Removal of arsenate from water by using an Fe-Ce oxide adsorbent: effects of coexistent fluoride and phosphate.
Removal of arsenate from water by using an Fe-Ce oxide adsorbent: effects of coexistent fluoride and phosphate.
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DOI：
10.1016/j.jhazmat.2010.02.081
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发表时间：
2010-07
影响因子：
13.6
通讯作者：
Yu Zhang;Xiao-min Dou;Min Yang;Hong He;Chang Jing;Zi-Yu Wu
中科院分区：
文献类型：
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作者：
Yu Zhang;Xiao-min Dou;Min Yang;Hong He;Chang Jing;Zi-Yu Wu
The Langmuir two-site equation, X-ray photoelectron spectroscopy, and extended X-ray absorption fine structure spectroscopy have been employed to study the competitive behaviors of fluoride (F) and phosphate (P) in relation to arsenate adsorption on an Fe–Ce adsorbent as well as the mechanisms involved. The two-site isotherm revealed the presence of two kinds of adsorption sites with different binding affinities for arsenate. Both the total and low-binding-energy maximum adsorption capacities (Q and Q1) of arsenate decreased significantly even at a molar ratio of As/P=1:0.1. The coexistence of F, only influenced the total Q of arsenate at high simultaneous F concentrations. The fact that Fe–Ce released 0.15–0.24mmol sulfate for every mmol arsenate adsorbed suggested that, while sulfate groups might have played a role for adsorption, surface hydroxyl groups should be the major active sites. The XPS results indicated that arsenate and P are mainly adsorbed through the substitution of Fe surface active sites, while F is mainly adsorbed through substitution of Ce surface active sites. The As k-edge EXAFS data show that the second peak of Fe–Ce after arsenate adsorption is As–Fe shell, which further supported that arsenate adsorption occurs mainly at the Fe surface active sites.
