Fundamental Mechanistic Studies of the Photo-Fenton Reaction for the Degradation of Organic Pollutants

Machulek, Amílcar; Quina, Frank H.; Gozzi, Fábio; Silva, Volnir O.; Friedrich, Leidi Cecília; Moraes, José Ermírio Ferreira de

doi:10.5772/30995

Cited by 42 publications

(27 citation statements)

References 83 publications

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“…, scavenging of Á OH by H ? , and deactivation of iron ions into iron oxyhydroxides (Nogueira et al 2007;Machulek et al 2012). Moreover, the best AB161 decolorization rates were obtained at the lowest L azo bond factor of 0.25, because the lower L azo bond factor stands for a higher amount of H 2 O 2 concentration per mole of AB 161 and corresponds to the higher O 2 concentration available for oxidizing the AB161 azo dye.…”

Section: Resultsmentioning

confidence: 99%

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Degradation of Acid Blue 161 by Fenton and photo-Fenton processes

Trovó

Hassan²,

Sillanpää

et al. 2015

Int. J. Environ. Sci. Technol.

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Degradation kinetics of azo dye, Acid Blue 161 (AB161), by Fenton and photo-Fenton processes in aqueous solution was investigated. At pH 3.5, the effects of H 2 O 2 , Fe 2? , and H 2 O 2 /Fe 2? molar ratios, on the AB161 decolorization kinetic rates, were evaluated. Experimental results confirmed that the optimal H 2 O 2 /Fe 2? molar ratio of 12 is close to the theoretical value of 11 as predicted by previously developed model. The influence of azo bond loading (L azo bond ), from 0.25 to 1.0, and pH values from 2.5 to 4.0 were evaluated on AB161 decolorization kinetic rates. A correlation between the natural logarithm of the decolorization rates and L azo bond was established at the different pH values. The decolorization rate increased linearly with decreasing L azo bond , in the order of pH: 3.5 [ 3.0 [ 2.5 [ 4.0. UV radiation of Fenton processes increases degradation of AB161 more than 40 % due to the regeneration of Fe 2? through photo-catalytic reactions. This phenomenon was confirmed by measuring H 2 O 2 concentration during the photo-Fenton processes. The results suggest that Fenton processes can effectively decolorize or degrade wastewater containing azo dye, AB161. Photo-Fenton processes may further increase the degradation efficiency of AB161 by 40 %.

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Section: Resultsmentioning

confidence: 99%

“…• OH radicals responsible for oxidation of AB161 (Nogueira et al 2007;Machulek et al 2012). Parallel experiments were conducted at four initial pH values (2.5, 3.0, 3.5, and 4.0) (without further adjustment).…”

Section: Resultsmentioning

confidence: 99%

Degradation of Acid Blue 161 by Fenton and photo-Fenton processes

Trovó

Hassan²,

Sillanpää

et al. 2015

Int. J. Environ. Sci. Technol.

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“…24 Although hydroxyl radicals do not absorb in the visible region (300-700 nm) and cannot be directly detected by conventional LFP, they can be detected indirectly via their reaction with a compound that generates a spectroscopically detectable intermediate. 24,26,27 A suitable system for the production of hydroxyl radicals by LFP is the photolysis MNO using a 355 nm Nd-YAG laser pulse, which also produces the pyrithiyl radical absorbing at 490 nm [Eqn (1)]: (1) In the presence of trans-stilbene (TS), the hydroxyl radical adds to TS with an absolute second-order rate constant of 6.1 ± 0.2 × 10 9 M −1 s −1 at 298 K in acetonitrile 26 to generate an adduct that absorbs at 390 nm [Eqn (2)]:…”

Section: Resultsmentioning

confidence: 99%

“…Wastewater containing toxic substances such as pesticides is generated in agricultural activities, which, without correct management and treatment, can cause soil, surface and groundwater contamination. 1 Contamination of the aquatic ecosystem by pesticides can occur by different routes, including direct application, spray drift, aerial spraying, atmospheric fallout, soil erosion and run-off from agricultural fields, discharge of industrial and domestic sewage, leaching, careless disposal of empty containers, and equipment washing. 2 Herbicides are an important class of pesticides that are abundantly used in agriculture to improve productivity; however, they can also increase environmental pollution.…”

Section: Introductionmentioning

confidence: 99%

Kinetic studies of the reaction between pesticides and hydroxyl radical generated by laser flash photolysis

et al. 2015

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“…De hecho, se puede operar prácti-camente a pH 7 debido a la formación del complejo hierro-oxalato. Adicionalmente, estos complejos tienen mayor fotorreactividad que los complejos formados en foto-Fenton como el Fe(OH) 2+ (Machulek et al 2012, Shanthi et al 2013.…”

Section: Introductionunclassified

Mineralización De Etilenglicol Por Foto-Fenton Asistido Con Ferrioxalato

Arias

Arriola

Calle

et al. 2016

Rev. Int. Contam. Ambie.

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Palabras clave: agua residual de la industria de pinturas, ion ferroso, peróxido de hidrógeno, ion oxálico RESUMEN Se evaluó la efectividad del proceso foto-Fenton asistido con ferrioxalato para la mineralización de 1000 mg/L de etilenglicol presente en agua destilada y en agua residual proveniente de una planta de producción de pinturas. Se observó que la eficiencia de mineralización del etilenglicol es función de las concentraciones iniciales de ion ferroso, oxalato y peróxido de hidrógeno. Los mayores niveles de degradación del etilenglicol (90 y 85 %, para el agua destilada y el agua residual, respectivamente), se obtuvieron con 10 mg/L de Fe 2+ , 150 mg/L de C 2 O 4 2-y 500 mg/L de H 2 O 2 , después de 3 h de irradiación artificial con lámparas UV a una longitud de onda máxima de 365 nm. La descomposición del etilenglicol produjo cantidades traza (< 136 mg/L) de ácido acético y ácido fórmico, por lo que la disminución en la demanda química de oxígeno debida a este contaminante fue prácticamente total, ya que no se detectó ningún otro producto intermediario. El hierro no actuó directamente de manera catalítica en el sistema.Key words: wastewater from the paint industry, hydrogen peroxide, ferrous ion, oxalic ion ABSTRACTThe effectiveness of the ethylene glycol mineralization using ferrioxalate-induced photo-Fenton was evaluated. The efficiency of 1000 mg/L ethylene degradation was a function of the initial concentrations of ferrous ion, oxalate and hydrogen peroxide. The highest levels of degradation (90 and 85 % for distilled water and wastewater from the paint industry, respectively) were obtained using 10 mg/L of Fe 2+ , 150 mg/L of C 2 O 4 2-and 500 mg/L of H 2 O 2 after 3 hours of UV artificial irradiation (wavelength ~ 365 nm). Ethylene glycol was converted to acetic acid and formic acid in trace amounts (< 136 mg/L) resulting in a decrease of chemical oxygen demand due this contaminant. No other intermediate products were detected.

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Fundamental Mechanistic Studies of the Photo-Fenton Reaction for the Degradation of Organic Pollutants

Cited by 42 publications

References 83 publications

Degradation of Acid Blue 161 by Fenton and photo-Fenton processes

Degradation of Acid Blue 161 by Fenton and photo-Fenton processes

Kinetic studies of the reaction between pesticides and hydroxyl radical generated by laser flash photolysis

Mineralización De Etilenglicol Por Foto-Fenton Asistido Con Ferrioxalato

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