Preparation of a novel polyfunctional and high adsorption capacity adsorbent by laccase-catalyzed self-polymerization of GAL and cross-linking with PEI

Abstract

A novel polyfunctional and high adsorption capacity adsorbent was prepared by laccase-catalyzed self-polymerization of GAL and cross-linking with PEI. When the mass ratio of GAL and PEI is 2 : 1, the self-polymerization temperature, pH and time are 50 °C, 4.5 and 24 h respectively, and the cross-linking temperature, pH and time are 70 °C, 8–9 and 24 h respectively, the PGAL–PEI has an excellent adsorption capacity for metal ions. The absorbed amounts reached 159 mg g⁻¹, 88.23 mg g⁻¹, 320.8 mg g⁻¹, 511.36 mg g⁻¹, 234.2 mg g⁻¹ and 174.8 mg g⁻¹ for Zn(II), Fe(III), Cu(II), Pb(II), Cd(II) and Cr(III) respectively at 25 °C and pH = 5. The stability experiment showed that PGAL–PEI has good stability under acidic conditions. These findings suggest that PGAL–PEI has considerable potential for application in metal ion removal from waste water.