Preparation and characterization of magnetic polyporous biochar for cellulase immobilization by physical adsorption

Because of the high specific surface area, polyporous structure and ease of preparation, porous biochar from lignocellulosic biomass is popular for being used as support for enzyme immobilization. In this work, polyporous biochar combined with magnetic particle gamma-Fe2O3 was prepared by calcination and then used as support for cellulase adsorption. The effects of calcination temperature and time on the properties of magnetic polyporous biochar were investigated and the optimum preparation condition was obtained. For the cellulase adsorption, the immobilization capacity for the magnetic support reached as high as 266 mg/g with a relative activity of 73.6% compared with that of free cellulase. The behavior of cellulase adsorption showed that an endothermic process occurred more easily at high temperatures, which resulted in a high adsorption amount.