Arsenic water contamination has been recognized as a serious environmental issue and there are reports on its epidemiological problems to human health. The objective of this study was to compare the performance of iron-coated pumice (ICP) and manganese-coated pumice (MCP) as the adsorbents for removing arsenate from water. Characterization of the solids was determined using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and specific surface area measurement by BET method. The effect of various parameters on arsenate removal from water by the solids such as adsorbent dose, contact time, pH and initial arsenate concentration were evaluated in batch mode. The results showed that arsenate sorption onto ICP and MCP were pH dependent. Although maximum efficiency for the adsorbents was observed at pH 3 the considerable uptake to remove arsenate from water was continued up to pH 7 as ICP removal efficiency was higher than MCP. The adsorption kinetics by both adsorbents followed pseudo-second-order equation. Two isotherm models of Freundlich and Langmuir were used to fit the experimental data. The results indicated that the uptake data of arsenate were well fitted with Langmuir isotherm model.
