A comprehensive insight into the transformation pathways and products of fluoxetine and venlafaxine in wastewater based on molecular networking nontarget screening

Gang Wu; Tianshu Wu; Yiran Chen; Xiwei He; Peng Liu; Depeng Wang; Jinju Geng; Xu-Xiang Zhang

doi:10.1016/j.scitotenv.2023.167727

A comprehensive insight into the transformation pathways and products of fluoxetine and venlafaxine in wastewater based on molecular networking nontarget screening

Sci Total Environ. 2024 Jan 10:907:167727. doi: 10.1016/j.scitotenv.2023.167727. Epub 2023 Oct 20.

Authors

Gang Wu¹, Tianshu Wu¹, Yiran Chen², Xiwei He¹, Peng Liu¹, Depeng Wang¹, Jinju Geng³, Xu-Xiang Zhang⁴

Affiliations

¹ State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, Jiangsu, China.
² State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, Jiangsu, China; School of Environment, Hohai University, Nanjing 211100, Jiangsu, China.
³ State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, Jiangsu, China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400044, China.
⁴ State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, Jiangsu, China. Electronic address: [email protected].

PMID: 37864996
DOI: 10.1016/j.scitotenv.2023.167727

Abstract

Fluoxetine (FLX) and venlafaxine (VEN) are widely used antidepressant pharmaceuticals and were frequently detected in wastewater. Despite incomplete mineralization during biological wastewater treatment processes has been revealed, little is known about their transformation products (TPs) formed in the biological systems. To fill this gap, batch reactors and molecular networking nontarget screening were employed to identify the TPs and explore the transformation pathways of FLX and VEN in wastewater. On the basis, the concentrations of the TPs in wastewater treatment plants (WWTPs) were determined and their toxicity was predicted. The removal rate constants per unit of biomass of FLX and VEN were up to 0.3192 and 0.1644 L/(gMLSS*d) in batch experiments, respectively. Subsequently, 11 TPs of VEN and 11 TPs of FLX were tentatively identified, among which 9 TPs of FLX and 5 TPs of VEN were newly reported in this study. The proposed transformation pathways provided new insights into the transformation reactions including dehydrogenation, N-formylation and hydroxylation for FLX, and formylation, epoxidation and methylation for VEN. Particularly, N-succinylation and demethylation were the dominant transformation pathways for FLX and VEN during transformation processes. The results of sampling campaigns revealed that the accumulated concentration of TPs were higher than the concentrations of VEN in effluent of WWTPs. In silico prediction results suggested that certain TPs have higher toxicity, persistence and biodegradability than their corresponding parent compounds of FLX and VEN. In addition, VEN-TP264(a) showed higher ecological risks than VEN. This study revealed the transformation processes and fate of FLX and VEN in wastewater, indicating that greater concerns should be exerted on the toxicity detection and control of the TPs of FLX and VEN in the treated wastewater.

Keywords: Fluoxetine; Molecular networking; Nontarget screening; Transformation products; Venlafaxine; Wastewater.

MeSH terms

Antidepressive Agents
Fluoxetine* / toxicity
Venlafaxine Hydrochloride / toxicity
Wastewater
Water Pollutants, Chemical* / analysis

Substances

Fluoxetine
Venlafaxine Hydrochloride
Wastewater
Water Pollutants, Chemical
Antidepressive Agents