Treatment of antimicrobial azole compounds via photolysis, electrochemical and photoelectrochemical oxidation: Degradation kinetics and transformation products

Environ Pollut. 2023 Oct 1:334:122220. doi: 10.1016/j.envpol.2023.122220. Epub 2023 Jul 17.

Abstract

The degradation kinetics and transformation products of pharmaceutical azole drugs from Watch List 2020/1161 (fluconazole, FCZ; miconazole, MCZ; clotrimazole, CTZ; and sulfamethoxazole, SMX) are examined individually and as a mixture in Milli-Q water and simulated wastewater (SWW) upon treatment with three different advanced oxidation processes: (i) photolysis (UV), (ii) electrochemical (eAOP), and (iii) photoelectrochemical (eAOP/UV). For individual pollutant degradation, UV was found to be significantly more effective for SMX and CTZ compared to MCZ and FCZ. Whereas when treating the azole drugs mixture, eAOP/UV was determined to be the most effective treatment method. The degradation efficiency was higher in Milli-Q than in SWW because the treatment efficiency depended on the matrix compositions. The degradation products formed under different processes were identified, and the routes of transformation were proposed. The results of this study can assist in the selection of the most suitable treatment technology depending upon the pollutant or matrix.

Keywords: Clotrimazole; Degradation pathway; Electrochemical advanced oxidation processes; Fluconazole; Miconazole; Sulfamethoxazole.

MeSH terms

  • Anti-Infective Agents*
  • Azoles
  • Hydrogen Peroxide / chemistry
  • Kinetics
  • Oxidation-Reduction
  • Photolysis
  • Sulfamethoxazole
  • Ultraviolet Rays
  • Water Pollutants, Chemical* / analysis

Substances

  • Azoles
  • Water Pollutants, Chemical
  • Anti-Infective Agents
  • Sulfamethoxazole
  • Hydrogen Peroxide