Bicarbonate-Activated Hydrogen Peroxide in Presence of CaCo0.5Fe0.5O3 Perovskite for Highly Efficient Carbamazepine Degradation

Abstract

This study aims to investigate the role of bicarbonate as a co-oxidant towards facile activation of hydrogen peroxide into reactive radicals during catalysis. A different set of bicarbonate to hydrogen peroxide dosage ratios (R = 0, 0.5, 1, 5, 10, 15, 20, 25, and ∞) were varied in the presence of CaCo0.5Fe0.5O3 perovskite during catalysis to enhance the oxidative degradation of carbamazepine (CBZ) micropollutants. It was found that only 10-13% of CBZ was degraded in the presence of a single oxidant (R = 0 and R = ∞). Interestingly, 98% degradation of CBZ was achieved within 45 min of reaction at an R-value of 20. This improvement in CBZ degradation was contributed to the facile generation of reactive radicals (•OH and •CO3–) due to the efficient redox cycle during catalysis. The degradation of CBZ in the bicarbonate-activated hydrogen peroxide-CaCo0.5Fe0.5O3 system at R = 20 agrees well with the Behnajady-Modirshahla-Ghanbery reaction kinetics model. These results provide new insights into the modulation of bicarbonate to hydrogen peroxide dosage ratio (R) for efficient oxidative degradation of recalcitrant micropollutants facilitated by CaCo0.5Fe0.5O3 perovskite catalysts in the bicarbonate-activated hydrogen peroxide system.