UV light photo-Fenton degradation of polyphenols in oolong tea manufacturing wastewater.
J Environ Sci Health A Tox Hazard Subst Environ Eng
; 49(2): 193-202, 2014.
Article
em En
| MEDLINE
| ID: mdl-24171419
ABSTRACT
The UV light photo-Fenton degradation of oolong tea polyphenols in tea manufacturing effluent that color the wastewater to a dark brown has been examined. In order to elucidate the photo-Fenton degradation mechanism of oolong tea polyphenols and find the optimal dosages of the Fenton reagents, systematic study has been conducted. For the UV light photo-Fenton degradation of oolong tea effluent being 70 mg-(polyphenol) L(-1), the optimum dosages of Fenton reagents were found to be 20 mgL(-1) of total Fe and 500 mgL(-1) of H2O2. The polyphenol degradation could be divided into two stages. The polyphenols concentration rapidly decreased to around 30% of the initial concentration within 2 min and the degradation rate significantly slowed down in the subsequent stage. After 60 min of UV light irradiation, 97% polyphenol removal was obtained. The initial quick degradation of oolong tea polyphenols suggests that hydroxyl radical generated by the photo-Fenton process might preferentially attack polyphenols having high antioxidant activity by scavenging hydroxyl radicals. Almost complete decolorization of the oolong tea effluent was achieved after 80 min. About 96% mineralization of 63 mgL(-1) TOC loading was achieved within 60 min and then further mineralization was rather slow. The complete COD removal of 239 mgL(-1) COD loading was obtained after 100 min. The present results indicate that the UV light photo-Fenton degradation process can treat tea manufacturing wastewaters very effectively.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Chá
/
Raios Ultravioleta
/
Poluentes Químicos da Água
/
Eliminação de Resíduos Líquidos
/
Polifenóis
Idioma:
En
Revista:
J Environ Sci Health A Tox Hazard Subst Environ Eng
Assunto da revista:
TOXICOLOGIA
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Japão