title: Improved biodegradation of synthetic azo dye by horseradish peroxidase cross-linked on nano-composite support.
abstract: A ZnO nanowires/macroporous SiO2composite was used as support to immobilize horseradish peroxidase (HRP) by in-situ cross-linking method. Using diethylene glycol diglycidyl ether (DDE) as a long-chained cross-linker, it was adsorbed on the surface of ZnO nanowires before reaction with HRPs, the resulted composite was quite different from the traditional cross-linking enzyme aggregates (CLEAs) on both structure and catalytic performance. The immobilized HRP showed high activity in the decolorization of azo dyes. The effect of various conditions such as the loading amount of HRP, solution pH, temperature, contact time and concentration of dye were optimized on the decolorization. The decolorization percentage of Acid Blue 113 and Acid black 10 BX reached as high as 95.4% and 90.3%, respectively. The immobilized HRP gave the highest decolorization rate under dye concentration as 50mg/L and reaction time of 35min. The immobilized HRP exhibited much better resistance to temperature and pH inactivation than free HRP. The storage stability and reusability were greatly improved through the immobilization, from the decolorization of Acid blue 113 it was found that 80.4% of initial efficiency retained after incubation at 4°C for 60 days, and that 79.4% of decolorization efficiency retained after 12 cycles reuse.
authors.affiliation: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, PR China.
authors.forename: Huaiyan
authors.initials: H
authors.lastname: Sun
authors.affiliation: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, PR China.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Jin
authors.affiliation: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, PR China.
authors.forename: Nengbing
authors.initials: N
authors.lastname: Long
authors.affiliation: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, PR China. Electronic address: zhangruifeng@nbu.edu.cn.
authors.forename: Ruifeng
authors.initials: R
authors.lastname: Zhang
mesh_terms: D000327:Adsorption; D001391:Azo Compounds / Q000737:chemistry*; D001673:Biodegradation, Environmental; D004396:Coloring Agents / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000737:chemistry*; D004853:Epoxy Resins / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D053761:Nanocomposites / Q000737:chemistry; D053770:Nanowires / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013696:Temperature; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D004853:Epoxy Resins; D006735:Horseradish Peroxidase; D012822:Silicon Dioxide; D062065:Wastewater; D014874:Water Pollutants, Chemical; D015034:Zinc Oxide; C035364:Quetol 651; C015967:Levanol Fast Cyanine 5RN
keywords: Azo dye; Decolorization; Epoxy cross-linker; Horseradish peroxidase; Nano-composites support