Emerging pharmaceutical pollutants including non-steroidal anti-inflammatory drugs (NSAIDs) are omnipresent in aquatic bodies such as groundwater, surface water, and seawater, as they are not fully removed through classic wastewater treatment. Solar-driven heterogeneous photocatalysis is a promising advanced oxidation technology for enhancing the removal and/or biodegradability of persistent pharmaceuticals. However, its multiparametric nature and the limited efficiency of the classic TiO2 photocatalysis have both motivated extensive process intensifications, lately. In this study, we report on the design of experiment screening of the solar photocatalytic degradation of ibuprofen (IBU), one of the most detected NSAIDs in aquatic environments, over a novel nano-hetero-structured, Bi2O3/CeO2/TiO2 photocatalyst. The TiO2-rich photocatalyst was prepared by sol-gel-assisted hydrothermal synthesis. CeO2 was incorporated for its peculiar surface redox properties, meanwhile, the addition of Bi2O3 served to improve the harvesting of visible light from the solar spectrum. The effects of IBU concentration (5-55 mg/L), pH (3-11), and salinity of the reaction medium (0-10,000 mg/L) on the removal percentage of the analyte, were investigated using a slurry reactor loaded with 1 g/L photocatalyst and irradiated with 1 SUN. The studies were conducted via a two-level, full factorial design, to screen for the most influential parameters and interactions among the selected variables. The thermodynamic and kinetic analyses of the adsorptive and photocatalytic removal of IBU were assessed by UV-vis spectrophotometry, LC-UV, and LC-MS/MS measurements of aliquots sampled under dark and solar irradiation. The results (including those of control photolysis experiments) confirmed an enhanced photocatalytic degradation of IBU irrespective of the starting pollutant concentration or salinity conditions. The pH was the most critical factor due to its effect on the photocatalyst surface charge and adsorption of IBU. Removals of 99.7-100% were achieved at low pH. Both salinity and initial IBU concentration mainly influenced the kinetics of photocatalysis and the extent of intermediates formed.

Degradation of ibuprofen over solar-light responsive Bi2O3/CeO2/TiO2 photocatalyst in saline water

Where thousands of chemistry professionals meet to share ideas and advance scientific and technical knowledge. Spring 2023 abstracts, posters, and presentations will launch at the end of March.

ACS Spring 2023

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.