Formation of brominated halonitromethanes from threonine involving bromide ion during the UV/chlorine disinfection. (1st November 2022)

• Record Type: Journal Article
• Authors: Wang, Tao; Deng, Lin; Dai, Wenjuan; Hu, Jun; Singh, Rajendra Prasad; Tan, Chaoqun
• Is Part Of: Journal of cleaner production. Volume 373(2022)
• Publication Date: 2022-11-01
• Subjects: DBPs -- Br-HNMs -- UV/chlorine -- Bromide ion -- Threonine; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2022.133897
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Numerous disinfection by-products (DBPs) are produced during the disinfection process of drinking water and wastewater, and brominated halonitromethanes (Br-HNMs) have aroused great concerns because of much higher cytotoxicity and genotoxicity than common regulated DBPs. Threonine was selected as the precursor for the investigation of Br-HNMs formation in the presence of bromide ion (Br − ) during the UV/chlorine disinfection. The results showed the yields of four Br-HNMs were enhanced with the increase of Br − concentration from 0.12 to 0.60 mM while tribromonitromethane (TBNM) was the most predominant species in the initial 5 min, and increasing Br − concentration promoted the yields of Br-HNMs species containing more bromine atoms. Besides, the yields of Br-HNMs were promoted with the increase of free chlorine dosage from 0.2 to 1.8 mM but inhibited with the increase of pH from 6.0 to 8.0. Subsequently, the possible formation pathways of Br-HNMs from threonine were proposed in the presence of Br − under the UV/chlorine condition. Finally, it was demonstrated that the formation laws of Br-HNMs in real waters in the presence of Br − were similar to that in simulated waters, whereas different concentrations of Br-HNMs and peak times in real waters were observed. These findings are beneficial for further understanding the formation of Br-HNMs and applying effective controls of the risks of Br-HNMs during the UV/chlorine disinfection. Graphical abstract: Image 1 Highlights: Four species of Br-HNMs were observed during the UV/chlorine disinfection process. The dominant species of Br-HNMs were converted from DBNM and TBNM to BNM with time. BUF values were affected by Br − concentration, free chlorine dosage, and pH. Possible formation pathways of Br-HNMs from threonine were proposed. The formation laws of Br-HNMs in real water were similar to that in stimulated water.