湘西汞矿区土壤中重金属的空间分布特征及其生态环境意义  

Spatial Distribution and Ecological Significance of Heavy Metals in Soils from Chatian Mercury Mining Deposit,Western Hunan Province

作　　者：孙宏飞[1,2] 李永华[1] 姬艳芳[1,2] 杨林生[1] 王五一[1] 

机构地区：[1]中国科学院地理科学与资源研究所,北京100101 [2]中国科学院研究生院,北京100049

出　　处：《环境科学》2009年第4期1159-1165,共7页Environmental Science

基　　金：中国科学院知识创新工程重要方向性项目(KZCX3-SW-437);国家自然科学基金项目(40571008)

摘　　要：采用HG-ICP-AES和ICP-MS法测定了湘西茶田汞矿区典型土壤剖面(远离矿口处的自然土壤剖面P1、矿口附近的自然土壤剖面P2和汞矿渣下覆土壤剖面P3)不同层次的土壤及矿区的矿石、废矿和矿渣等环境样品中Hg及其它重金属的含量,在此基础上,结合富集系数法和相关分析等地统计学方法,探讨了汞矿区土壤中Hg等重金属的来源、分布及迁移特征.结果表明,Hg在P1剖面中呈底层富集趋势,而在P2、P3剖面中均表现出明显的表层富集现象;P2、P3剖面土壤都遭受了Hg的污染,但P3的污染更为严重,其土壤表层的Hg含量达到640μg.g-1,剖面Hg平均含量为(76.74±171.71)μg.g-1,Hg向下迁移的深度超过100 cm,分别高于P2的6.5μg.g-1、(2.74±1.90)μg.g-1和40 cm;除成矿元素Hg污染严重外,矿区土壤中还存在着Cd、As、Pb、Zn的污染,且以Cd的污染较为严重;矿区土壤剖面中重金属的迁移能力为Hg>Cd>As>Zn≈Pb,并受元素在表土层的含量及土壤理化参数的影响.研究表明,矿区土壤剖面中重金属的来源、分布及迁移既受原生地质环境的影响,更与人类采选矿活动密切相关.Ores, waste tailings and slag, together with three typical soil profiles （natural soil profiles far from mine entrance and near mine entrance, soil profile under slag） in Chatian mercury mining deposit （CMD）, western Hunan province were sampled and their concentrations of mercury （Hg）, arsenic （As）, lead （Pb）, cadmium （Cd）, zinc （Zn） were determined by HG-ICP-AES and ICP-MS. Enrichment factor and correlation analysis were taken to investigate the origins, distribution and migration of Hg, as well as other heavy metals in the CMD. The results show that Hg is enriched in the bottom of the soil profile far from mine entrance but accumulated in the surface of soil profiles near mine entrance and under slag. The soil profiles near mine entrance and under slag are both contaminated by Hg, while the latter is contaminated more heavily. In the soil profile under slag, Hg concentration in the surface soil, Hg average concentration in the total profile, and the leaching depth of soil Hg are 640 μg·g^-1 , （76.74 ± 171.71） μg·g^-1 , and more than 100 em, respectively; while 6.5 μg·g^-1 , （2.74 ± 1.90） μg·g^-1 , and 40 cm, respectively, are found in the soil profile near mine entrance. Soil in the mercury mine area is also polluted by Cd, As, Pb, Zn besides metallogenic element Hg, among which Cd pollution is relatively heavier than others. The mobility of the studied heavy metals in soil follows the order as Hg 〉 Cd 〉 As 〉 Zn ≈ Pb. The leaching depth of the heavy metals is influenced by total concentration in the surface soil and soil physico-chemieal parameters. The origins, distribution and migration of heavy metals in soil profile in the mining area are related to primary geological environment, and strongly influenced by human mining activities.

关 键 词：汞 土壤剖面 矿渣 重金属 迁移 

分 类 号：X53[环境科学与工程—环境工程]