Geochemical fractionation and potential release behaviour of heavy metals in lead–zinc smelting soils  

作　　者：Xinghua Luo Chao Xiang Chuan Wu Wenyan Gao Wenshun Ke Jiaqing Zeng Waichin Li Shengguo Xue 

机构地区：[1]School of Metallurgy and Environment,Central South University,Changsha 410083,China [2]Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution,Central South University,Changsha 410083,China [3]Department of Science and Environmental Studies,The Education University of Hong Kong,Hong Kong 999077,China

出　　处：《Journal of Environmental Sciences》2024年第5期1-11,共11页环境科学学报（英文版）

基　　金：funded by the National Key Research and Development Program of China(No.2019YFC1803601);the National Natural Science Foundation of China(No.42177392);the Fundamental Research Funds for the Central Universities of Central South University(No.2021zzts0122)。

摘　　要：The lack of understanding of heavy metal speciation and solubility control mechanisms in smelting soils limits the effective pollution control.In this study smelting soils were investigated by an advanced mineralogical analysis(AMICS),leaching tests and thermodynamic modelling.The aims were to identify the partitioning and release behaviour of Pb,Zn,Cd and As.The integration of multiple techniques was necessary and displayed coherent results.In addition to the residual fraction,Pb and Zn were predominantly associated with reducible fractions,and As primarily existed as the crystalline iron oxide-bound fractions.AMICS quantitative analysis further confirmed that Fe oxyhydroxides were the common dominant phase for As,Cd,Pb and Zn.In addition,a metal arsenate(paulmooreite)was an important mineral host for Pb and As.The pH-stat leaching indicted that the release of Pb,Zn and Cd increased towards low pH values while release of As increased towards high p H values.The separate leaching schemes were associated with the geochemical behaviour under the control of minerals and were confirmed by thermodynamic modelling.PHREEQC calculations suggested that the formation of arsenate minerals(schultenite,mimetite and koritnigite)and the binding to Fe oxyhydroxides synchronously controlled the release of Pb,Zn,Cd and As.Our results emphasized the governing role of Fe oxyhydroxides and secondary insoluble minerals in natural attenuation of heavy metals,which provides a novelty strategy for the stabilization of multi-metals in smelting sites.

关 键 词：Smelting soils Heavy metal FRACTIONATION AMICS Geochemical modelling 

分 类 号：X53[环境科学与工程—环境工程]