Lumped kinetics and acute toxicity of intermediates in the ozonation of phenol in saline media

Azevedo, Eduardo Bessa; Neto, Francisco Radler de Aquino; Dezotti, Márcia

doi:10.1016/j.jhazmat.2005.07.058

Cited by 36 publications

(26 citation statements)

References 33 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ozonation performance is affected by salts and this is true even for readily oxidable substances like phenol, as previously reported [25]. The detrimental effect of salts (sodium sulfate, sodium chloride) on azo dyes ozonation was already reported [26] and the combined influence of pH and salt (sodium sulfate) content on color and COD removal of Acid Red 88 solutions was also investigated [17].…”

Section: Introductionmentioning

confidence: 66%

Ozonation of azo dyes (Orange II and Acid Red 27) in saline media

Silva

Pic

Sant’Anna

et al. 2009

Journal of Hazardous Materials

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 66%

Ozonation of azo dyes (Orange II and Acid Red 27) in saline media

Silva

Pic

Sant’Anna

et al. 2009

Journal of Hazardous Materials

View full text Add to dashboard Cite

“…Both lumped kinetic models have also been used in other works [21], but the difference is that here both were joined to fit the experimental data. In this scheme of reactions from (2) to (6), color is the sum of Rhodamine and the CI intermediate lump.…”

Section: Lumped Kinetic Modelmentioning

confidence: 99%

Lumped-intermediates analysis in the photooxidation of Rhodamine 6G in the H2O2/UV system

Menéndez

Lombraña

Luis

2011

Korean J. Chem. Eng.

View full text Add to dashboard Cite

The combination of H 2 O 2 with UV radiation was applied to study the degradation of Rhodamine 6G dye (Rh-6G). The lumped kinetic model proposed in this work is a reaction-system scheme to describe the degradation of dye using lumps of intermediate compounds grouped by their chemical and colorimetric behavior. Rate constants obtained by application of the model were shown to predict the progress of dye oxidation. The effects of pH and oxidant dosage on these rate constants were also analyzed. Finally, photodecoloration was studied considering the absorption at 528 nm (the maximum absorption wavelength of the dye) as the sum of all compounds absorbing at this wavelength: Rhodamine itself and the colored intermediates produced.

show abstract

“…Azevedo et al 17 suggested that the bromide ion, normally present as a contaminant of NaCl, reacts with O 3 faster then Cl -generating brominated compounds. However, in the conditions tested the bromide ion was neither identified in dye solutions (LOD < 2 mg L -1 ) nor in the NaCl solid reagent (< 0.02%) used.…”

Section: Influence Of Chloride Ion On Dye Ozonationmentioning

confidence: 99%

“…16,17 However, the available information concerning the role of these dye additives on the kinetics and by-product formation is scarce. 16 The inorganic salts are the most common additives used, as exhausting and retarding agents, during textiles dyeing processes and its quantity varies from 5 to 60 g L -1 .…”

Section: Introductionmentioning

confidence: 99%

Ozonation of azo dye acid black 1 under the suppression effect by chloride ion

Paprocki¹,

Santos²,

Hammerschitt³

et al. 2010

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

O objetivo deste estudo é determinar a cinética degradação do corante Acid Black 1 por ação oxidante do ozônio e avaliar a influência da contaminação de íons cloreto na degradação deste corante. Foram observadas cinéticas de pseudo-primeira ordem, tanto para a degradação das estruturas cromóforas (620 nm), quanto das aromáticas (321 nm). A completa remoção da coloração foi verificada em 25 min ([corante] 0 = 1,8 × 10 -5 mol L -1 ), enquanto que as estruturas aromáticas foram degradadas com menor velocidade. A presença de íon cloreto, principal impureza do reagente sólido, influencia significantemente a velocidade de ozonização (-42%), mesmo em baixa concentração (5,6 × 10 -4 mol L -1 ). O mecanismo mais provável para o efeito supressor do íon cloreto envolve a direta reação entre O 3 e Cl -gerando HOCl, dentre outros subprodutos. Apesar deste aspecto, a ozonização pode ser um processo de degradação competitivo para este corante.The aim of this study is to determine the kinetics of the Acid Black 1 dye by oxidizing action of ozone and to evaluate the influence of chloride ion contamination on the dye degradation. Pseudofirst order kinetics was observed for both decolorization (620 nm) and aromatic structure (321 nm) degradations. A complete color removal was verified in 25 min ([dye] 0 = 1.8 × 10 -5 mol L -1 ), while aromatic structures degraded at slower rates. The presence of chloride ion, the principal impurity of the solid dye reagents, influences significantly the ozonation rate (-42%), even at low chloride concentration (5.6 × 10 -4 mol L -1 ). The most probable mechanism for the chloride suppression effect involves a direct reaction between O 3 and Cl -generating HOCl, among other by-products. In despite of that, ozonation could be a competitive degradation process for this dye.

show abstract

Lumped kinetics and acute toxicity of intermediates in the ozonation of phenol in saline media

Cited by 36 publications

References 33 publications

Ozonation of azo dyes (Orange II and Acid Red 27) in saline media

Ozonation of azo dyes (Orange II and Acid Red 27) in saline media

Lumped-intermediates analysis in the photooxidation of Rhodamine 6G in the H2O2/UV system

Ozonation of azo dye acid black 1 under the suppression effect by chloride ion

Contact Info

Product

Resources

About