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-Mn O2(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.
Lead species significantly influences its mobility and bioavailability. In this study, improved BCR procedure, laboratory culture, laboratory micro X-ray fluorescence （Ix-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 （P04）2 （36%-55% ） , and Pb-MnO2 （3%-24% ） in soil samples. The results of this study showed that oxides of Fe and Mn, and Pbs （ PO4 ） 2 precipitate mainly comprise the pool of Pb in soils.
作者
孙晓艳
柳检
罗立强
SUN Xiao-yan;LIU Jian;LUO Li-qiang(National Research Center for Geoanalysis,Beijing 100037,China;School of Earth Seiences and Resources,China University of Geoseienees,Beijing 100083,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2018年第8期3835-3844,共10页
Environmental Science
基金
国家重点研发计划项目(2016YFC0600603)
国家高新技术研究发展计划(863)项目(2007AA06Z124)
中国地质调查项目(DD20160340)
国家自然科学基金项目(20775018
41201527)
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
lead
speciation
bioavailability
sequential extraction
micro X-ray fluorescence （μ-XRF）
X-ray absorption near-edgestructure （XANES）
