Study of Treating Wastewater by Attapulgite Clay Immobilized Horseradish Peroxidase
|School||Hefei University of Technology|
|Keywords||Horseradish peroxidase Attapulgite clay Immobilized Aniline Nitrophenol Enzyme kinetics|
In this paper, attapulgite clay ( attapulgite ) as raw material , sodium silicate is kinked agent , starch as a pore-forming agent , study prepared for horseradish peroxidase immobilized composite attapulgite and impact the orthogonal experimental carrier dissipation rate of the various factors to determine the best carrier preparation conditions ; parallel to the single factor experiment to determine the best conditions of the immobilized HRP degradation of aniline and nitrophenol best conditions and immobilized HRP reuse performance; Lineweaver-Burk linear fitting relationship between the initial nitro phenol concentration and reaction speed , determine a the immobilized HRP degradation of nitrophenols the kinetic equation , the maximum reaction velocity Vmax and the Michaelis constant Km . Experimental results show that : attapulgite with the silicate and the starch mass ratio of 100:12:20 , granulated at 550 ° C muffle furnace in the calcination time is 2 hours , the fixing of HRP carrier with a high mechanical strength ; immobilized process conditions for the room temperature , fixed time 1.5 h , the amount of unit activity carrier 1.5 mg / U, pH = 5.0; immobilized enzyme degradation of aniline wastewater reaction , the reaction time of 1.5 hours , buffer system is not required to control the pH value of 100 mg per ml / L aniline wastewater needs 4.8U fixed enzyme , H2O2 aniline in a molar ratio of 1.2:1 ; HRP immobilized in this condition can be reused 4 times , and able to maintain more than 90% of the aniline removal rate . Immobilized HRP processing nitrophenol wastewater optimum conditions for the reaction time is 1.5 h per ml of 100 mg / L of nitrophenol wastewater takes 6.0 U to the enzyme activity ( calculated at a fixed rate of 95% , a fixed activity 5.7 U ), of H2O2 and nitro phenols preferred stoichiometric ratio of 1.2:1; immobilized HRP has better reusability , 7 times after repeated use , nitrophenols removal rate is still greater than 60% ; the immobilized HRP degradation of nitrophenols kinetic equation : 1 / v = 1.403 / [ S] - 0.081 , the maximum reaction speed Vmax = 12.35 mg / L · min, Michaelis constant Km = 17.32 mg / L .