Izumi Yasuo, Masih Dilshad, Aika Ken-Ichi, Seida Yoshimi
Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259-G1-16, Nagatsuta, Midori-ku, Yokohama 226-8502, Japan. yizumi@ chemenv.titech.ac.jp
J Phys Chem B. 2005 Mar 3;109(8):3227-32. doi: 10.1021/jp047571o.
This paper first deals with the screening and optimization of Fe(III)-based adsorbents for arsenic adsorption from 0.2 to 16 ppm test solutions of arsenite/arsenate. The best adsorption capacity has been reported on alpha-FeO(OH) on an adsorbent weight basis. Better results were found on intercalated Fe-montmorillonites for arsenite adsorption below the equilibrium dissolved As concentration of 310 ppb and for arsenate adsorption in all of the concentrations studied. Next, the speciation of As adsorbed was performed by As K-edge x-ray absorption fine structure (XAFS) combined with high-energy-resolution fluorescence spectrometry. Major oxidative adsorption of arsenite was observed on Fe-montmorillonite from the 0.2-16 ppm test solutions. The reasons for the higher capacity of arsenic adsorption and oxidative adsorption of arsenite on Fe-montmorillonite are discussed.
本文首先探讨了用于从0.2至16 ppm亚砷酸盐/砷酸盐测试溶液中吸附砷的铁（III）基吸附剂的筛选和优化。据报道，以吸附剂重量计，α-FeO(OH)具有最佳吸附容量。对于亚砷酸盐吸附，在平衡溶解砷浓度低于310 ppb时，插层铁蒙脱石表现出更好的效果；对于所有研究浓度的砷酸盐吸附，插层铁蒙脱石也表现出更好的效果。接下来，通过结合高能分辨率荧光光谱的砷K边X射线吸收精细结构（XAFS）对吸附的砷进行形态分析。在0.2 - 16 ppm测试溶液中，观察到亚砷酸盐在铁蒙脱石上主要发生氧化吸附。文中讨论了铁蒙脱石对砷吸附能力较高以及对亚砷酸盐氧化吸附的原因。
