Abstract: Under a certain conditions, the experiment immobilizes proteases on silica gel, activated charcoal and largepore resin by physical adsorption, and then compares the immobilizing effect of the three supports to find out the optimal support. Subsequently, proteases on three different supports are used in enzymatic hydrolysis of soybean wastewater with highlyconcentrated protein in order to investigate the optimal pH for enzyme activity and treatment effect. At last, on optimal pH condition, study on the evolution of enzyme activity and treatment effect with the alteration of hydraulic retention time (HRT) is conducted. Comparing the immobilizing effect, enzyme activity and treatment effect at different pH and the evolution of enzyme activity and treatment effect with the alteration of HRT on the three supports, it can be concluded that resin has good immobilizing effect and best treatment effect on wastewater with highlyconcentrated protein. The optimal pH is 5.5, enzyme activity reaches the peak 30.82 mg/min at 0.5 h, and the loss of enzyme activity is relatively small, only 3.74 mg/min. The protein reduction ration is 39.93%.

Key words: immobilized enzyme, protease, highlyconcentrated organic wastewater, protein hydrolysis,  immobilizing support