Adsorption of arsenic (As(III) and As(V)) has been investigated, employing magnetite (Fe3O4), titania (TiO2), and alumina (Al2O3) as adsorbents. Three kinds of adsorbents possess high adsorption ability for both As(III) and As(V) in acidic and neutral pH region, which indicates the all adsorbents are applicable for the As removal from common geothermal waters. The maximum adsorption amounts determined by Langmuir isotherms are order of Al2O3≈TiO2>Fe3O4 in the case of As(III), and Al2O3>TiO2>Fe3O4 in the case of As(V), respectively. These adsorption abilities are affected by both of hydroxyl groups on the surface and specific surface area of the powdered adsorbents. Chromatographic removal of As(III) from aqueous solution was performed by using a laboratory-scale column packed with the granulated adsorbents of Fe3O4, TiO2 and Al2O3. The effective removal of As(III) from aqueous solution could be effectively achieved using granulated TiO2 adsorbent in the three kinds of adsorbents, due to its high adsorption kinetics.
2012 Japan Society of Ion Exchange