阳澄湖表层沉积物中氮磷及重金属的空间分布特征及污染评价

发布时间：2019-03-01 13:05

【摘要】：为了解阳澄湖表层沉积物中氮磷及重金属的空间分布和污染特征,对全湖开展了大范围调查,基于综合污染指数、地积累指数法和潜在生态风险指数法对沉积物污染风险进行评价.结果表明:阳澄湖表层沉积物中w(TN)、w(TP)平均值分别为3 433、379 mg/kg,湖区氮磷污染严重且空间差异明显,w(TN)高值区位于阳澄东湖,w(TP)高值区位于阳澄西湖;综合污染指数评价结果显示,整个阳澄湖TN均为重度污染状态,TP除阳澄西湖外大部分区域处于轻度污染状态.阳澄湖表层沉积物中w(Cu)、w(Zn)、w(Pb)、w(Cr)、w(Cd)、w(As)、w(Hg)、w(Ni)的平均值分别为35.0、141、12.6、62.6、0.36、27.5、0.145、47.6 mg/kg,分别是江苏省土壤重金属环境背景值的1.50、2.17、0.57、0.83、4.22、2.93、5.78、1.45倍,阳澄西湖的重金属含量要高于阳澄中湖和阳澄东湖.地积累指数法和潜在生态风险指数法评价结果均表明,Hg和Cd是主要的生态风险贡献因子,二者生态风险指数平均值分别为231.23、126.63.相关分析结果表明,阳澄湖表层沉积物中Cu、Zn、Pb、Cr、Cd、Hg和Ni的质量分数显著相关,说明其具有相似的来源,结合水系结构和周边企业分布,推测其主要来自于相城区和常熟市的工业企业.
[Abstract]:In order to understand the spatial distribution and pollution characteristics of nitrogen, phosphorus and heavy metals in surface sediments of Yangcheng Lake, a large-scale investigation was carried out in the whole lake, based on the comprehensive pollution index. Land accumulation index and potential ecological risk index were used to evaluate sediment pollution risk. The results showed that the average value of w (TN), w (TP) in surface sediment of Yangcheng Lake was 3 433379 mg/kg, and the high value area of, w (TN) in Yangcheng Lake was located in Yangcheng East Lake. The high value area of w (TP) is located in Yangcheng West Lake; The results of comprehensive pollution index evaluation showed that the TN of Yangcheng Lake was seriously polluted, and TP was slightly polluted in most areas except Yangcheng West Lake. The mean values of w (Cu), w (Zn), w (Pb), w (Cr), w (Cd), w (As), w (Hg), w (Ni) in surface sediments of Yangcheng Lake were 35.0, 141, 12.6, 62.6, 0.36, 27.5,0.145, 47.6 mg/kg, respectively. It was 1.50,2.17,0.57, 0.83, 4.22, 2.93, 5.78 and 1.45 times of the soil heavy metal background values in Jiangsu Province, respectively. The heavy metal content in Yangcheng West Lake was higher than that in Yangcheng Middle Lake and Yangcheng Dong Lake. The evaluation results of both the geoaccumulation index method and the potential ecological risk index method show that Hg and Cd are the main ecological risk contributing factors, and the average ecological risk indices of the two methods are 231.23126.63 respectively. The results of correlation analysis showed that the mass fraction of Cu,Zn,Pb,Cr,Cd,Hg and Ni in surface sediments of Yangcheng Lake were significantly correlated, indicating that they had similar sources, combined with the structure of water system and the distribution of surrounding enterprises. It is speculated that it mainly comes from the industrial enterprises in Xiangcheng District and Changshu City.
【作者单位】：中国科学院南京地理与湖泊研究所中国科学院流域地理学重点实验室;南京林业大学生物与环境学院;
【基金】：国家水体污染控制与治理科技重大专项(2014ZX07101-011) 科技部基础性工作专项(2013FY111800) 江苏省自然科学基金项目(BK20131055)
【分类号】：X524

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