Degradation of benzimidazoles by photoperoxidation: metabolites detection and ecotoxicity assessment using Raphidocelis subcapitata microalgae and Vibrio fischeri

• Published in: Environmental science and pollution research international 2021-05, Vol.28 (19), p.23742-23752
• Main Authors: Venancio, Wilson Augusto Lima, Rodrigues-Silva, Caio, Spina, Mylena, Diniz, Vinicius, Guimarães, José Roberto
• Format: Article
• Language: English
• Subjects: Advanced Oxidation/Reduction Technologies: An Perspective from Iberoamerican Countries; Albendazole; Algae; Aquatic microorganisms; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacteria; Benzimidazoles; Biodegradation; Dosage; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Free radicals; Hydrogen peroxide; Hydroxyl radicals; Metabolites; Microalgae; Microorganisms; Oxfendazole; Parasitic diseases; Raphidocelis subcapitata; Reaction products; Reaction time; Sulfur dioxide; Thiabendazole; Veterinary medicine; Vibrio fischeri; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-020-11294-x

Benzimidazoles (BZ) are among the most used drugs to treat parasitic diseases in both human and veterinary medicine. In this study, solutions fortified with albendazole (ABZ), fenbendazole (FBZ), and thiabendazole (TBZ) were subjected to photoperoxidation (UV/H 2 O 2 ). The hydroxyl radicals generated by the process removed up to 99% of ABZ, and FBZ, in the highest dosage of H 2 O 2 (i.e., 1.125 mmol L -1 ; 4.8 kJ L -1 ). In contrast, 20% of initial TBZ concentration remained in the residual solution. In the first 5 min of reaction (i.e., up to 0.750 mmol L -1 of H 2 O 2 ), formation of the primary metabolites of ABZ—ricobendazole (RBZ), albendazole sulfone (ABZ-SO 2 ), and oxfendazole (OFZ)—was observed. However, these reaction products were converted after the reaction time was doubled. The residual ecotoxicity was investigated using the Raphidocelis subcapitata microalgae and the marine bacteria Vibrio fischeri . The results for both microorganisms evidence that the residual solutions are less harmful to these microorganisms. However, after 30 min of reaction, the treated solution still presents a toxic effect for V. fischeri , meaning that longer reaction times are required to achieve an innocuous effluent.