Ion imprinted sodium alginate hydrogel beads enhanced with carboxymethyl cellulose and β-cyclodextrin to improve adsorption for Cu2+

Abstract Using Cu2+ as template ion, three sodium alginate hydrogel beads including SA, SAC, and SAB beads were prepared with sodium alginate blending with different precursors of carboxymethyl cellulose and β-cyclodextrin, respectively. The effect of pH, adsorption time, initial concentration of Cu2+, adsorbent dosage, and coexisting ions on the adsorption efficiency of three hydrogel beads was investigated. The results indicated that adding carboxymethyl cellulose and β-cyclodextrin into skeleton of beads increased the toughness of the beads and improved the adsorption capacity of Cu2+. The adsorption rate of Cu2+ on SA beads was conformed to the pseudo-first order kinetic equation, while the adsorption behavior of Cu2+ on SAC or SAB beads could be confirmed to the pseudo-second-order kinetic equation. Compared with the saturated adsorption capacity 510 mg/g of Cu2+ on SA, the saturated adsorption capacity of Cu2+ on SAB and SAC reached 817 mg/g and 822 mg/g, respectively, with their Cu2+ adsorption efficiency over 95% at 25°C. Thus, SAC and SAB beads could be used as adsorption material for detecting and removing Cu2+ from wastewater.