Biotransformation pathways of pharmaceuticals and personal care products (PPCPs) during acidogenesis and methanogenesis of anaerobic digestion

• Published in: Journal of hazardous materials Vol. 478; p. 135444
• Main Authors: Carneiro, Rodrigo B., Gil-Solsona, Rubén, Subirats, Jessica, Restrepo-Montes, Esteban, Zaiat, Marcelo, Santos-Neto, Álvaro J., Gago-Ferrero, Pablo
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.10.2024
• Subjects: Anaerobiosis; Biodegradation, Environmental; Biofilm; Bioreactors; Biotransformation; Biotransformation products; Cosmetics - metabolism; HRMS; Methane - metabolism; Non-target screening; Organic micropollutants; Pharmaceutical Preparations - metabolism; Water Pollutants, Chemical - metabolism; Biofilm; Biotransformation products; HRMS; Organic micropollutants; Non-target screening
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2024.135444

Pharmaceuticals and personal care products (PPCPs) exhibit varying biodegradability during the acidogenic and methanogenic phases of anaerobic digestion. However, there is limited information regarding the end products generated during these processes. This work investigates the biotransformation products (BTPs) generated in a two-phase (TP) acidogenic-methanogenic (Ac-Mt) bioreactor using advanced suspect and nontarget strategies. Fourteen BTPs were confidently identified from ten parent PPCPs including carbamazepine (CBZ), naproxen (NPX), diclofenac (DCF), ibuprofen (IBU), acetaminophen (ACT), metoprolol (MTP), sulfamethoxazole (SMX), ciprofloxacin (CIP), methylparaben (MPB) and propylparaben (PPB). These BTPs were linked with oxidation reactions such as hydroxylation, demethylation and epoxidation. Their generation was related to organic acid production, since all metabolites were detected during acidogenesis, with some being subsequently consumed during methanogenesis, e.g., aminothiophenol and kynurenic acid. Another group of BTPs showed increased concentrations under methanogenic conditions, e.g., hydroxy-diclofenac and epoxy-carbamazepine. The most PPCPs showed high removal efficiencies (> 90 %) – SMX, CIP, NPX, MTP, ACT, MPB, PPB, while DCF, CBZ and IBU demonstrated higher persistence - DCF (42 %); CBZ (40 %), IBU (47 %). The phase separation of anaerobic digestion provided a deeper understanding of the biotransformation pathways of PPCPs, in addition to enhancing the biodegradability of the most persistent compounds, i.e., DCF, CBZ and IBU. [Display omitted] •14 BTPs were confidently identified from ten investigated parent PPCPs.•Acidogenesis plays a crucial role on the PPCPs biotransformation.•Hydroxylation reaction was the main biotransformation pathway.•Two-phase reactor enhances the biodegradability of DCF, IBU and CBZ.