Adsorption and Separation of As(V) with N-Methylimidazolium Functionalized Anion Exchange Resin

The adsorption behavior of As(V) with N-methylimidazolium functionalized strongly basic anion exchange resin in Cl- form (RCl) was systematically investigated. The RCl had high thermal stability and good chemical stability under the experimental conditions, and it could be used in the wide pH range from 1 to 12. So RCl was very suitable for removing As(V) from water at a low concentration level. The adsorption mechanism was in accord with anion exchange mechanism. The adsorption equilibrium was attained at 60 min. To make sure true equilibrium was established, all the subsequent adsorption experiments were carried out for 2 h. The adsorption data for RCl was consistent with the Langmuir isotherm equation, and the maximum adsorption capacity of As(V) was 67.2 mg/g. The adsorption percentage increased slightly with increasing temperature, which showed that the reaction was endothermic. RCl was easily regenerated by 0.1 mol/L HCl, and the desorption percentage was up to 99.46%.