Laccase enzyme embedded on Zinc oxide/silver doped zinc oxide nanoparticle-chitosan-PVPP composite beads

Abstract

Laccase enzyme has gained popularity due to its wide range of substrates, use of only molecular oxygen as a co-factor and release of water as a by-product. In this study, laccase enzyme was immobilized on zinc oxide-chitosan/polyvinylpolypyrrolidone (Lac-Zn-CS-PVPP) composite beads and the beads explored for the degradation of Bismarck brown dye. The beads showed significant dye removal in batch studies (with 89 % and 94 %) after 24 hours and continuous packed bed (with 72 % and 86 %) for Lac enzyme free and Lac enzyme loaded beads respectively. FTIR showed that adsorption of the dyes onto the beads was due electrostatic interaction between the hydroxyl, carbonyl and amine functional groups on the beads and the dye molecules.