Behavior and kinetics study of As(III) adsorption on three kinds of absorbent

Montmorillonite, iron oxide and the composite, were synthesized and characterized. The behavior and kinetics of arsenic sorption on the three kinds of adsorbent were investigated under neutral conditions. The results indicated that the sorption capacities of iron oxide are higher than those of montmorillonite and composite. The kinetic data of arsenic adsorption can be well described by Lagergren-second-order equation. The arsenic adsorption data can be well fit to the Freundlich isotherm equation. The oxidizing surface such as the Fe-OH bond on iron oxides and Al-OH bond on montmorillonite were the key factors for adsorption, while the forming single-phase surface ligand group by combine the iron material of the montmorillonite and arsenate was the most likely reason for composite adsorption.