Bio-deoxygenation of water using glucose oxidase immobilized in mesoporous MnO2

In this research, removal of water dissolved oxygen reduced by glucose and catalyzed by glucose oxidase (GOD) was the focus of attention. In order to maintain the enzyme in repeated or continuous runs, its immobilization in the porous manganese dioxide support was carried out. In addition to enzyme immobilization support, manganese dioxide also plays catalytic role in the decomposition of hydrogen peroxide produced during the glucose oxidation reaction. In so doing synthesized porous MnO2 was applied with the specific surface area of 176.93 m2/g and total pore volume of 0.47 ml/g. The activity of hybrid GOD–MnO2 biocatalyst in the removal of dissolved oxygen was achieved to be 700 U/g. Deoxygenation of 150 ml of tap water with 6.50 mg/l O2 which was catalyzed by the 0.15 g hybrid catalyst in the presence of twice stochiometric amount of glucose was completed in less than 4 min at 35 °C.

► Water DO has been reduced by glucose and catalyzed by glucose oxidase.
► Glucose oxidase was immobilized on mesoporous MnO2.
► MnO2, beside enzyme support, plays catalytic role in the decomposition of H2O2.
► The biological DO removal is green technology and it is safe for operating.
► Gluconic acid (by-product) is one of the oxygen scavenger materials.