辽宁省柴河铅锌矿开采与重金属污染历史重建

摘要

The heavy metal pollution of soil resulting from Pb-Zn mining mainly appears within 3 to 5 km around the mine area of Chaihe Pb-Zn deposit,Liaoning Province,and the pH value clearly reveals soil acidifi-cation of the region,thanks on the results from soil geochemical survey over the mining area of Chaihe Pb-Zn deposit and its surrounding area.History of heavy metal pollution reconstructed from the profile of overbank sedi-ment indicates that S concentration kept continueously increasing,and the pH dropped by 2 units since 1820 at the outlet of Chaihe reservoir.Whereas after 1900,Cd,Pb,and Zn in overbank sediment accumulated evident-ly,and the content of Pb and Hg in sediment profile declined after the cease of Pb-Zn mining.Soil acidification may remove Cd and Zn from accumulated in soil to water and sediment,and to result a potential risks to fish in Chaihe reservoir.%通过对辽宁铁岭柴河铅锌矿及周边地区的土壤测量及柴河水库河漫滩沉积剖面的同位素测年研究，发现柴河铅锌矿开采导致的土壤重金属污染主要集中在柴河铅锌矿区周边3～5 km的范围内，土壤pH值表明土壤明显酸化。污染历史重建显示，1820年以来，随着沉积物中S含量的不断升高，其pH值累计下降2个单位；1900年以来河漫滩沉积物中的Cd、Pb、Zn累积明显；铅锌矿停止开采后，沉积剖面中Pb、Hg含量逐年降低；汇水域内的土壤酸化仍可导致土壤中累积的Cd和Zn对水库水体和库底沉积物造成二次污染，对水库鱼类的安全具有潜在风险。