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

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 degrees C, 4.5 and 24 h respectively, and the cross-linking temperature, pH and time are 70 degrees 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 degrees 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.