REMOVAL OF ZINC (II) FROM AQUEOUS SOLUTION BY N-HYDROXYMETHYL ACRYLAMIDE POLYMER: THE ROLE OF MONTMORILLONITE MODIFICATION

In the current study, the removal performance of Zn (II) from aqueous solution by raw and modified n-hydroxymethyl acrylamide polymer (HAM) was investigated. The high performance adsorbent (HAM-ML) containing montmorillonite was prepared by the monomer polymer, the novel composite adsorbent has an excellent adsorption for Zn(II) removal. After being characterized by SEM, BET and FTIR analysis, the hydrogel adsorbent had a typical three-dimensional network structure and montmorillonite particles were dispersed into the channel and pores structure. Adsorption experiment suggested that HAM-ML showed more excellent potential for Zn(II) removal than HAM did, and the maximum Zn2+ adsorption capacity was 131.2 mg/g. The Zn(II) adsorption on HAM-ML could be well fitted by Langmuir isotherm model. Pseudo-second-order equation was able to properly describe the adsorption kinetics, and the adsorption equilibrium can be reached in the first 120 min. Alkaline pH was in favor of the adsorption process, and the optimum pH of adsorption was determined to be 8.0. In addition, 0.7 mol/L of HCl was proven to be the effective regeneration agent, which could reach the desorption efficiency of 94%. The results suggest that this material can be a promising adsorbent for Zn2+ removal in several industrial processes.