A Novel UVA/ClO2 Advanced Oxidation Process for the Degradation of Micropollutants in Water.
Environ Sci Technol
; 56(2): 1257-1266, 2022 01 18.
Article
em En
| MEDLINE
| ID: mdl-34978792
ABSTRACT
Ultraviolet (UV)-based advanced oxidation processes (AOPs) are increasingly used for the degradation of micropollutants in water and wastewater. This study reports a novel UVA/chlorine dioxide (ClO2) AOP based on the photolysis of ClO2 using energy-efficient UV radiation sources in the UVA range (e.g., UVA-LEDs). At a ClO2 dosage of 74 µM (5.0 mg L-1 as ClO2) and a UV fluence at 47.5 mJ cm-2, the UVA365/ClO2 AOP generated a spectrum of reactive species, including chlorine oxide radicals (ClOâ¢), chlorine atoms (Clâ¢), hydroxyl radicals (HOâ¢), and ozone at a concentration of â¼10-13, â¼10-15, â¼10-14, and â¼10-7 M, respectively. A kinetic model to simulate the reactive species generation in the UVA365/ClO2 AOP was established, validated against the experimental results, and used to predict the pseudo-first-order rate constants and relative contributions of different reactive species to the degradation of 19 micropollutants in the UVA365/ClO2 AOP. Compared to the well-documented UVC254/chlorine AOP, the UVA365/ClO2 AOP produced similar levels of reactive species at similar oxidant dosages but was much less pH-dependent and required much lower energy input, with much lower formation of chloro-organic byproducts and marginal formation of chlorite and chlorate.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
/
Purificação da Água
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Environ Sci Technol
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Hong Kong