• Fibers and Polymers
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• v.7 no.1
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• pp.30-35
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• 2006

The influences of a series of new azo direct dyes including copper-complexes based on benzidine congeners, 2,2'-dimethyl-5,5'-dipropoxybenzidine and 5,5'-dipropoxybenzidine, were examined using microorganism, Daphnia magna. The purpose of the research described in this paper was to use bioassays with daphnids to determine the aquatic toxicity of new azo dyes in which copper was incorporated. The results clearly show that copper has negative effects to aquatic ecosystem as expected. The study also suggested that the assay with Daphnia magna was an excellent method to evaluate the influences of dyes to the aquatic environment.

• Fibers and Polymers
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• v.4 no.2
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• pp.66-70
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• 2003

Temporarily solubilized azo disperse dyes based on 1,2-substituted indoles were synthesized and characterized. Dispersant-free dyeing of polyester by using the synthesized dyes has been investigated. The colour yields of the dyes on the polyester fabric were found to be highly dependent on the dyeing pH, optimum results being obtained at pH 5. The dyes exhibited good to excellent fastness properties on polyester while lightfastness was moderate.

• Journal of Microbiology and Biotechnology
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• v.2 no.3
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• pp.215-219
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• 1992

Biodegradation of azo dyes such as Amaranth, Sudan III and Congo-Red by Aspergillus sojae B-10 was demonstrated using Aspergillus sojae B-10. Aspergillus sojae B-10 showed the greatest decolorization ability when it was cultivated in a nitrogen-limited medium containing, azo dyes(10 mg/l), 2.0% glucose, 0.06% sodium nitrate, 0.1% $KH_PO_4$, 0.5% MgSO_4$ㆍ$7H_2O$ at pH 5.0 and $37^\circ{C}$ for 5 days. Under optimal conditions, Amaranth started being decolorized within 24 hr and was almost complete after decolorization of 4 days incubation. Sudan III was completely decolorized after a cultivation of 5 days. However, Congo-Red was not completely decolorized until 5 days of cultivation.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.4
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• pp.309-312
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• 2004

Aspergillus sojae B-l0 was immobilized and used to treat model dye compounds. The model wastewater, containing 10 ppm of azo dyes such as Amaranth, Sudan III, and Congo Red, was treated with cells attached to a rotating disc contactor (RDC). Amaranth was decolorized more easily than were Sudan III and Congo Red. Decolorization of Amaranth began within a day, and the dye was completely decolorized within 5 days of incubation. Both Sudan III and Congo Red were almost completely decolorized after 5 days of incubation. Semicontinuous decolorization of azo by reusing attached mycelia resulted in almost complete decolorization in 20 days. This experiment indicated that decolorization was successfully conducted by removing azo dyes with Aspergillus sojae B-10.

• Mycobiology
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• v.46 no.1
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• pp.79-83
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• 2018

Azo dyes containing effluents from different industries pose threats to the environment. Though there are physico-chemical methods to treat such effluents, bioremediation is considered to be the best eco-compatible technique. In this communication, we discuss the decolorization potentiality of five azo dyes by Podoscypha elegans (G. Mey.) Pat., a macro-fungus, found growing on the leaf-litter layer of Bethuadahari Wildlife Sanctuary in West Bengal, India. The fungus exhibited high laccase and very low manganese peroxidase activities under different culture conditions. Decolorization of five high-molecular weight azo dyes, viz., Orange G, Congo Red, Direct Blue 15, Rose Bengal and Direct Yellow 27 by the fungus was found to be positive in all cases. Maximum and minimum mean decolorization percentages were recorded in Rose Bengal (70.41%) and Direct Blue 15 (24.8%), respectively. This is the first record of lignolytic study and dye decolorization by P. elegans.

• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.301-306
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• 2003

Twenty-one different fungi were tested for their ability to decolorize a wide range of structurally different dyes. Twenty fungal strains were isolated from fruiting bodies which were collected at the Kwangneung National Arboretum, Korea. One fungal strain were isolated from a rotting wood at Soongsil University, Korea. Nine kinds of dyes were used: three anthraquinone dyes and six azo dyes. The five fungal strains, Laetiporus sulphureus, Polyporus arcularius. Auricularia polytricha, Stereum ostrea, and Bjerkandera sp. UK-l showed decolorization ability. Except Auricularia polytricha, the four fungal strains were wood rotting fungi, and belonged to Aphyllophorales. Bjerkandera sp. UK-I, which was a white rot fungus, could decolorize all kinds of dyes tested in this study, indicating this fungus is one of candidates for applying in biological methods of dye waste treatment.

• Proceedings of the Korean Society of Life Science Conference
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• 2003.10a
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• pp.159-159
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• 2003

• KSBB Journal
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• v.14 no.1
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• pp.31-35
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• 1999

A biosorption of azo and reactive dyes into the intact and modified biomass of Penicillium janthinellum were investigated. Initial pH of medium affected the initial adsorption rate and decolorization. The initial optimum pH was found to be 2.0, and the maximum adsorption rates of dyes were $40^{\circ}C$. The reactive dyes called Apollocion Red 7EB, Apollofix Red SF-3B and Apollocion Red H-E3B showed the high initial adsorption rates as 0.06, 0.086 and 0.079 mg/g.min, respectively. A mixture of dyes containing azo and reactive dyes was adsorbed to the biomass of Pen. janthinellum and revealed that the initial adsorption rate was 0.084 mg/g.min. Both percent decolorization and the influence on the dye adsorption rate. Modified biomass of Pen. janthinellum was also investigated for the dye adsorption and the superior dye loading performance was observed compared with the ion-exchange/chelating resins used for removal of Apollocion Red 7EB.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.12
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• pp.1262-1267
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• 2008

Reductive discolorization studies were conducted. Azo-dyes usually have biological toxicity and it is known that the dyes are hardly removed by biological treatments. One of the simplest way to remove the color is to break the azo-bond and it is possible to break the bond with zero-valent metals. Three types of azo-dyes (Cibacron Briliant Yellow 3G-P (CBY3G-P), Benzopurpurin 4b (B-4B), Chicago sky blue 6b (CSB6B)) were tested. All tested azo-dyes were highly pH dependent and lower pH was preferred. The reaction mechanism was reductive cleavage and amines were expected as products. The dissolved iron ions from zero-valent iron can also remove the color through coagulation and precipitation and a set of experiments were conducted to evaluate the contribution by the dissolved iron. The results indicated that the contribution were also dependent on the type of dyes. This study showed that the reductive cleavage using zero-valent iron could be an alternative for the azo-dye waste water.

• Molecular & Cellular Toxicology
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• v.3 no.2
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• pp.145-149
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• 2007

Studies of relationship between structure and toxicity of azo dyes have been performed with comparative molecular field analysis (CoMFA) techniques. 3D QSTR analyses indicate that the steric and electrostatic interactions are important. The steric field based model gives strong correlation ($q^2$=0.57, $r^2$= 0.92). The steric field in conjunction with electrostatic field give more strong correlation ($q^2$=0.57, $r^2$=0.95). All study indicates that a bulky and electronegative group at benzene ring and a small group at position 3 of aniline ring might be significant to reduce the mutagenicity.