Perrhenate-ions adsorption by N-substituted chitosan derivatives

A comparative study of the sorption properties of N-(2-carboxyethyl)chitosan (CEC), N-(2-sulfoethyl)chitosan (SEC), N-(2,3-dihydroxy)propyl chitosan (HPC) and N-2-(2-pyridyl)ethyl chitosan (PEC) with respect to perrhenate ions in an acidic medium was carried out. On the basis of the analysis of the adsorption isotherms and the perrhenate ion adsorption degrees as functions of pH, it was found that the efficiency of adsorbents decreases in the sequence PEC > SEC > HPC > CEC. The investigated chitosan derivatives are characterized by a higher rate of sorption of perrhenate ions in comparison with known commercial anionites. In the case of PEC, accompanying ions have the least effect on the sorption.