Decolourisation of leather dye by ozonation

Srinivasan, S. V.; Rema, T.; Chitra, K. C.; Balakameswari, K. Sri; Suthanthararajan, R.; Maheswari, B. Uma; Ravindranath, E.; Rajamani, S.

doi:10.1016/j.desal.2007.07.032

Cited by 46 publications

(19 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The pH of the dye-laden synthetic wastewater was adjusted to pH 7 prior to ozonation using a 0.1 N NaOH solution. The ozonation was evaluated at 5,10,15,20,25,30,35, and 40 min. For a given time, an increase in contact time has resulted in an increase in colour, COD, and TOC removal.…”

Section: Resultsmentioning

confidence: 99%

“…Ozonation cleaves the conjugated bonds of azo dye chromophores, groups which are responsible for the colour of the dye, leading to colour removal and enhancing biodegradability [20][21][22][23] . The ozonation has excellent potential for dye-containing wastewater removal as it does not generate sludge or solid wastes, decolourization occurs simultaneous with degradation reducing operational costs 15,24,25 . Ozonation is effective in reducing the colour of the dye-containing wastewater, but not so effective in reducing the chemical oxygen demand (COD) and total organic carbon (TOC) 26 .…”

Section: Introductionmentioning

confidence: 99%

“…Treatments using physical, chemical, and biological procedures or its combinations are well established methods for colour removal 11 . Conventional physical or chemical treatment methods such as coagulation, flocculation, filtration, adsorption, ion exchange or ultra-filtration, although efficient, often produce sludge or solid waste which requires further disposal [12][13][14][15] . Biological treatment systems are often inefficient due to low biodegradability of dyes 13 .…”

Section: Introductionmentioning

confidence: 99%

“…Among these oxidants, ozone is the most widely used as it is highly reactive and it can remove colour efficiently 17 . In a process called selective oxidation, ozonation can effectively decolourize the wastewater by breaking the conjugated azo bonds associated with the dye 15,18 . In principle, ozonation should be able to oxidize inorganic substances to their highest stable oxidation states and organic compounds to CO 2 and water 14,19 .…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Decolourization of an azo dye in aqueous solution by ozonation in a semi-batch bubble column reactor

Abidin

Fahmi²,

Ong³

et al. 2015

ScienceAsia

View full text Add to dashboard Cite

ABSTRACT:The oxidative degradation of the azo dye Reactive Red 120 by ozonation was investigated. The decolourization was carried out by bubbling ozone at the bottom of a bubble column reactor containing the dye solution. The colour, chemical oxygen demand, and total organic carbon removal were evaluated, and the contaminants were characterized based on the changes in UV-Vis and FT-IR spectra. It was observed that changes of UV-Vis spectra represent the disappearance of both azo and aromatic groups, which causes the colour removal. FT-IR analysis indicated that ozonation shifts the functional groups in the azo dye which results in decolourization, a decrease in aromaticity, and an increase in acidity. The results indicate that the chromophore is destroyed and partially mineralized to small fragments during ozonation. The alkaline pH was favourable to decomposition by ozonation, initiated by the formation of the hydroxyl radicals. The oxidation followed first-order kinetics and the completed decolourization confirmed the capability of ozonation to cleave the azo bond from the dye.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Decolourization of an azo dye in aqueous solution by ozonation in a semi-batch bubble column reactor

Abidin

Fahmi²,

Ong³

et al. 2015

ScienceAsia

View full text Add to dashboard Cite

show abstract

“…Ozone (O 3 ) is a very strong oxidant and has attracted great interest for degrading organic pollutants, such as dyes (Wu et al, 2008a;Cuiping et al, 2009;Srinivasan et al, 2009) and other organic compounds (Perkowski et al, 1996;Yan et al, 2016), in wastewater, and it has been used in pilot-scale wastewater pre-treatment (Lucasa et al, 2010;Somensi et al, 2010). However, the reaction efficiency for ozonation alone is low (Gong et al, 2008;Cuiping et al, 2009;Rao and Chu, 2009) because the reactivity of O 3 depends on the chemical structure and hydrophilicity or hydrophobicity of pollutants, and the pH of the wastewater (Chang et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Ozone Catalytic Oxidation of Gaseous Toluene over MnO2-Based Ozone Decomposition Catalysts Immobilized on a Nonwoven Fabric

Sekiguchi

Kurita

Sankoda

et al. 2017

Aerosol Air Qual. Res.

View full text Add to dashboard Cite

Degradation of toluene gas by ozone catalytic oxidation (OZCO) by using a MnO 2 -based ozone decomposition catalyst (ODC) was investigated to clarify the reactive site of ODC material with O 3 . An optimum structure for the ODC to remove O 3 and toluene were proposed. For honeycomb ODC, toluene degradation by OZCO occurred only around the entrance of the honeycomb ODC, and we expected that a thinner ODC would increase the toluene degradation efficiency. A nonwoven fabric on which ODC was immobilized was developed to decompose O 3 and volatile organic compounds simultaneously. The toluene degradation ratio and the mineralization of toluene to CO 2 were determined to evaluate the performance of the fabric. Furthermore, the effects of relative humidity and O 3 concentration on the decomposition and mineralization ratios were also investigated with or without 254 nm UV irradiation (UV 254 ). The fabric decomposed and mineralized toluene to CO 2 , even at low O 3 concentrations. Although high humidity reduced the degradation ratio of toluene, UV 254 irradiation improved the recovery of the degradation ratio and increased the mineralization ratio.

show abstract