Degradation of 2,4-DCP by the Immobilized Laccase on the Carrier of Fe3O4@SiO2-NH2

In this paper, the laccase immobilized on Fe3O4@SiO2-NH2 nanoparticles was successfully prepared by the glutaraldehyde cross-linking method. The degradations of 2,4-dichlorophenol (2,4-DCP) catalyzed by laccase and immobilized laccase were carried out. The optimal conditions regarding degradation efficiency were also discussed, which include reaction time, pH value, temperature, concentration of 2,4-DCP and laccase. When laccase was immobilized on Fe3O4@SiO2-NH2 carrier by crosslinking with glutaraldehyde, the stability and repetition were improved significantly. The removal efficiency of 2,4-DCP by immobilized laccase still remained over 59% after six cycles of operation. Degradation of 2,4-DCP is a first-order reaction and the activation energies of 2,4-DCP catalyzed by laccase and immobilized laccase are 51.93 kJ.mol-1 and 44.12 kJ.mol-1, respectively. The results demonstrate the immobilized laccase had a faster degradation rate than the free laccase; the magnetic carrier Fe3O4@MSS-NH2 can promote the degradation reaction.