Selective Adsorption of Cd(II) and Zn(II) Ions by Nano-Hydrous Manganese Dioxide (HMO)-Encapsulated Cation Exchanger

A novel hybrid adsorbent HMO-001 was fabricated by impregnating nanosized hydrous manganese dioxide (HMO) onto a porous polystyrene cation exchanger resin (D-001) for enhanced removal of Cd(II) and Zn(II) ions from waters. The immobilized sulfonate anions covalently bound to the D-001 polymeric matrix are supposed to result in preconcentration and enhanced permeation of both target metal ions for favorable adsorption by HMO. Batch and column adsorption runs demonstrated that HMO-001 exhibited highly preferable Cd(II) and Zn(II) retention from waters in the presence of competing Ca(II) ions at much greater levels. The exhausted adsorbent particles are amenable to efficient regeneration by 2% HCl solution without any HMO loss during operation.