Formation and toxicity contribution of chlorinated and dechlorinated halobenzoquinones from dichlorophenols after ozonation.
Sci Total Environ
; 914: 169860, 2024 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-38199341
ABSTRACT
Halobenzoquinones (HBQs) are a class of disinfection byproducts with high cytotoxicity and potential carcinogenicity, which have been widely detected in chlorination of drinking water and swimming pool water. However, to date, the formation of HBQs upon ozonation and the HBQ precursors have been overlooked. This study investigated the formation of chlorinated and dechlorinated HBQs from six dichlorophenol (DCP) isomers. The monomeric and dimeric HBQs were identified in all the ozonation effluents, exhibiting 1-100 times higher toxicity levels than their precursors. The sum of detected HBQs intensity had a satisfactory linear relation with the maximum toxic unit (R2 = 0.9657), indicating the primary toxicity contribution to the increased overall toxicity of effluents. Based on density functional theory calculations, when ozone attacks the para carbon to the hydroxyl group of 2,3-DCP, the probability of producing chlorinated HBQs is 80.41 %, indicating that the para carbon attack mainly resulted in the formation of monomeric HBQs. 2,3-dichlorophenoxy radicals were successfully detected in ozonated 2,3-DCP effluent through electron paramagnetic resonance and further validated using theoretical calculation, revealing the formation pathway of dimeric HBQs. The results indicate that chlorinated phenols, regardless of the positions of chlorine substitution, can potentially serve as precursors for both chlorinated and dechlorinated HBQs formation during ozonation.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ozônio
/
Poluentes Químicos da Água
/
Água Potável
/
Purificação da Água
/
Compostos Alílicos
/
Hidrocarbonetos Clorados
Idioma:
En
Revista:
Sci Total Environ
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
China