Degradation of 2,4-dichlorophenol catalyzed by the immobilized laccase with the carrier of Fe_3O_4@MSS–NH_2

With the Fe3O4@MSS(magnetic mesoporous silica spheres)–NH2as the carrier and the glutaraldehyde as crosslinking agent,the immobilized laccase has been prepared and characterized by XRD,IR,SEM and BET etc.Under the optimal conditions,the removal efficiency of2,4-DCP reached 88%and the removal efficiency still remained 61.5%after five cycles of operations.In virtue of GC–MS analysis,2,5-dimethoxyl-1,4-quinone,2-chlorine-1,4-dimethoxyl benzene,3,30-dichlorine-4,40-dimethoxyl biphenyl,maleic acid phenol ester,and three kinds of maleic acid,alcohol ester,and para-hydroxyl phenol ester compounds have been identified as intermediate and final degradation products of 2,4-DCP,respectively.Besides,the degradation products of 2,4-DCP have been confirmed by performing the1H-NMR and13C-NMR experiments,further demonstrating the degradation mechanism of 2,4-DCP by the immobilized laccase.

With the Fe304@MSS （magnetic mesoporous silica spheres）-NH2 as the carrier and the glutaraldehyde as crosslinking agent, the immobilized laccase has been pre- pared and characterized by XRD, IR, SEM and BET etc. Under the optimal conditions, the removal efficiency of 2,4-DCP reached 88 % and the removal efficiency still remained 61.5 % after five cycles of operations. In virtue of GC-MS analysis, 2,5-dimethoxyl-l,4-quinone, 2-chlo- rine-l,4-dimethoxyl benzene, 3,3＇-dichlorine-4,4＇-dimeth- oxyl biphenyl, maleic acid phenol ester, and three kinds of maleic acid, alcohol ester, and para-hydroxyl phenol ester compounds have been identified as intermediate and final degradation products of 2,4-DCP, respectively. Besides, the degradation products of 2,4-DCP have been confirmed by performing the 1H-NMR and 13C-NMR experiments, further demonstrating the degradation mechanism of 2,4- DCP by the immobilized laccase.