Recovery of Au(III) by radiation synthesized aminomethyl pyridine functionalized adsorbents based on cellulose

Abstract

Three novel n-aminomethylpyridine (n-AMP, n=2, 3, 4) functionalized adsorbents (n-AMPRs) for recovery of Au(III) were synthesized by radiation grafting of glycidyl methacrylate (GMA) onto microcrystalline cellulose microsphere, followed by ring-opening processes with n-AMP. The FTIR and XPS spectra manifested that n-AMP were successfully introduced into the novel adsorbents. Batch and column mode adsorption experiments against Au(III) were conducted to evaluate the adsorption abilities of the adsorbents. The adsorption isotherms of Au(III) were well fitted with Langmuir mode, and adsorption kinetics were well described by pseudo-second-order model. The results presented that n-AMPRs exhibited good adsorption abilities for Au(III) with adsorption capacities in the order of 2-AMPR>3-AMPR>4-AMPR. Moreover, the different adsorption abilities of three n-AMPRs for Au(III) ion were studied by DFT calculations. The adsorbents adsorbed Au(III) ion through anion exchange combined with chelation process, after which a particular reduction process for loaded Au(III) ion was also found. The dynamic experiment revealed that Au(III) in HCl media could be efficiently adsorbed by 2-AMPR in perturbation of equal amounts of Cu(II), Ni(II) and Cr(III), which demonstrated that 2-AMPR would be a promising adsorbent for trace amount of Au(III) ion from industrial effluents and e-wastes.