UV/chlorine and chlorination of effluent organic matter fractions: Tracing nitrogenous DBPs using FT-ICR mass spectrometry.

Autor: Wang Y; Department of Environmental Science, School of Geography and Tourism, Shaanxi Normal University, Xi'an 710119, China., Xiang Y; Institut de Chimie des Milieux et des Matériaux IC2MP UMR 7285 CNRS, Université de Poitiers, France; Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, China., Marques Dos Santos M; Nanyang Environment & Water Research Institute (NEWRI), Nanyang Technological University, Singapore., Wei G; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China., Jiang B; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China., Snyder S; Nanyang Environment & Water Research Institute (NEWRI), Nanyang Technological University, Singapore., Shang C; Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, China., Croué JP; Institut de Chimie des Milieux et des Matériaux IC2MP UMR 7285 CNRS, Université de Poitiers, France. Electronic address: jean.philippe.croue@univ-poitiers.fr.
Jazyk: angličtina
Zdroj: Water research [Water Res] 2023 Mar 01; Vol. 231, pp. 119646. Date of Electronic Publication: 2023 Jan 19.
DOI: 10.1016/j.watres.2023.119646
Abstrakt: UV/chlorine process is a promising advanced treatment to eliminate pathogen and remove refractory micropollutants for reclamation of municipal secondary effluent. However, effluent organic matter (EfOM) featuring high organic nitrogen content serves as a potential precursor for nitrogenous disinfection byproducts (N-DBPs) of health concern. The molecular-level alteration of a hydrophobic (HPO) EfOM fraction and a transphilic (TPI) EfOM fraction isolated from the same municipal effluent and the formation of N-DBPs in the UV/chlorine were tracked by ultrahigh-resolution mass spectrometry. Compared with chlorination, UV/chlorine induced a significantly greater modification on the molecular composition of EfOM and resulted in formation of unique formulae and chlorinated molecules with higher degree of oxidation, lower aromaticity, and less carbon number due to the involvement of reactive radical species. For both EfOM fractions, UV/chlorine formed more diverse DBPs with higher intensity and Cl-incorporation than chlorination. The TPI fraction of EfOM characterized by higher O/C and N/C ratios generated more N-DBPs with higher intensity clustered in the high O/C region than the HPO fraction of EfOM by both UV/chlorine and chlorination. Totally, 207 and 117 nitrogen-containing chlorinated formulae were recorded after UV/chlorine treatment of TPI and HPO, respectively. Precursor tracking found a greater number of DBPs were originated from raw EfOM through electrophilic substitution pathway rather than chlorine addition. Toxicity bioassays demonstrated that DBPs can trigger oxidative stress-induced DNA damage, while HPO fraction of EfOM dominated the induction of cytotoxicity. However, no correlation could be established between the diversity/abundance of N-DBPs and the level of DNA damage. A total of 22 DBPs with a significant rank correlation with DNA damage were identified, while C 8 H 6 O 5 NCl was found as the N-DBP with the strongest correlation. The potential toxic chlorine-containing formula with the most abundant intensity was assigned to C 5 HO 3 Cl 3 . This study suggests that the character and transformation of EfOM and associated toxicity is critical to evaluate the UV/chlorine process toward practical application.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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