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

• Published in: Environmental science and pollution research international 2023-11, Vol.30 (54), p.116078-116090
• Main Authors: Rossi, Lucía, Villabrille, Paula I., Marino, Damián J., Rosso, Janina A., Caregnato, Paula
• Format: Article
• Language: English
• Subjects: Antiepileptic agents; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Carbamazepine; Catalysts; Cerium oxides; Contamination; Degradation; Diffuse reflectance spectroscopy; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Leaching; Municipal wastewater; Oxidation; Palladium; Pharmaceuticals; Photocatalysis; Photodegradation; Photoelectron spectroscopy; Photoelectrons; Raman spectroscopy; Research Article; Scanning electron microscopy; Sol-gel processes; Spectroscopy; Spectrum analysis; Surface water; Titanium dioxide; Waste Water Technology; Water Management; Water pollution; Water Pollution Control; X ray photoelectron spectroscopy; Zinc oxide
• ISSN: 1614-7499; 0944-1344; 1614-7499
• DOI: 10.1007/s11356-023-30531-7

Carbamazepine is a widely used antiepileptic drug to control and treat a variety of disorders that is frequently detected in surface water, and in municipal and urban wastewater. This recalcitrant pollutant could be removed by alternative advanced oxidation technology such as heterogeneous photocatalysis. Ce-modified ZnO and Pd-modified TiO 2 were synthesized by a microwave-assisted sol–gel method. According to the characterizations (Raman spectroscopy, UV–Vis diffuse reflectance spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy), a mixture of oxides was determined in both materials: CeO 2 /ZnO and PdO/TiO 2 . 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-modified ZnO, TiO 2 , and Pd-modified TiO 2 , 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 relevant concentration of carbamazepine (228 µg L −1 ) was assayed, using local surface water (pH = 8.3). Despite the presence of other compounds in the real water matrix, after 5 h of photocatalysis, a 56% of degradation of the pharmaceutical and low leaching of Zn were achieved. The use of Ce-modified ZnO activated by visible light is a promising strategy for the abatement of pharmaceutical active compounds.