Adsorption of Toxic Selenium Oxoanions on Surface-Modified Kaolins
a Department of Solid State Chemistry, b Department of Inorganic Chemistry, c Laboratory of Molecular Spectroscopy, Institute of Chemical Technology, Prague, d Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic
Se is a trace element and an important micronutrient. At higher concentrations it may become a serious threat for the environment and human health. Se occurs in nature in organic or inorganic compounds (SeO32, SeO42). The toxic compounds can be removed from water by adsorption on aluminosilicates (kaolins, bentonites, zeolites). The aim of this work was the preparation of new low-cost sorbents based on kaolins and determination of their stabi¬lity. The adsorbents were prepared by treatment of kaolin with Fe2+ or Al3+ solution yielding mesoporous amorphous FeIII or AlIII oxides/hydroxides. The obtained materials were selective adsorbents of SeIV in water. The batch sorption was performed with 101500 mg l1 aqueous Se solutions and evaluated using a Langmuir model. The removal of Se using the Al-treated kaolin was more effective than its Fe analog.
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