Speciation of Fe and As in cored sediments from an As-contaminated aquifer in Bangladesh
Speciation of Fe and As in sediment collected from As-contaminated alluvial aquifer in Bangladesh was performed using X-ray absorption spectroscopy and acid extraction. Reduction of arsenate and ferric oxyhydroxides was observed below 5 m from ground surface, while concentration of As in groundwater was highest below 15 m. Labile Fe concentration was not dependent on the depth, suggesting that significant amount of ferrous Fe compounds was presented as labile phases below 5 m. Comparison of K-edge XANES of Fe collected by both fluorescence and conversion electron yield modes suggested that ferric oxyhydroxide was not identified in either bulk sediment or on particle surface. As a result, ferric oxyhydroxide does not control As mobility below 5 m. Our data provides insight into As mobilization in subsurface environment in relation to the change in the speciation of Fe and As.
T.Itai Y.Takahashi H.Masuda M.Mitamura A.A.Seddique K.M.Ahmed
Department of Earth and Planetary Systems Science, Hiroshima University, Hiroshima, Japan Department of Earth Science, Osaka City University, Osaka, Japan Department of Geology, University of Dhaka, Dhaka, Bangladesh
国际会议
第十二届水-岩相互作用国际研讨会(P0roceedings of the 12th International Symposium on Water-Rock Interaction)
昆明
英文
1239-1242
2007-07-31（万方平台首次上网日期，不代表论文的发表时间）