湘江表层沉积物重金属的赋存形态及其环境影响因子分析  

Speciation of heavy metals in sediments from Xiang River and analysis of their environmental factors

作　　者：王鸣宇[1,2] 张雷[1] 秦延文[1] 李发生[2] 贾静[1] 曹伟[1] 郑丙辉[1] 

机构地区：[1]中国环境科学研究院环境基准与风险评估国家重点实验室,北京100012 [2]中国环境科学研究院国家环境保护河口与海岸带环境重点实验室,北京100012

出　　处：《环境科学学报》2011年第11期2447-2458,共12页Acta Scientiae Circumstantiae

基　　金：国家水体污染与控制重大专项课题(No.2009ZX07528-002)~~

摘　　要：采用BCR三步分级提取法分析了湘江衡阳段与岳阳段表层沉积物中4种重金属(Cd、Pb、Cu、Zn)不同赋存形态的含量,阐述了重金属赋存形态及其环境影响因子的关系,评估了这4种重金属的生物有效性.结果表明,4种元素均以弱酸溶解态、可还原态和可氧化态3种可提取态为主,各元素生物有效性即可提取态含量排序为:Cd>Pb>Zn>Cu,4种重金属的污染程度与其可提取态含量呈正相关关系.由相关性分析可知,有机质是湘江表层沉积物中重金属总量及赋存形态的主要环境影响因子.4种重金属生态风险指数的空间分布特征均表现出中下游明显高于上游的趋势,并在衡阳水口山地区达到峰值,表明沿江重金属污染源企业的排放是影响本次湘江调查水域沉积物重金属污染元素空间分布的主要因素.BCR three stages sequential extraction procedure was applied to investigate the speciation and contents of four types of heavy metals （Cd,Pb,Cu,Zn） in the surface sediments in Hengyang-to-Yueyang section of Xiang River.The relationship between the speciation of these heavy metals and their environmental factors were described.Morerover,the bioavailability of these four types of heavy metals was also determined preliminarily.The results showed that all of these four types of metals existed mainly in extractable fractions which included weak soluble fraction,reducible fraction and oxidisable fraction,and the bioavailability for four types of metals were in the descending order of CdPbZnCu.Heavy metals had positive correlation with their contents of extractable fractions.Correlation Analysis showed that organic matter was the most important environmental factor that influenced the contents and speciation of heavy metals deposited on surface sediments of Xiang River.Accumulation and ecological risk of these four types of metals in the middle and lower reaches were higher than that in the upper reaches,peaking at Shuikoushan aera in Hengyang.This phenomenon showed that emissions from industries along the river was the main impact factor of spatial distribution of heavy metals in sediments in Xiang River area.

关 键 词：湘江 表层沉积物 重金属形态 环境影响因子 

分 类 号：X171[环境科学与工程—环境科学]