scholarly journals Azo Dyes and Their Metabolites: Does the Discharge of the Azo Dye into Water Bodies Represent Human and Ecological Risks?

10.5772/19872 ◽  
2011 ◽  
Author(s):  
Farah Maria Drumond Chequer ◽  
Daniel Junqueira ◽  
Danielle Palma de Oliveir
Keyword(s):  
Azo Dyes ◽  
Azo Dye ◽  
Water Bodies ◽  
Ecological Risks

Use of a sequencing batch biofilter for degradation of azo dyes (acids and bases)

2000 ◽  
Vol 42 (5-6) ◽  
pp. 329-336 ◽  
Author(s):  
M. Quezada ◽  
I. Linares ◽  
G. Buitrón
Keyword(s):  
Azo Dyes ◽  
Azo Dye ◽  
Degradation Rate ◽  
Removal Rate ◽  
Textile Effluent ◽  
Colour Removal ◽  
Substrate Degradation ◽  
Acids And Bases ◽  
Removal Efficiencies ◽  
Basic Red 46

The degradation of azo dyes in an aerobic biofilter operated in an SBR system was studied. The azo dyes studied were Acid Red 151 and a textile effluent containing basic dyes (Basic Blue 41, Basic Red 46 and 16 and Basic Yellow 28 and 19). In the case of Acid Red 151 a maximal substrate degradation rate of 288 mg AR 151/lliquid·d was obtained and degradation efficiencies were between 60 and 99%. Mineralization studies showed that 73% (as carbon) of the initial azo dye was transformed to CO2 by the consortia. The textile effluent was efficiently biodegraded by the reactor. A maximal removal rate of 2.3 kg COD/lliquid·d was obtained with removal efficiencies (as COD) varying from 76 to 97%. In all the cycles the system presented 80% of colour removal.

Effect of Photo-Isomerization of Azo Dyes on the Photonic Bandgap in Chiral Nematics

2011 ◽  
Vol 181-182 ◽  
pp. 257-260
Author(s):  
David Statman ◽  
Andrew Jockers ◽  
Daniel Brennan
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Azo Dyes ◽  
Azo Dye ◽  
Photonic Bandgap ◽  
Methyl Red ◽  
Central Wavelength ◽  
Chiral Nematic ◽  
Anchoring Energy ◽  
Pitch Length

Chiral nematic liquid crystals prepared with Grandjean texture demonstrate a photonic bandgap whose central wavelength is proportional to the pitch length, P, of the liquid crystal and whose width is given by (ne – no)P. We show that methyl red doped chiral nematics undergo a shift in the photonic bandgap upon photo-isomerization. This shift is a result of (1) photo-induced change in anchoring energy on the nematic surface, and (2) change in the natural pitch length from the photo-isomerization of the azo dye.

Biodegradation of selected azo dyes under methanogenic conditions

1997 ◽  
Vol 36 (6-7) ◽  
pp. 65-72 ◽  
Author(s):  
Elías Razo-Flores ◽  
Maurice Luijten ◽  
Brian Donlon ◽  
Gatze Lettinga ◽  
Jim Field
Keyword(s):  
Azo Dyes ◽  
Textile Industry ◽  
Azo Dye ◽  
Biological Treatment ◽  
Present Report ◽  
Anaerobic Bacteria ◽  
Aminosalicylic Acid ◽  
Batch Experiments ◽  
Azo Reduction ◽  
Uasb Reactors

Biological treatment of wastewaters discharged by the textile industry could potentially be problematic due to the high toxicity and recalcitrance of the commonly-used azo dye compounds. In the present report, the fate of two azo dyes under methanogenic conditions was studied. Mordant Orange 1 (MO1) and Azodisalicylate (ADS) were completely reduced and decolorised in continuous UASB reactors in the presence of cosubstrates. In the MO1 reactor, both 5-aminosalicylic acid (5-ASA) and 1,4-phenylenediamine were identified as products of azo cleavage. After long adaptation periods, 5-ASA was detected at trace levels, indicating further mineralization. ADS, a pharmaceutical azo dye constructed from two 5-ASA units, was completely mineralized even in the absence of cosubstrate, indicating that the metabolism of 5-ASA could provide the reducing equivalents needed for the azo reduction. Batch experiments confirmed the ADS mineralization. These results demonstrate that some azo dyes could serve as a carbon, energy, and nitrogen source for anaerobic bacteria.

Development of novel pH-sensitive azo dyes from Cardanol as a bioresource

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Siddhesh Umesh Mestry ◽  
Umesh Ratan Mahajan ◽  
Aswathy M. ◽  
Shashank T. Mhaske
Keyword(s):  
Azo Dyes ◽  
Azo Dye ◽  
Density Functional ◽  
Ph Sensitivity ◽  
Water Soluble ◽  
Hydroxyl Group ◽  
Disulfonic Acid ◽  
Colour Properties ◽  
Content Type ◽  
Good Thermal Stability

Purpose The purpose of this paper is to use the bio-based resource as the starting material for the synthesis of azo dye. Cardanol is one of the most used bio-based resources for carrying out the synthesis of various compounds having numerous end applications. The study presents an attempt to develop an azo dye from Cardanol having end applications in pH-responsive dyes. Design/methodology/approach The cardanol was sulfonated to block the para position by which ortho positioned hydroxyl group after diazotization and coupling will provide necessary pH-sensitivity. The diazotization of two naphthalene derivatives, i.e. 1-naphthol-8-amino-3,6-disulfonic acid (H-acid) and 7-amino-4-hydroxy-2-naphthalene sulfonic acid (J-acid) was carried out using the standard practice, and the diazotized compounds were coupled with the sulfonated cardanol. The obtained dyes were characterized by Fourier transform infrared, nuclear magnetic resonance, carbon-hydrogen-nitrogen-sulfur analysis and hydroxyl value. The colour properties were checked using UV-vis spectrophotometry and density functional theory, while thermogravimetric analysis was used for the thermal degradation studies of both the dyes. Findings Water-soluble cardanol-based azo dyes were prepared successfully having good thermal stability, and the obtained results are being presented in this paper. Originality/value The originality lies between the use of cardanol as a bio-based resource for the synthesis of azo-dye and the obtained azo-dye has the pH-sensitivity.

Role of Enzymes From Microbes in the Treatment of Recalcitrant From Industries

2018 ◽  
pp. 395-420
Author(s):  
Veena Gayathri Krishnaswamy
Keyword(s):  
Fresh Water ◽  
Azo Dyes ◽  
Azo Dye ◽  
Dye Degradation ◽  
Anthropogenic Activities ◽  
Bacterial Degradation ◽  
Wide Range ◽  
Pharmaceutical Industries ◽  
Degradation Of Azo Dye

The limited availability of fresh water is a global crisis. The growing consumption of fresh water due to anthropogenic activities has taken its toll on available water resources. Unfortunately, water bodies are still used as sinks for waste water from domestic and industrial sources. Azo dyes account for the majority of all dye stuffs, produced because they are extensively used in the textile, paper, food, leather, cosmetics, and pharmaceutical industries. Bacterial degradation of azo dyes under certain environmental conditions has gained momentum as a method of treatment, as these are inexpensive, eco-friendly, and can be applied to wide range of such complex dyes. The enzymatic approach has attracted much interest with regard to degradation of azo dyes from wastewater. The oxido-reductive enzymes are responsible for generating highly reactive free radicals that undergo complex series of spontaneous cleavage reactions, due to the susceptibility of enzymes to inactivation in the presence of the other chemicals. The oxidoreductive enzymes, such as lignin peroxidase, laccases, tyrosinase, azoreductase, riboflavin reductive, polyphenol oxidase, and aminopyrine n-demethylase, have been mainly utilized in the bacterial degradation of azo dye. Along with the reductive enzymes, some investigators have demonstrated the involvement in some other enzymes, such as Lignin peroxides and other enzymes. This chapter reviews the importance of enzymes in dye degradation.

scholarly journals Magnetically retrievable Ce-doped Fe3O4 nanoparticles as scaffolds for the removal of azo dyes

RSC Advances ◽  
2019 ◽  
Vol 9 (40) ◽  
pp. 23129-23141 ◽  
Author(s):  
Aashima Aashima ◽  
Shivani Uppal ◽  
Arushi Arora ◽  
Sanjeev Gautam ◽  
Suman Singh ◽  
...  
Keyword(s):  
Azo Dyes ◽  
Fe3o4 Nanoparticles ◽  
Azo Dye ◽  
Reactive Black 5

Considering the significant impact of magnetically retrievable nanostructures, herein, Ce-doped Fe3O4 nanoparticles were employed as scaffolds for the removal of the Reactive Black 5 (RB5), an azo dye.

Spectrophotometric Behavior of Azobilirubin and Azotaurobilirubin

1959 ◽  
Vol 5 (6) ◽  
pp. 532-541 ◽  
Author(s):  
M Jirsa ◽  
V Jirsová
Keyword(s):  
Azo Dyes ◽  
Azo Dye ◽  
Absorption Maximum ◽  
Direct Bilirubin ◽  
Sulphanilic Acid ◽  
Indirect Bilirubin ◽  
Influence Of Ph ◽  
Colorimetric Methods

Abstract The authors studied the influence of pH, alcohol, and albumin on the spectrophotometric behavior of azo dyes prepared from direct and indirect bilirubin by coupling with sulphanilic acid. Synthetically prepared taurobilirubin was used as a model for direct bilirubin. It was found that extinction and absorption maximum values depend on all 3 factors. Most important for practical purposes is the observed rise of azo dye extinction in serum and in albumin caused by alcohol. This means, if the Malloy and Evelyn method for the quantitative colometric estimation of direct bilirubin in serum is used, that part of the directly reacting taurobilirubin is estimated as indirect bilirubin. Revision of colorimetric methods for direct bilirubin estimation in serum is recommended.

Characterization of aerobic azo dye-degrading bacteria and their activity in biofilms

1997 ◽  
Vol 36 (1) ◽  
pp. 215-220 ◽  
Author(s):  
M. F. Coughlin ◽  
B. K. Kinkle ◽  
A. Tepper ◽  
P. L. Bishop
Keyword(s):  
Phylogenetic Analysis ◽  
Azo Dyes ◽  
Azo Dye ◽  
Fluorescent Antibody ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Waste Water Treatment Plant ◽  
Rrna Gene ◽  
Degrading Bacterium ◽  
Degrading Bacteria

An azo dye-degrading strain, originally named TBX65, was isolated from the mixed liquor of the Mill Creek waste water treatment plant in Cincinnati, Ohio. Strain TBX65 has the unusual ability to aerobically reduce the azo bond of several azo dyes and is able to use some of these dyes as growth substrate. Subsequent investigations have revealed that TBX65 is actually composed of several strains including two azo dye-degrading strains, MC1 and MI2. Strain MI2 is able to use the azo dyes AO7 and AO8 as its sole source of carbon, energy, and nitrogen. In contrast, MC1 can aerobically reduce the azo bond of these dyes but only in the presence of an exogenous source of carbon and nitrogen. Both MC1 and MI2 are Gram negative, rod-shaped bacteria that form yellow colonies. Sequencing and phylogenetic analysis of the 16S rRNA gene of MC1 indicates that it is a strain of Sphingomonas. Based on this phylogenetic analysis, the most closely related strain to MC1 is strain C7, a previously described azo dye-degrading bacterium isolated from biofilms growing in our laboratories. A strain-specific fluorescent antibody has been developed for strains MC1 and MI2, and is being used to determine the survival and azo dye-degrading ability of these strains in biofilms generated in a rotating drum bioreactor.

scholarly journals A New Generation of Glycoconjugated Azo Dyes Based on Aminosugars

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Lorenzo Guazzelli ◽  
Giorgio Catelani ◽  
Felicia D’Andrea
Keyword(s):  
Acid Hydrolysis ◽  
Azo Dyes ◽  
Azo Dye ◽  
Protecting Groups ◽  
Third Generation ◽  
Sugar Moiety ◽  
The Third ◽  
New Generation ◽  
Monoazo Dyes ◽  
Hydrolysis Of

The third generation of glycoconjugated azo dyes (GADs) was prepared linking monoazo dyes to 6-amino-6-deoxy-d-galactose or 6′amino-6′-deoxylactose through mixed amido-ester connections. The complementary conjugation reactions were studied using the succinyl derivative of either the acetal protected aminosugar or the azo dye. Target “naturalized” GADs were obtained after acid hydrolysis of the acetal protecting groups present on the sugar moiety.

Sign in / Sign up

Export Citation Format

Share Document