中文关键词铅形态生物有效性BCR微区分布X射线近边吸收结构谱 英文关键词leadspeciationbioavailabilitysequential extractionmicro X-ray fluorescence (μ-XRF)X-ray absorption near-edge structure (XANES)

作者	单位	E-mail
孙晓艳	国家地质实验测试中心, 北京 100037 中国地质大学(北京)地球科学与资源学院, 北京 100083	sunxiaoyan2020@126.com
柳检	国家地质实验测试中心, 北京 100037
罗立强	国家地质实验测试中心, 北京 100037 中国地质大学(北京)地球科学与资源学院, 北京 100083	luoliqiang@cags.ac.cn

中文摘要 土壤中铅的可迁移性和生物有效性受土壤中铅形态影响.本工作采用改进的BCR顺序提取法、植物栽培、微区X射线荧光（μ-XRF）和同步辐射X射线吸收近边结构谱（XANES）研究了铅锌矿区土壤中铅生物有效性.结果表明：①铅在土壤中的分布规律为：可还原态 > 酸溶态 > 残渣态 > 可氧化态；②植物组织中铅浓度与土壤中酸溶态铅浓度呈一定相关性；③微米水平上，铅在土壤中呈非均匀分布，与Fe和Mn存在一定相关性；④土壤中铅的分子形态主要以Pb-goethite（铅-针铁矿为41%~46%）、Pb₃（PO₄）₂（36%~55%）和Pb-MnO₂（铅-锰氧化物为3%~24%）形式存在.研究表明BCR、μ-XRF和XANES分析方法结果可以相互印证，均表明土壤中铁锰氧化物吸附和磷酸铅沉淀是降低铅生物有效性的主要机制. 英文摘要 Lead species significantly influences its mobility and bioavailability. In this study, improved BCR procedure, laboratory culture, laboratory micro X-ray fluorescence (μ-XRF), and synchrotron radiation X-ray absorption near-edge structure (XANES) were used to investigate the distribution, speciation, and bioavailability of Pb in soils from a Pb/zinc (Zn) mining area contaminated with heavy metals. The results showed that ① Pb was mainly distributed in the reducible[which binds to oxides of iron (Fe) and manganese (Mn)], acid soluble, residual, and oxidizable fractions, ② Pb content in plant tissues correlated with acid-soluble Pb content in soil, ③ μ-XRF results indicated that Pb was distributed heterogeneously, and correlated with the hot spot with high concentration of Mn. In some area, Pb also correlated with Fe, and ④ Pb was predominantly present as Pb-goethite (41%-46%), Pb₃(PO₄)₂(36%-55%), and Pb-MnO₂(3%-24%) in soil samples. The results of this study showed that oxides of Fe and Mn, and Pb₃(PO₄)₂precipitate mainly comprise the pool of Pb in soils.

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