Comparison of chelating ligands on manganese (II) removal from aqueous solution

The removal of manganese, Mn2+, by chelating ion exchange resins of Lewatit TP 260 and Lewatit TP 207, which contain aminomethylphosphonic and iminodiacetic acid as functional groups, was studied under various experimental conditions such as solution pH and resin dosage. The ion exchange process indicated that the maximum removal could be achieved at pH3. The results of adsorption equilibrium experiments fit well in Langmuir isotherm, and also indicated that the sorption was a monolayer process. Additionally, kinetic experiments showed that the pseudo-first-order model was suitable for TP 260 as well as pseudo-second-order for TP 207 resin. It was found out that the rate-determining step is the chemical reaction for both resins according to unreacted core model. Resins were also regenerated and obtained results showed that both resins can be reused after regeneration either with HCl or H2SO4.