Catalysed ozonation for removal of an endocrine-disrupting compound using the O3/Fenton reagents system.
Environ Technol
; 36(13-16): 1721-30, 2015.
Article
em En
| MEDLINE
| ID: mdl-25609021
ABSTRACT
Aqueous solutions of diethyl phthalate (DEP) were oxidized by using ozone combined with Fenton reagents. The effects of operating parameters such as initial pH; initial concentration of DEP, H2O2 and Fe2+; [H2O2]0/[Fe2+]0 ratio and O3 dosage on the degradation rates of DEP were investigated. The results showed that DEP degradation is strongly dependant on the pH; initial concentrations of the phthalate, H2O2 and Fe2+; [H2O2]0/[Fe2+]0 ratio and O3 dosage. The addition of H2O2 and Fe2+ ions was effective to achieve almost 98% degradation of 200â
mgâ
L(-1) of DEP in about 40â
min using a dose of O3=45â
gâ
m(-3) NTP; [H2O2]0=2.5×10(-2)â
molâ
L(-1) and [Fe(II)]0=5×10(-3)â
molâ
L(-1), as compared to over 60â
min by using O3 and Fenton processes applied separately. DEP degradation followed apparent pseudo-first-order kinetics under ozonation, Fenton's reagents oxidation and the combined ozonation/Fenton reagents oxidation process. The overall reaction rates were significantly enhanced in the O3/Fe2+/H2O2 oxidation system, and allows achieving 100% degradation of DEP (100â
mgâ
L(-1)) in 30â
min of reaction time. The notable decrease in DEP removal rate observed in the presence of a radical scavenger indicates that there was an obvious synergetic effect in the combined ozonation/Fenton reagent process most likely because ozonation could accelerate Fenton reagents to generate hydroxyl radical HOâ¢. Thus, the reaction between DEP and HO⢠proceeds mainly in the bulk of the aqueous phase. Under optimal conditions, the O3/Fe2+/H2O2 system oxidation was the most effective in DEP removal in water.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Ozônio
/
Ácidos Ftálicos
/
Poluentes Químicos da Água
/
Purificação da Água
/
Disruptores Endócrinos
/
Águas Residuárias
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article