannan estuary is the highest,and the other areas occur potential ecological risk.