Enzymatic Degradation of Micropollutants in Water: the Case of Tetracycline Degradation by Enzymes Immobilized on Monoliths

Abstract

Enzymatic monolithic reactors were applied for the degradation of micropollutants through flow-through reactor configuration. Silica monoliths with uniform macro-/mesoporous structures (20 µm and 20 nm macro- and mesopores diameters) high porosity (83%) and high surface area (370 m2 g-1) were prepared. The monoliths were cladded in steel tubing and laccase from Trametes versicolor was immobilized by covalent grafting. Enzymatic monoliths presented a very good oxidation activity and were used for the degradation of tetracycline (TC) in aqueous solutions in a tubular plug reactor with recycling configuration. TC degradation efficiency was found to be 40-50 % after 5 h of reaction at pH 7. The immobilized laccase on silica monoliths exhibited high operational stability during 75 hours of sequential operation.