Study On Degradation Of Anthraquinone Dyes By Laccase And The Laccase Immobilization

As one of polyphenoloxidas, the laccase(EC 1. 10. 3. 2) is widely used in the areas o f treating of textile dyeing wastewater, chemical industry and medicine. Here the laccase i s from trametes versicolor, which is one kind of fungal laccases. We have studied that th e degradation effect of the laccase in some conditions, for example, which includes differe nt pH, temperature, concentration of dye and optimized laccase concentration at the certai n concentration of dye. We also studied the degradation activity of laccase in the system of ultrapure water and degradation of different dyes by laccase. This thesis also studied t he immobilization of laccase based on modified silicon and the experiment on degrading o f dyes by to the immobilized laccase. We also obtained the functional silicon with di-pyri dinemethanamine, which was characterized by TGA, FITR and elemental analyzer. The ex perimental results agree with the theoretical ones and the effect of extraction of copper io n was assessed.According to the experimental results, the laccase from trametes versicolor could effici ently degrade some anthraquinone dyes. To take reactive brilliant blue K-NR as a represe ntative, the research results show that the best pH value range is 6.0 to 7.0 in the laccase reaction, the upper limit of losing enzyme activity is 8.0 and the lower is 3.0. The opti mum temperature is 40 ℃ and the upper limit of losing enzyme activity is 60℃. The op timum concentration of laccase in the reaction system is 7.5U/mL. The range of the dye of degradation by laccase is between 0m g/L and 150 mg/L. If the concentration of lacca se is 7.5 U/mL, the concentration of dye is about 75 mg/L, which can be efficiently degr aded. We also evaluate the activity of immobilized laccase from trametes versicolor, the e nzyme activity of immobilization is U = 0.0740 U/mg and rate of immobilization(R) is 8.0%. Silica gel with 2,2’-dipicolylamine can bind the copper ion in the water, the rate of extraction is 0.0079.After study on the experiment results, It shows that the laccase from trametes versicolor has the good degradation activity on reactive brilliant blue K-NR. it can also work well on other dyes. Interestingly, laccase in the system of ultrapure water has a strong degradation activity on reactive brilliant blue K-NR. We have made a research on the process of immobilization of laccase on modified silicon and degradation of reactive brilliant blue K-NR by immobilized laccase. The mechanism of dye degradation by laccase was investgated. In addition, the extractive effect on copper ion in water by the functionalized silicon gel with 2,2’-dipicolylamine was also investgated. It will be worthy that the textile dyeing wastewater is treated by the laccase, immobilized laccase and the functional silicon ligand as a extraction agent of copper ion.