Degradation of carbamazepine in surface water: performance of Pd-modified TiO2 and Ce-modified ZnO as photocatalysts

ROSSI, LUCÍA; VILLABRILLE, PAULA I.; MARINO, DAMIÁN J.; ROSSO, JANINA A.; CAREGNATO, PAULA

Environmental Science and Pollution Research

SPRINGER HEIDELBERG

Año: 2023 vol. 30 p. 116078 - 116090

Carbamazepine is a widely used antiepileptic drug to control and treat a variety of disorders that is frequently detected insurface water, and in municipal and urban wastewater. This recalcitrant pollutant could be removed by alternative advancedoxidation technology such as heterogeneous photocatalysis. Ce-modified ZnO and Pd-modified TiO2were synthesized by amicrowave-assisted sol–gel method. According to the characterizations (Raman spectroscopy, UV–Vis diffuse reflectancespectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy), a mixture of oxides was determinedin both materials: CeO2/ZnO and PdO/TiO2. Photocatalytic degradation of carbamazepine in pure water under visible light(3 h) was assayed. The degradation percentage obtained with each catalyst was 80%, 53%, 20%, and 9% for ZnO, Ce-modifiedZnO, TiO2,and Pd-modified TiO2,respectively. The leaching of Zn as a possible source of water contamination was tested,finding the lowest value for Ce-modified ZnO by adjusting the initial pH up to neutrality. Later, an environmentally relevantconcentration of carbamazepine (228 μg L−1) was assayed, using local surface water (pH = 8.3). Despite the presence ofother compounds in the real water matrix, after 5 h of photocatalysis, a 56% of degradation of the pharmaceutical and lowleaching of Zn were achieved. The use of Ce-modified ZnO activated by visible light is a promising strategy for the abatementof pharmaceutical active compounds.