Design and optimization of an enzymatic membrane reactor for tetracycline degradation

The tetracycline, antibiotic considered as a recalcitrant pollutant, was successfully depleted from model aqueous solutions by immobilized laccase from Trametes versicolor in an enzymatic membrane reactor. The results obtained show that tetracycline is depleted from water solutions at room temperature and without adding any extra chemicals. The degradation of tetracycline in aqueous solutions at 20 mg L-1 during 24 h, with equivalent amounts of free or immobilized biocatalyst, allowed reaching a tetracycline degradation yield of 56% with an enzymatic membrane whereas it was only of 30% with free laccase. This result highlights the good reactivity and stability of the immobilized enzyme for the degradation of tetracycline. Moreover, the enzymatic membrane reactor was able to reach a constant degradation rate of 0.34 mg of tetracycline per hour during 10 days. (C) 2014 Elsevier B.V. All rights reserved.