Mineral-organic interactions drive the aging and stabilization of exogenous Pb in soils

文献类型： 外文期刊

第一作者： Hu, Xiping

作者： Hu, Xiping;Qu, Chenchen;Cai, Peng;Chen, Wenli;Huang, Qiaoyun;Hu, Xiping;Qu, Chenchen;Cai, Peng;Huang, Qiaoyun;Hu, Xiping;Qu, Chenchen;Cai, Peng;Huang, Qiaoyun;Shi, Hanzhi

作者机构：

关键词： Interfacial reaction; Heavy metal contamination; Pb Modeling; Soil organic matter; Metal oxides

期刊名称：GEODERMA （ 影响因子：6.1； 五年影响因子：7.0 ）

ISSN： 0016-7061

年卷期： 2023 年 437 卷

页码：

收录情况： SCI

摘要： The interactions of soil components have profound impacts on the speciation, bioavailability and transformation of heavy metals. However, these interactions have not been well included in multi-surface model (MSM) as most of the models adopt component additive method. Here, an incubation experiment was conducted with three contrasting soils spiked with 200 mg/kg Pb and rice straw to investigate the impact of mineral-organic in-teractions on Pb speciation and to validate the MSM for Pb in soils. With the aid of chemical extraction and instrumental analysis (XANES and SEM-EDS), the results show that metal oxides and soil organic matter are the main scavengers for Pb, accounting for the stabilization of exogenous Pb by -40% -80% and -13% -30%, respectively. The accumulation of the most stable residual Pb was driven by Fe/Al oxides, which was fostered by organic matter through the formation of amorphous Fe/Al oxides. Unexpectedly, the introduction of straw promoted the activation of metal oxides and the competition from Fe/Al/Ca ions reduced the binding of Pb by soil organic matter. Simulation of organic-Fe/Al/Ca interactions largely improved the accuracy of the MSM model results for the prediction of Pb speciation distribution. Overall, this study highlights that mineral-organic interactions play important role in the stabilization of exogenous Pb in soils, while incorporate of these in-teractions into MSM is recommended in future heavy metal studies.

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