Immobolization Of Horseradish Peroxidase On Quartz Sands And Its Application On Pollution Control

Immobilized enzyme technology is defined by physical or chemical methods of fixing enzyme in a suitable carrier, to facilitate its separation and repeated use. This paper adopts the quartz sand as the carrier, through covalent bonding method in the surface of the carrier immobilized horseradish peroxidase.At the same time, characterize the physicochemical properties and stability of the immobilized enzyme. And the immobilized enzyme used in bisphenol A removal and decoloration of dyes. This paper mainly includes the following aspects of the study.Exploring the use of Chitosan on quartz sand carrier pretreatment method,Quartz sand first with2%chitosan immersion, and then with2%glutaraldehyde solution cross-linked, on the surface can be covered with a layer of stable chitosan membrane, topped with amine, creates a condition for covalent bond cross-linked enzyme protein.The best conditions for carrier load HRP are:HRP0.1mg/mL, cross-linking agent glutaraldehyde concentration0.1%, temperature4℃, reaction time3h at pH5.0. The condition of the immobilized enzyme activity recovery rate is6.23%, average per gram carrier enzyme loading1.18U.Studied the most suitable pH, thermal stability, storage stability and recycling use of immobilized enzyme. The results show that the immobilized enzyme have a lower optimum pH than free enzyme, from5.0to4.5. Immobilized enzyme activity in acidic conditions is higher than that of free enzyme; Have a wider temperature range than the free enzyme, the immobilized enzyme at60℃can keep more than50%of the enzyme activity, while the free enzyme at60℃enzyme activity is only the original30%; Immobilized enzyme have storaged for10days the relative enzyme activity remained at90%, while the free enzyme kept only83%; immobilized enzyme recycles5times, the activity of the enzyme as the original20%or so.Study on sewage treatment by BPA. The results showed that the same unit of enzyme activity of the immobilized enzyme degradation effect is better than the free enzyme, the BPA degradation rate is55%by immobilized enzyme in3h, the free enzyme is25%; Immobilized enzyme was first used on the degradation rate of BPA was60%, After three times of repeated use the degradation rate was20%; With the H2O2concentration elevated, BPA degradation rate increased slightly.The study on the decolorization of methyl orange. The results show that, The optimum pH is4, with the increase of pH, the decolorization rate decreased gradually; Immobilized enzyme was first used the decolorization rate is50%, after three times of repeated use, the decolorization rate was20%, immobilized enzyme for repeated use needs to be further improved.