Chemical state analysis of lead and zinc in soil of xitieshan mining area in the northern margin of qaidam basin

2018 International Conference of Green Buildings and Environmental Management

土木建筑工程;生态环境科学

Wang, Jianguo^1 ; Zhang, Wen^1 ; Ren, Erfeng^1

Department of Geological Engineering, Qinghai University, Xining

810016, China^1

关键词: Chemical state analysis;    Coefficient of variation;    Continuous extraction;    Degree of dispersion;    Environmental conditions;    External sources;    Heavy metal pollution;    Redox potentials;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/186/3/012066/pdf
DOI  :  10.1088/1755-1315/186/3/012066

来源: IOP

【 摘 要 】

The chemical state of Pb, Zn can explain the migration law, and evaluate the threat of heavy metal pollution. The three-step continuous extraction method of BCR was adopted to divide the chemical forms of Pb and Zn in the soil into the acid-exchanged, oxidizable, reducible, and residual states. It was found that the coefficient of variation and the degree of dispersion of exchangeable, oxidizable, and reducible states were large, the results showed that all the chemical forms of Pb, Zn in soil were greatly affected by external sources except the residual state. Most of the Pb chemical forms in the mining area exist in the reducible and residual state, Zn is mainly in the oxidizable state and the reducible state; Pb is mainly in the oxidizable state, and most of the Zn is in the residual state in reference area. The oxidizable state and the reducible state are easily released when the redox potential changes, and the residual Zn may be released under severe environmental conditions, it is shown that the migration of silicate, primary and secondary minerals is difficult after natural geological weathering, etc. The contents of Pb, Zn in all forms were positively correlated with Ph of soil, positively correlated with sand content, and negatively correlated with clay content. The reasons were related to the enrichment of Pb, Zn mineralization elements in the mining area. These chemical states can indicate the chemical effects and accumulation patterns of Pb, Zn in soil.