期刊名称：International Research Journal of Environmental Sciences
电子版ISSN：2319-1414
出版年度：2013
卷号：2
期号：2
页码：30-37
语种：English
出版社：International Science Community Association
摘要：Acid-Base properties of the raw mixed clay TOU from Burkina Faso, were study as well as the potential of the sample, in removing of chromium(III). The interactions of chromium(III) cation with the natural mixed clay minerals were examined using extended X-ray absorption fine structure (EXAFS) spectroscopy. Chemical elementary composition study of the mixed clay revealed presence of Silicon, Aluminum and Iron as mains elements. Qualitative mineralogical characterization of the clay by X-Ray diffraction, point out quartz and 7Å Halloysite as the dominating component in the sample. pHpzc of the clays, as determined by potentiometric titrations, was 8.21. Cr3+ adsorption on clay started at pH below pHpzc indicating inner-sphere complexes formation. More than 95% of chromium(III) is achieved at pH greater than 7. Chromium(III) forms a tetramer hydrolysis complex on the mineral surface with CrO bond and Cr· · ·Cr distances of 2.487, 3.087 and 3.636 Å, respectively, which is indicative of a chain structure with edge sharing CrO octahedra.
