論文

査読有り
2009年7月

Incomplete transformations of Pb to pyromorphite by phosphate-induced immobilization investigated by X-ray absorption fine structure (XAFS) spectroscopy

CHEMOSPHERE
  • Yohey Hashimoto
  • ,
  • Masaki Takaoka
  • ,
  • Kazuyuki Oshita
  • ,
  • Hajime Tanida

76
5
開始ページ
616
終了ページ
622
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1016/j.chemosphere.2009.04.049
出版者・発行元
PERGAMON-ELSEVIER SCIENCE LTD

For an accurate assessment of immobilization technologies, it is necessary to illustrate the transformation of target metal species into their final products. The present study employed extended X-ray absorption fine structure (EXAFS) spectroscopy combined with linear combination fitting (LCF) to determine Pb species and their proportions in contaminated soils treated with phosphate amendments. Lead contaminated soils collected from a shooting range were separately treated with calcium phosphate (CP), hydroxyapatite synthesized from ceramic waste (CHA), and incinerated poultry litter (PW). Soils were incubated at 32% water content for 7 and 380 d. The EXAFS-LCF analysis illustrated that Ph speciation in the control soil included organically-complexed phases (Pb-org, 32%), PbO (22%), PbCO3 (28%), and Pb-3(CO3)(2)(OH)(2) (8%). As the incubation period increased, the proportion of chloropyromorphite [Pb-5(PO4)(3)Cl] increased from 20% to 27% in CHA and from 19% to 31% in CP soils. The spectra of PW-amended soils were reproduced adequately with a combination of Pb-org, PbO, and chloropyromorphite in the proportion of about 20%, 45%, and 23%, respectively. The effectiveness of amendments on Pb immobilization as indicated by the chloropyromorphite proportion was in the order of CP (31%) > CHA (27%) > PW (23%) after 380 d of incubation. Our study indicates that about 70% of Pb species was not immobilized as a form of chloropyromorphite, and the additional supply of phosphate amendment scarcely promoted chloropyromorphite formation. The EXAFS-LCF approach illustrated that organically-complexed Pb was persistent in all amended soils, suggesting that an enriched soil organic carbon may be an inhibitory factor for pyromorphite transformations. (C) 2009 Elsevier Ltd. All rights reserved.

リンク情報
DOI
https://doi.org/10.1016/j.chemosphere.2009.04.049
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000268197400006&DestApp=WOS_CPL
ID情報
  • DOI : 10.1016/j.chemosphere.2009.04.049
  • ISSN : 0045-6535
  • eISSN : 1879-1298
  • Web of Science ID : WOS:000268197400006

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