Development of modified kaolins for the removal of As (Ⅲ) in waters

摘要

Some inorganic species of arsenic (As) present in drinking waters are highly dangerous for human health. Adsorption technique is considered a promising technology for the selective removal of As from aqueous systems. Iron (Fe), and iron-containing clays are adsorbents commonly used for arsenic elimination from water due to the strong affinity between Fe and inorganic species of As. Natural and acid-treated kaolinites, impregnated with iron oxides (30 % and 20 % of the Fe (III)) were developed in the present work. The selected clays were physico-chemically characterised, and the As adsorption capability was tested in batch experiments at pH = 7. Arsenic removal studies showed 97% effectiveness for the 30% iron sedimented kaolinite at 1 h of treatment, being the most effective developed material. These preliminary results showed that the Fe (III) impregnated kaolinites could be considered as promising adsorbent materials for As removal from aqueous systems.