微束X射线荧光和X射线吸收近边结构谱分析云南某铅锌矿区苔藓中铅的分布和形态

发布时间：2018-10-29 15:28

【摘要】：苔藓对重金属胁迫具有良好耐受性和一定的积累能力。本研究采集并测定了铅锌矿区苔藓和苔下土壤中重金属元素含量,利用微束X射线荧光光谱(Micro-X-ray fluorescence spectrometry,micro-XRF)测定了苔藓中重金属元素的分布,采用X射线吸收近边结构(X-ray absorption near edge structure,XANES)分析了苔藓中Pb的元素形态。研究表明,矿区苔藓具有较强的Pb、Zn、Cd、As积累能力,Pb和Zn最高含量可达1.06和1.23 mg/g,Cd和As最高含量可达30.5和13.2μg/g。苔藓地上部(尤其是新生组织)是苔藓吸收并积累重金属的主要部位;矿区采集的小灰藓和匍枝青藓中部分金属元素分布规律不同,反应了不同苔藓种属对金属元素的吸收、积累和耐受机制的差异。XANES结果显示,Pb在小灰藓中主要以Pb_3(PO_4)_2形态存在(约78%),表明生成Pb_3(PO_4)_2沉淀可能是苔藓对Pb的耐受机制之一。
[Abstract]:Moss has good tolerance and accumulation ability to heavy metal stress. In this study, the contents of heavy metals in moss and moss soil in lead-zinc mining area were measured. The distribution of heavy metals in bryophytes was determined by microbeam X-ray fluorescence (Micro-X-ray fluorescence spectrometry,micro-XRF). The elemental morphology of Pb in bryophytes was analyzed by X ray absorption near edge structure (X-ray absorption near edge structure,XANES). The results showed that bryophytes had strong Pb,Zn,Cd,As accumulation ability and the highest contents of Pb and Zn were 1.06 and 1.23 mg/g,Cd and As were 30.5 渭 g / g and 13.2 渭 g / g respectively. The aboveground part of moss (especially new tissue) is the main site of heavy metal uptake and accumulation in bryophytes. The distribution of some metal elements in the grayophytes collected from the mining area is different from that in the bryophytes, which reflects the difference of the absorption, accumulation and tolerance mechanism of the metal elements in different species of bryophytes. The results of XANES showed that, Pb exists mainly in the form of Pb_3 (PO_4) _ 2 (about 78%), indicating that the formation of Pb_3 (PO_4) _ 2 precipitation may be one of the mechanisms of moss tolerance to Pb.
【作者单位】：国家地质实验测试中心;中国地质大学(武汉)材料与化学学院;国土资源部生态地球重点实验室;
【基金】：国家重点研发计划(No.2016YFC0600603) 国家高新技术研究发展项目(863项目,No.2007AA06Z124) 中国地质调查项目(No.DD20160340) 中国地质科学院基本科研业务费项目(No.YYWF201620)资助~~
【分类号】：O657.34;X835

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