Removal Efficiency of Arsenic by Adsorbents having Different Type of Metal Oxides

In this study, oxidation of As (Ⅲ) as well as removal of total arsenic by adsorbents coated with single oxides or multi-oxides (Fe (Ⅲ), Mn (Ⅳ), Al (Ⅲ)) was investigated. In addition, multi-functional properties of adsorbents coated with multi-oxides were evaluated. Finally, application of activated carbon impregnated with Fe or Mn-oxides on the treatment of As (Ⅲ) or As (Ⅴ) was studied. As (Ⅴ) adsorption results with adsorbents containing Fe and Al shows that adsorbents containing Fe show a greater removal of As (Ⅴ) at pH 4 than at pH 7. In contrast adsorbents containing Al shows a favorable removal of As (Ⅴ) at pH 7 than at pH 4. In case of iron sand, it has a negligible adsorption capacity for As (Ⅴ) although it contains 217.9 g-Fe/kg-adsorbent. Oxidation result shows that manganese coated sand (MCS) has the greatest As (Ⅲ) oxidation capacity among all metal oxides at pH 4. Oxidation efficiency of As (Ⅲ) by IMCS (iron and manganese coated sand) was less than that by MCS. However the total removed amount of arsenic by IMCS was greater than that by MCS.