Encapsulation Of Enzymes In GELS By One-Step Polymerization For Decoloration Of AZO DYES Application

As we all known, printing and dyeing industry produced large mounts of wastewater, besides dyeing wastewater. The dyeing wastewater characterized by high chromaticity,color changeable.containing toxic substances.Traditional and conventional physical&chemical methods could cause secondary pollution. However.biological enzyme treatment of dyeing wastewater is not only environment friendly, but also decreasing double pollution, because enzymes have high decomposition efficiency, low toxicity,easy operation and wide use range.Laccase is efficient green catalyst,because its catalytic oxidation by-products is only water. Its reported that laccase not only can degrade and decolorize many kinds of dyes,but also transfer the toxic substances into non-toxic molecules. Many factors limit the application of laccase, such as the expensive price,the complex composition of dyeing wastewater, the high temperature, strong acid and alkali, high salt content and additives. All of the factors cause laccase inactivation. In addition, the stability storage of laccase is poor,and the repeated utilization ratio is low.The improvement of laccase stability and the repeated utilization ratio realized by the new type enzyme immobilization techniques. The gels as the carrier encapsulated laccase in gels three-dimensional network structure,since the gels have good biological compatibility,the immobilization method improved laccase activity,stability and reuse.This article tried to polymerize P(NIPAAm-co-AAc)gels and encapsulate laccase in gels. Then gels entrapped laccse applied to the study of decolorization of azo dyes.Firstly,by the method of "W/O inverse emulsion polymerization" prepare P(NIPAAm-co-AAc)gels and P(NIPAAm-co-AAc)/E,which is also called "one-step polymerization". Investigate the effect of different molar ratios of monomer concentration in gels and gels entrapped laccase properties (size, shape, temperature responsive and pH responsive).we found that the size of gels and gel entrapped laccase spherical particle is20～40μm, the particle size distribution is uneven and monodispersity is poor. Besides, gels and gel entrapped laccase all have temperature and pH-responsive performance.Secondly,by adding EDC,the activating agent,in the late reaction of synthesis,activating the-COOH in P(NIPAAm-co-AAc)gels. Activated-COOH groups covalently binding with laccase, in order to improve the combine fastness of laccase in gel system. The proteins contained and activity of P(NIPAAm-co-AAc)/E were tested in the paper. Though the monomer molar ratio of P(NIPAAm-co-AAc)/E was different,the protein content were about O.lmg/mL, the difference was not significant. P(NIPAAm-co-AAc)/E activity and the specific activity were both improved with the increase of AAc/NIPAAm molar ratio. Moreover,the specific activity of P (NIPAAm-co-AAc)-6%/E (125.32U/mg) was much larger than that of PNIPAAm/E(33.10U/ng)Finally, P(NIPAAm-co-AAc)/E was applied in decolorization of azo dyes. The azo dyes was much used in industry, it’s toxic,and hard to biodegradable. The production contains free aromatic amines,which hurt human. Under appropriate conditions,laccase can catalyze the degradation of azo dyes.This paper compares and analyzes the decolorization of Acid Orange II azo dye between the free laccase and gel entrapped laccase, the amount of enzymes and decolorization conditions were same.The color of dyes was characterized by decolorization rate. Meanwhile,we studied the factors,such as dye concentration, pH, temperature, time,which could effect the decolorization process. The recycling of gel entrapped laccase was researched.Research showed that the immobilized laccase had a higher decolorization(70%) than free laccase(60%). High concentrations of dye severe inhibition of enzyme activity; P(NIPAAm-co-AAc)/E presented highest catalytic activity when pH was4.0,and the the decolorization effect was significant (57%); maintaining good stability and the high recycling at pH7.0; P(NIPAAm-co-AAc)/E played a good role in the room temperature and short time (25℃,1h).