Degradation Of MXC By Immobilized Cellulase With Magnetic Hydrotalcite

Methoxychlor (MXC) as insecticide, is widely used in fruit, crop protection. It is anti-biodegradable and easily to accumulate, which is important environmental hormones contaminants. Studies show that MXC also enter the body through food and accumulate in the body, when reaches a certain amount, and it will damage the body function. So the research of MXC is imminent, it has been attracted wide concern coming from different countries.Cellulase is a highly effective catalyst and used to degradation of pesticides, which has wide application in many fields, for example, biological, food, environmental, and chemical. But because of its instability and easily deactivated affecting its wide application, it can improve the stability and reuse through the immobilized cellulase. In this paper, layered hydrotalcite material as a carrier for immobilized cellulase to degradation of MXC is studied. The synthesis of needle-like nano-hydrotalcite with particle size of about 10 nm is by a co-precipitation method.Then, FeCl3·6H2O and FeCl2@4H2O as the iron source, NaOH as a precipitating agent, PEG-4000 as surfactant synthesis suspension, the preparation of Fe3O4 is got. Hydrotalcite as a template, Fe3O4 were assembled to intercalated hydrotalcite to obtain a magnetic hydrotalcite. Synthetic magnetic hydrotalcite as a carrier immobilize cellulase with glutaraldehyde as the cross-linking agent. Effects of various factors on the activity of immobilized cellulase is Studied. Experiments show:0.1g magnetic hydrotalcite after amination was added 5 mL of 5% glutaraldehyde aqueous solution, shaken at room temperature 6h, centrifuged, then the carrier is added to 5 mL pH 5.5, at a concentration of 0.8g/L of cellulase solution, shaken for 8 h at 45℃, centrifuged, washed with a buffer solution to get immobilized cellulase with the maximum activity. At MXC concentration 20mg/L, the pH value of 6.0 and a temperature of 50℃, the concentration of AOT is 5g/L, shaken for 10 h, the immobilized cellulase for degradation MXC is best. ABTS is added to promote the immobilized cellulase for degradation of MXC, MXC degradation efficiency increased about 5%. After continuous use of immobilized enzyme seven times on MXC degradation, the degradation rate remained at around 23%. At different reaction time and temperature, According to results of degradation MXC, we can see that the activation energy of free cellulase and immobilized cellulase degradation is 44.53 KJ/mol and 38.32 KJ/mol, reflecting the immobilized cellulase is in favor of MXC degradation.