The effects of sorption of air oxygen onto chitosan weredemonstrated by evaluation of the changes in dissolved oxygenconcentrations (Fig. 3, curves 1 and 2). When chitosan beads wereadditionally treated with air oxygen, the dissolved oxygen con-centration during the first 10–15 min remarkably increases, thenit rather rapidly decreases and after some time (∼300 h) increasesagain. When 1 g of dry chitosan is kept in 100 mL of deoxygenatedwater, the dissolved oxygen concentration increases from ∼0 to0.7 mg O2L−1. It could be assumed that only a small amount of oxy-gen is adsorbed from air. When the sample kept in deionized waterFig