表面铜螯合磁性二氧化硅固定化漆酶及其催化降解水中2,4-二氯酚

Immobilization of laccase on Cu(Ⅱ) chelating magnetic silica and its catalytic degradation of 2,4-dichlorophenol

利用磁性二氧化硅表面接枝的聚丙烯酰胺络合Cu2+离子,制备了表面铜螯合磁性SiO2材料,采用傅立叶红外光谱(FT-IR),X射线衍射(XRD)对该磁性材料进行了表征,并通过配位作用固定化漆酶,考察了其对水中2,4-二氯酚(2,4-DCP)的催化降解效能及主要影响因素。结果表明,表面铜螯合磁性SiO2固定化漆酶对2,4-DCP具有较好的催化降解效能,利用8 g/L固定化漆酶催化降解50 mL初始浓度为24.25 mg/L的2,4-DCP,反应12 h 2,4-DCP去除率达91%;当pH值在3.0～6.0范围内时,2,4-DCP的去除率随反应pH值的增加而升高;2,4-DCP初始浓度在14.39～257.6 mg/L范围内时,反应12 h,2,4-DCP的去除率均达85%以上;给酶量增加促进2,4-DCP的去除,但过多的给酶量导致单位质量固定化漆酶催化降解2,4-DCP的速率下降;水中硫酸根离子对固定化漆酶催化降解2,4-DCP具有明显的促进作用,而碳酸氢根离子明显抑制反应的进行。

Cu（II） chelating magnetic silica composite particles were prepared by chelating Cu（II） ions on polyaerylamide which was grafted onto the surface of magnetic silica particles. The particles were characterized by Fourier transform infrared spectroscopy （FT-IR） and X-ray diffraction （XRD）. Laeease was immobilized on the Cu（II） chelating magnetic silica by coordination. The catalytic capacity of the immobilized laeease for 2,4- diehlorophnol （DCP） removal and influeneial factors were discussed. The results indicated that the immobilized lacease had a good catalytic capacity for 2,4-DCP removal. The removal efficiency reached 91% after 12 h when 8 g/L of immobilization laccase for the degradation of 2,4-DCP （volume： 50 mL; the initial concentration： 24.25 mg/L） was used. When the pH increased from 3.0 to 6.0, the removal efficiency of 2,4-DCP increased. When the concentration of 2,4-DCP ranged from 14.39 mg/L to 257.6 mg/L, the removal efficiency all excee- ded 85% after 12 h. The removal efficiency increased with the increasing amount of immobilized laecase. How- ever, too much immobilized laccase would cause the removal velocity decreased. Sulfate ions in the aqueous so- lution can promote the removal efficiency significantly, while bicarbonate ions inhibited the reaction.