Adsorption of Arsenic by Fe3O4, TiO2, and Al2O3 Adsorbents

Abstract

Adsorption of arsenic (As(III) and As(V)) has been investigated, employing magnetite (Fe 3 O 4 ), titania (TiO 2 ), and alumina (Al 2 O 3 ) 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 Al 2 O 3 TiO 2 ＞ Fe 3 O 4 in the case of As(III), and Al 2 O 3 ＞TiO 2 ＞Fe 3 O 4 in the case of As(V), respectively. These adsorption abilities are aŠected by both of hydroxyl groups on the surface and speciˆc 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 Fe 3 O 4 , TiO 2 and Al 2 O 3 . The eŠective removal of As(III) from aqueous solution could be eŠectively achieved using granulated TiO 2 adsorbent in the three kinds of adsorbents, due to its high adsorption kinetics.