Use of chemically modified chitosan beads for sorption and enzyme immobilization

The sorption of reactive dye RR222 and Cu(II), as well as the immobilization of acid phosphatase and β-glucosidase, onto swollen chitosan beads were investigated at 30°C. Chitosan was prepared from cuttlefish wastes and was cross-linked with different dosages of glutaraldehyde and glyoxal (100-80000 mg/l). It was shown that the degree of cross-linking could be well described by the Freundlich equation. The amounts of sorption of solutes and the immobilization capacities of enzymes onto the swollen chitosan beads were significantly affected by the degrees of cross-linking. Activities and lifetimes of the immobilized enzymes were measured to evaluate the potential of practical applications.