Formation of halonitromethanes from glycine during LED-UV265/chlorine disinfection

Qian Tang; Liangwen Zhu; Qing Wang; Lin Deng; Jun Hu; Rajendra Prasad Singh

doi:10.1016/j.jenvman.2023.119225

Formation of halonitromethanes from glycine during LED-UV₂₆₅/chlorine disinfection

J Environ Manage. 2023 Dec 15:348:119225. doi: 10.1016/j.jenvman.2023.119225. Epub 2023 Oct 11.

Authors

Qian Tang¹, Liangwen Zhu¹, Qing Wang¹, Lin Deng², Jun Hu³, Rajendra Prasad Singh¹

Affiliations

¹ Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, School of Civil Engineering, Southeast University, Nanjing 211189, China.
² Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, School of Civil Engineering, Southeast University, Nanjing 211189, China. Electronic address: lindeng@seu.edu.cn.
³ Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, School of Civil Engineering, Southeast University, Nanjing 211189, China; College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.

PMID: 37832297
DOI: 10.1016/j.jenvman.2023.119225

Abstract

LED-UV₂₆₅/chlorine is a promising alternative disinfection technology that emits mono-wavelength light for high germicidal efficiency. Halonitromethanes (HNMs) are highly cytotoxic and genotoxic disinfection byproducts that can be formed during LED-UV₂₆₅/chlorine disinfection. Thus, this work aimed to investigate the HNMs formation from glycine (Gly) during LED-UV₂₆₅/chlorine disinfection. The results indicated that the concentrations of chlorinated-HNMs (Cl-HNMs) increased first and then decreased as the reaction proceeded. Besides, the effects of operating parameters (UV intensity, free chlorine dosage, and pH) and coexisting ions (Cu²⁺ and Br^-) on HNMs formation were investigated. It was found that the formation concentrations of Cl-HNMs increased with the increase of LED-UV₂₆₅ intensity and free chlorine dosage but decreased with increased pH. The presence of Cu²⁺ promoted the formation of Cl-HNMs. The total concentration of HNMs (at 3 min) with adding 1.5 mg/L Cu²⁺ was 30.90% higher than that without Cu²⁺. Notably, nine species of HNMs were detected after adding Br^-, and the total concentrations of HNMs were enhanced. Moreover, Cl-HNMs were gradually transformed into brominated (chlorinated)-HNMs and brominated-HNMs as Br^- concentration increased. According to the findings, the possible formation mechanism of HNMs from Gly during LED-UV₂₆₅/chlorine disinfection was deduced. Finally, it was demonstrated that the formation laws of HNMs from Gly in real water samples were basically consistent with those in simulated water. Insights obtained in this study help to comprehend the HNMs formation from Gly and provide strategies for controlling the production of HNMs during LED-UV₂₆₅/chlorine disinfection.

Keywords: Br(−); Cu(2+); Glycine; Halonitromethanes formation; LED-UV(265)/chlorine disinfection.

MeSH terms

Chlorine / analysis
Disinfectants* / pharmacology
Disinfection / methods
Glycine
Halogenation
Water
Water Pollutants, Chemical* / analysis
Water Purification* / methods

Substances

Chlorine
Disinfectants
Glycine
Water
Water Pollutants, Chemical