https://scholars.lib.ntu.edu.tw/handle/123456789/444641
Title: | XANES evidence of arsenate removal from water with magnetic ferrite | Authors: | Chang, Chien-Kuei Tu, Yao-Jen Wang, Shan-Li SHAN-LI WANG |
Keywords: | Adsorption | Arsenate | As K-edge XANES | Contaminated groundwater | Magnetic ferrite;Adsorption; Arsenate; As K-edge XANES; Contaminated groundwater; Magnetic ferrite | Issue Date: | 2013 | Journal Volume: | 120 | Source: | Journal of Environmental Management | Abstract: | Arsenic (As) in groundwater and surface water is a worldwide problem possessing a serious threat to public health. In this study, a magnetic ferrite, was synthesized and investigated for its As(V) removal efficiency. The adsorption of As(V) by magnetic ferrite exhibited an L-shaped nonlinear isotherm, suggesting limiting binding sites on the adsorbent surface. The As K-edge X-Ray Absorption Near-Edge Structure (XANES) revealed that the adsorbed As(V) on ferrite was not reduced to more toxic As(III) by Fe2+ in the ferrite structure. The maximum As adsorption capacity of ferrite was 14 mg/g at pH 3 and decreased with increasing pH due to enhanced electrostatic repulsion between As(V) and the adsorbent surface. Desorption of As(V) using six different acid and salt solutions showed that the desorption rate decreased in an order of H3PO4 > Na3PO4 > H2SO4 > Na2SO4 > HCl > HNO3. These results suggest that magnetic ferrite without surface modification is an effective adsorbent for removing As(V) from water, which was confirmed by the effective removal of As(V) from contaminated groundwater using this material. The used material can then be recovered using a magnet because of its paramagnetism; the adsorbed As(V) on the material can be recovered using H3PO4 or Na3PO4 solutions. © 2013 Elsevier Ltd. |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/444641 | ISSN: | 0301-4797 | DOI: | 10.1016/j.jenvman.2013.02.006 9423240 |
SDG/Keyword: | acid; arsenic acid; ferrite; magnetic ferrite; sodium chloride; unclassified drug; adsorption; arsenate; arsenic; desorption; ferrite; groundwater pollution; inorganic acid; nonlinearity; pH; pollutant removal; public health; salt; toxicity; XANES spectroscopy; adsorption kinetics; article; binding site; chemical structure; desorption; magnetism; paramagnetism; pH; static electricity; synthesis; waste component removal; water treatment; Absorption; Arsenates; Ferric Compounds; Water Purification |
Appears in Collections: | 農業化學系 |
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