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Sample records for azo dye reactive

  1. 40 CFR 721.9717 - Azo monochloro triazine reactive dye.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Azo monochloro triazine reactive dye... Substances § 721.9717 Azo monochloro triazine reactive dye. (a) Chemical substance and significant new uses... reactive dye (PMN P-96-238) is subject to reporting under this section for the significant new...

  2. 40 CFR 721.9717 - Azo monochloro triazine reactive dye.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Azo monochloro triazine reactive dye... Substances § 721.9717 Azo monochloro triazine reactive dye. (a) Chemical substance and significant new uses... reactive dye (PMN P-96-238) is subject to reporting under this section for the significant new...

  3. 40 CFR 721.9717 - Azo monochloro triazine reactive dye.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Azo monochloro triazine reactive dye... Substances § 721.9717 Azo monochloro triazine reactive dye. (a) Chemical substance and significant new uses... reactive dye (PMN P-96-238) is subject to reporting under this section for the significant new...

  4. 40 CFR 721.9717 - Azo monochloro triazine reactive dye.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Azo monochloro triazine reactive dye... Substances § 721.9717 Azo monochloro triazine reactive dye. (a) Chemical substance and significant new uses... reactive dye (PMN P-96-238) is subject to reporting under this section for the significant new...

  5. 40 CFR 721.9717 - Azo monochloro triazine reactive dye.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Azo monochloro triazine reactive dye... Substances § 721.9717 Azo monochloro triazine reactive dye. (a) Chemical substance and significant new uses... reactive dye (PMN P-96-238) is subject to reporting under this section for the significant new...

  6. Oxidation of Levafix CA reactive azo-dyes in industrial wastewater of textile dyeing by electro-generated Fenton's reagent.

    PubMed

    El-Desoky, Hanaa S; Ghoneim, Mohamed M; El-Sheikh, Ragaa; Zidan, Naglaa M

    2010-03-15

    The indirect electrochemical removal of pollutants from effluents has become an attractive method in recent years. Removal (decolorization and mineralization) of Levafix Blue CA and Levafix Red CA reactive azo-dyes from aqueous media by electro-generated Fenton's reagent (Fe(2+)/H(2)O(2)) using a reticulated vitreous carbon cathode and a platinum gauze anode was optimized. Progress of oxidation (decolorization and mineralization) of the investigated azo-dyes with time of electro-Fenton's reaction was monitored by UV-visible absorbance measurements, Chemical oxygen demand (COD) removal and HPLC analysis. The results indicated that the electro-Fenton's oxidation system is efficient for treatment of such types of reactive dyes. Oxidation of each of the investigated azo-dyes by electro-generated Fenton's reagent up to complete decolorization and approximately 90-95% mineralization was achieved. Moreover, the optimized electro-Fenton's oxidation was successfully applied for complete decolorization and approximately 85-90% mineralization of both azo-dyes in real industrial wastewater samples collected from textile dyeing house at El-Mahalla El-Kobra, Egypt. PMID:19926217

  7. Application of redox mediators to accelerate the transformation of reactive azo dyes in anaerobic bioreactors.

    PubMed

    van der Zee, F P; Bouwman, R H; Strik, D P; Lettinga, G; Field, J A

    2001-12-20

    Azo dyes are nonspecifically reduced under anaerobic conditions but the slow rates at which reactive azo dyes are converted presents a serious problem for the application of anaerobic technology as a first stage in the complete biodegradation of these compounds. As quinones have been found to catalyze reductive transfers by acting as redox mediators, the application of anthraquinone-2,6-disulfonic acid (AQDS) during continuous anaerobic treatment of the reactive azo dye, Reactive Red 2 (RR2), was evaluated. A mixture of volatile fatty acids was used as the electron-donating primary substrate. Batch experiments demonstrated that AQDS could increase the first-order rate constant of RR2 reductive cleavage by one order of magnitude. In the continuous experiment, treatment of RR2 containing synthetic wastewater in a lab-scale upflow anaerobic sludge blanket (UASB) reactor yielded low dye removal efficiencies (<30%). Consequently, severe toxicity problems occurred, eventually resulting in almost complete inhibition of the methanogenic activity. Addition of catalytic concentrations of AQDS (19 microM) to the reactor influent caused an immediate increase in the dye removal efficiency and recovery of biological activity. Ultimately, RR2 removal efficiency stabilized at 88%, and higher AQDS loads resulted in higher RR2 removal efficiencies (up to 98% at 155 microM AQDS). Examination of the RR2 decolorizing properties of dye-adapted reactor sludge and of nonadapted reactor seed sludge revealed that RR2 decolorization was principally a biologically driven transfer of reducing equivalents from endogenous and added substrates to the dye. Hydrogen, added in bulk, was clearly the preferred electron donor. Bacteria that couple dye decolorization to hydrogen oxidation were naturally present in seed sludge. However, enrichment was required for the utilization of electrons from volatile fatty acids for dye reduction. The stimulatory effect of AQDS on RR2 decolorization by AQDS

  8. Application of 'waste' wood-shaving bottom ash for adsorption of azo reactive dye.

    PubMed

    Leechart, Piyawan; Nakbanpote, Woranan; Thiravetyan, Paitip

    2009-02-01

    The utilization of wood-shaving bottom ash (WBA) for the removal of Red Reactive 141 (RR141), an azo reactive dye, was investigated. WBA/H(2)O and WBA/H(2)SO(4) were made by treating WBA with water and 0.1M H(2)SO(4), respectively, to increase adsorption capacity. Adsorption of RR141 from reactive dye solution (RDS) and reactive dye wastewater (RDW) by WBA/H(2)O and WBA/H(2)SO(4) involved the BET surface area and pore size diameter. Properties of adsorbents, effect of contact time, initial pH of solution, dissolved metals and elution studies indicated that the decolorisation mechanism involved both chemical adsorption and precipitation with calcium ions. In addition, the WBA/H(2)SO(4) surface might contain sulphate-cation complexes that were specific to enhancing dye adsorption from RDW. The adsorption isotherm had a best fit by the Freundlich model. Freundlich parameters showed that WBA/H(2)O used more heterogeneous surface than WBA/H(2)SO(4) and activated carbon for RDW adsorption. A thermodynamic study indicated that RDW adsorption was an endothermic process. The maximum dye adsorption capacities of WBA/H(2)O, WBA/H(2)SO(4) and activated carbon obtained from a Langmuir model at 30 degrees C were 24.3, 29.9, and 41.5mgl(-1), respectively. In addition, WBA/H(2)O and WBA/H(2)SO(4) could reduce colour and high chemical oxygen demand (COD) of real textile wastewater. According to the difficulty in the elution study, it was an environmentally safe disposal of this waste. Therefore, WBA, a waste from combustion of wood shavings, was suitable to be used as an effective adsorbent for azo reactive dye removal. PMID:18436367

  9. Decolourization of azo, heterocyclic and reactive dyes using spent mycelium substrate of Hypsizygus ulmarius.

    PubMed

    Ranjini, R; Padmavathi, T

    2015-09-01

    Cultivation of Hypsizygus ulmarius to generate spent mycelium substrate (SMS) for dye decolourization gave better yield, biological efficiency, fruitwidth and moisture content (145 gm, 33%, 4 cm, 91%) on paddy straw as compared to coconut husk (59 gm, 21%, 3 cm, 90%). Solid-phase decolourization of Congo red (Azo dye) and Methylene blue (Heterocyclic dye) showed that maximum decolourization (3.31), measured as Decolourization Index, occurred at dye concentration of 25 mg l(-1), while in Solochrome black (Reactive dye), it was at 100 mg l(-1) (1.7). Time taken for maximum decolourization was 10 days in Congo red and Solochrome black; 20 days in Methylene blue. Decolourization Index was maximum in Methylene blue (3.1), followed by Congo red (1.9) and Solochrome black (1.2). Liquid-phase decolourization of Methylene blue and Solochrome black showed that maximum decolourization (62.5%) measured as percent decolourization occurred at 25 mg l(-1), while it was at 50 mg l(-1) (36%) for Congo red. Time taken for maximum decolourization for all three dyes was 10 days. During this period, the percent decolourization was maximum in Methylene blue (91.3%), followed by Solochrome black (82.2%) and Congo red (79.7%). Decolourization potential in solid-phase was observed till 100 mg l(-1) and day 25 for all the three dyes, however, in liquid-phase it was observed till 50 mg I(-1) and day 20 for Congo red, 75 mg l(-1) and day 10 for Solochrome black, 100 mg I(-1) and day 20 for Methylene blue. Maximum laccase was produced on day 25 during decolourization of 25 mg I(-1) Congo red, while maximum Manganese peroxidase was noted on day 20 at 50 mg l(-1) Congo red. PMID:26521548

  10. The role of sulphate reduction on the reductive S decolorization of the azo dye reactive orange 14.

    PubMed

    Cervantes, F J; Enriquez, J E; Mendoza-Hernandez, M R; Razo-Flores, E; Field, J A

    2006-01-01

    The aim of this study was to investigate the impact of a broad range of sulphate concentrations (0-10g SO4(-2) L(-1)) on the reduction of an azo dye (reactive orange 14 (RO14)) by an anaerobic sludge. An increase in the sulphate concentration generally stimulated the reduction of RO14 by sludge incubations supplemented with glucose, acetate or propionate as electron donor. Sulphate and azo dye reductions took place simultaneously in all incubations. However, there was a decrease on the rate of decolorization when sulphate was supplied at 10g SO4(-2) L(-1). Abiotic incubations at different sulphide concentrations (0-2.5 g sulphide L(-1)) promoted very poor reduction of RO14. However, addition of riboflavin (20 microM), as a redox mediator, accelerated the reduction of RO14 up to 44-fold compared to a control lacking the catalyst. Our results indicate that sulphate-reduction may significantly contribute to the reduction of azo dyes both by biological mechanisms and by abiotic reductions implicating sulphide as an electron donor. The contribution of abiotic decolorization by sulphide, however, was only significant when a proper redox mediator was included. Our results also revealed that sulphate-reduction can out-compete with azo reduction at high sulphate concentrations leading to a poor decolorising performance when no sufficient reducing capacity is available. PMID:16939099

  11. Decolorization and degradation of xenobiotic azo dye Reactive Yellow-84A and textile effluent by Galactomyces geotrichum.

    PubMed

    Govindwar, Sanjay P; Kurade, Mayur B; Tamboli, Dhawal P; Kabra, Akhil N; Kim, Pil Joo; Waghmode, Tatoba R

    2014-08-01

    Galactomyces geotrichum MTCC 1360 exhibited 86% decolorization of azo dye Reactive Yellow-84A (50mgL(-1)) within 30h at 30°C and pH 7.0 under static condition. Examination of azoreductase, laccase and tyrosinase enzyme activities confirmed their prominent role in Reactive Yellow-84A degradation. Considerable reduction of COD (73%) and TOC (62%) during degradation of the dye was indicative of conversion of complex dye into simple products, which were further analyzed by HPLC, FTIR, GC-MS and HPTLC. The degradation products were identified as 4(5-hydroxy, 4-amino cyclopentane) sulfobenzene and 4(5-hydroxy cyclopentane) sulfobenzene by GC-MS. In addition, when G. geotrichum was applied to decolorize textile effluent, it showed 85% of true color removal (ADMI removal) within 72h, along with a significant reduction in TOC and COD. Phytotoxicity studies revealed the less toxic nature of degraded Reactive Yellow-84A as compared to original dye. PMID:24630455

  12. Mineralization of reactive azo dyes present in simulated textile waste water using down flow microaerophilic fixed film bioreactor.

    PubMed

    Balapure, Kshama; Bhatt, Nikhil; Madamwar, Datta

    2015-01-01

    The present research emphasizes on degradation of azo dyes from simulated textile wastewater using down flow microaerophilic fixed film reactor. Degradation of simulated textile wastewater (COD 7200mg/L and dye concentration 300mg/L) was studied in a microaerophilic fixed film reactor using pumice stone as a support material under varying hydraulic retention time (HRT) and organic loading rate (OLR). The intense metabolic activity of the inoculated bacterial consortium in the reactor led to 97.5% COD reduction and 99.5% decolorization of simulated wastewater operated under OLR of 7.2kgCODm(3)/d and 24h of HRT. FTIR, (1)H NMR and GC-MS studies revealed the formation of lower molecular weight aliphatic compounds under 24h of HRT, leading to complete mineralization of simulated wastewater. The detection of oxido-reductive enzyme activities suggested the enzymatic reduction of azo bonds prior to mineralization. Toxicity studies indicated that microbial treatment favors detoxification of simulated wastewater. PMID:25459797

  13. Detoxification of azo dyes by bacterial oxidoreductase enzymes.

    PubMed

    Mahmood, Shahid; Khalid, Azeem; Arshad, Muhammad; Mahmood, Tariq; Crowley, David E

    2016-08-01

    Azo dyes and their intermediate degradation products are common contaminants of soil and groundwater in developing countries where textile and leather dye products are produced. The toxicity of azo dyes is primarily associated with their molecular structure, substitution groups and reactivity. To avoid contamination of natural resources and to minimize risk to human health, this wastewater requires treatment in an environmentally safe manner. This manuscript critically reviews biological treatment systems and the role of bacterial reductive and oxidative enzymes/processes in the bioremediation of dye-polluted wastewaters. Many studies have shown that a variety of culturable bacteria have efficient enzymatic systems that can carry out complete mineralization of dye chemicals and their metabolites (aromatic compounds) over a wide range of environmental conditions. Complete mineralization of azo dyes generally involves a two-step process requiring initial anaerobic treatment for decolorization, followed by an oxidative process that results in degradation of the toxic intermediates that are formed during the first step. Molecular studies have revealed that the first reductive process can be carried out by two classes of enzymes involving flavin-dependent and flavin-free azoreductases under anaerobic or low oxygen conditions. The second step that is carried out by oxidative enzymes that primarily involves broad specificity peroxidases, laccases and tyrosinases. This review focuses, in particular, on the characterization of these enzymes with respect to their enzyme kinetics and the environmental conditions that are necessary for bioreactor systems to treat azo dyes contained in wastewater. PMID:25665634

  14. Effect of trace metals and electron shuttle on simultaneous reduction of reactive black-5 azo dye and hexavalent chromium in liquid medium by Pseudomonas sp.

    PubMed

    Mahmood, Shahid; Khalid, Azeem; Arshad, Muhammad; Ahmad, Riaz

    2015-11-01

    This study demonstrates the role of electron shuttles and trace metals in the biotransformation of azo dye reactive black-5 and hexavalent chromium (CrVI) that are released simultaneously in tannery effluent. Previously isolated bacterial strain Pseudomonas putida KI was used for the simultaneous reduction of the dye (100 mg L(-1)) and CrVI (2 mg L(-1)) in a mineral salts medium (MSM). Among various trace metals, only Cu(II) had a stimulating effect on the bacterial-mediated reduction process. Application of electron shuttles such as hydroquinone and uric acid at a low concentration (1mM) had a positive effect on the reduction process and caused simultaneous reduction of 100% dye and 97% CrVI in 12-18 h. Mannitol, EDTA and sodium benzoate at all concentrations (ranging from 1 to 9 mM) showed an inhibitory effect on the reduction of reactive black-5 and CrVI. An inverse linear relationship between the velocity of reaction (V) and the concentration [S] of electron shuttles was observed. The results imply that both types and concentration of an electron shuttle and trace metals can affect the simultaneous reduction of reactive black-5 and CrVI. PMID:25556007

  15. 40 CFR 721.5917 - Phenyl azo dye (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phenyl azo dye (generic). 721.5917... Substances § 721.5917 Phenyl azo dye (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenyl azo dye (PMN P-02-17) is subject...

  16. 40 CFR 721.5917 - Phenyl azo dye (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phenyl azo dye (generic). 721.5917... Substances § 721.5917 Phenyl azo dye (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenyl azo dye (PMN P-02-17) is subject...

  17. 40 CFR 721.5917 - Phenyl azo dye (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phenyl azo dye (generic). 721.5917... Substances § 721.5917 Phenyl azo dye (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenyl azo dye (PMN P-02-17) is subject...

  18. 40 CFR 721.5917 - Phenyl azo dye (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phenyl azo dye (generic). 721.5917... Substances § 721.5917 Phenyl azo dye (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenyl azo dye (PMN P-02-17) is subject...

  19. 40 CFR 721.5917 - Phenyl azo dye (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phenyl azo dye (generic). 721.5917... Substances § 721.5917 Phenyl azo dye (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenyl azo dye (PMN P-02-17) is subject...

  20. Comprehensive review and compilation of treatment for azo dyes using microbial fuel cells.

    PubMed

    Murali, V; Ong, Soon-An; Ho, Li-Ngee; Wong, Yee-Shian; Hamidin, Nasrul

    2013-03-01

    Microbial fuel cells (MFCs) represent an emerging technology that focuses on power generation and effluent treatment. This review compiles articles related to MFCs using azo dye as the substrate. The significance of the general components in MFCs and systems of MFCs treating azo dye is depicted in this review. In addition, degradation of azo dyes such as Congo red, methyl orange, active brilliant red X-3B, amaranth, reactive blue 221, and acid orange 7 in MFCs are summarized. Further exploration and operational modification are suggested to address the challenges of complete removal of azo dye with maximum power generation in an MFC. In addition, a sequential treatment system with MFCs is suggested for complete mineralization of azo dye. PMID:23581242

  1. Degradation of a textile reactive azo dye by a combined biological-photocatalytic process: Candida tropicalis Jks2 -Tio2/Uv

    PubMed Central

    2012-01-01

    In the present study, the decolorization and degradation of Reactive Black 5 (RB5) azo dye was investigated by biological, photocatalytic (UV/TiO2) and combined processes. Application of Candida tropicalis JKS2 in treatment of the synthetic medium containing RB5 indicated complete decolorization of the dye with 200 mg/L in less than 24 h. Degradation of the aromatic rings, resulting from the destruction of the dye, did not occur during the biological treatment. Mineralization of 50 mg/L RB5 solution was obtained after 80 min by photocatalytic process (in presence of 0.2 g/L TiO2). COD (chemical oxygen demand) was not detectable after complete decolorization of 50 mg/L RB5 solution. However, photocatalytic process was not effective in the removal of the dye at high concentrations (≥200 mg/L). With 200 mg/L concentration, 74.9% of decolorization was achieved after 4 h illumination under photocatalytic process and the absorbance peak in UV region (attributed to aromatic rings) was not completely removed. A two-step treatment process, namely, biological treatment by yeast followed by photocatalytic degradation, was also assessed. In the combined process (with 200 mg/L RB5), absorbance peak in UV region significantly disappeared after 2 h illumination and about 60% COD removal was achieved in the biological step. It is suggested that the combined process is more effective than the biological and photocatalytic treatments in the remediation of aromatic rings. PMID:23369285

  2. Effectiveness of Rice Agricultural Waste, Microbes and Wetland Plants in the Removal of Reactive Black-5 Azo Dye in Microcosm Constructed Wetlands.

    PubMed

    Saba, Beenish; Jabeen, Madeeha; Khalid, Azeem; Aziz, Irfan; Christy, Ann D

    2015-01-01

    Azo dyes are commonly generated as effluent pollutants by dye using industries, causing contamination of surface and ground water. Various strategies are employed to treat such wastewater; however, a multi-faceted treatment strategy could be more effective for complete removal of azo dyes from industrial effluent than any single treatment. In the present study, rice husk material was used as a substratum in two constructed wetlands (CWs) and augmented with microorganisms in the presence of wetland plants to effectively treat dye-polluted water. To evaluate the efficiency of each process the study was divided into three levels, i.e., adsorption of dye onto the substratum, phytoremediation within the CW and then bioremediation along with the previous two processes in the augmented CW. The adsorption process was helpful in removing 50% dye in presence of rice husk while 80% in presence of rice husk biocahr. Augmentation of microorganisms in CW systems has improved dye removal efficiency to 90%. Similarly presence of microorganisms enhanced removal of total nitrogen (68% 0 and Total phosphorus (75%). A significant improvement in plant growth was also observed by measuring plant height, number of leaves and leave area. These findings suggest the use of agricultural waste as part of a CW substratum can provide enhanced removal of textile dyes. PMID:25849115

  3. Degradation of azo dyes by environmental microorganisms and helminths

    SciTech Connect

    Kingthom Chung; Stevens, S.E. Jr. . Dept. of Biology)

    1993-11-01

    The degradation of azo dyes by environmental microorganisms, fungi, and helminths is reviewed. Azo dyes are used in a wide variety of products and can be found in the effluent of most sewage treatment facilities. Substantial quantities of these dyes have been deposited in the environment, particularly in streams and rivers. Azo dyes were shown to affect microbial activities and microbial population sizes in the sediments and in the water columns of aquatic habitats. Only a few aerobic bacteria have been found to reduce azo dyes under aerobic conditions, and little is known about the process. A substantial number of anaerobic bacteria capable of azo dye reduction have been reported. The enzyme responsible for azo dye reduction has been partially purified, and characterization of the enzyme is proceeding. The nematode Ascaris lumbricoides and the cestode Moniezia expanza have been reported to reduce azo dyes anaerobically. Recently the fungus Phanerochaete chrysoporium was reported to mineralize azo dyes via a peroxidation-mediated pathway. A possible degradation pathway for the mineralization of azo dye is proposed and future research needs are discussed.

  4. 40 CFR 721.4594 - Substituted azo metal complex dye.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted azo metal complex dye. 721... Substances § 721.4594 Substituted azo metal complex dye. (a) Chemical substance and significant new uses... dye (PMN P-94-499) is subject to reporting under this section for the significant new uses...

  5. 40 CFR 721.4594 - Substituted azo metal complex dye.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted azo metal complex dye. 721... Substances § 721.4594 Substituted azo metal complex dye. (a) Chemical substance and significant new uses... dye (PMN P-94-499) is subject to reporting under this section for the significant new uses...

  6. 40 CFR 721.4594 - Substituted azo metal complex dye.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Substituted azo metal complex dye. 721... Substances § 721.4594 Substituted azo metal complex dye. (a) Chemical substance and significant new uses... dye (PMN P-94-499) is subject to reporting under this section for the significant new uses...

  7. 40 CFR 721.4594 - Substituted azo metal complex dye.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Substituted azo metal complex dye. 721... Substances § 721.4594 Substituted azo metal complex dye. (a) Chemical substance and significant new uses... dye (PMN P-94-499) is subject to reporting under this section for the significant new uses...

  8. An Interdisciplinary Experiment: Azo-Dye Metabolism by "Staphylococcus Aureus"

    ERIC Educational Resources Information Center

    Brocklesby, Kayleigh; Smith, Robert; Sharp, Duncan

    2012-01-01

    An interdisciplinary and engaging practical is detailed which offers great versatility in the study of a qualitative and quantitative metabolism of azo-dyes by "Staphylococcus aureus". This practical has broad scope for adaptation in the number and depth of variables to allow a focused practical experiment or small research project. Azo-dyes are…

  9. Modification of azo dyes by lactic acid bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Identification of microorganisms capable of utilizing azo dyes have been an area of significant interest due to their role in the treatment of waste water derived from the textile industry. The ability of L. casei LA1133 and L. paracasei LA0471 to modify the azo dye tartrazine was recently document...

  10. SonoFenton degradation of an azo dye, Direct Red.

    PubMed

    Harichandran, G; Prasad, S

    2016-03-01

    The degradation of a reactive azo dye, Direct Red 81 (DR81), by Fenton process and in conjunction with sonolysis (SonoFenton) was studied. The synergistic effect of Fenton process and sonolysis enhanced the degradation of Direct Red 81 in aqueous solutions and the reaction followed the mechanism of hydroxyl radical (HO) oxidation. The influence of the initial substrate concentration, pH and catalyst loading on the rate of decolorisation were studied. The dye decolorisation followed apparent first order kinetics. The optimum conditions for decolorisation were pH=3.0, [Fe(2+)]=0.2 g/l, [H2O2]=5.1×10(-3) mol/l and ultrasonic frequency=120 kHz, 60 W. These conditions yielded 99% decolorisation of DR81 within 75 min. The sonolytic degradation products of DR81 were identified using Electrospray Ionization-Mass Spectrometry (ESI-MS). The presence of CO3(2-), HCO3(-), Cl(-), NO3(-), and SO4(2-) ions in the dye solution did not have a considerable effect on the decolorisation efficiency. This study demonstrates that Fenton and SonoFenton methods can effectively decolorize DR81 dye in waste water. The dye concentration used in this study is higher compared to earlier studies illustrating the effective mineralization by the SonoFenton process. The mechanism of dye degradation is also proposed. PMID:26584996

  11. Universal dark quencher based on "clicked" spectrally distinct azo dyes.

    PubMed

    Chevalier, Arnaud; Hardouin, Julie; Renard, Pierre-Yves; Romieu, Anthony

    2013-12-01

    The first synthesis of an heterotrifunctional molecular scaffold derived from the popular DABCYL azo dye quencher has been achieved. The sequential derviatization of this trivalent azobenzene derivative with two other nonfluorescent azo dyes (Black Hole Quencher BHQ-1 and BHQ-3) and through effective reactions from the "bioconjugation chemistry" repertoire has led to an universal dark quencher (UDQ). This "clicked" poly azo dye is able to turn off an array of fluorophores covering the UV/NIR (300-750 nm) spectral range. PMID:24215300

  12. Multiwavelength spectrophotometric determination of acidity constants of some azo dyes.

    PubMed

    Shamsipur, Mojtaba; Maddah, Bozorgmehr; Hemmateenejad, Bahram; Rouhani, Shohreh; Haghbeen, Kamaladin; Alizadeh, Kamal

    2008-06-01

    A multiwavelength spectrophotometric titration method was applied to study the acidity constants of some azo dyes in water. The UV-vis absorption spectra of azo dye solutions were recorded in the course of their pH-metric titration with a standard base solution. The protolytic equilibrium constants, spectral profiles, concentration diagrams and also the number of components have been calculated. The quantitative effects of the substituents on the acidity of the studied azo dyes were investigated by the linear free energy relationship (LFER) using Hammet sigma constant (sigma) and field and resonance effects of Kamlet and Taft (f and Re, respectively). PMID:17719268

  13. Multiwavelength spectrophotometric determination of acidity constants of some azo dyes

    NASA Astrophysics Data System (ADS)

    Shamsipur, Mojtaba; Maddah, Bozorgmehr; Hemmateenejad, Bahram; Rouhani, Shohreh; Haghbeen, Kamaladin; Alizadeh, Kamal

    2008-06-01

    A multiwavelength spectrophotometric titration method was applied to study the acidity constants of some azo dyes in water. The UV-vis absorption spectra of azo dye solutions were recorded in the course of their pH-metric titration with a standard base solution. The protolytic equilibrium constants, spectral profiles, concentration diagrams and also the number of components have been calculated. The quantitative effects of the substituents on the acidity of the studied azo dyes were investigated by the linear free energy relationship (LFER) using Hammet sigma constant ( σ) and field and resonance effects of Kamlet and Taft ( f and ℜ, respectively).

  14. 40 CFR 721.4594 - Substituted azo metal complex dye.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4594 Substituted azo metal complex dye. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted azo metal...

  15. REMOVAL OF AZO DYES BY THE ACTIVATED SLUDGE PROCESS

    EPA Science Inventory

    The Water Engineering Research Laboratory, Office of Research & Development, U.S. Environmental Protection Agency (EPA) is conducting research designed to develop techniques for predicting the fate of azo dyes in typical wastewater treatment systems which are treating wastewater ...

  16. Photobleaching effect in azo-dye containing epoxy resin films: the potentiality of carbon nanotubes as azo-dye dispensers

    NASA Astrophysics Data System (ADS)

    Díaz Costanzo, Guadalupe; Goyanes, Silvia; Ledesma, Silvia

    2015-04-01

    Azo-dye molecules may suffer from bleaching under certain illumination conditions. When this photoinduced process occurs, it generates an irreversible effect that is characterized by the loss of absorption of the dye molecule. Moreover, the well-known isomerization of azodye molecules does not occur anymore. In this work it is shown how the addition of a small amount of multi-walled carbon nanotubes (MWCNTs) helps to decrease the bleaching effect in a photosensitive guest-host azo-polymer film. Two different systems were fabricated using an epoxy resin as polymer matrix. An azo-dye, Disperse Orange 3, was used as photosensitive material in both systems and MWCNTs were added into one of them. The optical response of the polymeric systems was studied considering the degree of photoinduced birefringence. Photobleaching of the azo-dye was observed in all cases however, the effect is lower for the composite material containing 0.2 wt % MWCNTs. The weak interaction between MWCNTs and dye molecules is less favorable when the material is heated. The optical behavior of the heated composite material suggests that carbon nanotubes can be potentially used as azo dye dispensers. The results are interpreted in terms of the non-covalent interaction between azo-dye molecules and MWCNTs.

  17. Biological waste-water treatment of azo dyes

    SciTech Connect

    Shaul, G.M.; Dempsey, C.R.; Dostal, K.A.

    1988-05-01

    The U.S. Environmental Protection Agency's (EPA) Office of Toxic Substances evaluates existing chemicals under Section 4 of the Toxic Substances Control Act (TSCA) and Premanufacture Notification (PMN) submissions under Section 5 of TSCA. Azo dyes constitute a significant portion of these PMN submissions and specific azo dyes have recently been added to the priority list for considerations in the development of test rules under Section 4. Azo dyes are of concern because some of the dyes, dye precurors, and/or their degradation products such as aromatic amines (which are also dye precurors) have been shown to be, or are suspected to be, carcinogenic. The fate of azo dyes in biological waste-water treatment systems was studied to aid in the review of PMN submissions and to assist in the possible development of test rules. Results from extensive pilot-scale activated-sludge process testing for 18 azo dyes are presented. Results from fate studies of C.I. Disperse Blue 79 in aerobic and anaerobic waste-water treatment will also be presented.

  18. Development of an activated carbon-packed microbial bioelectrochemical system for azo dye degradation.

    PubMed

    Cardenas-Robles, Arely; Martinez, Eduardo; Rendon-Alcantar, Idelfonso; Frontana, Carlos; Gonzalez-Gutierrez, Linda

    2013-01-01

    A microbial bioelectrochemical reactor (BER) was employed for the degradation of azo dyes without the use of an external electron donor, using activated carbon (GAC) as a redox mediator. Contribution of pH values, open circuit potential (OCP), dye concentration and applied current were individually studied. A batch system and an upflow fixed bed bioreactor were built for analyzing the effect of the applied current on biodegradation of the azo dye Reactive Red 272. The presence of GAC (20% w/v) regulated both pH and OCP values in solution and led to a removal efficiency of 98%. Cyclic voltammetry results indicate a dependence of the electron transfer mechanism with the concentration of the azo compound. With these results, a continuous flow reactor operating with J=0.045 mA cm(-2), led to removal rates of 95% (± 3.5%) in a half-residence time of 1 hour. PMID:23128299

  19. The stability of textile azo dyes in soil and their impact on microbial phospholipid fatty acid profiles.

    PubMed

    Imran, Muhammad; Shaharoona, Baby; Crowley, David E; Khalid, Azeem; Hussain, Sabir; Arshad, Muhammad

    2015-10-01

    The aim of this study was to examine the stability of structurally different azo dyes in soil and their impact on the microbial community composition by analyzing phospholipid fatty acid (PLFA) profiles. Sterile and non-sterile soils were amended with three azo dyes, including: Direct Red 81, Reactive Black 5 and Acid Yellow 19 at 160mgkg(-1) soil. The results showed that the azo dyes were quite stable and that large amounts of these dyes ranging from 17.3% to 87.5% were recoverable from the sterile and non-sterile soils after 14 days. The maximum amount of dye was recovered in the case of Direct Red 81. PLFA analysis showed that the azo dyes had a significant effect on microbial community structure. PLFA concentrations representing Gram-negative bacteria in dye-amended soil were substantially less as compared to the PLFA concentration of Gram-positive bacteria. Acid Yellow 19 dye had almost similar effects on the PLFA concentrations representing bacteria and fungi. In contrast, Reactive Black 5 had a greater negative effect on fungal PLFA than that on bacterial PLFA, while the opposite was observed in the case of Direct Red 81. To our knowledge, this is the first study reporting the stability of textile azo dyes in soil and their effects on soil microbial community composition. PMID:26074308

  20. Growth and physiology of Clostridium perfringens wild-type and ΔazoC knockout: an azo dye exposure study.

    PubMed

    Morrison, Jessica M; John, Gilbert H

    2016-02-01

    Clostridium perfringens, a strictly anaerobic micro-organism and inhabitant of the human intestine, has been shown to produce the azoreductase enzyme AzoC, an NAD(P)H-dependent flavin oxidoreductase. This enzyme reduces azo dyes to aromatic amines, which are carcinogenic in nature. A significant amount of work has been completed that focuses on the activity of this enzyme; however, few studies have been completed that focus on the physiology of azo dye reduction. Dye reduction studies coupled with C. perfringens growth studies in the presence of ten different azo dyes and in media of varying complexities were completed to compare the growth rates and dye-reducing activity of C. perfringens WT cells, a C. perfringens ΔazoC knockout, and Bifidobacterium infantis, a non-azoreductase-producing control bacterium. The presence of azo dyes significantly increased the generation time of C. perfringens in rich medium, an effect that was not seen in minimal medium. In addition, azo dye reduction studies with the ΔazoC knockout suggested the presence of additional functional azoreductases in this medically important bacterium. Overall, this study addresses a major gap in the literature by providing the first look, to our knowledge, at the complex physiology of C. perfringens upon azo dye exposure and the effect that both azo dyes and the azoreductase enzyme have on growth. PMID:26566621

  1. Detection of azo dyes and aromatic amines in women undergarment.

    PubMed

    Nguyen, Thao; Saleh, Mahmoud A

    2016-07-28

    Women are exposed to several chemical additives including azo dyes that exist in textile materials, which are a potential health hazard for consumers. Our objective was to analyze suspected carcinogenic azo dyes and their degradation aromatic amines in women underwear panties using a fast and simple method for quantification. Here, we evaluated 120 different samples of women underwear for their potential release of aromatic amines to the skin. Seventy-four samples yielded low level mixtures of aromatic amines; however eighteen samples were found to produce greater than 200 mg/kg (ppm) of aromatic amines. Azo dyes in these 18 samples were extracted from the fabrics and analyzed by reverse phase thin layer chromatography in tandem with atmospheric pressure chemical ionization mass spectrometry. Eleven azo dyes were identified based on their mass spectral data and the chemical structure of the aromatic amine produced from these samples. We demonstrate that planar chromatography and mass spectrometry can be really helpful in confirming the identity of the azo dyes, offering highly relevant molecular information of the responsible compounds in the fabrics. With the growing concern about the consumer goods, analysis of aromatic amines in garments has become a highly important issue. PMID:27149414

  2. Biosorption of Azo dyes by spent Rhizopus arrhizus biomass

    NASA Astrophysics Data System (ADS)

    Salvi, Neeta A.; Chattopadhyay, S.

    2016-05-01

    In the present study, spent Rhizopus arrhizus biomass was used for the removal of six azo dyes from aqueous solutions. The dye removal capacity of the biomass was evaluated by conducting batch tests as a function of contact time, biomass dosage, pH and initial dye concentrations. The pseudo-second-order kinetic model fitted well with the experimental data with correlation coefficients greater than 0.999, suggesting that chemisorptions might be the rate limiting step. The equilibrium sorption data showed good fit to the Langmuir isotherm model. Among the six dyes tested, the maximum monolayer adsorption capacity for fast red A and metanil yellow was found to be 108.8 and 128.5 mg/g, respectively. These encouraging results suggest that dead Rhizopus arrhizus biomass could be a potential biomaterial for the removal of azo dyes from aqueous dye solution.

  3. 40 CFR 721.10633 - Aromatic sulfonic acid amino azo dye salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aromatic sulfonic acid amino azo dye... Specific Chemical Substances § 721.10633 Aromatic sulfonic acid amino azo dye salts (generic). (a) Chemical... as aromatic sulfonic acid amino azo dye salts (PMN P-12-276) is subject to reporting under...

  4. 40 CFR 721.10633 - Aromatic sulfonic acid amino azo dye salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aromatic sulfonic acid amino azo dye... Specific Chemical Substances § 721.10633 Aromatic sulfonic acid amino azo dye salts (generic). (a) Chemical... as aromatic sulfonic acid amino azo dye salts (PMN P-12-276) is subject to reporting under...

  5. 40 CFR 721.980 - Sodium salt of azo acid dye.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Sodium salt of azo acid dye. 721.980... Substances § 721.980 Sodium salt of azo acid dye. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a sodium salt of azo acid dye (PMN...

  6. 40 CFR 721.980 - Sodium salt of azo acid dye.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sodium salt of azo acid dye. 721.980... Substances § 721.980 Sodium salt of azo acid dye. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a sodium salt of azo acid dye (PMN...

  7. 40 CFR 721.980 - Sodium salt of azo acid dye.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sodium salt of azo acid dye. 721.980... Substances § 721.980 Sodium salt of azo acid dye. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a sodium salt of azo acid dye (PMN...

  8. 40 CFR 721.980 - Sodium salt of azo acid dye.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Sodium salt of azo acid dye. 721.980... Substances § 721.980 Sodium salt of azo acid dye. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a sodium salt of azo acid dye (PMN...

  9. 40 CFR 721.980 - Sodium salt of azo acid dye.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sodium salt of azo acid dye. 721.980... Substances § 721.980 Sodium salt of azo acid dye. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a sodium salt of azo acid dye (PMN...

  10. Photoinduced translational molecular mobility in solid nanostructured azo dye films

    SciTech Connect

    Ezhov, A A; Kozenkov, V M; Magnitskii, Sergey A; Nagorskii, Nikolay M; Panov, Vladimir I

    2011-11-30

    A new mechanism controlling the molecular motion in thin azo-containing films during a photoinduced change in the surface nanorelief is found. It is shown experimentally that exposure of a solid AD-1 azo dye, deposited on a glass substrate, to incoherent linearly polarised light leads to formation of nanostructures with a characteristic size of 200 nm, which are similar to droplets of melt of this dye on the same substrate. It is shown that photoinduced mass transport in a solid AD-1 azo dye film can be explained by the mobility of molecules related to their trans-cis-photoisomerisation, which leads to film softening with subsequent formation of spherical protrusions under surface tension forces.

  11. Metabolism of azo dyes: implication for detoxication and activation.

    PubMed

    Levine, W G

    1991-01-01

    Azo dyes are consumed and otherwise utilized in varying quantities in many parts of the world. Such widely used chemicals are of great concern with regard to their potential toxicity and carcinogenic properties. Their metabolism has been studied extensively and is significant for detoxication and metabolic activation. Both oxidative and reductive pathways are involved in these processes. The majority of azo dyes undergo reduction catalyzed by enzymes of the intestinal microorganisms and/or hepatic enzymes including microsomal and soluble enzymes. The selectivity of substrate and enzyme may to a large extent be determined by the oxygen sensitivity of reduction since a normal liver is mainly aerobic in all areas, whereas the microorganisms of the lower bowel exist in an anaerobic environment. However, it should be pointed out that the pO2 of centrilobular cells within the liver is only a fraction that of air, where pO2 = 150 torr. Therefore, an azo dye reduction experiment performed aerobically may not be an accurate predictor of reductive metabolism in all areas of the liver. Many of the azo dyes in common use today have highly charged substituents such as sulfonate. These resist enzymic attack and for the most part are poorly absorbed from the intestinal tract, providing poor access to the liver, the major site of the mixed-function oxidase system. Lipophilic dyes, such as DAB, which are often carcinogenic, readily access oxidative enzymes and are activated by both mixed-function oxidase and conjugating systems. Reduction of the carcinogenic dyes usually leads to loss of carcinogenic activity. By contrast, most of the highly charged water-soluble dyes become mutagenic only after reduction. Even then, most of the fully reduced amines required oxidative metabolic activation. An outstanding example is the potent human bladder carcinogen benzidine, which derives from the reduction of several azo dyes. Many problems regarding mutagenic and carcinogenic activation remain

  12. FATE OF WATER SOLUBLE AZO DYES IN THE ACTIVATED SLUDGE PROCESS

    EPA Science Inventory

    The objective of this study was to determine the partitioning of water soluble azo dyes in the activated sludge process (ASP). Azo dyes are of concern because some of the dyes, dye precursors , and/or their degradation products such as aromatic amines (which are also dye precurso...

  13. Catalyzed degradation of azo dyes under ambient conditions.

    PubMed

    Wu, Jin-Ming; Wen, Wei

    2010-12-01

    Phase-pure layered perovskite La(4)Ni(3)O(10) powders were synthesized by a solution combustion approach. It is found that, in the presence of the La(4)Ni(3)O(10) powders, aqueous azo dyes can be degraded catalytically and efficiently under ambient conditions. Neither light nor additional reagents are needed in the catalytic reaction. The dye degradation procedure can be accelerated markedly by magnetic stirring. A systemic series of chemical and electrochemical experiments suggested that the dye degradation proceeds through electron transfers from the dye molecules to the catalyst and then to electron acceptors such as dissolved oxygen. The present catalytic degradation requires no additional reagents or external energy input, which hence provides a potentially low-cost alternative for the remediation of azo-dye effluents. PMID:21049925

  14. Use of highly absorptive azo dyes in photoresist coatings

    NASA Astrophysics Data System (ADS)

    Lu, Ping-Hung; Ding, Shuji; Hannigan, T. T.; Eberly, D. E.; Kokinda, Elaine; Dixit, Sunit S.; Mehtsun, Salem; Corso, Anthony J.; Khanna, Dinesh N.

    1997-07-01

    We recently synthesized and studied a number of highly absorptive diketo azo dyes. These materials, existed in the hydrazo tautomeric forms, showed high extinction coefficients, typically (epsilon) approximately equals 25,000 - 39,000 at 365 nm. They also exhibited good solubility in common resist casting solvents such as propylene glycol monoethyl acetate (PGMEA) and ethyl lactate. The thermostability of the materials was investigated. The impact of these diketo azo dyes on i-line resist performance in terms of swing reduction, reflective notching control and lithographic performance is discussed.

  15. Using protein nanofibrils to remove azo dyes from aqueous solution by the coagulation process.

    PubMed

    Morshedi, Dina; Mohammadi, Zeinab; Akbar Boojar, Masoud Mashhadi; Aliakbari, Farhang

    2013-12-01

    The ever-increasing applications of hazardous azo dyes as industrialized coloring agents have led to serious remediation challenges. In this study, proteinaceous nanofibrils were examined as coagulants for decolorization of azo dyes in aqueous solutions. The results provided some insight regarding the mechanism of dye removal. The strength of nanofibrils to remove dyes from solution was evaluated by remediation of acid red 88, Bismarck brown R, direct violet 51, reactive black 5, and Congo red. However, the efficiency of nanofibrils to coagulate with different dyes was variable (60-98%) and dependent on the structures of dyes and the physicochemical conditions of the solutions. Increasing the temperature or ionic strength declined the coagulation time and induced the rate of dye removal. Changing pH had contradictory effects on the dye removal efficiency which was more affected by the chemical structure of the dye rather than the change in stability of the coagulant. The efficiency of nanofibrils to remove dyes was more than that of charcoal, which is considered as one of the most common substances used for azo dye remediation which may be due to its well dispersion in the aqueous solutions, and slower rates of the coagulation than that of the adsorption process. Furthermore, cytotoxicity was not detected after treating cell cultures with the decolorized solutions. Accordingly, by integrating biological and biophysicochemical processes, proteinaceous nanofibrils can be promising candidates for treatment of colored wastewaters. Ease of production, proper and quick dispersion in water, without the production of dangerous dye by-products and derivatives, are some of the main advantages of nanofibrils. PMID:23999142

  16. A comparative study on decolorization of reactive azo and indigoid dyes by free/immobilized pellets of Trametes versicolor and Funalia trogii.

    PubMed

    Yildirim, Seval Cing; Yesilada, Ozfer

    2015-11-01

    The objective of the present study was to investigate decolorization of Acid Blue 74 and Reactive Blue 198 dyes by free and immobilized white rot fungal pellets in order to confirm the possibility of practical application via repeated-batch cultivation. Decolorization studies were conducted using free pellets (FP), fungal cells immobilized on activated carbon (IFCAC) and pinewood (IFCP), and also fungal cells entrapped in alginate beads (FCEAB). No additional nitrogen and carbon source was used and high decolorization rates were achieved in only dye-contained media without pH adjustment. Acid Blue 74 was decolorized 96 and 94% within 2 hr by Trametes versicolor and Funalia trogii free pellets, respectively. These values were 87 and 84% for Reactive Blue 198, in this respect. Immobilization of fungal cells on pinewood increased the usability of pellets and the average decolorization efficiency of both dyes. The micro environment changed in the presence of pinewood and increased the stability of immobilized pellets. Decolorization was performed rapidly and efficiently. Laccase activity enhanced with availability of pinewood, and high laccase production with F. trogii was obtained. After separation by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), the molecular weight of T versicolor and F. trogii laccase bands was determined 64 and 61 kDa approximately. Green bands were obtained by the activity staining process with laccase substrate (ABTS) after gel renaturation step. PMID:26688979

  17. Toxicity assessment and microbial degradation of azo dyes.

    PubMed

    Puvaneswari, N; Muthukrishnan, J; Gunasekaran, P

    2006-08-01

    Toxic effluents containing azo dyes are discharged from various industries and they adversely affect water resources, soil fertility, aquatic organisms and ecosystem integrity. They pose toxicity (lethal effect, genotoxicity, mutagenicity and carcinogenicity) to aquatic organisms (fish, algae, bacteria, etc.) as well as animals. They are not readily degradable under natural conditions and are typically not removed from waste water by conventional waste water treatment systems. Benzidine based dyes have long been recognized as a human urinary bladder carcinogen and tumorigenic in a variety of laboratory animals. Several microorganisms have been found to decolourize, transform and even to completely mineralize azo dyes. A mixed culture of two Pseudomonas strains efficiently degraded mixture of 3-chlorobenzoate (3-CBA) and phenol/cresols. Azoreductases of different microorganisms are useful for the development of biodegradation systems as they catalyze reductive cleavage of azo groups (-N=N-) under mild conditions. In this review, toxic impacts of dyeing factory effluents on plants, fishes, and environment, and plausible bioremediation strategies for removal of azo dyes have been discussed. PMID:16924831

  18. Laboratory studies of electrochemical treatment of industrial azo dye effluent.

    PubMed

    Vaghela, Sanjay S; Jethva, Ashok D; Mehta, Bhavesh B; Dave, Sunil P; Adimurthy, Subbarayappa; Ramachandraiah, Gadde

    2005-04-15

    Removal of color and reduction of chemical oxygen demand (COD) in an industrial azo dye effluent containing chiefly reactive dyes were investigated under single-pass conditions at a dimensionally stable anode (DSA) in a thin electrochemical flow reactor at different current densities, flow rates, and dilutions. With 50% diluted effluent, decolorization was achieved up to 85-99% at 10-40 mA/ cm2 at 5 mL/min flow rate and 50-88% at 30-40 mA/ cm2 at high (10-15 mL/min) flow rates. The COD reduction was maximum (81%) at 39.9 mA/cm2 or above when solution-electrode contact time (Ct) was as high as 21.7 s/cm2 and decreased as Ct declined at a given current density. Cyclic voltammetric studies suggesting an indirect oxidation of dye molecules over the anode surface were carried out at a glassy carbon electrode. The effect of pH on decolorization and COD reduction was determined. An electrochemical mechanism mediated by OCl- operating in the decolorization and COD reduction processes was suggested. The effluent was further treated with NaOCI. The oxidized products from the treated effluents were isolated and confirmed to be free from chlorine-substituted products by IR spectroscopy. From the apparent pseudo-first-order rate data, the second-order rate coefficients were evaluated to be 2.9 M(-1) s(-1) at 5 mL/ min, 76.2 M(-1) s(-1) at 10 mL/min, and 156.1 M(-1) s(-1) at 15 mL/ min for color removal, and 1.19 M(-1) s(-1) at 5 mL/min, 1.79 M(-1) s(-1) at 10 mL/min, and 3.57 M(-1) s(-1) at 15 mL/min for COD reduction. Field studies were also carried out with a pilot-scale cell at the source of effluent generation of different plants corresponding to the industry. Decolorization was achieved to about 94-99% with azo dye effluents at 0.7-1.0 L/min flow costing around Indian Rupees 0.02-0.04 per liter, and to about 54-75% in other related effluents at 0.3-1.0 L/min flow under single-pass conditions. PMID:15884385

  19. Decolorization of azo dye C.I. Reactive Black 5 by ozonation in aqueous solution: influencing factors, degradation products, reaction pathway and toxicity assessment.

    PubMed

    Zheng, Qing; Dai, Yong; Han, Xiangyun

    2016-01-01

    In this study, ozonation treatment of C.I. Reactive Black 5 (RB5) was investigated at various operating parameters. The results showed that the aqueous solution initially containing 200 mg/L RB5 was quickly decolorized at pH 8.0 with an ozone dose of 3.2 g/h. Reaction intermediates with m/z 281, 546, 201, 350, 286 and 222 were elucidated using liquid chromatography-mass spectrometry, while sulfate ion, nitrate ion and three carboxylic acids (i.e., oxalic acid, formic acid, and acetic acid) were identified by ion exchange chromatography. Thus, the cleavage of the azo bond and the introduction of OH groups in the corresponding positions were proposed as the predominant reaction pathway. The detachment of sulfonic groups was also commonly observed during the ozonation treatment. The proposed degradation mechanism was confirmed by frontier electron density calculations, suggesting the feasibility of predicting the major events in the whole ozonation process with the computational method. Compared with RB5 degradation, the reduction of total organic carbon (TOC) proceeded much more slowly, and approximately 54% TOC was removed after 4 h of ozonation. Acute toxicity tests with Photobacterium phosphoreum showed that the toxicity of reaction solution was firstly increased and then decreased to a negligible level after 160 min. PMID:27054721

  20. Irradiation treatment of azo dye containing wastewater: An overview

    NASA Astrophysics Data System (ADS)

    Wojnárovits, László; Takács, Erzsébet

    2008-03-01

    The radiation-induced decolouration and degradation of aqueous solutions of azo dyes and their model compounds (anilines, phenols, triazines) are reviewed together with practical applications and the experimental methods (pulse radiolysis, steady-state gamma radiolysis, as well as end-product analysis) used for studying the reactions. The proposed mechanisms and the rate coefficients for the reactions of rad OH, e aq- and rad H water radiolysis intermediates with the dye molecules and with model compounds are summarized.

  1. Detoxification of azo dyes in the context of environmental processes.

    PubMed

    Rawat, Deepak; Mishra, Vandana; Sharma, Radhey Shyam

    2016-07-01

    Azo dyes account for >70% of the global industrial demand (∼9 million tons). Owing to their genotoxic/carcinogenic potential, the annual disposal of ∼4,500,000 tons of dyes and/or degraded products is an environmental and socio-economic concern. In comparison to physico-chemical methods, microbe-mediated dye degradation is considered to be low-input, cost-effective and environmentally-safe. However, under different environmental conditions, interactions of chemically diverse dyes with metabolically diverse microbes produce metabolites of varying toxicity. In addition, majority of studies on microbial dye-degradation focus on decolorization with least attention towards detoxification. Therefore, the environmental significance of microbial dye detoxification research of past >3 decades is critically evaluated with reference to dye structure and the possible influence of microbial interactions in different environments. In the absence of ecosystem-based studies, the results of laboratory-based studies on dye degradation, metabolite production and their genotoxic impact on model organisms are used to predict the possible fate and consequences of azo dyes/metabolites in the environment. In such studies, the predominance of fewer numbers of toxicological assays that too at lower levels of biological organization (molecular/cellular/organismic) suggests its limited ecological significance. Based on critical evaluation of these studies the recommendations on inclusion of multilevel approach (assessment at multiple levels of biological organization), multispecies microcosm approach and native species approach in conjunction with identification of dye metabolites have been made for future studies. Such studies will bridge the gap between the fundamental knowledge on dye-microbe-environment interactions and its application to combat dye-induced environmental toxicity. Thus an environmental perspective on dye toxicity in the background of dye structure and effects of

  2. Anaerobic/aerobic treatment of selected azo dyes in wastewater

    SciTech Connect

    Seshadri, S.; Bishop, P.L. . Dept. of Civil and Environmental Engineering); Agha, A.M. . Faculty of Civil Engineering)

    1994-01-01

    Azo dyes represent the largest class of dyes in use today. Current environmental concern with these dyes revolves around the potential carcinogenic health risk presented by these dyes or their intermediate biodegradation products when exposed to microflora in the human digestive tract. These dyes may build up in the environment, since many wastewater treatment plants allow these dyes to pass through the system virtually untreated. The initial step in the degradation of these dyes is the cleavage of the Azo bond. This cleavage is often impossible under aerobic conditions, but has been readily demonstrated under anaerobic conditions. The focus of the study was to determine the feasibility of using an anaerobic fluidized-bed reactor to accomplish this cleavage. The effects of typical process variables such as hydraulic retention time (HRT), influent dye concentration levels, and degree of bed fluidization on removal efficiencies were also studied. The four dyes selected for this study were Acid-Orange 7, Acid-Orange 8, Acid-Orange 10, and Acid-Red 14. The effectiveness of using a bench-scale-activated sludge reactor as a sequenced second stage was also examined. Results indicate that nearly complete cleavage of the Azo bond is easily accomplished for each of the four dyes under hydraulic retention times of either 12 or 24 h. Initial results indicate, though, that aromatic amine by-products remain. The sequenced second stage was able to remove the remaining Chemical Oxygen Demand (COD) load to acceptable levels. Work is presently underway to determine the face of the anaerobic by-products in the aerobic second stage.

  3. Photocatalytic Degradation of Azo Dyes using Doped Titania Fibers

    NASA Astrophysics Data System (ADS)

    Shanmugasundaram, Prasad

    Photo-catalytic degradation using semiconductor particle as dispersion in aqueous medium has been gaining increased attention over the past several years. Their versatility in application makes them unique along with their easy processing techniques and low cost. Titania semiconductor is one of the most important members of this family. It has been widely used for various applications ranging from environmental to bio-medical. Titanium dioxide has gained importance as an effective photo-catalyst because of its advantages over other semiconductor oxides which include high photo-stability, inexpensive, reusable property, chemical and biological inertness, high reactivity, non-toxicity, corrosion resistance, operation at ambient temperatures and its ability to treat trace level pollutants. Its use as a photocatalyst is primarily because of its band gap of 3.0-3.3 eV which can be effectively activated under ultraviolet radiation (wavelength lambda < 400 nm), which leads to electron jump from valence to conduction band. This project aims at developing electrospun titania fibers doped with copper in order to study and demonstrate photocatalytic activity in the visible light spectrum, resulting in quick formation of holes which are ready to react with water to form -OH radicals. A comparative study of pure titania and copper doped titania for degradation of azo dyes were carried out. SEM, EDAX, XRD were carried out to thoroughly understand the structure of the fibers. The photocatalytic activity measurements for different dyes were noted using Uv-Vis method. The fibers when fully developed will be disposable photocatalytic materials for degrading dyes, Organic pollutants and for bio-medical applications when exposed to visible light.

  4. Enhanced anaerobic fermentation with azo dye as electron acceptor: simultaneous acceleration of organics decomposition and azo decolorization.

    PubMed

    Li, Yang; Zhang, Yaobin; Quan, Xie; Zhang, Jingxin; Chen, Shuo; Afzal, Shahzad

    2014-10-01

    Accumulation of hydrogen during anaerobic processes usually results in low decomposition of volatile organic acids (VFAs). On the other hand, hydrogen is a good electron donor for dye reduction, which would help the acetogenic conversion in keeping low hydrogen concentration. The main objective of the study was to accelerate VFA composition through using azo dye as electron acceptor. The results indicated that the azo dye serving as an electron acceptor could avoid H2 accumulation and accelerate anaerobic digestion of VFAs. After adding the azo dye, propionate decreased from 2400.0 to 689.5mg/L and acetate production increased from 180.0 to 519.5mg/L. It meant that the conversion of propionate into acetate was enhanced. Fluorescence in situ hybridization analysis showed that the abundance of propionate-utilizing acetogens with the presence of azo dye was greater than that in a reference without azo dye. The experiments via using glucose as the substrate further demonstrated that the VFA decomposition and the chemical oxygen demand (COD) removal increased by 319.7mg/L and 23.3% respectively after adding the azo dye. Therefore, adding moderate azo dye might be a way to recover anaerobic system from deterioration due to the accumulation of H2 or VFAs. PMID:25288539

  5. Isolation, development and identification of salt-tolerant bacterial consortium from crude-oil-contaminated soil for degradation of di-azo dye Reactive Blue 220.

    PubMed

    Patel, Vipul R; Bhatt, Nikhil

    2015-01-01

    The objective of this study was development and characterization of a halophilic bacterial consortium for rapid decolorization and degradation of a wide range of dyes and their mixtures. The 16S rRNA gene analysis of developed halophilic consortium VN.1 showed that the bacterial consortium contained six bacterial strains, which were identified as Pseudomonas fluorescens HM480360, Enterobacter aerogenes HM480361, Shewanella sp. HM589853, Arthrobacter nicotianae HM480363, Bacillus beijingensis HM480362 and Pseudomonas aeruginosa JQ659549. Halophilic consortium VN.1 was able to decolorize up to 2,500 mg/L RB220 with >85% chemical oxygen demand (COD) reduction under static condition at 30 °C and pH 8.0 in the presence of 7% NaCl. VN.1 also exhibited more than 85% COD reduction with >25 mg/(L h) rate of decolorization in the case of different reactive dye mixtures. We propose the symmetric cleavage of RB220 using Fourier transform infrared, high-performance liquid chromatography (HPLC), nuclear magnetic resonance and gas chromatography-mass spectrometry analysis, and confirmed the formation of sodium-4-aminobenzenesulfonate, sodium-6-aminonepthalenesulfonate, and sodiumbenzene/nepthalenesulfonate. Toxicity studies confirm that the biodegraded products of RB220 effluent stimulate the growth of plants as well as the bacterial community responsible for soil fertility. PMID:26177415

  6. Biodegradation and detoxification of textile azo dyes by bacterial consortium under sequential microaerophilic/aerobic processes.

    PubMed

    Lade, Harshad; Kadam, Avinash; Paul, Diby; Govindwar, Sanjay

    2015-01-01

    Release of textile azo dyes to the environment is an issue of health concern while the use of microorganisms has proved to be the best option for remediation. Thus, in the present study, a bacterial consortium consisting of Providencia rettgeri strain HSL1 and Pseudomonas sp. SUK1 has been investigated for degradation and detoxification of structurally different azo dyes. The consortium showed 98-99 % decolorization of all the selected azo dyes viz. Reactive Black 5 (RB 5), Reactive Orange 16 (RO 16), Disperse Red 78 (DR 78) and Direct Red 81 (DR 81) within 12 to 30 h at 100 mg L(-1) concentration at 30 ± 0.2 °C under microaerophilic, sequential aerobic/microaerophilic and microaerophilic/aerobic processes. However, decolorization under microaerophilic conditions viz. RB 5 (0.26 mM), RO 16 (0.18 mM), DR 78 (0.20 mM) and DR 81 (0.23 mM) and sequential aerobic/microaerophilic processes viz. RB 5 (0.08 mM), RO 16 (0.06 mM), DR 78 (0.07 mM) and DR 81 (0.09 mM) resulted into the formation of aromatic amines. In distinction, sequential microaerophilic/ aerobic process doesn't show the formation of amines. Additionally, 62-72 % reduction in total organic carbon content was observed in all the dyes decolorized broths under sequential microaerophilic/aerobic processes suggesting the efficacy of method in mineralization of dyes. Notable induction within the levels of azoreductase and NADH-DCIP reductase (97 and 229 % for RB 5, 55 and 160 % for RO 16, 63 and 196 % for DR 78, 108 and 258 % for DR 81) observed under sequential microaerophilic/aerobic processes suggested their critical involvements in the initial breakdown of azo bonds, whereas, a slight increase in the levels of laccase and veratryl alcohol oxidase confirmed subsequent oxidation of formed amines. Also, the acute toxicity assay with Daphnia magna revealed the nontoxic nature of the dye-degraded metabolites under sequential microaerophilic/aerobic processes. As biodegradation under sequential microaerophilic

  7. Biodegradation and detoxification of textile azo dyes by bacterial consortium under sequential microaerophilic/aerobic processes

    PubMed Central

    Lade, Harshad; Kadam, Avinash; Paul, Diby; Govindwar, Sanjay

    2015-01-01

    Release of textile azo dyes to the environment is an issue of health concern while the use of microorganisms has proved to be the best option for remediation. Thus, in the present study, a bacterial consortium consisting of Providencia rettgeri strain HSL1 and Pseudomonas sp. SUK1 has been investigated for degradation and detoxification of structurally different azo dyes. The consortium showed 98-99 % decolorization of all the selected azo dyes viz. Reactive Black 5 (RB 5), Reactive Orange 16 (RO 16), Disperse Red 78 (DR 78) and Direct Red 81 (DR 81) within 12 to 30 h at 100 mg L-1 concentration at 30 ± 0.2 °C under microaerophilic, sequential aerobic/microaerophilic and microaerophilic/aerobic processes. However, decolorization under microaerophilic conditions viz. RB 5 (0.26 mM), RO 16 (0.18 mM), DR 78 (0.20 mM) and DR 81 (0.23 mM) and sequential aerobic/microaerophilic processes viz. RB 5 (0.08 mM), RO 16 (0.06 mM), DR 78 (0.07 mM) and DR 81 (0.09 mM) resulted into the formation of aromatic amines. In distinction, sequential microaerophilic/ aerobic process doesn’t show the formation of amines. Additionally, 62-72 % reduction in total organic carbon content was observed in all the dyes decolorized broths under sequential microaerophilic/aerobic processes suggesting the efficacy of method in mineralization of dyes. Notable induction within the levels of azoreductase and NADH-DCIP reductase (97 and 229 % for RB 5, 55 and 160 % for RO 16, 63 and 196 % for DR 78, 108 and 258 % for DR 81) observed under sequential microaerophilic/aerobic processes suggested their critical involvements in the initial breakdown of azo bonds, whereas, a slight increase in the levels of laccase and veratryl alcohol oxidase confirmed subsequent oxidation of formed amines. Also, the acute toxicity assay with Daphnia magna revealed the nontoxic nature of the dye-degraded metabolites under sequential microaerophilic/aerobic processes. As biodegradation under sequential microaerophilic

  8. Ultrafast degradation of azo dyes catalyzed by cobalt-based metallic glass

    NASA Astrophysics Data System (ADS)

    Qin, X. D.; Zhu, Z. W.; Liu, G.; Fu, H. M.; Zhang, H. W.; Wang, A. M.; Li, H.; Zhang, H. F.

    2015-12-01

    Reactivity and mass loss are considered mutually exclusive in conventional zero-valent metal (ZVM) technology to treat environmental contaminants. Here, we report the outstanding performance of Co-based metallic glass (MG) in degrading an aqueous solution of azo dye, thus eliminating this trade-off. Ball-milled Co-based MG powders completely degrade Acid Orange II at an ultrafast rate. The surface-area-normalized rate constant of Co-based MG powders was one order of magnitude higher than that of Co-based crystalline counterparts and three orders of magnitude higher than that of the widely studied Fe0 powders. The coordinatively unsaturated local structure in Co-based MG responds to the catalysis for degradation, resulting in very low mass loss. Wide applicability and good reusability were also present. Co-based MG is the most efficient material for azo dye degradation reported thus far, and will promote the practical application of MGs as functional materials.

  9. Non-classical azoreductase secretion in Clostridium perfringens in response to sulfonated azo dye exposure.

    PubMed

    Morrison, Jessica M; John, Gilbert H

    2015-08-01

    Clostridium perfringens, a strictly anaerobic microorganism and inhabitant of the human intestine, has been shown to produce an azoreductase enzyme (AzoC), an NADH-dependent flavin oxidoreductase. This enzyme reduces azo dyes into aromatic amines, which can be carcinogenic. A significant amount of work has been completed on the activity of AzoC. Despite this, much is still unknown, including whether azoreduction of these dyes occurs intracellularly or extracellulary. A physiological study of C. perfringens involving the effect of azo dye exposure was completed to answer this question. Through exposure studies, azo dyes were found to cause cytoplasmic protein release, including AzoC, from C. perfringens in dividing and non-dividing cells. Sulfonation (negative charge) of azo dyes proved to be the key to facilitating protein release of AzoC and was found to be azo-dye-concentration-dependent. Additionally, AzoC was found to localize to the Gram-positive periplasmic region. Using a ΔazoC knockout mutant, the presence of additional azoreductases in C. perfringens was suggested. These results support the notion that the azoreduction of these dyes may occur extracellularly for the commensal C. perfringens in the intestine. PMID:25881497

  10. Liquid-Crystal Photoalignment by Super Thin Azo Dye Layer

    NASA Astrophysics Data System (ADS)

    Li, Xihua; Kozenkov, Vladimir M.; Yeung, Fion Sze-Yan; Xu, Peizhi; Chigrinov, Vladimir G.; Kwok, Hoi-Sing

    2006-01-01

    A novel liquid crystal (LC) photoalignment method, based on a super thin azo dye molecular layer is proposed. The basic idea of this method is to form a very neat textile knitwear and uniform alignment by azo dye layer without spin coating and rubbing processes. The thickness of the alignment layer is smaller than 3 nm, which is much thinner than traditional PI alignment film. In addition to the advantages of a conventional photoalignment method, the use of super thin layer simplifies the alignment procedure, making possible a high electrooptical performance, good photo-tolerance and thermal stability, better adhesion on indium tin oxide (ITO) surface and compatibility with roll-to-roll process.

  11. Cobalt ferrite nano-composite coated on glass by Doctor Blade method for photo-catalytic degradation of an azo textile dye Reactive Red 4: XRD, FESEM and DRS investigations.

    PubMed

    Habibi, Mohammad Hossein; Parhizkar, Janan

    2015-11-01

    Cobalt ferrite nano-composite was prepared by hydrothermal route using cobalt nitrate, iron nitrate and ethylene glycol as chelating agent. The nano-composite was coated on glass by Doctor Blade method and annealed at 300 °C. The structural, optical, and photocatalytic properties have been studied by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and UV-visible spectroscopy (UV-Vis DRS). Powder XRD analysis confirmed formation of CoFe2O4 spinel phase. The estimated particle size from FESEM data was 50 nm. The calculated energy band gaps, obtained by Tauc relation from UV-Vis absorption spectra was 1.3 eV. Photocatalytic degradation of Reactive Red 4 as an azo textile was investigated in aqueous solution under irradiation showed 68.0% degradation of the dye within 100 min. The experimental enhanced activity compare to pure Fe2O3 can be ascribed to the formation of composite, which was mainly attributable to the transfer of electron and hole to the surface of composite and hinder the electron hole recombination. PMID:26116997

  12. Biogenic sulphide plays a major role on the riboflavin-mediated decolourisation of azo dyes under sulphate-reducing conditions.

    PubMed

    Cervantes, Francisco J; Enríquez, Javier E; Galindo-Petatán, Eden; Arvayo, Héctor; Razo-Flores, Elías; Field, Jim A

    2007-06-01

    The effect of high concentrations of sulphate on the reductive decolourisation of different azo dyes by anaerobic sludge was studied in batch cultures. Sludge cultures were pre-incubated under sulphate-reducing conditions prior addition of dyes. Little or no effects of sulphate (5-10 g sulphate l(-1)) on the rate of decolourisation of Reactive Orange 14 (RO14), Direct Blue 53 (DB53) and Direct Blue 71 (DB71) were observed when no external redox mediator was provided. However, an increase in sulphate concentration, in the presence of riboflavin (20 microM), enhanced the decolourisation of all dyes. The first-rate constant of decolourisation (k) was increased up to 2-, 3.6- and 2-fold for RO14, DB53 and DB71, respectively, by supplying high sulphate concentrations, compared to the controls lacking sulphate, in the presence of the redox mediator. Sulphate reduction did not take place during the course of azo reductions, but was only evident before dye addition and after complete decolourisation, suggesting azo dyes reduction out-competed sulphate reduction for the available reducing equivalents. The experimental data suggest that reduction of azo dyes by riboflavin, which had been reduced by biogenic sulphide, was the major mechanism implicated during decolourisations, which was corroborated by abiotic incubations. Riboflavin greatly accelerated the abiotic reduction of RO14, so that the k value was increased up to 44-fold compared to the control lacking riboflavin. PMID:17350080

  13. Metabolism of azo dyes by human skin microbiota.

    PubMed

    Stingley, Robin L; Zou, Wen; Heinze, Thomas M; Chen, Huizhong; Cerniglia, Carl E

    2010-01-01

    Reduction of Methyl Red (MR) and Orange II (Or II) by 26 human skin bacterial species was monitored by a rapid spectrophotometric assay. The analysis indicated that skin bacteria, representing the genera Staphylococcus, Corynebacterium, Micrococcus, Dermacoccus and Kocuria, were able to reduce MR by 74-100 % in 24 h, with only three species unable to reduce completely the dye in that time. Among the species tested, only Corynebacterium xerosis was unable to reduce Or II to any degree by 24 h, and only Staphylococcus delphini, Staphylococcus sciuri subsp. sciuri and Pseudomonas aeruginosa were able to reduce completely this dye within 24 h. MR reduction started with early-exponential growth in Staphylococcus aureus and Staphylococcus epidermidis, and around late-exponential/early-stationary growth in P. aeruginosa. Reduction of Or II, Ponceau S and Ponceau BS started during late-exponential/early-stationary growth for all three species. Using liquid chromatography/electrospray ionization mass spectrometry analyses, MR metabolites produced by Staph. aureus, Staph. epidermidis and P. aeruginosa were identified as N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid. Searches of available genomic and proteomic data revealed that at least four of the staphylococci in this study, Staphylococcus haemolyticus, Staph. epidermidis, Staphylococcus cohnii and Staphylococcus saprophyticus, have hypothetical genes with 77, 76, 75 and 74 % sequence identity to azo1 encoding an azoreductase from Staph. aureus and hypothetical proteins with 82, 80, 72 and 74 % identity to Azo1, respectively. In addition, Staphylococcus capitis has a protein with 79 % identity to Azo1. Western analysis detected proteins similar to Azo1 in all the staphylococci tested, except Staph. delphini, Staph. sciuri subsp. sciuri and Staphylococcus auricularis. The data presented in this report will be useful in the risk assessment process for evaluation of public exposure to products containing these dyes

  14. Oxidative degradation of azo dyes using tourmaline.

    PubMed

    Wang, Cuiping; Zhang, Yanwei; Yu, Li; Zhang, Zhiyuan; Sun, Hongwen

    2013-09-15

    This study aimed to investigate the catalyzed degradation ability of tourmaline on the dyes methylene blue (MB), rhodamine B (RhB), and congo red (CR) at different pH values. Interestingly, tourmaline strongly adsorbed anionic dyes, but it did not adsorb cationic dyes. When H₂O₂ was introduced into the tourmaline-dye systems, the degradation percentage for CR catalysis by tourmaline was lower than the percentage of adsorption, whereas the opposite was true for MB and RhB systems. Notably, the catalyzed degradation decreased from 100% to 45% for MB, 100% to 15% for RhB and 100% to 25% for CR as the pH increased from 3.0 to 10.0, respectively, which was much greater than the degradation obtained for previously reported materials at pH values ranging from 4.0 to 10.0. Tourmaline catalytically degraded the dyes over a broad range of pH values, which was attributed to tourmaline automatically adjusting the pH of the dye solutions to approximately 5.5 from an initial range of 4.2-10.0. An electron paramagnetic resonance spin trapping technique observed peroxyl (ROO·) and alkoxy (RO·) or alkyl (R·) radicals originated from the attack of ·OH radicals and O₂(·-) radicals, indicating that these radicals were involved in the catalyzed degradation of MB. Importantly, four intermediate products of MB at m/z 383, 316, 203 and 181 were observed by LC/MS. PMID:23876254

  15. Abatement of Azo Dye from Wastewater Using Bimetal-Chitosan

    PubMed Central

    Asgari, Ghorban; Farjadfard, Sima

    2013-01-01

    We introduce a new adsorbent, bimetallic chitosan particle (BCP) that is successfully synthesized and applied to remove the orange II dye from wastewater. The effects of pH, BCP quantity, and contact time are initially verified on the basis of the percentage of orange II removed from the wastewater. Experimental data reveal that the Cu/Mg bimetal and chitosan have a synergistic effect on the adsorption process of the adsorbate, where the dye adsorption by Cu/Mg bimetal, chitosan alone, and bimetal-chitosan is 10, 49, and 99.5%, respectively. The time required for the complete decolorization of orange II by 1 mg/L of BCP is 10 min. The Langmuir model is the best fit for the experimental data, which attains a maximum adsorption capacity of 384.6 mg/g. The consideration of the kinetic behavior indicates that the adsorption of orange II onto the BCP fits best with the pseudo-second-order and Elovich models. Further, the simulated azo dye wastewater can be effectively treated using a relatively low quantity of the adsorbent, 1 mg/L, within a short reaction time of 20 min. Overall, the use of BCP can be considered a promising method for eliminating the azo dye from wastewater effectively. PMID:24348163

  16. Chitosan beads as barriers to the transport of azo dye in soil column.

    PubMed

    Lazaridis, Nikolaos K; Keenan, Helen

    2010-01-15

    The development of chitosan-based materials as useful adsorbent polymeric matrices is an expanding field in the area of adsorption science. Although chitosan has been successfully used for the removal of dyes from aqueous solutions, no consideration is given to the removal of dyes from contaminated soils. Therefore this study focuses on the potential use of chitosan as an in situ remediation technology. The chitosan beads were used as barriers to the transport of a reactive dye (Reactive Black 5, RB5) in soil column experiments. Batch sorption experiments, kinetic and equilibrium, were performed to estimate the sorption behavior of both chitosan and soil. The chitosan beads were prepared in accordance with published literature and a synthetic soil was prepared by mixing quantities of sand, silt and clay. The synthetic soil was classified according to British Standards. Calcium chloride was used as tracer to define transport rates and other physical experimental parameters. Dye transport reaction parameters were determined by fitting dye breakthrough curves (BTCs) to the HYDRUS-1D version 4.xx software. Fourier Transform-Infra Red (FT-IR) spectroscopy was used to reveal the sorption mechanism. The study showed that chitosan exhibited a high sorption capacity (S(max)=238 mg/g) and pseudo-first sorption rate (k(1)=1.02 h(-1)) coupled with low swelling and increased retardation for the azo dye tested. Thus it has potential as a Permeable Reactive Barrier (PRB) for containment and remediation of contaminated sites. PMID:19740603

  17. 40 CFR 721.10239 - Trivalent chromium complexes of a substituted beta-naphthol amine azo dye (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... substituted beta-naphthol amine azo dye (generic). 721.10239 Section 721.10239 Protection of Environment... a substituted beta-naphthol amine azo dye (generic). (a) Chemical substance and significant new uses... a substituted beta-naphthol amine azo dye (PMNs P-09-152 and P-09-153) are subject to...

  18. 40 CFR 721.10239 - Trivalent chromium complexes of a substituted beta-naphthol amine azo dye (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substituted beta-naphthol amine azo dye (generic). 721.10239 Section 721.10239 Protection of Environment... a substituted beta-naphthol amine azo dye (generic). (a) Chemical substance and significant new uses... a substituted beta-naphthol amine azo dye (PMNs P-09-152 and P-09-153) are subject to...

  19. 40 CFR 721.10239 - Trivalent chromium complexes of a substituted beta-naphthol amine azo dye (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... substituted beta-naphthol amine azo dye (generic). 721.10239 Section 721.10239 Protection of Environment... a substituted beta-naphthol amine azo dye (generic). (a) Chemical substance and significant new uses... a substituted beta-naphthol amine azo dye (PMNs P-09-152 and P-09-153) are subject to...

  20. Azo dye biodecolorization enhanced by Echinodontium taxodii cultured with lignin.

    PubMed

    Han, Yuling; Shi, Lili; Meng, Jing; Yu, Hongbo; Zhang, Xiaoyu

    2014-01-01

    Lignocellulose facilitates the fungal oxidization of recalcitrant organic pollutants through the extracellular ligninolytic enzymes induced by lignin in wood or other plant tissues. However, available information on this phenomenon is insufficient. Free radical chain reactions during lignin metabolism are important in xenobiotic removal. Thus, the effect of lignin on azo dye decolorization in vivo by Echinodontium taxodii was evaluated. In the presence of lignin, optimum decolorization percentages for Remazol Brilliant Violet 5R, Direct Red 5B, Direct Black 38, and Direct Black 22 were 91.75% (control, 65.96%), 76.89% (control, 43.78%), 43.44% (control, 17.02%), and 44.75% (control, 12.16%), respectively, in the submerged cultures. Laccase was the most important enzyme during biodecolorization. Aside from the stimulating of laccase activity, lignin might be degraded by E. taxodii, and then these degraded low-molecular-weight metabolites could act as redox mediators promoting decolorization of azo dyes. The relationship between laccase and lignin degradation was investigated through decolorization tests in vitro with purified enzyme and dozens of aromatics, which can be derivatives of lignin and can function as laccase mediators or inducers. Dyes were decolorized at triple or even higher rates in certain laccase-aromatic systems at chemical concentrations as low as 10 µM. PMID:25285777

  1. Azo Dye Biodecolorization Enhanced by Echinodontium taxodii Cultured with Lignin

    PubMed Central

    Meng, Jing; Yu, Hongbo; Zhang, Xiaoyu

    2014-01-01

    Lignocellulose facilitates the fungal oxidization of recalcitrant organic pollutants through the extracellular ligninolytic enzymes induced by lignin in wood or other plant tissues. However, available information on this phenomenon is insufficient. Free radical chain reactions during lignin metabolism are important in xenobiotic removal. Thus, the effect of lignin on azo dye decolorization in vivo by Echinodontium taxodii was evaluated. In the presence of lignin, optimum decolorization percentages for Remazol Brilliant Violet 5R, Direct Red 5B, Direct Black 38, and Direct Black 22 were 91.75% (control, 65.96%), 76.89% (control, 43.78%), 43.44% (control, 17.02%), and 44.75% (control, 12.16%), respectively, in the submerged cultures. Laccase was the most important enzyme during biodecolorization. Aside from the stimulating of laccase activity, lignin might be degraded by E. taxodii, and then these degraded low-molecular-weight metabolites could act as redox mediators promoting decolorization of azo dyes. The relationship between laccase and lignin degradation was investigated through decolorization tests in vitro with purified enzyme and dozens of aromatics, which can be derivatives of lignin and can function as laccase mediators or inducers. Dyes were decolorized at triple or even higher rates in certain laccase–aromatic systems at chemical concentrations as low as 10 µM. PMID:25285777

  2. Solid-phase extraction and simultaneous determination of trace amounts of sulphonated and azo sulphonated dyes using microemulsion-modified-zeolite and multivariate calibration.

    PubMed

    Al-Degs, Yahya S; El-Sheikh, Amjad H; Al-Ghouti, Mohammad A; Hemmateenejad, Bahram; Walker, Gavin M

    2008-05-30

    A simple and rapid analytical method for the determination of trace levels of five sulphonated and azo sulphonated reactive dyes: Cibacron Reactive Blue 2 (C-Blue, trisulphonated dye), Cibacron Reactive Red 4 (C-Red, tetrasulphonated azo dye), Cibacron Reactive Yellow 2 (C-Yellow, trisulphonated azo dye), Levafix Brilliant Red E-4BA (L-Red, trisulphonated dye), and Levafix Brilliant Blue E-4BA (L-Blue, disulphonated dye) in water is presented. Initially, the dyes were preconcentrated from 250 ml of water samples with solid-phase extraction using natural zeolite sample previously modified with a microemulsion. The modified zeolite exhibited an excellent extraction for the dyes from solution. The parameters that influence quantitative recovery of reactive dyes like amount of extractant, volume of dye solution, pH, ionic strength, and extraction-elution flow rate were varied and optimized. After elution of the adsorbed dyes, the concentration of dyes was determined spectrophotometrically with the aid of principle component regression (PCR) method without separation of dyes. The results obtained from PCR method were comparable to those obtained from HPLC method confirming the effectiveness of the proposed method. With the aid of SPE by M-zeolite, the concentration of dyes could be reproducibly detected over the range 25-200 ppb for C-Yellow and L-Blue and from 50 to 250 ppb for C-Blue, C-Red, and L-Red. The multivariate detection limits of dyes were found to be 15 ppb for C-Yellow and L-Blue and 25 ppb for C-Blue, C-Red, and L-Red dyes. The proposed chemometric method gave recoveries from 85.4 to 115.3% and R.S.D. from 1.0 to 14.5% for determination of the five dyes without any prior separation for solutes. PMID:18585163

  3. Spectral Studies of UV and Solar Photocatalytic Degradation of AZO Dye and Textile Dye Effluents Using Green Synthesized Silver Nanoparticles

    PubMed Central

    Mariselvam, R.; Ranjitsingh, A. J. A.; Mosae Selvakumar, P.; Alarfaj, Abdullah A.; Munusamy, Murugan A.

    2016-01-01

    The photocatalytic degradation of the chemical dye AZO and dye effluents in different time duration has been investigated using biologically synthesized silver nanoparticles. Dye industry effluents and AZO dye undergo degradation to form harmless intermediate and colourless products following irradiation by UV and solar light in the presence of green synthesized silver nanoparticles. The degree of degradation was tested under the experimental conditions such as PH, temperature, and absorbance of the dye in UV and solar light was measured. The degradation was higher in the UV light source than in the solar light source. Green synthesized silver nanoparticles in the UV light source were found to expedite the dye degradation process. PMID:27382364

  4. Evaluation of in vitro efficacy for decolorization and degradation of commercial azo dye RB-B by Morganella sp. HK-1 isolated from dye contaminated industrial landfill.

    PubMed

    Pathak, Hilor; Soni, Dhaval; Chauhan, Kishor

    2014-06-01

    Reactive Black-B (RB-B) - one of the multi-sulphonated reactive azo dye - is being used extensively in textile as well as paper industries. Reactive azo dyes comprise of a significant group of synthetic compounds categorized as xenobiotics and its abatement from the environment still remains a challenge. In the present study, a newly isolated indigenous bacterial strain Morganella sp. HK-1 was exploited for its ability to decolorize and degrade RB-B dye. The isolate completely degraded RB-B (20 g L(-1)) within 24h under static conditions. Furthermore, the visible and FTIR spectral analysis established the bio-degradation of RB-B. The degraded metabolites of RB-B by Morganella sp. HK-1 were identified by GC-MS analysis as disodium 3,4,6-triamino-5-hydroxynaphthalene-2,7-disulfonate, 4-aminophenylsulfonylethyl hydrogen sulfate, naphthalene-1-ol, aniline and benzene. Based on this information, a putative pathway of degradation of RB-B by Morganella sp. HK-1 has been proposed. This study is the first report on elucidation of mechanism of bacterial degradation of RB-B dye. Furthermore, phytotoxicity, genotoxicity and aquatic acute toxicity studies of the parent dye and the bio-degraded dye products revealed drastic reduction in the toxicity of metabolites as compared to the parent dye. This implies that the biotreatment of the dye is of non-toxic nature. This study thus indicates the effectiveness of Morganella sp. HK-1 for the treatment of textile effluents containing sulphonated azo dyes. PMID:24480425

  5. Synthesis, characterization and application of new azo dyes derived from uracil for polyester fibre dyeing

    NASA Astrophysics Data System (ADS)

    Yazdanbakhsh, Mohamad-reza; Abbasnia, Masoumeh; Sheykhan, Mehdi; Ma'mani, Leila

    2010-08-01

    Some novel uracil derived azo compounds were synthesized by diazotization of substituted aromatic amines, amidine- and guanidine-like amines such as 2-aminopyridine and 2-aminopyrimidine, ortho-hydroxy aniline and ortho-hydroxy naphthyl amines and coupling reaction with 6-amino-1,3-dimethyluracil. Structures of the dyes were fully characterized by spectroscopic techniques (UV, 1H NMR, 13C NMR, CHN and IR). The dyes were applied to polyester, affording orange-yellow shades and the wash fastness of the dyeings was excellent.

  6. Photoluminescence analysis of self induced planer alignment in azo dye dispersed nematic liquid crystal complex

    SciTech Connect

    Kumar, Rishi Sood, Srishti Raina, K. K.

    2014-04-24

    We have developed azo dye doped nematic liquid crystal complex for advanced photonic liquid crystal display technology aspects. Disperse orange azo dye self introduced planer alignment in the nematic liquid crystal without any surface anchoring treatment. Planer alignment was characterized by optical polarizing microscopy. The electro-optical switching response of dye disperse planer aligned nematic cell was investigated as a function of applied voltage with the help of photoluminescence spectrophotometer for the tuning of photoluminescence contrast.

  7. Properties and construction of azo-dye reagents for inorganic photometric analysis.

    PubMed

    Pilipenko, A T; Savransky, L I

    1978-08-01

    An approach to constructing new organic reagents (based on azo dyes) for photometric analysis is described. Its essence is the detailed consideration of the electronic structure of the chromophore nuclei of the dyes in the ground and excited states. Knowing the nature of the electron transition, it is possible to construct the organic reagents with optimal properties. The electronic structure of the azo dyes has been analysed in a pi-approximation by an MO LCAO SCF method. PMID:18962298

  8. WASTES FROM MANUFACTURE OF DYES AND PIGMENTS. VOLUME 2. AZO DYES AND PIGMENTS (EXCLUDING BENZIDINE AND ITS CONGENERS)

    EPA Science Inventory

    In a study of the manufacture of azo dyes and pigments, several solid wastes that could contain hazardous material were identified. These solid wastes included filter cake from clarifying operations, wastewater treatment solids, intermediates on discarded shipping containers, and...

  9. Deciphering effects of functional groups and electron density on azo dyes degradation by graphene loaded TiO2

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Liang, Xiao; Chen, Bor-Yann; Chang, Chang-Tang

    2015-12-01

    This study tended to decipher the mechanism of photo degradation of azo dyes, which bond was favorable to be broken for application of wastewater decolorization. That is, from chemical structure perspective, the critical substituents to affect electron donor/acceptor for dye degradation would be identified in this research. The model reactive blacks (RB5), reactive blue 171 (RB171) and reactive red 198 (RR198) were degraded by graphene loaded TiO2, indicating how the electron withdrawing and releasing groups affect azo dye degradability. The byproducts and intermediate products were analyzed by ultraviolet-visible spectroscopy (UV-vis), gas chromatography-mass spectrometry (GC-MS) and ion chromatography (IC). Furthermore, the radicals involved in the reaction were found by electron paramagnetic resonance (ESR) to confirm the main oxidized species of hydroxyl radicals rather than the light generated positive holes. The finding revealed that the breakages of the bonds were due to the electron density changes around the bonds. This principle can be applicable not only for RB5 degradation, but also for reactive blue 171 (RB171), reactive red 198 (RR198) and some other textile dyes.

  10. Phenylazoindole dyes 3: Determination of azo-hydrazone tautomers of new phenylazoindole dyes in solution and solid state

    NASA Astrophysics Data System (ADS)

    Babür, Banu; Seferoğlu, Nurgül; Aktan, Ebru; Hökelek, Tuncer; Şahin, Ertan; Seferoğlu, Zeynel

    2015-02-01

    A new two series of phenylazo indole dyes was synthesized and the structures of the dyes were confirmed by UV-vis, FT-IR, HRMS and 1H/13C NMR spectroscopic techniques. Five of these dyes (I, I‧, II‧, III and III‧) were also characterized in solid state by using single crystal X-ray diffraction studies besides other spectroscopic techniques. The geometries of the azo and hydrazone tautomeric forms of the dyes were optimized by using Density Functional Theory (DFT). In addition, the effects of the donor and acceptor groups on the azo and hydrazone forms of the dyes were evaluated experimentally and theoretically. The results indicate that the phenylazoindole dyes derived from 2-phenyl indole as coupling component exist as azo form in solution, gas phase and solid state.

  11. THE MUTAGENICITY OF METALLIZED AND UNMETALLIZED AZO AND FORMAZAN DYES IN THE SALMONELLA MUTAGENICITY ASSAY

    EPA Science Inventory

    The mutagenicity of metallized and unmetallized azo and formazan dyes in the Salmonella mutagenicity
    Laura. C. Edwards', Harold S. Freeman'*, and Larry D. Claxton2

    Abstract
    In previous papers, the synthesis and chemical properties of iron complexed azo and formazan d...

  12. REDUCTION OF AZO DYES WITH ZERO-VALENT IRON. (R827117)

    EPA Science Inventory

    The reduction of azo dyes by zero-valent iron metal (Fe0) at pH 7.0 in 10 mM HEPES buffer was studied in aqueous, anaerobic batch systems. Orange II was reduced by cleavage of the azo linkage, as evidenced by the production of sulfanilic acid (a substituted ani...

  13. Study of azo dye decolorization and determination of cathode microorganism profile in air-cathode microbial fuel cells.

    PubMed

    Kumru, Mert; Eren, Hilal; Catal, Tunc; Bermek, Hakan; Akarsubaşi, Alper Tunga

    2012-09-01

    Five textile azo dyes, as part of an artificial mixture, were treated in single-chamber air-cathode microbial fuel cells while simultaneously utilizing acetate for electricity production. Remazol Black, Remazol Brilliant Blue, Remazol Turquoise Blue, Reactive Yellow and Reactive Red at concentrations of 40 or 80 mg L(-1) were decolorized to a similar extent, at averages of 78, 95, 53, 93 and 74%, respectively, in 24 hours. During the process of decolorization, electricity generation from acetate oxidation continued. Power densities obtained in the presence of textile dyes ranged from 347 to 521 mW m(-2) at the current density range of 0.071 - 0.086 mA cm(-2). Microbial community analyses of cathode biofilm exhibited dynamic changes in abundant species following dye decolorization. Upon the addition of the first dye, a major change (63%) in microbial diversity was observed; however, subsequent addition of other dyes did not affect the community profile significantly. Actinobacteria, Aquamicrobium, Mesorhizobium, Ochrobactrum, Thauera, Paracoccus, Achromobacter and Chelatacoccus affiliated phylotypes were the major phylotypes detected. Our results demonstrate that microbial fuel cells could be a promising alternative for treatment of textile wastewaters and an active bacterial community can rapidly be established for simultaneous azo dye decolorization and sustainable electricity generation. PMID:23240212

  14. Decolorization of azo dyes (Direct Blue 151 and Direct Red 31) by moderately alkaliphilic bacterial consortium

    PubMed Central

    Lalnunhlimi, Sylvine; Krishnaswamy, Veenagayathri

    2016-01-01

    Removal of synthetic dyes is one of the main challenges before releasing the wastes discharged by textile industries. Biodegradation of azo dyes by alkaliphilic bacterial consortium is one of the environmental-friendly methods used for the removal of dyes from textile effluents. Hence, this study presents isolation of a bacterial consortium from soil samples of saline environment and its use for the decolorization of azo dyes, Direct Blue 151 (DB 151) and Direct Red 31 (DR 31). The decolorization of azo dyes was studied at various concentrations (100–300 mg/L). The bacterial consortium, when subjected to an application of 200 mg/L of the dyes, decolorized DB 151 and DR 31 by 97.57% and 95.25% respectively, within 5 days. The growth of the bacterial consortium was optimized with pH, temperature, and carbon and nitrogen sources; and decolorization of azo dyes was analyzed. In this study, the decolorization efficiency of mixed dyes was improved with yeast extract and sucrose, which were used as nitrogen and carbon sources, respectively. Such an alkaliphilic bacterial consortium can be used in the removal of azo dyes from contaminated saline environment. PMID:26887225

  15. Ultrafast degradation of azo dyes catalyzed by cobalt-based metallic glass.

    PubMed

    Qin, X D; Zhu, Z W; Liu, G; Fu, H M; Zhang, H W; Wang, A M; Li, H; Zhang, H F

    2015-01-01

    Reactivity and mass loss are considered mutually exclusive in conventional zero-valent metal (ZVM) technology to treat environmental contaminants. Here, we report the outstanding performance of Co-based metallic glass (MG) in degrading an aqueous solution of azo dye, thus eliminating this trade-off. Ball-milled Co-based MG powders completely degrade Acid Orange II at an ultrafast rate. The surface-area-normalized rate constant of Co-based MG powders was one order of magnitude higher than that of Co-based crystalline counterparts and three orders of magnitude higher than that of the widely studied Fe(0) powders. The coordinatively unsaturated local structure in Co-based MG responds to the catalysis for degradation, resulting in very low mass loss. Wide applicability and good reusability were also present. Co-based MG is the most efficient material for azo dye degradation reported thus far, and will promote the practical application of MGs as functional materials. PMID:26656918

  16. Ultrafast degradation of azo dyes catalyzed by cobalt-based metallic glass

    PubMed Central

    Qin, X. D.; Zhu, Z. W.; Liu, G.; Fu, H. M.; Zhang, H. W.; Wang, A. M.; Li, H.; Zhang, H. F.

    2015-01-01

    Reactivity and mass loss are considered mutually exclusive in conventional zero-valent metal (ZVM) technology to treat environmental contaminants. Here, we report the outstanding performance of Co-based metallic glass (MG) in degrading an aqueous solution of azo dye, thus eliminating this trade-off. Ball-milled Co-based MG powders completely degrade Acid Orange II at an ultrafast rate. The surface-area-normalized rate constant of Co-based MG powders was one order of magnitude higher than that of Co-based crystalline counterparts and three orders of magnitude higher than that of the widely studied Fe0 powders. The coordinatively unsaturated local structure in Co-based MG responds to the catalysis for degradation, resulting in very low mass loss. Wide applicability and good reusability were also present. Co-based MG is the most efficient material for azo dye degradation reported thus far, and will promote the practical application of MGs as functional materials. PMID:26656918

  17. Azo dye decolorization by Shewanella aquimarina under saline conditions.

    PubMed

    Meng, Xianming; Liu, Guangfei; Zhou, Jiti; Shiang Fu, Q; Wang, Guanghui

    2012-06-01

    Decolorization of azo dyes under saline conditions was studied with Shewanella aquimarina, which demonstrated good growth at up to 7% NaCl. No inhibition on acid red 27 (AR27) decolorization was caused by 1-3% NaCl. Additionally, 14.5% AR27 (0.2mM) could still be removed in 12h in the presence of 10% NaCl. The relationship between specific decolorization rate and AR27 concentration followed Michaelis-Menten kinetics (K(m)=0.34 mM, V(max)=6.44 μmol mg cell(-1) h(-1)). Lactate and formate were efficient electron donors for AR27 decolorization. The initial decolorization rate was in direct proportion to biomass concentration (0.18-0.72 g l(-1)). Compared to NaCl, slighter inhibitive effects were found with Na(2)SO(4) whereas more severe inhibition was caused by NaNO(3). Lower NaCl concentration stimulated azoreductase, laccase and NADH-DCIP reductase activities of cell extracts. AR27 decolorization products were found to be aromatic amines, which were less phytotoxic than the untreated dye. PMID:22449986

  18. Photo-stimulated phase and anchoring transitions of chiral azo-dye doped nematic liquid crystals.

    PubMed

    Kundu, Sudarshan; Kang, Shin-Woong

    2013-12-16

    We report concurring phase and anchoring transitions of chiral azo-dye doped nematic liquid crystals. The transitions are induced by photo-stimulation and stable against light and thermal treatments. Photochromic trans- to cis-isomerization of azo-dye induces an augmented dipole moment and strong dipole-dipole interaction of the cis-isomers, resulting in the formation of nano-sized dye-aggregates. Consequent phase separation of the aggregates of a chiral azo-dye induces phase transition from a chiral to nonchiral nematic phase. In addition, the deposition of dye-aggregates at the surfaces brings about anchoring transition of LC molecules. The stability and irreversibility of the transition, together with no need of pretreatments for LC alignment, provide fascinating opportunity for liquid crystal device applications. PMID:24514707

  19. A spectral approach to determine location and orientation of azo dyes within surfactant aggregates

    NASA Astrophysics Data System (ADS)

    Karukstis, Kerry K.; Litz, Jonathan P.; Garber, Matthew B.; Angell, Laura M.; Korir, George K.

    2010-04-01

    The UV-vis absorption properties of azo dyes are known to exhibit a variation with the polarity and acidity of the dye environment. The spectral properties of a series of anionic azo dyes were characterized to further probe the interaction of these dyes with two types of surfactant aggregates: (1) the spherical micelles formed in aqueous solution by alkyltrimethylammonium bromide (C nTAB) surfactants with n = 10-16 and (2) the unilamellar vesicles spontaneously formed in water from binary mixtures of the oppositely-charged double-tailed surfactants cationic didodecyldimethylammonium bromide (DDAB) and anionic sodium dioctylsulfosuccinate (Aerosol OT or AOT). The observed dye spectra reflect the solvatochromic behavior of the dyes and suggest the location and orientation of the dye within the surfactant aggregates. Deconvolution of the overall spectra into sums of Gaussian curves more readily displays any contributions of tautomeric forms of the azo dyes resulting from intramolecular hydrogen bonding. The rich variation in UV/vis absorption properties of these anionic azo dyes supports their use as sensitive tools to explore the nanostructures of surfactant aggregates.

  20. Role of brown-rot fungi in the bioremoval of azo dyes under different conditions

    PubMed Central

    Ali, Naeem; Hameed, Abdul; Ahmed, Safia

    2010-01-01

    The present study is vital to the understanding of bioremediation of structurally different azo dyes by some unusual Brown-rot fungi. Bioremoval of each dye (20 mg l-1) was tested in two different culture media under static and shaking conditions by taking inocula from different fungi. Fungal strains showed varying dyes removal abilities, though considerable high in case of Acid Red (AR) 151(di-azo) as compared to Orange (Or) II (mono-azo). With an exception of Aspergillus tereus SA3, all the fungal isolates showed higher removal of dyes in SDB. Under static condition, the maximum decolorizing fungal strains were; Aspergillus flavus SA2 (67%) and Alternaria spp. SA4 (57%) in AR 151, while Penicillium spp. (34 and 33 %) in Orange II, in SDB and STE, respectively. Bioremoval of dyes was considerably increased when experiments were shifted from static to shaking mode. It was specifically increased (%) in; AR 151 (255) with Penicillium spp., Or II with A. flavus SA2 (112) and Alternaria spp. (111). The primary mechanism of dyes removal proved to be fungal biosorption. However, reduction of dyes (onto fungal) with formation of their products (α. naphthol, sulphalinic acid and aniline) furthermore revealed that dyes (specifically azo) were actually biodegraded. PMID:24031570

  1. SORPTION AND TOXICITY OF AZO AND TRIPHENYLMETHANE DYES TO AQUATIC MICROBIAL POPULATIONS

    EPA Science Inventory

    Toxicity and sorption of five azo and triphenylmethane dyes to freshwater microbiota were determined to assessment, in part, the risks that these dyes may pose to the aquatic environment. The toxicities of Basic Violet 1, Basic Violet 2, Basic Violet 3, Basic Green 4 and Tropaeol...

  2. ENVIRONMENTAL APPLICATIONS OF THERMOSPRAY LCMS: QUALITATIVE ANALYSIS OF SULFONATED AZO DYES

    EPA Science Inventory

    Thermospray mass spectra (TSMS) has been used to obtain mass spectra of several di- and tetra- sulfonated azo dyes. Commercial dye preparations were dissolved in various mobile phases and injected into the TSMS system. Mobile phases investigated included pure water and varying co...

  3. Dielectric characteristic of photoinduced isomerization in azo-dye doped polymeric matrices

    SciTech Connect

    Luo Duanbin; Deng Li

    2006-05-01

    The dielectric permittivities and losses of poly(methyl methacrylate) doped with different concentrations of azo dye are investigated under the irradiation of 532 nm light for the first time. The dielectric permittivities increase with the concentration of chromophores increasing, and the dielectric relaxation is mainly influenced by the doped azo-dye chromophores. Given the dye concentration, the dielectric permittivities depend on the pump power of 532 nm light. With the increase of pumping light power, the low frequency dielectric losses increase while the high frequency dielectric losses decrease. The results are explained based on the photoinduced isomerization of chromophores and the interaction between the chromophores and polymer matrices.

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

    PubMed

    Silva, Alessandra C; Pic, Jean Stephane; Sant'Anna, Geraldo L; Dezotti, Marcia

    2009-09-30

    Ozonation of two azo dyes was investigated in a monitored bench scale bubble column reactor (8.5-L), varying liquid media salt content (0, 1, 40 and 100 g L(-1), NaCl). In experiments with Orange II pH was varied (5, 7.5 and 9) but ozonation of Acid Red 27 was performed at pH 7.5. Ozone self-decomposition rate-constant increased with salt concentration. Color removal was very effective and fast achieved under all experimental conditions. For the two azo dyes tested, more than 98% of color intensity was removed in 30-min ozonation assays. However, only partial mineralization of azo dyes (45%-Orange II; 20%-Acid Red 27) was attained in such experiments. The degree of mineralization (TOC removal) was negatively affected by salt concentration. Biodegradation assays conducted by respirometry revealed the inhibitory effect of dye degradation products formed during ozonation. PMID:19443113

  5. Electrolysis within anaerobic bioreactors stimulates breakdown of toxic products from azo dye treatment.

    PubMed

    Gavazza, Sávia; Guzman, Juan J L; Angenent, Largus T

    2015-04-01

    Azo dyes are the most widely used coloring agents in the textile industry, but are difficult to treat. When textile effluents are discharged into waterways, azo dyes and their degradation products are known to be environmentally toxic. An electrochemical system consisting of a graphite-plate anode and a stainless-steel mesh cathode was placed into a lab-scale anaerobic bioreactor to evaluate the removal of an azo dye (Direct Black 22) from synthetic textile wastewater. At applied potentials of 2.5 and 3.0 V when water electrolysis occurs, no improvement in azo dye removal efficiency was observed compared to the control reactor (an integrated system with electrodes but without an applied potential). However, applying such electric potentials produces oxygen via electrolysis and promoted the aerobic degradation of aromatic amines, which are toxic, intermediate products of anaerobic azo dye degradation. The removal of these amines indicates a decrease in overall toxicity of the effluent from a single-stage anaerobic bioreactor, which warrants further optimization in anaerobic digestion. PMID:25750156

  6. Excellent capability in degrading azo dyes by MgZn-based metallic glass powders

    PubMed Central

    Wang, Jun-Qiang; Liu, Yan-Hui; Chen, Ming-Wei; Louzguine-Luzgin, Dmitri V.; Inoue, Akihisa; Perepezko, John H.

    2012-01-01

    The lack of new functional applications for metallic glasses hampers further development of these fascinating materials. In this letter, we report for the first time that the MgZn-based metallic glass powders have excellent functional ability in degrading azo dyes which are typical organic water pollutants. Their azo dye degradation efficiency is about 1000 times higher than that of commercial crystalline Fe powders, and 20 times higher than the Mg-Zn alloy crystalline counterparts. The high Zn content in the amorphous Mg-based alloy enables a greater corrosion resistance in water and higher reaction efficiency with azo dye compared to crystalline Mg. Even under complex environmental conditions, the MgZn-based metallic glass powders retain high reaction efficiency. Our work opens up a new opportunity for functional applications of metallic glasses. PMID:22639726

  7. Methods for the analysis of azo dyes employed in food industry--A review.

    PubMed

    Yamjala, Karthik; Nainar, Meyyanathan Subramania; Ramisetti, Nageswara Rao

    2016-02-01

    A wide variety of azo dyes are generally added for coloring food products not only to make them visually aesthetic but also to reinstate the original appearance lost during the production process. However, many countries in the world have banned the use of most of the azo dyes in food and their usage is highly regulated by domestic and export food supplies. The regulatory authorities and food analysts adopt highly sensitive and selective analytical methods for monitoring as well as assuring the quality and safety of food products. The present manuscript presents a comprehensive review of various analytical techniques used in the analysis of azo dyes employed in food industries of different parts of the world. A brief description on the use of different extraction methods such as liquid-liquid, solid phase and membrane extraction has also been presented. PMID:26304415

  8. Degradation of Azo Dyes by Trametes villosa Laccase over Long Periods of Oxidative Conditions

    PubMed Central

    Zille, Andrea; Górnacka, Barbara; Rehorek, Astrid; Cavaco-Paulo, Artur

    2005-01-01

    Trametes villosa laccase was used for direct azo dye degradation, and the reaction products that accumulated after 72 h of incubation were analyzed. Liquid chromatography-mass spectrometry (LC-MS) analysis showed the formation of phenolic compounds during the dye oxidation process as well as a large amount of polymerized products that retain azo group integrity. The amino-phenol reactions were also investigated by 13C-nuclear magnetic resonance and LC-MS analysis, and the polymerization character of laccase was shown. This study highlights the fact that laccases polymerize the reaction products obtained during long-term batch decolorization processes with azo dyes. These polymerized products provide unacceptable color levels in effluents, limiting the application of laccases as bioremediation agents. PMID:16269701

  9. Molecular Interactions in Monolayers οf Azo Dye/Liquid Crystal Mixtures at Interfaces

    NASA Astrophysics Data System (ADS)

    Bauman, D.; Płóciennik, A.; Inglot, K.

    2009-08-01

    Full Text PDF A study of azo dye/liquid crystal mixtures in monolayers formed at an air-water interface (the Langmuir films) and at a solid surface (the Langmuir-Blodgett films) has been performed. Five azo dyes with various molecular structure and the liquid crystal 4-octyl-4' cyanobiphenyl (8CB) have been used. The dyes have been added to the liquid crystal at various molar fractions. Surface pressure and surface potential versus mean molecular area isotherms for the Langmuir films have been recorded and information about intermolecular interactions at the air-water interface has been obtained. On the basis of electronic absorption measurements for the Langmuir and Langmuir-Blodgett films the conclusions about the ability of dyes molecules to form self aggregates at the interfaces have been drawn. The influence of the dye molecular structure and its concentration on aggregates' geometry has been found.

  10. Influence of peripheral substituents on the optical properties of heterocyclic azo dyes

    NASA Astrophysics Data System (ADS)

    Derkowska-Zielinska, B.; Skowronski, L.; Kozlowski, T.; Smokal, V.; Kysil, A.; Biitseva, A.; Krupka, O.

    2015-11-01

    Optical properties, such as the real and imaginary parts of the dielectric function and the optical energy band gap, of new heterocyclic azo dyes thin films were investigated using spectroscopic ellipsometry combined with transmittance measurements. The topography of studied compounds was also examined by atomic force microscopy. It was found that the optical properties of the azo dyes materials strongly depend on the type of substitution in the azobenzene moiety, namely leads to a change in the value of refractive index, as well as bathochromic shifts of the absorption structure.

  11. Spontaneous photoinduced patterning of azo-dye polymer films: the facts

    SciTech Connect

    Hubert, Christophe

    2007-08-15

    We describe the spontaneous photoinduced patterning of azo-dye polymer films. We have observed that the illumination of an azo-dye polymer film by a uniform single laser beam with normal incidence leads to a self-structurization process that results in the formation of well-ordered submicrometer-sized structures whose organization depends on the light polarization direction. A modulation depth as high as 100 nm can be achieved. The influence of several experimental parameters on the structure formation is studied. Results are discussed and confronted to different models and phenomena already investigated in the literature. A physical origin to this peculiar photopatterning process is proposed.

  12. Optical orientation of azo dye molecules in a thin solid film upon nonlinear excitation by femtosecond laser pulses

    SciTech Connect

    Yongseok, Jung; Kozenkov, V M; Magnitskiy, Sergey A; Nagorskiy, Nikolay M

    2006-11-30

    The orientation of molecules in an amorphous pure azo dye film upon nonlinear excitation is detected for the first time. The simultaneous increase and decrease in the film transmission by a factor of 2.5 for orthogonal polarisations of probe radiation indicated the appearance of orientation order in the film caused by the reorientation of azo dye molecules. Due to a high photostability of the AD-1 azo dye demonstrated in single-photon experiments and a high efficiency of nonlinear orientation obtained in experiments with femtosecond pulses, this dye can be widely used in three-dimensional nanophotonic devices such as photonic crystals, optical computers, and optical memory. (letters)

  13. Rapid decolorization of azo dye methyl orange in aqueous solution by nanoscale zerovalent iron particles.

    PubMed

    Fan, Jing; Guo, Yanhui; Wang, Jianji; Fan, Maohong

    2009-07-30

    Azo dyes are recalcitrant and refractory pollutants that constitute a significant burden on the environment. The report here is focused on the decolorization treatment of water soluble azo dye methyl orange (MO) by chemically synthesized nanoscale zerovalent iron (NZVI) particles. Experimental variables such as initial dye concentration, iron dosage, solution pH and temperature were studied systematically. Batch experiments suggest that the decolorization efficiency was enhanced with the increase of NZVI dosage and reaction temperature, but decreased with increasing initial dye concentration and initial solution pH. Further studies indicated that existence of inorganic salt (Na(2)SO(4)) could inhibit the decolorization of MO. Kinetic analyses based on the experimental data elucidated that the decolorization process followed a first order exponential decay kinetics model. The activation energy was determined to be 35.9 kJ/mol. PMID:19128873

  14. Degradation of sulphonated azo dye Red HE7B by Bacillus sp. and elucidation of degradative pathways.

    PubMed

    Thakur, Jyoti Kumar; Paul, Sangeeta; Dureja, Prem; Annapurna, K; Padaria, Jasdeep C; Gopal, Madhuban

    2014-08-01

    Bacteria capable of degrading the sulfonated azo dye Red HE7B were isolated from textile mill effluent contaminated soil. The most efficient isolate was identified as Bacillus sp. Azo1 and the isolate could successfully decolorize up to 89% of the dye. The decolorized cultural extract analyzed by HPLC confirmed degradation. Enzymatic analysis showed twofold and fourfold increase in the activity of azoreductase and laccase enzymes, respectively, indicating involvement of both reductive and oxidative enzymes in biodegradation of Red HE7B. Degraded products which were identified by GC/MS analysis included various metabolites like 8-nitroso 1-naphthol, 2-diazonium naphthalene. Mono azo dye intermediate was initially generated from the parent molecule. This mono azo dye was further degraded by the organism, into additional products, depending on the site of cleavage of R-N=N-R molecule. Based on the degradation products identified, three different pathways have been proposed. The mechanism of degradation in two of these pathways is different from that of the previously reported pathway for azo dye degradation. This is the first report of a microbial isolate following multiple pathways for azo dye degradation. Azo dye Red HE7B was observed to be phytotoxic, leading to decrease in root development, shoot length and seedling fresh weight. However, after biotreatment the resulting degradation products were non-phytotoxic. PMID:24682261

  15. DEVELOPING AZO AND FORMAZAN DYES BASED ON ENVIRONMENTAL CONSIDERATIONS: SALMONELLA MUTAGENICITY

    EPA Science Inventory

    Abstract
    In previous papers, the synthesis and chemical properties of iron-complexed azo and formazan dyes were reported. In this regard, it was shown that in certain cases iron could be substituted for the traditionally used metals, chromium and cobalt, without having an adve...

  16. COLLISIONAL ACTIVATION MASS SPECTRA OF M-. IONS OF AZO DYES CONTAINING 2-NAPHTHOL

    EPA Science Inventory

    Collisionally activated decomposition mass spectra of M- ions of azo dyes are presented. he compounds are of general structure Ar(l)-N=N-Ar(2), where Ar(l) is substituted phenyl and Ar(2) is 2-naphthol. Characteristic fragment ions observed include m/z 157, which corresponds to t...

  17. INFLUENCE OF EXPERIMENTAL CONDITIONS ON THE LIQUID SECONDARY ION MASS SPECTRA OF SULFONATED AZO DYES

    EPA Science Inventory

    Two monosulfonated and eight disulfonated azo dyes of varying relative molecular mass were examined by liquid secondary ion mass spectrometry (LSIMS). he effects of matrix, concentration, primary beam energy, and mode of operation were addressed in order to optimize sample ioniza...

  18. STRUCTURAL CHARACTERIZATION OF SULFONATED AZO DYES USING LIQUID SECONDARY ION MASS SPECTROMETRY/TANDEM MASS SPECTROMETRY

    EPA Science Inventory

    Eight monosulfonated and disulfonated azo dyes were analyzed using liquid secondary ion mass spectrometry/tandem mass spectrometry, in the negative ion mode, under low-energy conditions (110-150 eV). any structurally characteristic fragment ions were obtained, several of which ha...

  19. Parallel Combinatorial Synthesis of Azo Dyes: A Combinatorial Experiment Suitable for Undergraduate Laboratories

    ERIC Educational Resources Information Center

    Gung, Benjamin W.; Taylor, Richard T.

    2004-01-01

    An experiment in the parallel synthesis of azo dyes that demonstrates the concepts of structure-activity relationships and chemical diversity with vivid colors is described. It is seen that this experiment is suitable for the second-semester organic chemistry laboratory and also for the one-semester organic laboratory.

  20. Optical properties of Azo Dye (1-Phenylazo-2-Naphthol) thin films

    NASA Astrophysics Data System (ADS)

    Aziz, M. S.; El-Mallah, H. M.; Mansour, A. N.

    2009-11-01

    Thin Films of Azo Dye (1-Phenylazo-2-Naphthol) have been prepared by thermal evaporation technique onto quartz substrates held at about 300 K during the deposition process with different thicknesses range 625-880 nm. X-ray diffraction and the differential thermal analysis showed that the Azo Dye sample is crystalline nature and thermal stable in temperature range from room temperature to 100 circC. The optical constants (the refractive index n, the absorption index k and the absorption coefficient α) were calculated for Azo Dye (1-Phenylazo-2-Naphthol) thin films by using spectrophotometer measurements of the transmittance and reflectance at normal incidence in the spectral range 400-2200 nm. The obtained values of both n and k were found to be independent of the film thicknesses. The refractive index has anomalous behavior in the wavelength range 400-1000 nm besides a high energy transition at 2.385 eV. The optical parameters (the dispersion energy Ed, the oscillation energy Eo, the room temperature optical dielectric constant \\varepsilonl, the lattice dielectric constant \\varepsilonL, the high frequency dielectric constant \\varepsilon∞ and the ratio of carrier concentration to the effective mass N/mast) were calculated. The allowed optical transition responsible for optical absorption was found to be direct transition with optical energy gap of 1.5 eV for Azo Dye sample. The band tail obeys Urbach's empirical relation. in here

  1. TREATABILITY OF WATER SOLUBLE AZO DYES BY THE ACTIVATED SLUDGE PROCESS

    EPA Science Inventory

    The U.S. Environmental Protection Agency's (EPA) Office of Toxic Substances (OTS) evaluates submissions to the Premanufacture Notification process under section 5 of the Toxic Substances Control Act. Azo dyes constitute a significant portion of these submissions. OTS is concerned...

  2. Study of bio-degradation and bio-decolourization of azo dye by Enterobacter sp. SXCR.

    PubMed

    Prasad, Shiv Shankar; Aikat, Kaustav

    2014-01-01

    The objective of this study was to evaluate the decolourization potential of textile dyes by a relatively newly identified bacteria species, Enterobacter sp. SXCR which was isolated from the petroleum polluted soil samples. The bacterial strain was identified by 16S rRNA gene sequence analysis. The effects of operational conditions like initial dye concentration, pH, and temperature were optimized to develop an economically feasible decolourization process. The isolate was able to decolourize sulphonated azo dye (Congo red) over a wide range (0.1-1 gl(-1)), pH 5-9, and temperature 22-40 degrees C in static condition. Anaerobic condition with minimal salt medium supplemented with 2 gl(-1) glucose, pH 7 and 34 degrees C were considered to be the optimum decolourizing condition. The bacterial isolate SXCR showed a strong ability to decolourize dye (0.2 gl(-1)) within 93 h. The biodegradation was monitored by UV-vis, fourier transform infra-red spectroscopy (FTIR) spectroscopy and high performance liquid chromatography (HPLC). Furthermore, the involvement of azoreductase in the decolourization process was identified in this strain. Cells of Enterobacter cloacae were immobilized by entrapment in calcium-alginate beads. Immobilized bacterial cells were able to reduced azo bonds enzymatically and used as a biocatalyst for decolourization of azo dye Congo red. Michaelis-Menten kinetics was used to describe the correlation between the decolourization rate and the dye concentration. PMID:24645479

  3. Some heterocyclic azo dyes derived from thiazolyl derivatives; synthesis; substituent effects and solvatochromic studies

    NASA Astrophysics Data System (ADS)

    Yazdanbakhsh, M. R.; Mohammadi, A.; Abbasnia, M.

    2010-12-01

    A series of azo disperse dyes were synthesized by coupling reaction of N, N-diethylaniline, 2-anilinoethanol and N-phenyl-2,2'-iminodiethanol with diazotized aminothiazolyl derivatives as diazo components. These dyes have been prepared in good yields, and were characterized by UV-Vis, FT-IR and 1H NMR spectroscopic techniques. The effects of solvent polarity and various pH on dyes in the visible absorption spectra were evaluated. All dyes exhibit an excellent correlation coefficient ( r > 0.92) for the linear solvation energy relationship with π* values calculated by Kamlet et al. The influence of the pH on the dyes with electron-donating group implied that these dyes exist in acid-base equilibrium in acidic environment. The effect of substituents of both coupler and diazo component on the color of dyes was investigated as well.

  4. Application of the central composite design to study the flocculation of an anionic azo dye using quaternized cellulose nanofibrils.

    PubMed

    Quinlan, Patrick James; Tanvir, Aafia; Tam, Kam Chiu

    2015-11-20

    Cellulose nanofibrils (CNF) grafted with glycidyltrimethylammonium chloride (GTMAC), containing quaternary ammonium contents of 0.44 (QCNF-1), 1.47 (QCNF-2), and 2.28 (QCNF-3) meqg(-1), were evaluated as flocculants for the removal of Reactive Orange 16, an anionic azo dye, from aqueous solution. A rotatable and orthogonal central composite design was used to examine the performance of QCNFs under a range of experimental conditions. Removal efficiencies at the centre point of the design space were found to be 236.9±7.8, 254.2±3.8, and 264.6±2.8mgg(-1) for QCNF-1, QCNF-2 and QCNF-3, respectively. The highest removal efficiency, 295.1mgg(-1), was observed when using QCNF-3 at a low monovalent salt concentration. The QCNF reported herein provides a sustainable and biodegradable alternative to traditional synthetic flocculants for the decolorization of dye-containing effluents. PMID:26344258

  5. New 1,2,4-triazole-based azo-azomethine dyes. Part I: Synthesis, characterization and spectroscopic studies

    NASA Astrophysics Data System (ADS)

    Khanmohammadi, Hamid; Erfantalab, Malihe

    2012-02-01

    Four new 1,2,4-triazole-based azo-azomethine dyes were synthesized via condensation of 3,5-diamino-1,2,4-triazole with azo-coupled o-vanillin precursors. The prepared dyes were characterized by IR, UV-vis and 1H NMR spectroscopic methods as well as elemental analyses. Thermal properties of the prepared dyes were examined by thermogravimetric analysis. Results indicated that the framework of the dyes was stable up to 225 °C. Also, the influence of various factors including time and mixed DMSO/EtOH solution on UV-vis spectra of the dyes were investigated.

  6. Novel push-pull heterocyclic azo disperse dyes containing piperazine moiety: Synthesis, spectral properties, antioxidant activity and dyeing performance on polyester fibers.

    PubMed

    Mohammadi, Asadollah; Khalili, Behzad; Tahavor, Marzieh

    2015-11-01

    Six novel push-pull azo disperse dyes were synthesized via classical azo coupling reaction using 2-amino-thiazolyl derivatives as the diazo components and 1-(4-bromobenzyl)-4-phenylpiperazine as a key coupling intermediate. The structures of the dyes and synthesized intermediate were confirmed by FT-IR, (1)H NMR, (13)C NMR and UV-vis analyses. The solvatochromic behavior of the dyes was studied in a set of 10 solvents of different polarity and considerable results were obtained. The prepared heterocyclic azo dyes were applied for dyeing polyester fibers and their dyeing properties were studied. The fastness properties of the dyed fabrics such as wash, light and rubbing fastness degrees were measured by standard methods. Investigation of antioxidant activity of compounds was carried out by ferric reducing antioxidant power (FRAP) method. The synthesized dyes exhibited significant antioxidant activities. PMID:26112103

  7. Influence of Methyl Substituents on Azo-Dye Photoalignment in Thin Films

    NASA Astrophysics Data System (ADS)

    Mikulich, V. S.; Murawski, An. A.; Muravsky, Al. A.; Agabekov, V. E.

    2016-03-01

    Photoalignment of azo dyes derived from salicylic acid in thin films (80-200 nm) was studied upon irradiation with polarized light (λmax = 457 nm). It is shown that different trends of molecular reorientation, i.e., in the layer plane or orthogonal to it, are observed depending on the position of the methyl substituent in the dye structure. A new distribution parameter Z that allows the portion of molecules reoriented in the layer plane during exposure to be determined is introduced. The novel azo dye potassium 3,7-bis[1-(4-hydroxy-3-carboxylate)phenylazo]-5,5'-dioxodibenzothiophene was synthesized. Its molecules are photoaligned in the layer plane upon irradiation with polarized light.

  8. Synthesis and anion recognition studies of novel bis (4-hydroxycoumarin) methane azo dyes

    NASA Astrophysics Data System (ADS)

    Panitsiri, Amorn; Tongkhan, Sukanya; Radchatawedchakoon, Widchaya; Sakee, Uthai

    2016-03-01

    Four new bis (4-hydroxycoumarin) methane azo dyes were synthesized by the condensation of 4-hydroxycoumarin with four different azo salicylaldehydes and their structures were characterized by FT-IR, 1H NMR, 13C NMR, HRMS. Anion binding ability in dimethyl sulfoxide (DMSO) solutions with tetrabutylammonium (TBA) salts (F-, Cl-, Br-, I-, AcO- and H2PO4-) was investigated by the naked eye, as well as UV-visible spectroscopy. The sensor shows selective recognition towards fluoride and acetate. The binding affinity of the sensors with fluoride and acetate was calculated using UV-visible spectroscopic technique.

  9. Photoreversible optical data recording in films of amorphous azo dye-containing polymers

    SciTech Connect

    Simonov, A N; Uraev, D V; Shibaev, Valerii P; Kostromin, S G

    2002-02-28

    The photoreversible properties of films of amorphous azo-containing polymers (AAPs) are studied theoretically and experimentally. The control of the sign of a photoinduced addition {Delta}n{sup ind} to the refractive index of the polymer by changing polarisation of the incident light is demonstrated. A theoretical model of photoinduced processes in AAP films is proposed, which takes into account the orientation diffusion of trans-isomers of azo dyes, and simplified analytic approaches describing the photoorientation dynamics in AAPs are considered. The theoretical results are in good agreement with our experimental data. (laser applications and other topics in quantum electronics)

  10. Energy-efficient photodegradation of azo dyes with TiO(2) nanoparticles based on photoisomerization and alternate UV-visible light.

    PubMed

    Zhang, Hao; Chen, Da; Lv, Xiaojun; Wang, Ying; Chang, Haixin; Li, Jinghong

    2010-02-01

    Herein, we demonstrated a UV-vis light alternate photocatalysis (UVLAP) strategy in the photodegradation of azo dyes. The UVLAP of azo dyes over TiO(2) catalysts exhibited significantly higher energy efficiency than the conventional UV process by 40%, which was attributed to the photoisomerization of azo dyes and the resulting diversity of dyes' cis and trans states in interfacial properties, including conductance and spatial effects. This UVLAP strategy could contribute to the energy-saving photodegradation of azo dyes and other pollutants with photoisomerization properties and facilitate the practical application of TiO(2) in the environmental remediation. PMID:20039724

  11. Synthesis and investigation of antimicrobial activity and spectrophotometric and dyeing properties of some novel azo disperse dyes based on naphthalimides.

    PubMed

    Shaki, Hanieh; Gharanjig, Kamaladin; Khosravi, Alireza

    2015-01-01

    A series of novel disperse dyes containing azo group were synthesized through a diazotization and coupling process. The 4-amino-N-2-aminomethylpyridine-1,8-naphthalimide was diazotized by nitrosylsulphuric acid and coupled with various aromatic amines such as N,N-diethylaniline, N,N-dihydroxyethylaniline, 8-hydroxyquinoline, and 2-methylindole. Chemical structures of the synthesized dyes were characterized by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), proton nuclear magnetic resonance ((1) H NMR), carbon nuclear magnetic resonance ((13) C NMR), elemental analysis, and ultraviolet-visible (UV-visible) spectroscopy. The spectrophotometric data of all dyes were evaluated in various solvents with different polarity. Eventually, the dyes were applied on polyamide fabrics in order to investigate their dyeing properties. The fastness properties of the dyed fabrics such as wash, light, and rubbing fastness degrees were measured by standard methods. Moreover, the color gamut of the synthesized dyes was measured on polyamide fabrics. Results indicated that some of the synthesized dyes were able to dye polyamide fabrics with deep shades. They had very good wash and rubbing fastness degrees and moderate-to-good light fastness on polyamide fabrics. The antibacterial and antifungal activities of the synthesized dyes were evaluated in soluble state and on the dyed fabrics. The results indicated that dye 2 containing N,N-dihydroxyethylaniline as coupler had the highest activity against all the bacteria and fungi used. PMID:25967675

  12. Are Phragmites australis enzymes involved in the degradation of the textile azo dye acid orange 7?

    PubMed

    Carias, Cátia C; Novais, Júlio M; Martins-Dias, Susete

    2008-01-01

    The role of antioxidant and detoxification enzymes of Phragmites australis, in the degradation of an azo dye, acid orange 7 (AO7), was studied. Activities of several enzymes involved in plant protection against stress were assayed through the activity characterization of superoxide dismutase (SOD), peroxidases (POD), catalase (CAT), ascorbate peroxidase (APOX), dehydroascorbate reductase (DHAR) and glutathione S-transferase (GST), obtained from P. australis crude extracts of leaves, stems and roots. A sub-surface vertical flow constructed wetland, planted with P. australis was used to test the plants response to the AO7 exposure at two different concentrations (130 and 700 mg l(-1)). An activity increase was detected for an AO7 concentration of 130 mg l(-1) for most enzymes studied (SOD, CAT and APOX), especially in leaves, suggesting a response of the reactive oxygen species scavenging enzymes to the chemical stress imposed. GST activity increase in this situation can also be interpreted as an activation of the detoxification pathway and subsequent AO7 conjugation. A totally different behaviour was observed for AO7 at 700 mg l(-1). An evident decrease in activity was observed for SOD, CAT, APOX and GST, probably due to enzymatic inhibition by AO7. Contrarily, DHAR activity augmented drastically in this situation. POD activity was not greatly affected during trial. Altogether these results suggest that P. australis effectively uses the ascorbate-glutathione pathway for the detoxification of AO7. PMID:17336060

  13. Impact of Photo-Induced Surface Adsorption of Azo-Dyes on the Liquid Crystal Anchoring Conditions

    NASA Astrophysics Data System (ADS)

    Statman, David

    2013-03-01

    Using optical techniques, we measured the anchoring conditions of azo-dye doped nematic liquid crystals on rubbed polyimide surfaces. Linearly polarized light induces the formation of a second easy axis on the polymer surface oriented toward the polarization direction of the pump laser beam. This additional easy axis is the result of photo-induced adsorption of the cis isomer of the azo dye. An effective easy axis is the weighted average of the original easy axis and this new easy axis.

  14. Fastest non-ionic azo dyes and transfer of their thermal isomerisation kinetics into liquid-crystalline materials.

    PubMed

    Garcia-Amorós, Jaume; Castro, M Cidália R; Coelho, Paulo; Raposo, M Manuela M; Velasco, Dolores

    2016-04-14

    Push-pull bithienylpyrrole-based azo dyes exhibit thermal isomerisation rates as fast as 1.4 μs in acetonitrile at 298 K becoming, thus, the fastest neutral azo dyes reported so far. These remarkably low relaxation times can be transferred into liquid-crystalline matrices enabling light-triggered oscillations in the optical density of the final material up to 11 kHz under ambient conditions. PMID:26990527

  15. Emerging adsorptive removal of azo dye by metal-organic frameworks.

    PubMed

    Ayati, Ali; Shahrak, Mahdi Niknam; Tanhaei, Bahareh; Sillanpää, Mika

    2016-10-01

    Adsorptive removal of toxic compounds using advanced porous materials is one of the most attractive approaches. In recent years, the metal-organic frameworks (MOFs), a subset of advanced porous nano-structured materials, due to their unique characteristics are showing great promise for better adsorption/separation of various water contaminants. Given the importance of azo dye removal, as an important class of pollutants, this paper aims to review and summarize the recently published research on the effectiveness of various MOFs adsorbents under different physico-chemical process parameters in dyes adsorption. The effect of pH, the adsorption mechanism and the applicability of various adsorption kinetic and thermodynamic models are briefly discussed. Most of the results observed showed that the adsorption kinetic and isotherm of azo dyes onto the MOFs mostly followed the pseudo-second order and Langmuir models respectively. Also, the optimum pH value for the removal of majority of azo dyes by MOFs was observed to be in the range of ∼5-7. PMID:27355417

  16. Biodegradation of textile azo-dyes byPhanerochaete chrysosporium.

    PubMed

    Capalash, N; Sharma, P

    1992-05-01

    Of 18 commercially used textile dyes, eight were degraded by the white rot fungus,Phanerochaete chrysosporium, by 40 to 73% based on decrease of colour. Both the lignin-degrading enzyme system ofP. chrysosporium and adsorption to its cell mass were involved in the degradation of the diazo dye, Reactofix Gold Yellow. Degradation was best achieved by adding the dye to the medium and then inoculating with pre-grown mycelium; inoculation with spores resulted mainly in dye adsorption. PMID:24425485

  17. Dyeing of Polyester with Disperse Dyes: Part 2. Synthesis and Dyeing Characteristics of Some Azo Disperse Dyes for Polyester Fabrics.

    PubMed

    Al-Etaibi, Alya M; Alnassar, Huda S; El-Apasery, Morsy Ahmed

    2016-01-01

    The goal of this study was to utilize carrier for accelerating the rate of dyeing not only to enhance dyeing of polyester fabrics dyed with disperse dyes 3a,b, but also to save energy. Both the color strength expressed as dye uptake and the fastness properties of the dyed fabrics were evaluated. PMID:27367659

  18. Synthesis and photo-induced birefringence of pyrazoline substituted azo-dyes in PMMA films

    NASA Astrophysics Data System (ADS)

    Jin, Ming; Xin Yang, Qing; Lu, Ran; Yun Pan, Ling; Chong Xue, Peng; Zhao, YingYing

    2003-12-01

    Three push-pull type azo dyes, 4 '-{[(2-hydroxylethyl)methyl]amino}-4-nitroazobenzene (compound I), 1-[4-(4 '-nitrophenyl)-azophenyl]-3,5-biphenyl-2-pyrazoline (compound II) and 1-[4-(4 '-nitrophenyl)-azophenyl]-3-(3 '-trifluoromethyl)-phenyl-5-phenyl-2-pyrazoline (compound III) were synthesized. The cis- trans isomerization process and polarized photoinduced birefringence of those azo dyes doped PMMA films were investigated. It was found that the rise and relaxation process of birefringence signals were fit with biexponential functions and the molecular structures have effects on their photo-induced birefringence. This suggests that the three films have similar storage speed when the laser intensity is high enough. Compound III, which has the biggest substituent, has the largest long-term storage ability and can even keep 90% of its saturated birefringence.

  19. Adsorption studies of cationic, anionic and azo-dyes via monodispersed Fe3O4 nanoparticles.

    PubMed

    Chaudhary, Ganga Ram; Saharan, Priya; Kumar, Arun; Mehta, S K; Mor, Suman; Umar, Ahmad

    2013-05-01

    The present paper reports the applicability of magnetite (Fe3O4) nanoparticles as an adsorbent for the removal of three dyes viz. Acridine orange (cationic dye), Comassie Brilliant Blue R-250 (anionic dye) and Congo red (azo dye) from their aqueous solution. The Fe3O4 nanoparticles were synthesized via simple chemical precipitation method using CTAB, as surfactant. The as-prepared nanoparticles were characterized in terms of their morphological, structural and optical properties by using transmission electron microscopy X-ray diffraction and UV-visible spectroscopic measurements. The dye removal efficiency of Fe3O4 NPs have been determined by investigating several factors such as effect of pH, amount of adsorbent dose and effect of contact time on different dye concentrations. Langmuir and Freundlich adsorption isotherms have also been studied to explain the interaction of dyes. The experimental data indicate that the adsorption rate follows pseudo- second-order kinetics for the removal of all the three dyes. Moreover, the nanoparticles and the adsorbed dyes were desorbed. The identities of recovered nanoparticles as well as the three dyes have been found, as same and were reused. PMID:23858837

  20. Performance of microbial fuel cell coupled constructed wetland system for decolorization of azo dye and bioelectricity generation.

    PubMed

    Fang, Zhou; Song, Hai-Liang; Cang, Ning; Li, Xian-Ning

    2013-09-01

    A microbial fuel cell coupled constructed wetland (planted with Ipomoea aquatica) system (planted CW-MFC) was used for azo dye decolorization. Electricity was simultaneously produced during the co-metabolism process of glucose and azo dye. A non-planted and an open-circuit system were established as reference to study the roles of plants and electrodes in azo dye decolorization and electricity production processes, respectively. The results indicated that plants grown in cathode enhanced the cathode potential and slightly promoted dye decolorization efficiency. The electrodes promoted the dye decolorization efficiency in the anode. The planted CW-MFC system achieved the highest decolorization rate of about 91.24% and a voltage output of about 610 mV. The connection of external circuit promoted the growth of electrogenic bacteria Geobacter sulfurreducens and Beta Proteobacteria, and inhibited the growth of Archaea in anode. PMID:23867535

  1. Fluorescence energy transfer in quantum dot/azo dye complexes in polymer track membranes

    NASA Astrophysics Data System (ADS)

    Gromova, Yulia A.; Orlova, Anna O.; Maslov, Vladimir G.; Fedorov, Anatoly V.; Baranov, Alexander V.

    2013-10-01

    Fluorescence resonance energy transfer in complexes of semiconductor CdSe/ZnS quantum dots with molecules of heterocyclic azo dyes, 1-(2-pyridylazo)-2-naphthol and 4-(2-pyridylazo) resorcinol, formed at high quantum dot concentration in the polymer pore track membranes were studied by steady-state and transient PL spectroscopy. The effect of interaction between the complexes and free quantum dots on the efficiency of the fluorescence energy transfer and quantum dot luminescence quenching was found and discussed.

  2. Dark spatial solitons in bulk azo-dye-doped polymer using photoinduced molecular reorientation

    SciTech Connect

    Bian Shaoping; Kuzyk, Mark G.

    2004-08-16

    We report the generation of dark spatial solitons in bulk Disperse Red 1 doped poly(methyl methacrylate) using photoinduced reorientation of azo-dye molecules. Planar solitions are formed when illuminated with a continuous-wave laser at intensities of the order of hundreds of miliwatts per square centimeter. The width of the soliton saturates to a minimum value at high intensity; and when the width of the initial dark notch is reduced, the equilibrium minimum width is unchanged.

  3. Preparation of Dis-Azo Dyes Derived from p-Aminophenol and Their Fastness Properties for Synthetic Polymer-Fibres

    NASA Astrophysics Data System (ADS)

    Otutu, J. O.; Okoro, D.; Ossai, E. K.

    The preparation and properties of a series of dis-azo dyes derived from p-aminophenol is described. The influence on colour, dyeing fastness properties of the dyes on synthetic polymer-fibres is reported. Most of the dyes synthesized afford better light fastness and better wet (wash, perspiration) fastness on PET than on nylon 6 fabric. The structure of each compound was confirmed by using infrared, UV-VIS and elemental analysis.

  4. Kinetics of photoinduced ordering in azo-dye films: Two-state and diffusion models

    SciTech Connect

    Kiselev, Alexei D.; Chigrinov, Vladimir G.; Kwok, Hoi-Sing

    2009-07-15

    We theoretically study the kinetics of photoinduced ordering in azo-dye photoaligning layers and present the results of modeling performed using two different phenomenological approaches. A phenomenological two-state model is deduced from the master equation for the one-particle distribution functions of an ensemble of two-level molecular systems by specifying the angular redistribution probabilities and by expressing the order parameter correlation functions in terms of the order parameter tensor. Using an alternative approach that describes light-induced reorientation of azo-dye molecules in terms of a rotational Brownian motion, we formulate the two-dimensional diffusion model as the free energy Fokker-Planck equation simplified for the limiting regime of purely in-plane reorientation. The models are employed to interpret the irradiation time dependence of the absorption order parameters defined in terms of the principal extinction (absorption) coefficients. Using the exact solution to the light transmission problem for a biaxially anisotropic absorbing layer, these coefficients are extracted from the absorbance-vs-incidence angle curves measured at different irradiation doses for the probe light linearly polarized parallel and perpendicular to the plane of incidence. It is found that, in the azo-dye films, the transient photoinduced structures are biaxially anisotropic whereas the photosteady and the initial states are uniaxial.

  5. Photorefractivity and holographic applications of azo-dye doped PMMA recording materials

    NASA Astrophysics Data System (ADS)

    Pham, Vinh P.; Manivannan, Gurusamy; Lessard, Roger A.

    1995-09-01

    Azo-dye doped polymer (ADP) systems have been the focus of many research groups for realizing various holographic applications for the past twenty years due to their remarkable optical properties such as grainless media, real-time capabilities, dynamic polarization holographic recording, etc. In this paper, we are reporting the photorefractivity of azo-dye doped Poly(methyl methacrylate) (PMMA) films. Under actinic lighting (lambda equals 488 nm), real-time dynamic phase holograms resulting from a local change in refractive index, with reasonable high diffraction efficiency, have been recorded and a maximum of 10% has been achieved. The diffraction efficiency obtained is higher than the similar earlier reported systems. The real-time kinetics of photoreversibility (bleaching and evolution) of azo dyes in PMMA matrices has also been studied. Some interesting applications in optical processing have been realized, exploiting the special properties of ADP systems such as complete auto- reversibility, high rise and erase times, absence of memory effect, and uniform write/read/erase (WRE) cycles.

  6. Process and kinetics of azo dye decolourization in bioelectrochemical systems: effect of several key factors.

    PubMed

    Yang, Hou-Yun; He, Chuan-Shu; Li, Lei; Zhang, Jie; Shen, Jin-You; Mu, Yang; Yu, Han-Qing

    2016-01-01

    This study explored the influence of several key factors on the process and kinetics of azo dye decolourization in bioelectrochemical systems (BESs), including cathode potential, dissolved oxygen (DO) concentration of catholyte and biofilm formed on the cathode. The results show that azo dye methyl orange (MO) decolourization in the BES could be well described with the pseudo first-order kinetics. The MO decolourization efficiency increased from 0 to 94.90 ± 0.01% and correspondingly the reaction rate constant increased from 0 to 0.503 ± 0.001 h(-1) with the decrease in cathodic electrode potential from -0.2 to -0.8 V vs Ag/AgCl. On the contrary, DO concentration of the catholyte had a negative impact on MO decolourization in the BES. When DO concentration increased from zero to 5.80 mg L(-1), the MO decolourization efficiency decreased from 87.19 ± 4.73% to 27.77 ± 0.06% and correspondingly the reaction rate constant reduced from 0.207 ± 0.042 to 0.033 ± 0.007 h(-1). Additionally, the results suggest that the biofilm formed on the cathode could led to an adverse rather than a positive effect on azo dye decolourization in the BES in terms of efficiency and kinetics. PMID:27270398

  7. Density functional theory study of new azo dyes with different π-spacers for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Bagheri Novir, Samaneh; Hashemianzadeh, Seyed Majid

    2015-05-01

    Some of new azo-based metal-free dyes with different π-conjugation spacers, such as carbazole, fluorene, pyrrole, thiophene, furan and thiazole, have been investigated with density functional theory (DFT) and time-dependent DFT (TDDFT) calculations. Theoretical calculations allow us to quantify factors such as light harvesting efficiency (LHE), electron injection driving force (ΔGinject) and the weight of the LUMO orbital on the carboxylic group (QLUMO) related to the short-circuit photocurrent density (Jsc), and to evaluate both charge recombination between the semiconductor conduction band electrons and the oxidized dyes and/or electrolyte, and also the shift of the conduction band of the semiconductor as a result of the adsorption of the dyes onto the semiconductor surface, associated with the open-circuit photovoltage (Voc). According to the results, we could predict that how the π-conjugation spacers influence the Jsc as well as the Voc of DSSCs. Among these dyes, the carbazole and fluorene-based dyes (dyes 1 and 2) show the highest LHE, ΔGinject, QLUMO, and the slowest recombination rate. Consequently, the obtained results show that the carbazole and fluorene-based dyes could have the better Jsc and Voc compared to the other dyes.

  8. pI-Control in Comparative Fluorescence Gel Electrophoresis (CoFGE) using amphoteric azo dyes.

    PubMed

    Hanneken, Marina; Šlais, Karel; König, Simone

    2015-06-01

    Amphoteric azo dyes were used for internal control of pI values in Comparative two-dimensional Fluorescence Gel Electrophoresis (CoFGE) [1]. The 2D-gel images of separated Escherichia coli proteins as well as those of colored amphoteric dyes separated by isoelectric focussing are presented. The latter were used to correct for variation in the first electrophoretic dimension and further improve protein coordinate assignment in 2D-gel electrophoresis. Data tables are supplied to demonstrate pI-value calibration and the effect on the assignment of protein spot coordinates. PMID:26217748

  9. pI-Control in Comparative Fluorescence Gel Electrophoresis (CoFGE) using amphoteric azo dyes

    PubMed Central

    Hanneken, Marina; Šlais, Karel; König, Simone

    2015-01-01

    Amphoteric azo dyes were used for internal control of pI values in Comparative two-dimensional Fluorescence Gel Electrophoresis (CoFGE) [1]. The 2D-gel images of separated Escherichia coli proteins as well as those of colored amphoteric dyes separated by isoelectric focussing are presented. The latter were used to correct for variation in the first electrophoretic dimension and further improve protein coordinate assignment in 2D-gel electrophoresis. Data tables are supplied to demonstrate pI-value calibration and the effect on the assignment of protein spot coordinates. PMID:26217748

  10. Functional behavior of bio-electrochemical treatment system with increasing azo dye concentrations: Synergistic interactions of biocatalyst and electrode assembly.

    PubMed

    Sreelatha, S; Velvizhi, G; Naresh Kumar, A; Venkata Mohan, S

    2016-08-01

    Treatment of dye bearing wastewater through biological machinery is particularly challenging due to its recalcitrant and inhibitory nature. In this study, functional behavior and treatment efficiency of bio-electrochemical treatment (BET) system was evaluated with increasing azo dye concentrations (100, 200, 300 and 500mg dye/l). Maximum dye removal was observed at 300mg dye/l (75%) followed by 200mg dye/l (65%), 100mg dye/l (62%) and 500mg dye/l (58%). Concurrent increment in dye load resulted in enhanced azo reductase and dehydrogenase activities respectively (300mg dye/l: 39.6U; 4.96μg/ml). Derivatives of cyclic voltammograms also supported the involvement of various membrane bound redox shuttlers, viz., cytochrome-c, cytochrome-bc1 and flavoproteins during the electron transfer. Bacterial respiration during BET operation utilized various electron acceptors such as electrodes and dye intermediates with simultaneous bioelectricity generation. This study illustrates the synergistic interaction of biocatalyst with electrode assembly for efficient treatment of azo dye wastewater. PMID:27067459

  11. Simultaneous determination of three azo dyes in food product by ion mobility spectrometry.

    PubMed

    Jiao, Jiandong; Wang, Jinfeng; Li, Mingfeng; Li, Junqing; Li, Qihong; Quan, Qinbo; Chen, Jinquan

    2016-07-01

    Color is an important property for food evaluation. Synthetic azo dyes are usually used in food product to obtain better appearance because of their stability and low cost. However, such dyes should be strictly controlled because of their potential threat to human health. A simple, rapid and sensitive method has been developed to determine orange II, allura red, and para red simultaneously by ion mobility spectrometry. The three dyes could be separated at the same time and the migration time of orange II, allura red, and para red are 12.070±0.010, 8.180±0.015, and 11.037±0.016ms, respectively. The effects of different parameters, such as pH, solvent, percentage of water, were investigated to establish the optimal condition. The detection limits were 0.1, 0.05, and 0.2μg/mL for orange II, allura red, and para red, respectively. The recoveries of the three azo dyes from jellies were all higher than 81%. The developed method is fast and accurate for the detection of the three synthetic dyes. PMID:27235999

  12. ESTIMATION OF IONIZATION CONSTANTS OF AZO DYES AND RELATED AROMATIC AMINES: ENVIRONMENTAL IMPLICATIONS

    EPA Science Inventory

    Ionization constants for 214 dye molecules were calculated from molecular structures using the chemical reactivity models developed in SPARC (SPARC Performs Automated Reasoning in Chemistry). hese models used fundamental chemical structure theory to predict chemical reactivities ...

  13. Degradation of Reactive Black 5 dye by a newly isolated bacterium Pseudomonas entomophila BS1.

    PubMed

    Khan, Sana; Malik, Abdul

    2016-03-01

    The textile and dye industries are considered as one of the major sources of environmental pollution. The present study was conducted to investigate the degradation of the azo dye Reactive Black 5 (RB 5) using a bacterium isolated from soil samples collected around a textile industry. The bacterial strain BS1 capable of degrading RB 5 was isolated and identified as Pseudomonas entomophila on the basis of 16S rDNA sequencing. The effects of different parameters on the degradation of RB 5 were studied to find out the optimal conditions required for maximum degradation, which was 93% after 120 h of incubation. Static conditions with pH in the range of 5-9 and a temperature of 37 °C were found to be optimum for degrading RB 5. Enzyme assays demonstrated that P. entomophila possessed azoreductase, which played an important role in degradation. The enzyme was dependent on flavin mononucleotide and NADH for its activity. Furthermore, a possible degradation pathway of the dye was proposed through gas chromatography - mass spectrometry analysis, which revealed that the metabolic products were naphthalene-1,2-diamine and 4-(methylsulfonyl) aniline. Thus the ability of this indigenous bacterial isolate for simultaneous decolorization and degradation of the azo dye signifies its potential application for treatment of industrial wastewaters containing azo dyes. PMID:26911309

  14. Bioremediation of textile azo dyes by an aerobic bacterial consortium using a rotating biological contactor.

    PubMed

    Abraham, T Emilia; Senan, Resmi C; Shaffiqu, T S; Roy, Jegan J; Poulose, T P; Thomas, P P

    2003-01-01

    The degradation of an azo dye mixture by an aerobic bacterial consortium was studied in a rotating biological reactor. Laterite pebbles of particle size 850 microm to 1.44 mm were fixed on gramophone records using an epoxy resin on which the developed consortium was immobilized. Rate of degradation, BOD, biomass determination, enzymes involved, and fish bioassay were studied. The RBC has a high efficiency for dye degradation even at high dye concentrations (100 microg/mL) and high flow rate (36 L/h) at alkaline pH and salinity conditions normally encountered in the textile effluents. Bioassays (LD-50) using Thilapia fish in treated effluent showed that the percentage mortality was zero over a period of 96 h, whereas the mortality was 100% in untreated dye water within 26 h. Fish bioassay confirms that the effluent from RBC can be discharged safely to the environment. PMID:12892505

  15. Synthesis, spectroscopic, thermal and electrochemical studies on thiazolyl azo based disperse dyes bearing coumarin

    NASA Astrophysics Data System (ADS)

    Özkütük, Müjgan; İpek, Ezgi; Aydıner, Burcu; Mamaş, Serhat; Seferoğlu, Zeynel

    2016-03-01

    In this study, seven novel thiazolyl azo disperse dyes (6a-g) were synthesized and fully characterized by FT-IR, 1H NMR, 13C NMR, and mass spectral techniques. The electronic absorption spectra of the dyes in solvents of different polarities cover a λmax range of 404-512 nm. The absorption properties of the dyes changed drastically upon acidification. This was due to the protonation of the nitrogen in the thiazole ring, which in turn increased the donor-acceptor interplay of the π system in the dyes, and therefore increased the absorption properties of the prepared dyes. Thermal analysis showed that these dyes are thermal stable up to 269 °C. Additionally, the electrochemical behavior of the dyes (6a-g) were investigated using cyclic voltammetric and chronoamperometric techniques, in the presence of 0.10 M tetrabutylammonium tetrafluoroborate, in dimethylsulfoxide, at a glassy carbon electrode. The number of transferred electrons, and the diffusion coefficient were determined by electrochemical methods. The results showed that, for all the dyes, one oxidation peak and two reduction peaks were observed.

  16. Experimental data for synthesis of bi-metalized chitosan particle for attenuating of an azo dye from wastewater

    PubMed Central

    Hajivandi, Abdollah; Farjadfard, Sima; Ramavandi, Bahman; Akbarzadeh, Samad

    2016-01-01

    In this data article, we introduce data acquired from new adsorbent, bi-metalized chitosan particle that is successfully synthesized and applied to remove the orange II dye, an azo dye, from textile wastewater. The adsorbent was meso- and macro-porous material with BET surface area of 12.69 m2/g and pHzpc 6.6. The simulated textile-wastewater can be significantly treated using a relatively low quantity of the adsorbent. Overall, the use of bi-metalized chitosan particle can be considered a promising method for eliminating the azo dye from wastewater effectively. Accordingly, these data will be useful for decolorizing of azo dyes from textile wastewater. PMID:26955651

  17. Experimental data for synthesis of bi-metalized chitosan particle for attenuating of an azo dye from wastewater.

    PubMed

    Hajivandi, Abdollah; Farjadfard, Sima; Ramavandi, Bahman; Akbarzadeh, Samad

    2016-06-01

    In this data article, we introduce data acquired from new adsorbent, bi-metalized chitosan particle that is successfully synthesized and applied to remove the orange II dye, an azo dye, from textile wastewater. The adsorbent was meso- and macro-porous material with BET surface area of 12.69 m(2)/g and pHzpc 6.6. The simulated textile-wastewater can be significantly treated using a relatively low quantity of the adsorbent. Overall, the use of bi-metalized chitosan particle can be considered a promising method for eliminating the azo dye from wastewater effectively. Accordingly, these data will be useful for decolorizing of azo dyes from textile wastewater. PMID:26955651

  18. Synthesis of magnetic biocomposite for efficient adsorption of azo dye from aqueous solution.

    PubMed

    Sivashankar, R; Sathya, A B; Krishnakumar, Uma; Sivasubramanian, V

    2015-11-01

    A novel magnetic biocomposite was synthesized using metal chlorides and aquatic macrophytes by co-precipitation method. The resulting product, magnetic biocomposite was characterized by Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX) and Scanning electron microscope (SEM). The adsorption performance of the magnetic biocomposite was tested with removal of Metanil Yellow dye from aqueous solution. The effect of influencing parameters such as initial dye concentration, solution pH and agitation were investigated. The equilibrium isotherm was well described by the Langmuir model with the with maximum adsorption capacity of 90.91mg/g. Adsorption kinetics experiments were carried out and the data were well fitted by a pseudo-second-order equation. The results revealed that the magnetic biocomposite could efficiently adsorb the azo dyes from aqueous solution, and the spent adsorbents could be recovered completely by magnetic separation process. Therefore, the prepared magnetic biocomposite could thus be used as promising adsorbent for the removal of azo dyes from polluted water. PMID:25957848

  19. Revealing characteristics of mixed consortia for azo dye decolorization: Lotka-Volterra model and game theory.

    PubMed

    Chen, Bor-Yann

    2007-10-22

    This study provides a novel explanation to put forward, in Lotka-Volterra competition model and game theory, interspecific competition in bioaugmentation using constructed mixed consortia for azo dye decolorization. As mixed cultures are regularly used in industrial dye-laden wastewater treatment, understanding species competition of mixed consortia is apparently of great importance to azo dye decolorization. In aerobic growth conditions, Escherichia coli DH5alpha owned a growth advantage to out-compete Pseudomonas luteola due to preferential growth rate of DH5alpha. However, in static decolorization conditions DH5alpha surrendered some proportion of its advantage (i.e., a decrease in its competitive power for metabolite stimulation) to enhance color removal of P. luteola for total coexistence. In aerobic growth, DH5alpha had its growth advantage to exclude P. luteola for dominance (i.e, conflict strategy) according to competitive exclusion principle. In static decolorization conditions, as the removal of a common dye threat was crucial to both species for survival, both species selected cooperation strategy through metabolite stimulation of DH5alpha to enhance effective decolorization of P. luteola for long-term sustainable management. This analysis of game theory clearly unlocked unsolved mysteries in previous studies. PMID:17499918

  20. Differential gene expression in Staphylococcus aureus exposed to Orange II and Sudan III azo dyes.

    PubMed

    Pan, Hongmiao; Xu, Joshua; Kweon, Oh-Gew; Zou, Wen; Feng, Jinhui; He, Gui-Xin; Cerniglia, Carl E; Chen, Huizhong

    2015-05-01

    We previously demonstrated the effects of azo dyes and their reduction metabolites on bacterial cell growth and cell viability. In this report, the effects of Orange II and Sudan III on gene expression profiling in Staphylococcus aureus ATCC BAA 1556 were analyzed using microarray and quantitative RT-PCR technology. Upon exposure to 6 μg/ml Orange II for 18 h, 21 genes were found to be differently expressed. Among them, 8 and 13 genes were up- and down-regulated, respectively. Most proteins encoded by these differentially expressed genes involve stress response caused by drug metabolism, oxidation, and alkaline shock indicating that S. aureus could adapt to Orange II exposure through a balance between up and down regulated gene expression. Whereas, after exposure to 6 μg/ml Sudan III for 18 h, 57 genes were differentially expressed. In which, 51 genes were up-regulated and 6 were down-regulated. Most proteins encoded by these differentially expressed genes involve in cell wall/membrane biogenesis and biosynthesis, nutrient uptake, transport and metabolite, and stress response, suggesting that Sudan III damages the bacterial cell wall or/and membrane due to binding of the dye. Further analysis indicated that all differentially expressed genes encoded membrane proteins were up-regulated and most of them serve as transporters. The result suggested that these genes might contribute to survival, persistence and growth in the presence of Sudan III. Only one gene msrA, which plays an important role in oxidative stress resistance, was found to be down-regulated after exposure to both Orange II and Sudan III. The present results suggested that both these two azo dyes can cause stress in S. aureus and the response of the bacterium to the stress is mainly related to characteristics of the azo dyes. PMID:25720844

  1. An improved method for removal of azo dye orange II from textile effluent using albumin as sorbent.

    PubMed

    Ohashi, Tadashi; Jara, Alícia M T; Batista, Anabelle C L; Franco, Luciana O; Barbosa Lima, Marcos A; Benachour, Mohand; Alves da Silva, Carlos A; Campos-Takaki, Galba M

    2012-01-01

    Azo dyes are generally resistant to biodegradation due to their complex structures. Acid orange II is one of the most widely used dyes in the textile industry. The influence of bovine serum albumin (BSA) in different concentrations, pH, and time of contact on Orange II was investigated using kinetics and adsorption-isotherm experiments. The results showed that the maximum colour removed from dye/albumin was 99.50% and that a stable dye-protein complex had been formed at pH 3.5 and in a proportion of 1:3 (v/v), respectively. The synthetic effluent did not show toxicity to the microcrustacean Artemia salina, and showed a CL₅₀ equal to 97 µg/mL to azo dye orange II. Additionally, the methodology was effective in removing the maximum of orange II using BSA by adsorption at pH 3.5 which mainly attracted ions to the azo dye during the adsorption process. This suggests that this form of treatment is economical and easy to use which potentially could lead to bovine serum albumin being used as a sorbent for azo dyes. PMID:23201641

  2. Probing horseradish peroxidase catalyzed degradation of azo dye from tannery wastewater.

    PubMed

    Preethi, Sadhanandam; Anumary, Ayyappan; Ashokkumar, Meiyazhagan; Thanikaivelan, Palanisamy

    2013-01-01

    Biocatalysis based effluent treatment has outclassed the presently favored physico-chemical treatments due to nil sludge production and monetary savings. Azo dyes are commonly employed in the leather industry and pose a great threat to the environment. Here, we show the degradation of C. I. Acid blue 113 using horseradish peroxidase (HRP) assisted with H2O2 as a co-substrate. It was observed that 0.08 U HRP can degrade 3 mL of 30 mg/L dye up to 80% within 45 min with the assistance of 14 μL of H2O2 at pH 6.6 and 30°C. The feasibility of using the immobilized HRP for dye degradation was also examined and the results show up to 76% dye degradation under similar conditions to that of free HRP with the exception of longer contact time of 240 min. Recycling studies reveal that the immobilized HRP can be recycled up to 3 times for dye degradation. Kinetics drawn for the free HRP catalyzed reaction marked a lower K m and higher V max values, which denotes a proper and faster affinity of the enzyme towards the dye, when compared to the immobilized HRP. The applicability of HRP for treating the actual tannery dye-house wastewater was also demonstrated. PMID:23961406

  3. Catalytic wet peroxide oxidation of azo dye (Congo red) using modified Y zeolite as catalyst.

    PubMed

    Kondru, Arun Kumar; Kumar, Pradeep; Chand, Shri

    2009-07-15

    The present study explores the degradation of azo dye (Congo red) by catalytic wet peroxide oxidation using Fe exchanged commercial Y zeolite as a catalyst. The effects of various operating parameters like temperature, initial pH, hydrogen peroxide concentration and catalyst loading on the removal of dye, color and COD from an aqueous solution were studied at atmospheric pressure. The percent removals of dye, color and COD at optimum pH(0) 7, 90 degrees C using 0.6 ml H(2)O(2)/350 ml solution and 1g/l catalyst was 97% (in 4h), 100% (in 45 min) and 58% (in 4h), respectively. The % dye removal has been found to be less in comparison to % color removal at all conditions, e.g. dye removal in 45 min and at above conditions was 82%, whereas the color removal was 100%. The results indicate that the Fe exchanged Y zeolite is a promising catalyst for dye removal. Fe exchanged catalyst is characterized using XRD, SEM/EDAX, surface area analyzer and FTIR. Though the dye, color and COD removals were maximum at pH(0) 2 but as the leaching of Fe from the catalyst was more in acidic pH range, pH(0) 7 was taken as operating pH due to almost comparable removals as of pH(0) 2 and no leaching of Fe ions. PMID:19135790

  4. Metabolism of azo dyes by Lactobacillus casei TISTR 1500 and effects of various factors on decolorization.

    PubMed

    Seesuriyachan, Phisit; Takenaka, Shinji; Kuntiya, Ampin; Klayraung, Srikarnjana; Murakami, Shuichiro; Aoki, Kenji

    2007-03-01

    Lactobacillus casei TISTR 1500 was isolated from soil of a dairy wastewater treatment plant and selected as the most active azo dye degrader of 19 isolates. Growing cells and freely suspended cells of this strain completely degraded methyl orange, thereby decolorizing the medium. The strain stoichiometrically converted methyl orange to N,N-dimethyl-p-phenylenediamine and 4-aminobenzenesulfonic acid, which were identified by HPLC, GC, and GC-MS analyses. The enzyme activity responsible for the cleavage of the azo bond of methyl orange was localized to the cytoplasm of cells grown on modified MRS medium containing methyl orange. The effect of sugars, oligosaccharides, organic acids, metal ions, pHs, oxygen and temperatures on methyl orange decolorization by freely suspended cells was investigated. The optimal conditions for the decolorization of methyl orange by the Lactobacillus casei TISTR 1500 are incubation at 35 degrees C and pH 6 with sucrose provided as the energy source. PMID:17254626

  5. [Adverse reaction to the azo dye Pigment Red 170 in a tattoo].

    PubMed

    Steinbrecher, Iris; Hemmer, Wolfgang; Jarisch, Reinhart

    2004-12-01

    A 30-year old white male presented with sharply demarcated pruritic lesions in a black and red tattoo on his wrist. The strongly infiltrated and slightly scaly eruptions started four months after tattoo application and were notably restricted to the red-colored areas. Symptoms got worse after UV exposure. Patch testing and photo patch testing with the used azo dye Pigment Red 170 (C.I. 12475) was negative. Histology revealed lichenoid dermatitis without signs of a granulomatous reaction. The verification of allergic sensitization in hypersensitivity reactions to tattoos by patch testing may be difficult due to the poor penetration into the skin of the applied azo pigments. Intradermal testing may be more sensitive but bears the risk of long lasting skin reactions. PMID:16285314

  6. Effect of temperature on the photoalignment of azo dyes in thin films

    NASA Astrophysics Data System (ADS)

    Mikulich, V. S.; Murauski, An. A.; Muravsky, Al. A.; Agabekov, V. E.

    2016-03-01

    The temperature dependences of the induced dichroic ratios (DRs) of azo dyes after their photoalignment in thin films 80 to 200 nm thick are studied. It is found that the DR values of layers containing dyes of the benzeneazodiphenyl series fall from 6.0 to 1.6 as the temperature rises from 60 to 130°C, respectively. A reduction in induced DR as the temperature rises (from 20 to 100°C) is also observed for the thin films of the dyes of benzeneazo-5,5'-dioxodibenzothiophene group. The absence of induced DR after irradiation with polarized light at 100°C indicates there is no alignment of molecules at this temperature.

  7. Cold Pad-Batch dyeing method for cotton fabric dyeing with reactive dyes using ultrasonic energy.

    PubMed

    Khatri, Zeeshan; Memon, Muhammad Hanif; Khatri, Awais; Tanwari, Anwaruddin

    2011-11-01

    Reactive dyes are vastly used in dyeing and printing of cotton fibre. These dyes have a distinctive reactive nature due to active groups which form covalent bonds with -OH groups of cotton through substitution and/or addition mechanism. Among many methods used for dyeing cotton with reactive dyes, the Cold Pad Batch (CPB) method is relatively more environment friendly due to high dye fixation and non requirement of thermal energy. The dyed fabric production rate is low due to requirement of at least twelve hours batching time for dye fixation. The proposed CPB method for dyeing cotton involves ultrasonic energy resulting into a one third decrease in batching time. The dyeing of cotton fibre was carried out with CI reactive red 195 and CI reactive black 5 by conventional and ultrasonic (US) method. The study showed that the use of ultrasonic energy not only shortens the batching time but the alkalis concentrations can considerably be reduced. In this case, the colour strength (K/S) and dye fixation (%F) also enhances without any adverse effect on colour fastness of the dyed fabric. The appearance of dyed fibre surface using scanning electron microscope (SEM) showed relative straightening of fibre convolutions and significant swelling of the fibre upon ultrasonic application. The total colour difference values ΔE (CMC) for the proposed method, were found within close proximity to the conventionally dyed sample. PMID:21550289

  8. Evaluation of an azo and two anthraquinone dyes for allergic potential.

    PubMed

    Sailstad, D M; Tepper, J S; Doerfler, D L; Qasim, M; Selgrade, M K

    1994-11-01

    Two dye mixtures and the individual component dyes were evaluated for the potential to induce contact or pulmonary hypersensitivity. These dye mixtures were suspect because of anecdotal reports of both pulmonary and contact hypersensitivity in assembly workers, and because the component dyes were structurally related to dyes known to be contact sensitizers. One mixture consisted of disperse blue 3 (DB3) and disperse red 11 (DR11), which are anthraquinones, and the other mixture contained DR11 and solvent red 1 (SR1), an azo dye. Contact hypersensitivity was examined using the local lymph node assay (LLNA) and a modified mouse ear swelling test (MEST). Both the MEST and the LLNA indicated that SR1 has weak contact-sensitizing potential. None of the other individual dye compounds or the two mixtures were identified as contact sensitizers by either method. To evaluate the mixtures as potential pulmonary allergens, guinea pigs were repeatedly exposed by inhalation (300 mg/m3, 6 hr/day) 5 days/week, for 1 week. Weekly exposures were repeated three times with 2 weeks of nonexposure time in between. Guinea pigs were then challenged through the jugular vein using a dye-dimethylsulfoxide mixture. During the challenge, breathing mechanics (dynamic compliance and resistance) were measured in mechanically ventilated animals. Changes in these measurements, indicative of bronchoconstriction, were not observed in animals exposed to either dye mixture, nor were antibodies detected in the sera of exposed animals using individual dye-specific enzyme-linked immunosorbent assays. In conclusion, two methods indicate that SR1 may have contact-sensitizing potential.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7867908

  9. Synthesis, biological activity and dyeing performance of some novel azo disperse dyes incorporating pyrazolo[1,5-a]pyrimidines for dyeing of polyester fabrics

    NASA Astrophysics Data System (ADS)

    Sayed, Ahmed Z.; Aboul-Fetouh, Mahmoud S.; Nassar, Hesham S.

    2012-02-01

    Several novel pyrazolopyrimidine azo compounds were achieved from diazotization of 4-aminoacetanilide and coupling with malononitrile and then refluxed with hydrazine hydrate to furnish 3,5-diamino-4-(4-acetamidophenylazo)-1H-pyrazole. The later compound was diazotized and coupled with substituted α-cyanocinnamate, α-cyanocinnamonitrile, 2-cyano-3-ethoxyacrylic acid ethyl ester, chalcones and ethylacetoacetate to produce novel dyestuffs. Structures of the dyes were fully characterized by using FT-IR, 1H NMR, mass spectroscopy and elemental analysis. The dyes were applied to polyester fiber, affording satisfactory results and showed biological activity towards various microorganisms.

  10. Statistical optimization of synthetic azo dye (orange II) degradation by azoreductase from Pseudomonas oleovorans PAMD_1.

    PubMed

    Aranganathan, V; Kanimozhi, A M; Palvannan, T

    2013-01-01

    Pseudomonas oleovorans PAMD_1 produced an intracellular azoreductase as the more prominent enzyme that reduces the azo bridge during the azo dye decolorization process. In order to optimize the expression of azoreductase, statistically based experiments were applied. Eleven significant factors were screened on decolorization activity using Plackett-Burman design. Dye, NADH, glucose, and peptone were identified as having highest positive influence on the decolorization activity. Central composite design of response surface methodology was employed for the concerted effect of these four factors on decolorization activity. This method showed that the optimum medium containing dye (200 mg L(-1)), NADH (1.14 mM), glucose (2.07 g L(-1)), and peptone (6.44 g L(-1)) for the decolorization of Orange II up to 87% in 48 hr. The applied methodology was validated through the adequacy and accuracy of the overall experiments, and the results proved that the applied methods were most effective. Further, the enzyme was purified ninefold with 16% yield by anion-exchange chromatography and a specific activity of 26 U mg(-1). The purified enzyme with a molecular mass of 29,000 Da gave a single band on sodium dodecyl sulfate (SDS) gel, and the degradation products sulfanilic acid and 1-amino-2-napthol of Orange II by azoreductase were analyzed by using an ultraviolet-visible (UV-Vis) spectrophotometer and hish-performance liquid chromatography (HPLC). PMID:23768111

  11. Integration of photocatalysis and biological treatment for azo dye removal--application to AR183.

    PubMed

    Chebli, Derradji; Fourcade, Florence; Brosillon, Stephan; Nacef, Saci; Amrane, Abdeltif

    2011-04-01

    The feasibility of coupling photocatalysis with biological treatment to treat effluents containing azo dyes was examined in this work. With this aim, the degradation of Acid Red 183 was investigated. The very low biodegradability of AR183 was confirmed beforehand by measuring the biological oxygen demand (BOD5). Photocatalysis experiments were carried out in a closed-loop step photoreactor. The reactor walls were covered by TiO2 catalyst coated on non-woven paper, and the effluent flowed over the photocatalyst as a thin falling film. The removal of the dye was 82.7% after 4 h, and a quasi-complete decolorization (98.5%) was obtained for 10 h of irradiation (initial concentration 100 mg L(-1)). The decrease in concentration followed pseudo-first-order kinetics, with a constant k of 0.47 h(-1). Mineralization and oxidation yields were 80% and 75%, respectively, after 10 h of pretreatment. Therefore, even if target compound oxidation occurs (COD removal), indicating a modification to the chemical structure, the concomitant high mineralization was not in favour of subsequent microbial growth. The BOD5 measurement confirmed the non-biodegradability of the irradiated solution, which remained toxic since the EC50 decreased from 35 to 3 mg L(-1). The proposed integrated process appeared, therefore, to be not relevant for the treatment of AR183. However, this result should be confirmed for other azo dyes. PMID:21877531

  12. Adsorption of azo dyes from aqueous solution by the hybrid MOFs/GO.

    PubMed

    Li, Ling; Shi, Zhennan; Zhu, Hongyang; Hong, Wei; Xie, Fengwei; Sun, Keke

    2016-01-01

    In this work, a hybrid of chromium(III) terephthalate metal organic framework (MIL-101) and graphene oxide (GO) was synthesized and its performance in the removal of azo dyes (Amaranth, Sunset Yellow, and Carmine) from water was evaluated. The adsorption for azo dyes on MIL-101/GO was compared with that of MIL-101, and it was found that the addition of GO enhanced the stability of MIL-101 in water and increased the adsorption capacity. The maximum adsorption capacities of MIL-101/GO were 111.01 mg g(-1) for Amaranth, 81.28 mg g(-1) for Sunset Yellow, and 77.61 mg g(-1) for Carmine. The adsorption isotherms and kinetics were investigated, showing that the adsorption fits the Freundlich isotherm and the pseudo-second-order kinetic model. The recyclability of MIL-101/GO was shown by the regeneration by acetone. The high adsorption capability and excellent reusability make MIL-101/GO a competent adsorbent for the removal dyes from aqueous solution. PMID:27054746

  13. Process and kinetics of azo dye decolourization in bioelectrochemical systems: effect of several key factors

    PubMed Central

    Yang, Hou-Yun; He, Chuan-Shu; Li, Lei; Zhang, Jie; Shen, Jin-You; Mu, Yang; Yu, Han-Qing

    2016-01-01

    This study explored the influence of several key factors on the process and kinetics of azo dye decolourization in bioelectrochemical systems (BESs), including cathode potential, dissolved oxygen (DO) concentration of catholyte and biofilm formed on the cathode. The results show that azo dye methyl orange (MO) decolourization in the BES could be well described with the pseudo first-order kinetics. The MO decolourization efficiency increased from 0 to 94.90 ± 0.01% and correspondingly the reaction rate constant increased from 0 to 0.503 ± 0.001 h−1 with the decrease in cathodic electrode potential from −0.2 to −0.8 V vs Ag/AgCl. On the contrary, DO concentration of the catholyte had a negative impact on MO decolourization in the BES. When DO concentration increased from zero to 5.80 mg L−1, the MO decolourization efficiency decreased from 87.19 ± 4.73% to 27.77 ± 0.06% and correspondingly the reaction rate constant reduced from 0.207 ± 0.042 to 0.033 ± 0.007 h−1. Additionally, the results suggest that the biofilm formed on the cathode could led to an adverse rather than a positive effect on azo dye decolourization in the BES in terms of efficiency and kinetics. PMID:27270398

  14. Transflective spatial filter based on azo-dye-doped cholesteric liquid crystal films

    SciTech Connect

    Lin, T.-H.; Fuh, Andy Y.-G.

    2005-07-04

    This work demonstrates the feasibility of exploiting the photoisomerization effect in azo-dye-doped cholesteric liquid crystal (DDCLC) films with a concomitant decline of the phase transition temperature from the cholesteric to an isotropic phase (T{sub Ch-I}) as a spatial filter. The fabrication depends on the fact that the various intensities of the diffracted orders are responsible for the various degrees of transparency associated with the photoisomerized DDCLC film. High- and low-pass images in the Fourier optical signal process can be simultaneously observed via reflected and transmitted signals, respectively. A simulation is also performed, and the results are consistent closely with experimental data.

  15. Rapid degradation of azo dye methyl orange using hollow cobalt nanoparticles.

    PubMed

    Sha, Yingying; Mathew, Iswarya; Cui, Qingzhou; Clay, Molly; Gao, Fan; Zhang, Xiaoqi Jackie; Gu, Zhiyong

    2016-02-01

    A rapid and efficient method for methyl orange degradation using hollow cobalt (Co) nanoparticles is reported. Hollow Co nanoparticles were fabricated by a galvanic replacement reaction using aluminum (Al) nanoparticles as the template material. The methyl orange degradation characteristics were investigated by measuring the time dependent UV-Vis absorption of the dye solution, which showed a very fast degradation rate under acidic conditions. At an initial methyl orange concentration of 100 mg/L (pH = 2.5) and Co nanoparticle dosage of 0.5 g/L, the azo dye degradation efficiency reached up to 99% within 4 min, and the degradation constant rate was up to 2.444 min(-1), which is the highest value among other studies. A comparison of the decolorization rates at similar conditions with several other azo dyes, including Congo red, Amaranth, and Orange G, showed that the dye with a simpler structure and lower molecular mass decolorized considerably faster than the ones having a more complicated structure (higher molecular mass). The methyl orange degradation was also conducted using hollow nickel (Ni) nanoparticles and commercially available solid spherical Co and Ni nanoparticles. The results showed that Co-based nanoparticles outperformed Ni-based nanoparticles, with the hollow Co nanoparticles exhibiting the fastest degradation rate. Using the hollow Co nanoparticles is a very promising approach for the remediation of methyl orange dye containing wastewater due to the fast degradation rate and high degradation efficiency. In addition, these hollow Co nanoparticles are easily recycled because of their magnetic property. PMID:26498101

  16. FRET efficiency in surface complexes of CdSe/ZnS quantum dots with azo-dyes

    NASA Astrophysics Data System (ADS)

    Annas, Kirill I.; Gromova, Yuliya A.; Orlova, Anna O.; Maslov, Vladimir G.; Fedorov, Anatoly V.; Baranov, Alexander V.

    2016-04-01

    Photoinduced dissociation of surface complexes of CdSe/ZnS quantum dots with azo-dye 1-(2- pyridylazo)-2-naphthol (PAN) was investigated. It was shown that the Förster resonance energy transfer contributes in the complexes photodissociation rate, which depends on resonance condition between electronic levels of donor (quantum dots) and acceptor (azo-dye) and donor photoluminescent quantum yield. It has allowed to estimate energy transfer efficiency in the complexes and disclosed a new nonradiative channel that has minor contribution in the deactivation of excited states of quantum dots in the complexes.

  17. Decolourization of azo dyes by a newly isolated Klebsiella sp. strain Y3, and effects of various factors on biodegradation

    PubMed Central

    Cui, Daizong; Li, Guofang; Zhao, Min; Han, Song

    2014-01-01

    In this study, we isolated and characterized a new strain of Klebsiella sp. Y3, which was capable of decolourizing azo dyes under anaerobic conditions. The effects of physico-chemical parameters on the Methyl Red degradation by the strain were determined. The results indicated that strain Y3 exhibited a good decolourization ability in the range of pH from 4 to 9, temperature from 30 °C to 42 °C and salinity from 1% to 4%. A broad spectrum of azo dyes with different structures could be decolourized by the strain. The isolate decolourized Methyl Red, Congo Red, Orange I and Methyl Orange by almost 100% (100 mg/L) in 48 h. The culture exhibited an ability to decolourize repeated additions of dye, showing that the strain could be used for multiple cycles of biodegradation. Azo dyes at high concentrations could be tolerated and degraded by Y3. An almost complete mineralization of Methyl Red and Congo Red at the concentration of 800 mg/L was observed within 48 h. The high degradation potential of this bacterium supports its use in the treatment of industrial wastewater containing azo dyes. PMID:26019533

  18. Decolorization of azo dyes with Enterobacter agglomerans immobilized in different supports by using fluidized bed bioreactor.

    PubMed

    Moutaouakkil, Adnane; Zeroual, Youssef; Dzayri, Fatima Zohra; Talbi, Mohamed; Lee, Kangmin; Blaghen, Mohamed

    2004-02-01

    Immobilized cells of Enterobacter agglomerans, able to reduce azo dyes enzymatically, were used as a biocatalyst for the decolorization of synthetic medium containing the toxic azo dye methyl red (MR). This bacterial strain exhibits high ability to completely decolorize 100 mg/L of MR after only 6 h of incubation under aerobic conditions. Cells of E. agglomerans were immobilized in calcium alginate, polyacylamide, cooper beech, and vermiculite, and were used for the decolorization of MR from synthetic water by using a fluidized bed bioreactor. The highest specific decolorization rate was obtained when E. agglomerans was entrapped in calcium alginate beads and was of about 3.04 mg MR/g cell/h with a 50% conversion time ( t(1/2)) of about 1.6 h. Moreover, immobilized cells in calcium alginate continuously decolorized MR even after seven repeated experiments without significant loss of activity, while polyacrylamide-, cooper beech-, and vermiculite-immobilized cells retained only 62, 15, and 13% of their original activity, respectively. PMID:15057480

  19. Microbial dynamics during azo dye degradation in a UASB reactor supplied with yeast extract

    PubMed Central

    Silva, S.Q.; Silva, D.C.; Lanna, M.C.S.; Baeta, B.E.L.; Aquino, S.F.

    2014-01-01

    The present work aimed to investigate the microbial dynamics during the anaerobic treatment of the azo dye blue HRFL in bench scale upflow anaerobic sludge bed (UASB) reactor operated at ambient temperature. Sludge samples were collected under distinct operational phases, when the reactor were stable (low variation of color removal), to assess the effect of glucose and yeast extract as source of carbon and redox mediators, respectively. Reactors performance was evaluated based on COD (chemical oxygen demand) and color removal. The microbial dynamics were investigated by PCR-DGGE (Polimerase Chain Reaction - Denaturing Gradient of Gel Electrophoresis) technique by comparing the 16S rDNA profiles among samples. The results suggest that the composition of microorganisms changed from the beginning to the end of the reactor operation, probably in response to the presence of azo dye and/or its degradation byproducts. Despite the highest efficiency of color removal was observed in the presence of 500 mg/L of yeast extract (up to 93%), there were no differences regarding the microbial profiles that could indicate a microbial selection by the yeast extract addition. On the other hand Methosarcina barkeri was detected only in the end of operation when the best efficiencies on color removal occurred. Nevertheless the biomass selection observed in the last stages of UASB operation is probably a result of the washout of the sludge in response of accumulation of aromatic amines which led to tolerant and very active biomass that contributed to high efficiencies on color removal. PMID:25763018

  20. Reductive-degradation of carcinogenic azo dyes using Anacardium occidentale testa derived silver nanoparticles.

    PubMed

    Edison, Thomas Nesakumar Jebakumar Immanuel; Atchudan, Raji; Sethuraman, Mathur Gopalakrishnan; Lee, Yong Rok

    2016-09-01

    In the present work, reductive-degradation of azo dyes such as congo red (CR) and methyl orange (MO) was manifested using Anacardium occidentale testa derived silver nanoparticles (AgNPs) as a catalyst. The formation of highly stable AgNPs were visually confirmed by the appearance of yellow color and further substantiated by the existence of surface plasmon resonance (SPR) peak around 425nm. The effect of A. occidentale concentration, reaction time and pH in the formations of AgNPs was corroborated by UV-visible (UV-Vis) spectroscopy. The Fourier transform infrared (FT-IR) spectroscopic results proved that phytoconstituents of A. occidentale testa acts as a capping agent and thereby protects the AgNPs from aggregation. The crystalline nature of the AgNPs was validated from the XRD patterns. The average size of synthesized AgNPs was 25nm, with distorted spherical shape was ascribed from the high resolution transmission electron microscopic (HR-TEM) images. Due to the high stability of the as-synthesized AgNPs, they were utilized for the degradation of carcinogenic azo dyes such as CR and MO using NaBH4 and its catalytic activity was studied via UV-Vis spectroscopy. The results proved that extraordinary catalytic activity of synthesized AgNPs towards the reductive-degradation of both CR and MO. PMID:27479841

  1. Microbial dynamics during azo dye degradation in a UASB reactor supplied with yeast extract.

    PubMed

    Silva, S Q; Silva, D C; Lanna, M C S; Baeta, B E L; Aquino, S F

    2014-01-01

    The present work aimed to investigate the microbial dynamics during the anaerobic treatment of the azo dye blue HRFL in bench scale upflow anaerobic sludge bed (UASB) reactor operated at ambient temperature. Sludge samples were collected under distinct operational phases, when the reactor were stable (low variation of color removal), to assess the effect of glucose and yeast extract as source of carbon and redox mediators, respectively. Reactors performance was evaluated based on COD (chemical oxygen demand) and color removal. The microbial dynamics were investigated by PCR-DGGE (Polimerase Chain Reaction - Denaturing Gradient of Gel Electrophoresis) technique by comparing the 16S rDNA profiles among samples. The results suggest that the composition of microorganisms changed from the beginning to the end of the reactor operation, probably in response to the presence of azo dye and/or its degradation byproducts. Despite the highest efficiency of color removal was observed in the presence of 500 mg/L of yeast extract (up to 93%), there were no differences regarding the microbial profiles that could indicate a microbial selection by the yeast extract addition. On the other hand Methosarcina barkeri was detected only in the end of operation when the best efficiencies on color removal occurred. Nevertheless the biomass selection observed in the last stages of UASB operation is probably a result of the washout of the sludge in response of accumulation of aromatic amines which led to tolerant and very active biomass that contributed to high efficiencies on color removal. PMID:25763018

  2. Synthesis and characterization of Fe (III) complex of an azo dye derived from (2-amino-5-chlorophenyl) phenyl methanone

    NASA Astrophysics Data System (ADS)

    Mini, S.; Meena, S. S.; Bhatt, Pramod; Sadasivan, V.; Vidya, V. G.

    2013-06-01

    The synthesis of Fe (III) complex with an azo dye derived from (2-Amino-5-Chlorophenyl) phenyl methanone is presented. The newly prepared ligand and complex are characterized by elemental analysis, IR, UV-Visible and Mössbauer spectral studies, Molar conductance, and magnetic susceptibility measurements. The thermal stability of the complex is determined from the thermo gravimetric analysis.

  3. Synthesis of MoO{sub 3} nanoparticles for azo dye degradation by catalytic ozonation

    SciTech Connect

    Manivel, Arumugam; Lee, Gang-Juan; Chen, Chin-Yi; Chen, Jing-Heng; Ma, Shih-Hsin; Horng, Tzzy-Leng; Wu, Jerry J.

    2015-02-15

    Highlights: • Synthesis of one-dimensional MoO{sub 3} nanostructures using hydrothermal, microwave, and sonochemical methods. • Sonochemical synthesized MoO{sub 3} presents the best efficiency for the dye removal by catalytic ozonation. • Efficient environmental remediation process. - Abstract: One-dimensional molybdenum trioxide nanostructures were prepared in three different approaches, including thermal, microwave, and sonochemical methods. The physicochemical properties of the obtained MoO{sub 3} nanoparticles were investigated by diffused reflectance spectroscopy, X-ray diffraction analysis, field emission scanning electron microscopy, high resolution transmission electron microscopy, and Brunauer–Emmett–Teller surface area analysis. Among the methods as investigated, sonochemical synthesis gave well-dispersed fine MoO{sub 3} nanoparticles compared with the other approaches. All the synthesized MoO{sub 3} nanostructures were examined for the catalytic ozonation to degrade azo dye in aqueous environment. Different performances were obtained for the catalyst prepared in different methods and the catalytic efficiencies were found to be the order of sonochemical, microwave, and then thermal methods. The sonochemical MoO{sub 3} catalyst allowed the total dye removal within 20 min and its good performance was justified according to their higher surface area with higher number of active sites that provide effective dye interaction for better degradation.

  4. Degradation of azo dyes by the lignin-degrading fungus Phaerochaete chrysosporium

    SciTech Connect

    Spadaro, J.T.; Gold, M.H.; Renganathan, V. )

    1992-08-01

    Under nitrogen-limiting, secondary metabolic conditions, the white rat basidiomycete Phanerochaete chrysosporium extensively mineralized the specifically [sup 14]C-ring-labeled azo dyes 4-phenylazophenol, 4-phenylazo-2-methoxyphenol, Disperse Yellow 3 [2-(4[prime]-acetamidophenylaso)-4-methylphenol], 4-phenylazoaniline, N,N-dimethyl-4-phenylazoaniline, Disperse Orange 3 [4-(4[prime]-nitrophenylazo)-aniline], and Solvent Yellow 14 (1-phenylazo-2-naphthol). Twelve days after addition to cultures, the dyes had been mineralized 23.1 to 48.1%. Aromatic rings with substituents such as hydroxyl, amino, acetamido, or nitro functions were mineralized to a greater extent than unsubstituted rings. Most of the dyes were degraded extensively only under nitrogen-limiting, ligninolytic conditions. However, 4-phenylazo-[U-[sup 14]C] phenol and 4-phenylazo-[U-[sup 14]C] 2-methoxyphenol were mineralized to a lesser extent under nitrogen-sufficient, nonligninolytic conditions as well. These results suggest that P. chrysosporium has potential applications for the cleanup of textile mill effluents and for the bioremediation of dye-contaminated soil.

  5. Degradation of azo dyes by the lignin-degrading fungus Phanerochaete chrysosporium.

    PubMed

    Spadaro, J T; Gold, M H; Renganathan, V

    1992-08-01

    Under nitrogen-limiting, secondary metabolic conditions, the white rot basidiomycete Phanerochaete chrysosporium extensively mineralized the specifically 14C-ring-labeled azo dyes 4-phenylazophenol, 4-phenylazo-2-methoxyphenol, Disperse Yellow 3 [2-(4'-acetamidophenylazo)-4-methylphenol], 4-phenylazoaniline, N,N-dimethyl-4-phenylazoaniline, Disperse Orange 3 [4-(4'-nitrophenylazo)-aniline], and Solvent Yellow 14 (1-phenylazo-2-naphthol). Twelve days after addition to cultures, the dyes had been mineralized 23.1 to 48.1%. Aromatic rings with substituents such as hydroxyl, amino, acetamido, or nitro functions were mineralized to a greater extent than unsubstituted rings. Most of the dyes were degraded extensively only under nitrogen-limiting, ligninolytic conditions. However, 4-phenylazo-[U-14C]phenol and 4-phenylazo-[U-14C]2-methoxyphenol were mineralized to a lesser extent under nitrogen-sufficient, nonligninolytic conditions as well. These results suggest that P. chrysosporium has potential applications for the cleanup of textile mill effluents and for the bioremediation of dye-contaminated soil. PMID:1514787

  6. Iron nanoparticles decoration onto three-dimensional graphene for rapid and efficient degradation of azo dye.

    PubMed

    Wang, Wei; Cheng, Yilin; Kong, Tao; Cheng, Guosheng

    2015-12-15

    Porous three-dimensional graphene (3DG) prepared by chemical vapor deposition, was utilized as a matrix to support nanoscale zero-valent iron (nZVI) particles. The strategies to manipulate the morphology, distribution and size of nZVI particles on the 3DG support were demonstrated. The immobilized nZVI particles with a size of 100 nm and dense deposition were achieved. A 94.5% of orange IV azo dye was removed in 60 min using nZVI particles immobilized 3DG (3DG-Fe), whereas only 70.9% was removed by free Fe nanoparticles in aqueous solution. Meanwhile, a reaction rate with orange IV of 3DG-Fe was approximately 5-fold faster than that of free Fe nanoparticles. The effects of 3DG-Fe dosage, dye concentration, reaction pH and temperature on dye degradation were also addressed. Those results imply that both lowering pH and increasing temperature led to higher reaction efficiency and rate. The kinetic data reveal that the degradation process of orange IV dye, modeled by the pseudo-first-order kinetics, might involve adsorption and redox reaction with an activation energy of 39.2 kJ/mol. PMID:26091894

  7. Degradation of azo dyes by the lignin-degrading fungus Phanerochaete chrysosporium.

    PubMed Central

    Spadaro, J T; Gold, M H; Renganathan, V

    1992-01-01

    Under nitrogen-limiting, secondary metabolic conditions, the white rot basidiomycete Phanerochaete chrysosporium extensively mineralized the specifically 14C-ring-labeled azo dyes 4-phenylazophenol, 4-phenylazo-2-methoxyphenol, Disperse Yellow 3 [2-(4'-acetamidophenylazo)-4-methylphenol], 4-phenylazoaniline, N,N-dimethyl-4-phenylazoaniline, Disperse Orange 3 [4-(4'-nitrophenylazo)-aniline], and Solvent Yellow 14 (1-phenylazo-2-naphthol). Twelve days after addition to cultures, the dyes had been mineralized 23.1 to 48.1%. Aromatic rings with substituents such as hydroxyl, amino, acetamido, or nitro functions were mineralized to a greater extent than unsubstituted rings. Most of the dyes were degraded extensively only under nitrogen-limiting, ligninolytic conditions. However, 4-phenylazo-[U-14C]phenol and 4-phenylazo-[U-14C]2-methoxyphenol were mineralized to a lesser extent under nitrogen-sufficient, nonligninolytic conditions as well. These results suggest that P. chrysosporium has potential applications for the cleanup of textile mill effluents and for the bioremediation of dye-contaminated soil. PMID:1514787

  8. Yeast extract promotes decolorization of azo dyes by stimulating azoreductase activity in Shewanella sp. strain IFN4.

    PubMed

    Imran, Muhammad; Arshad, Muhammad; Negm, Fayek; Khalid, Azeem; Shaharoona, Baby; Hussain, Sabir; Mahmood Nadeem, Sajid; Crowley, David E

    2016-02-01

    Biological treatment of azo dyes commonly requires a combined anaerobic-aerobic process in which initial decolorization is achieved by reductive cleavage of azo bonds on the parent molecule. The present study was conducted to examine the relative importance of co-substrates for driving reductive decolorization of azo dyes by Shewanella sp. strain IFN4 using whole cells and enzyme assays. Results showed that the dye decolorization by strain IFN4 was faster in medium containing 1gL(-1) yeast extract (YE) as compared to nine other co-substrates. Moreover, only YE stimulated azoreductase activity (increased from 1.32 to 4.19U/mg protein). Increasing the level of YE up to 8gL(-)(1) resulted into 81% decolorization of the dye in 1h along with an increase in azoreductase activity up to 6.16U/mg protein. Among the components of YE, only riboflavin stimulated the decolorization process as well as enzyme activity. Moreover, strain IFN4 demonstrated flavin reductase activity, and a significant correlation (r(2)=0.98) between flavin reduction and dye reduction by this strain emphasized the involvement of flavin compounds in the decolorization process. The results of this study show that YE serves both as a source of reducing equivalents and an electron shuttle for catalyzing dye reduction. PMID:26454074

  9. Bladder cancer in crack testers applying azo dye-based sprays to metal bodies.

    PubMed

    Golka, Klaus; Kopps, Silke; Prager, Hans-Martin; Mende, Stephan v; Thiel, Ralf; Jungmann, Olaf; Zumbe, Jürgen; Bolt, Hermann M; Blaszkewicz, Meinolf; Hengstler, Jan G; Selinski, Silvia

    2012-01-01

    Bladder cancer may be produced by azo dyes due to the presence of carcinogenic aromatic amines. Nine cases of suspected occupational bladder cancer that were exposed to different crack test sprays in metal-related jobs were examined. A detailed occupational history was taken and, if possible, the N-acetyltransferase 2 (NAT2) status was determined. The first exposure to crack test sprays ranged from 1957 to 1986. Age at first exposure was between 14 and 33 yr. Age at first diagnosis of bladder cancer varied from 35 to 64 yr. Latency periods were between 17 and 45 yr. The maximal reported exposure period was 29 yr. Four of six genotyped cases were slow NAT2 acetylators. The handling of the crack test spray included spraying the red dye-containing matter on the metal body and washing off the spray with a rag. Thus, workers were exposed by dermal contact as well as by inhalation. The crack test spray, which makes the cracks visible after washing off the red testing spray compounds and applying an additional white spray, contained dyes such as solvent red 19 (Sudan red 7B, N-ethyl-1[[4-(phenylazo)phenyl]azo]-2-naphthylamine) or a mixture of p-phenylazoaniline-N-ethyl-2-naphthylamine and p-phenylazoaniline-N-ethyl-1-naphthylamine. The aromatic amine 2-naphthylamine is classified as human carcinogen by IARC and the national authorities and has been banned in many countries since the mid 1950s. Bladder cancer patients with metal-related jobs need to be explicitly asked about the use of crack test sprays. PMID:22686317

  10. In-situ formation and immobilization of biogenic nanopalladium into anaerobic granular sludge enhances azo dyes degradation.

    PubMed

    Quan, Xiangchun; Zhang, Xin; Xu, Hengduo

    2015-07-01

    Azo dyes are toxic and recalcitrant wastewater pollutants. An innovative technology based on biogenic nanopalladium (Bio-Pd) supported anaerobic granular sludge (AGS) was developed for azo dyes reduction. In-situ formation of Bio-Pd in the AGS was observed by Scanning Electron Microscopy coupled with Energy Dispersive Spectrometer (SEM-EDS). The Pd associated AGS (Pd-AGS) showed enhanced decolorization rates to the three azo dyes of Congo Red, Evans Blue and Orange II, with the degradation kinetic constants increased by 2.3-10 fold compared to the control AGS in the presence of electron donor formate. Impacts of different electron donors on Orange II decolorization were further investigated. Results showed that formic acid, formate, acetate, glucose, ethanol and lactate could serve as electron and hydrogen donors to stimulate Orange II decolorization by the Pd-AGS, and their activities followed the order: formic acid > formate > ethanol > glucose > lactate > acetate. Most of the Bio-Pd was bound with microbes in the AGS with a small fraction in the extracellular polymer substances (EPS). Transmission Electronic Microscopy analysis revealed that the Bio-Pd formed in the periplasmic space, cytoplasm and on the cell walls of bacteria. This study provides a new concept for azo dye reduction, which couples sludge microbial degradation ability with Bio-Pd catalytic ability via in-situ formation and immobilization of Bio-Pd into AGS, and offers an alternative for the current azo dye treatment technology. PMID:25912251

  11. Investigation of the azo-hydrazone tautomeric equilibrium in an azo dye involving the naphthalene moiety by UV-vis spectroscopy and quantum chemistry

    NASA Astrophysics Data System (ADS)

    Ünal, Arslan; Eren, Bilge; Eren, Erdal

    2013-10-01

    Photophysical properties of the azo-hydrazone tautomerism of Eriochrome Blue Black B (1-(1-hydroxy-2-naphthylazo)-2-naphthol-4-sulphonic acid) in DMF, MeCN and water were investigated using UV-visible spectroscopy and quantum chemical calculations. The optimized molecular structure parameters, relative energies, mole fractions, electronic absorption spectra and HOMO-LUMO energies for possible stable tautomeric forms of EBB were theoretically calculated by using hybrid density functional theory, (B3LYP) methods with 6-31G(d) basis set level and polarizable continuum model (PCM) for solvation effect. The effects of varying pH-, dye concentration-, solvent-, temperature-, and time-dependences on the UV-vis spectra of Eriochrome Blue Black B were also investigated experimentally. The calculations showed that the dye exhibited acid-base, azo-hydrazone and aggregate equilibria in DMF solution, while the most probably preferred form in MeCN solution was azo form. Thermodynamic parameters of dimerization reaction in DMF solution proved that entropy was the driving force of this reaction.

  12. Photocatalytic degradation of an azo textile dye (C.I. Reactive Red 195 (3BF)) in aqueous solution over copper cobaltite nanocomposite coated on glass by Doctor Blade method

    NASA Astrophysics Data System (ADS)

    Habibi, Mohammad Hossein; Rezvani, Zoya

    2015-08-01

    The degradation of C.I. Reactive Red 195 (3BF) in aqueous solution using copper cobaltite nanocomposite coated on glass by Doctor Blade method was studied. Structural, optical and morphological properties of nanocomposite coatings were characterized by X-ray powder diffractometry (XRD), diffuse reflectance spectroscopy (DRS) and field emission scanning electron microscopy (FESEM). The nanoparticles exhibit a particle size of 31 nm, showing a good nanoscale crystalline morphology. The photocatalytic activity of copper cobaltite nanocomposite coated on glass was studied by performing the photocatalytic degradation of 3BF at different irradiation time. The effect of irradiation time on the degradation of 3BF was studied and the results showed that more than 85% of the 3BF was degraded in 45 min of irradiation. The pseudo-first-order kinetic models were used and the rate constants were evaluated with pseudo first order rate constants of 4.10 × 10-2 min-1. The main advantage of the photocatalyst coated on glass overcomes the difficulties in separation and recycle of photocatalyst suspensions.

  13. Photocatalytic degradation of an azo textile dye (C.I. Reactive Red 195 (3BF)) in aqueous solution over copper cobaltite nanocomposite coated on glass by Doctor Blade method.

    PubMed

    Habibi, Mohammad Hossein; Rezvani, Zoya

    2015-08-01

    The degradation of C.I. Reactive Red 195 (3BF) in aqueous solution using copper cobaltite nanocomposite coated on glass by Doctor Blade method was studied. Structural, optical and morphological properties of nanocomposite coatings were characterized by X-ray powder diffractometry (XRD), diffuse reflectance spectroscopy (DRS) and field emission scanning electron microscopy (FESEM). The nanoparticles exhibit a particle size of 31 nm, showing a good nanoscale crystalline morphology. The photocatalytic activity of copper cobaltite nanocomposite coated on glass was studied by performing the photocatalytic degradation of 3BF at different irradiation time. The effect of irradiation time on the degradation of 3BF was studied and the results showed that more than 85% of the 3BF was degraded in 45 min of irradiation. The pseudo-first-order kinetic models were used and the rate constants were evaluated with pseudo first order rate constants of 4.10 × 10(-2) min(-1). The main advantage of the photocatalyst coated on glass overcomes the difficulties in separation and recycle of photocatalyst suspensions. PMID:25840025

  14. High-throughput determination of Sudan Azo-dyes within powdered chili pepper by paper spray mass spectrometry.

    PubMed

    Taverna, Domenico; Di Donna, Leonardo; Mazzotti, Fabio; Policicchio, Barbara; Sindona, Giovanni

    2013-05-01

    A high-throughput mass spectrometric method is presented for the simultaneous detection of Sudan I, II, III, IV and Para-Red azo-dyes in foodstuff. The method is based on the use of paper spray mass spectrometry (MS) and deuterium-labeled internal standards on a triple-quadrupole instrument. A detailed assay of each azo-dye was performed by the isotope dilution method, through the precursor ion scan approach, using deuterium-labeled internal standards. The gas-phase breakdown pattern of each labeled and unlabeled analogue displays the naphthoic moiety as a common fragment. Sudan dyes can be determined above the threshold of 1 ppm. Paper spray allows for a wide range of analytes and samples to be investigated by MS in the open air and without sample preparation and bypassing chromatography. PMID:23674278

  15. Active manganese oxide: a novel adsorbent for treatment of wastewater containing azo dye.

    PubMed

    Chakrabarti, S; Dutta, B K; Apak, R

    2009-01-01

    A new variety of active manganese oxide was prepared, characterized, and tested for its potential of adsorbing Congo Red, a dis-azo dye, from aqueous solutions. Both equilibrium and kinetics were investigated over different values of process parameters such as temperature (25-45 degrees C), adsorbent loading (0.4-0.6%), initial dye concentration (50-500 mg/L), presence of salts (sodium sulphate, 500 mg/L) and the oxygen content (MnO(x), x=1.2, 1.33 and 2) of the adsorbent. The equilibrium adsorption data were fitted to Langmuir and Freundlich isotherms. Langmuir adsorption capacity of the sorbent (x=1.33) for Congo Red was 38.6 mg/g at room temperature which is substantially higher than those for commercial manganese dioxide, red mud, coir pith, activated carbon, and fly ash. The kinetic data were best interpreted using a pseudo-second order model. The results show that the active manganese oxide used in this work removes the dye by reversible adsorption and has the potential for practical use for remediation of textile industry effluents. PMID:19955624

  16. Enzyme-mediated bacterial biodegradation of an azo dye (C.I. Acid blue 113): reuse of treated dye wastewater in post-tanning operations.

    PubMed

    Senthilvelan, T; Kanagaraj, J; Panda, R C

    2014-11-01

    "Dyeing" is a common practice used to color the hides during the post-tanning operations in leather processing generating plenty of wastewater. The waste stream containing dye as pollutant is severely harmful to living beings. An azo dye (C.I. Acid Blue 113) has been biodegraded effectively by bacterial culture mediated with azoreductase enzyme to reduce the pollution load in the present investigation. The maximum rate of dye degradation was found to be 96 ± 4 and 92 ± 4 % for the initial concentrations of 100 and 200 mg/l, respectively. The enzyme activity was measured using NADH as a substrate. Fourier transform infrared spectroscopy (FT-IR) analysis was confirmed that the transformation of azo linkage could be transformed into N2 or NH3 or incorporated into complete biomass. Breaking down of dye molecules to various metabolites (such as aniline, naphthalene-1,4-diamine, 3-aminobenzenesulfonic acid, naphthalene-1-sulfonic acid, 8-aminonaphthalene-1-sulfonic acid, 5,8-diaminonaphthalene-1-sulfonic acid) was confirmed by gas chromatography and mass spectra (GC-MS) and mass (electrospray ionization (ESI)) spectra analysis. The treated wastewater could be reused for dyeing operation in the leather processing, and the properties of produced leather were evaluated by conventional methods that revealed to have improved dye penetration into the grain layer of experimental leather sample and resulted in high levelness of dyeing, which helps to obtain the desired smoothness and soft leather properties. PMID:25163883

  17. Synthesis and characterization of Mg-based amorphous alloys and their use for decolorization of Azo dyes

    NASA Astrophysics Data System (ADS)

    Iqbal, M.; Wang, W. H.

    2014-06-01

    Mg-based alloys are light weight and have wide range of applications in the automotive industry. These alloys are widely used because of their very attractive physical and mechanical properties and corrosion resistance. The properties and applications can be further improved by changing the nature of materials from crystalline to amorphous. In this study, melt spun ribbons (MSRs) of Mg70Zn25Ca5 Mg68Zn27Ca5 alloys were prepared by melt spinning technique by using 3-4N pure metals. Characterization of the samples was done by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and energy dispersive x-ray analyzer (EDAX). Microstructural investigations were conducted by using scanning electron microscopy (SEM), atomic force microscopy (AFM) as well as optical and stereo scan microscopy techniques. DSC results showed multistage crystallization. Activation energy was found to be 225 kJ/mol by Kissinger method indicating good thermal stability against crystallization. XRD, DSC, SEM and EDS (energy dispersive spectroscopy) results are agreed very well. In order to study decolorization, the MSRs of Mg70Zn25Ca5 Mg68Zn27Ca5 alloys were treated repeatedly with various azo dyes at room temperature. In order to compare the results, MSRs of amorphous Zr- and Ni-based metallic glasses were also treated. Reaction of MSRs with azo dyes results in their decolorization in a few hours. Decolorization of azo dyes takes place by introducing amorphous MSRs which results in breaking the -N=N- bonds that exist in dye contents. It is concluded that Mg-based alloys are useful for paint and dye industries and will be beneficial to control water pollution. Comparison of results showed that Mg-based alloys are more efficient than Zr- and Ni-based amorphous alloys for decolorization of azo dyes.

  18. Nanomechanical actuation of a silicon cantilever using an azo dye, self-assembled monolayer.

    PubMed

    Rastegar, A Joseph; Vosgueritchian, Michael; Doll, Joseph C; Mallon, Joseph R; Pruitt, Beth L

    2013-06-11

    The emerging fields of nanomotors and optomechanics are based on the harnessing of light to generate force. However, our ability to detect small surface stresses is limited by temperature drift, environmental noise, and low-frequency flicker electronic noise. To address these limitations, we functionalized microfabricated silicon cantilevers with an azo dye, silane-based self-assembled monolayer and modulated the surface stress by exciting the optical switch with a 405-nm laser. Atomic force microscopy, contact angle analysis, ellipsometry, and X-ray photoelectron spectroscopy verified successful assembly of molecules on the cantilever. Ultraviolet and visible spectra demonstrate optical switching of the synthesized molecule in solution. By turning the laser on and off at a specific rate (e.g., 1 Hz), the cantilever deflection can be measured via Fourier techniques, thus separating the signal of interest from the noise. This technique empowers the design of highly sensitive surface stress measurements. PMID:23663108

  19. Optical Poling of Phenyl-Silica Hybrid Thin Films Doped with Azo-Dye Chromophore

    NASA Astrophysics Data System (ADS)

    Kitaoka, Kenji; Matsuoka, Nobuaki; Si, Jinhai; Mitsuyu, Tsuneo; Hirao, Kazuyuki

    1999-09-01

    Azo-dye doped phenly group substituted silica films were prepared by a sol-gel method from a solution of triethoxyphenlysilane (TEPh), tetraethoxysilane (TEOS) and 4-[N-ethyl-N-(2-hydroxyethyl)]amino-4‧-nitro-azobenzene (DR1). The films were optically poled by the coherent superposition of 1064 nm and 532 nm beams from a Q-switched Nd:YAG laser. Second-order susceptibility χeff of a DR1 doped phenyl group substituted film induced by the optical poling was approximately four times as large as that of the phenyl-free film. The phenyl group in the silica matrix was found to be effective for increasing the second-order nonlinearity and increasing the thermal stability.

  20. Pulsed laser induced birefringence switching in a biopolymer matrix containing azo-dye molecules

    NASA Astrophysics Data System (ADS)

    Mysliwiec, Jaroslaw; Ziemienczuk, Marta; Miniewicz, Andrzej

    2011-07-01

    All optical switching has been studied using the Optical Kerr Effect (OKE) configuration in a biopolymer matrix containing an azo-dye: the Disperse Orange 3 (DO3). The biopolymer system consisted of a deoxyribonucleic acid blended with cationic surfactant molecule cetyltrimethyl-ammonium chloride is suitable for optical quality thin film fabrication. The excitation beams inducing birefringence were delivered from a continuous wave laser at 532 nm and another nanosecond pulsed Nd: YAG laser. The birefringence was instantaneously monitored under crossed polarizer system by a weak non-absorbed light from a cw He-Ne laser working at 632.8 nm. Fast all optical switching process (in the range of microseconds) and excellent reversibility have been observed.

  1. Optical phase conjugation in azo-dye doped chiral liquid crystal

    SciTech Connect

    Karpinski, Pawel; Miniewicz, Andrzej

    2012-10-15

    We report on optical phase conjugation phenomenon observed in chiral nematic liquid crystal showing band gap type Bragg reflection. The phase conjugate to the signal beam is observable only in the small temperature interval when the Bragg condition is fulfilled and only for circularly polarized light. The optical phase conjugation signals were observed at low cw laser light intensities (<100 mW/cm{sup 2}, {lambda} = 532 nm). Estimated value of third order optical susceptibility {chi}{sup (3)} = 2.8 Multiplication-Sign 10{sup -17} m{sup 2}/V{sup 2} is attributed to enhancement due to photoisomerisation of azo-dye (disperse red 1) inducing molecular reorientation process of liquid crystal molecules.

  2. Holographic gratings recorded in poly(lactic acid)/azo-dye films

    NASA Astrophysics Data System (ADS)

    Cambiasso, Javier; Goyanes, Silvia; Ledesma, Silvia

    2015-09-01

    Diffraction gratings were recorded in biodegradable polymer films of poly(lactic acid) doped with the photoisomerisable azo-dye (Disperse Orange 3). It is shown that the diffraction efficiency of the recorded grating can be improved by 220% via an all-optical treatment. This all-optical treatment consists of a pre-irradiation of the sample with the writing laser beam at high power during a short period of time, preventing damage of the material, followed by a much longer inscription at relatively low power. Furthermore, it is shown that the addition of a small amount of 0.05 wt% of multi-walled carbon nanotubes to the photoresponsive polymer increases the maximum diffraction efficiency as well as the remanent efficiency by 20%. Finally, this last photoresponsive nano-composite is also sensitive to the pre-irradiation treatment.

  3. Electrochemical degradation of reactive dye in the presence of water jet cavitation.

    PubMed

    Wang, Xiaoning; Jia, Jinping; Wang, Yalin

    2010-03-01

    Degradation of a reactive dye, Brilliant Red X-3B, induced by electrolysis coupled with water jet cavitation was studied. The experiment was performed in 4.5L of aqueous solution containing X-3B concentrations ranging from 40 to 120mg/L by applying Ti-IrO(2) as anode and graphite as cathode. The water jet cavitation process decreased the diffusion layer thickness and consequently increased the current density. Compared to water jet cavitation and electrolysis alone, the combination of the two methods enhanced X-3B removal and showed a synergistic effect. The azo bond of the dye molecule was broken down and the naphthalene ring was transformed to multi-substituted benzene during the combined process. The dye degradation rate increased with increasing concentration. Acidic conditions (e.g., pH 1) favored the decolorization of the reactive dye. The use of TiO(2) coated with IrO(2) as anode and graphite as cathode showed the best performance for the dye removal efficiency, compared to other electrode pairs. Addition of SO(4)(2-), NO(3)(-), and especially Cl(-) ions into solution significantly enhanced the degradation. However, CO(3)(2-) inhibited the dye decolorization. PMID:19945899

  4. The accelerating effect and mechanism of a newly functional bio-carrier modified by redox mediators for the azo dyes decolorization.

    PubMed

    Guo, Jianbo; Kang, Li; Lian, Jing; Yang, Jingliang; Yan, Bin; Li, Zaixing; Liu, Chun; Yue, Lin

    2010-11-01

    In this study, a functional bio-carrier modified by redox meditors was developed as a redox mediator for application in azo dye decolorization processes. Its accelerating effect and mechanism for azo dyes decolorization were also examined. The decolorization rates of 10 azo dyes were enhanced about 1.5-3 fold by the functional bio-carrier modified with disperse turquoise blue S-GL, and the ORP value during the acid red GR decolorization process was changed to a more negative value of 20-25 mV. Non-dissolved redox mediator on the functional bio-carrier played a similar role as NADH during the azo dyes decolorization process. At the same time, the functional bio-carrier exhibited good reusability and the combinational technology of the redox mediator and bio-carrier was a great improvement of the redox mediator application and represents a new bio-treatment concept. PMID:20490625

  5. Aerobic degradation of a mixture of azo dyes in a packed bed reactor having bacteria-coated laterite pebbles.

    PubMed

    Senan, Resmi C; Shaffiqu, T S; Roy, J Jegan; Abraham, T Emilia

    2003-01-01

    A microbial consortium capable of aerobic degradation of a mixture of azo dyes consisting of two isolated strains (RRL,TVM) and one known strain of Pseudomonas putida (MTCC 1194) was immobilized on laterite stones. The amount of bacterial biomass attached to the laterite stones was 8.64 g per 100 g of the stone on a dry weight basis. The packed bed reactor was filled with these stones and had a total capacity of 850 mL and a void volume of 210 mL. The feed consisted of an equal mixture of seven azo dyes both in water as well as in a simulated textile effluent, at a pH of 9.0 and a salinity of 900 mg/L. The dye concentrations of influent were 25, 50, and 100 microg/mL. The residence time was varied between 0.78 and 6.23 h. It was found that at the lowest residence time 23.55, 45.73, and 79.95 microg of dye was degraded per hour at an initial dye concentration of 25, 50, and 100 microg, respectively. The pH was reduced from 9.0 to 7.0. Simulated textile effluent containing 50 microg/mL dye was degraded by 61.7%. Analysis of degradation products by TLC and HPLC showed that the dye mixture was degraded to nontoxic smaller molecules. The bacteria-coated pebbles were stable, there was no washout even after 2 months, and the reactor was found to be suitable for the aerobic degradation of azo dyes. PMID:12675610

  6. All optical controlled photonic integrated circuits using azo dye functionized sol-gel material

    NASA Astrophysics Data System (ADS)

    Ke, Xianjun

    The main focus of this dissertation is development and characterization of all-optical controllable azo dye functionized sol gel material, demonstrating a PIC fabrication technique on glass substrate using such material, and exploration and feasibility demonstration of three PIC functional devices namely optical variable attenuator, optical switches, and optical tunable filters using the material. The realization of all the devices in this dissertation are based on one material: dye functionalized sol-gel material. A photochromic sol-gel material functionalized with azo dye was synthesized and characterized. It possesses a photochromic characteristic under the control of green laser beam illumination. The material characteristics suggest the possibility of a new promising material platform candidate for the fabrication of alloptical controlled photonic integrated circuits. As the first potential application of the dye functionalized sol-gel material, an alloptical variable attenuator was designed and demonstrated. The optical variable attenuation is achieved in Mach-Zehnder interferometric configuration through all-optical modulation of sol-gel waveguide phase shifters. A 2 x 2 optical switch based on multimode interference (MMI) waveguide structure is proposed in the dissertation. The schematic configuration of the optical switch consists of a cascade of two identical MMIs with two all-optical controlled phase shifters realized by using the photochromic sol-gel material. The cross or bar switch state of the optical switch is determined by the phase difference between the two sol-gel waveguide phase shifters. An all-optical tunable filter is designed and its feasibility demonstrated by using the sol-gel photochromic material. Except for the phase change demonstrated on sol-gel waveguide phase shifters, dynamic gratings were observed on sol-gel film when exposed to two interference beams. This reveals the possibility of realizing Bragg grating-based tunable filters

  7. Evaluating the effectiveness of marine actinobacterial extract and its mediated titanium dioxide nanoparticles in the degradation of azo dyes.

    PubMed

    Priyaragini, S; Veena, S; Swetha, D; Karthik, L; Kumar, G; Bhaskara Rao, K V

    2014-04-01

    Aim of the present study was to synthesize titanium dioxide nanoparticles (TiO2 NPs) from marine actinobacteria and to develop an eco-friendly azo-dye degradation method. A total of five actinobacterial isolates were isolated from Chennai marine sediments, Tamilnadu, India and analyzed for the synthesis of TiO2 NPs using titanium hydroxide. Among these, the isolate PSV 3 showed positive results for the synthesis of TiO2 NPs, which was confirmed by UV analysis. Further characterization of the synthesized TiO2 NPs was done using XRD, AFM and FT-IR analysis. Actinobacterial crude extract and synthesized TiO2 NPs was found efficient in degrading azo dye such as Acid Red 79 (AR-79) and Acid Red 80 (AR-80). Degradation percentage was found to be 81% for AR-79, 83% for AR-80 using actinobacterial crude extract and 84% for AR-79, 85% for AR-80 using TiO2 NPs. Immobilized actinobacterial cells showed 88% for AR-79 and 81% for AR-80, dye degrading capacity. Degraded components were characterized by FT-IR and GC-MS analysis. The phytotoxicity test with 500 μg/mL of untreated dye showed remarkable phenotypic as well as cellular damage to Tagetes erecta plant. Comparatively no such damage was observed on plants by degraded dye components. In biotoxicity assay, treated dyes showed less toxic effect as compared to the untreated dyes. PMID:25079407

  8. Selective recognition and discrimination of water-soluble azo dyes by a seven-channel molecularly imprinted polymer sensor array.

    PubMed

    Long, Zerong; Lu, Yi; Zhang, Mingliang; Qiu, Hongdeng

    2014-10-01

    A seven-channel molecularly imprinted polymer sensor array was prepared and characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, UV-Vis spectroscopy, and nitrogen physisorption studies. The results revealed that the imprinted polymers have distinct-binding affinities from those of structurally similar azo dyes. Analysis of the UV-Vis spectral response patterns of the seven dye analytes against the imprinted polymer array suggested that the different selectivity patterns of the array were closely connected to the imprinting process. To evaluate the effectiveness of the array format, the binding of a series of analytes was individually measured for each of the seven polymers, made with different templates (including one control polymer synthesized without the use of a template). The response patterns of the array to the selected azo dyes were processed by canonical discriminant analysis. The results showed that the molecularly imprinted array was able to discriminate each analyte with 100% accuracy. Moreover, the azo dyes in two real samples, spiked chrysoidin in smoked bean curd extract and Fanta lime soda (containing tartrazine), were successfully classified by the array. PMID:25099151

  9. Red Emitting Coumarin-Azo Dyes : Synthesis, Characterization, Linear and Non-linear Optical Properties-Experimental and Computational Approach.

    PubMed

    Tathe, Abhinav B; Sekar, Nagaiyan

    2016-07-01

    The coumarin molecules with 7-(N,N-diethylamino) substitution and aryl azo (Ar-N=N-) at 3-position were synthesized, by reacting diazonium salt of substituted amines and 7-(N, N-diethylamino)-4-hydroxy coumarin under basic conditions. They were found to be fluorescent despite the presence of azo group. The azo group rotation was blocked by complexing with -BF2, so as to get a red shift in absorption. The azo molecules show charge transfer, whereas BF2-complexes do not. The dipole moment ratios between the ground and excited states calculated suggest highly polar excited state and an intra-molecular charge transfer at the excited state in the case of azo dyes. The NLO properties were calculated by solvatochromic method and computationally. Second order hyperpolarizability was found to be 46 to 1083 times more than urea. DFT and TDTDF calculations were performed to understand the electronic properties of the molecules at the ground as well as excited states. PMID:27155862

  10. Sonoenzymatic decolourization of an azo dye employing immobilized horse radish peroxidase (HRP): a mechanistic study.

    PubMed

    Malani, Ritesh S; Khanna, Swati; Moholkar, Vijayanand S

    2013-07-15

    For degradation of biorefractory pollutants, enzymatic treatments and sonochemical treatments have shown high potential. A combined technique of sono-enzymatic treatment is of special interest as it has shown enhancement effect than the individual techniques. This work has attempted to give a mechanistic insight into the interaction of sonochemical and enzymatic treatments using immobilized horseradish peroxidase (HRP) enzyme on the decolourization of acid red dye (an azo dye). In order to segregate the effect of ultrasound and cavitation, experiments were conducted at elevated static pressure. The kinetic parameters of HRP, viz. Vmax and Km were marginally affected by immobilization. There was a minor change in pH optima and temperature optima for immobilized HRP (6.5, 25°C) from free HRP (7.0, 20-25°C). Though the specific activity of free enzyme (0.272U/mg) was found to be higher than the immobilized enzyme (0.104U/mg), immobilized enzyme exhibited higher stability (up to 3 cycles) and degradation potential than free enzyme in all experiments. The results revealed that the coupling of sonication and enzymatic treatment at high pressure in presence of polyethylene glycol (PEG) yielded the highest decolourization of acid red (61.2%). However, the total decolourization achieved with combined technique was lesser than the sum of individual techniques, indicating negative synergy between the sonochemical and enzymatic techniques. PMID:23708258

  11. Fe3O4@Nico-Ag magnetically recyclable nanocatalyst for azo dyes reduction

    NASA Astrophysics Data System (ADS)

    Kurtan, U.; Amir, Md.; Baykal, A.

    2016-02-01

    In this study, we report the successful synthesis of Fe3O4@Nico-Ag nanocomposite as magnetically recyclable nanocatalyst (MRCs) via reflux process at 80 °C for 5 h followed by reduction of Ag+. FeCl3·6H2O, FeCl2·4H2O, AgNO3 as starting reactants and nicotinic acid as linker. The structure, morphology, thermal behaviour and magnetic properties of the product were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectrometry (EDX), thermal gravimetry (TG) and vibrating sample magnetometry (VSM), respectively. The catalytic activity of product for various azo dyes such as methylene blue (MB), methyl orange (MO), Rhodamine B (RhB) and eosin Y (EY) and their double mixtures were studied. It was found that Fe3O4@Nico-Ag MRCs is an efficient catalyst and can also rapidly separated from the reaction medium using magnet without considerable loss in its catalytic activity and used several times. Fe3O4@Nico-Ag MRCs has potential for the treatment of industrial dye pollutants.

  12. Accelerated azo dye removal by biocathode formation in single-chamber biocatalyzed electrolysis systems.

    PubMed

    Wang, You-Zhao; Wang, Ai-Jie; Liu, Wen-Zong; Kong, De-Yong; Tan, Wen-Bo; Liu, Chong

    2013-10-01

    Biocatalyzed electrolysis systems (BES) have been the topic of a great deal of research. However, the biocathodes formed in single-chamber BES without extra inocula have not previously been researched. Along with the formation of biocathodes, the polarization current increased to 1.76 mA from 0.35 mA of abio-cathodes at -1.2 V (vs. SCE). Electrochemical impedance spectroscopy (EIS) results also indicated that the charge transfer resistance (Rct) was decreased to 148.9 Ω, less than 1978 Ω of the abio-cathodes cleared. The performance of the biocathodes was tested for azo dye decolorization, and the dye removal efficiency was 13.3±3.2% higher than abio-cathodes with a 0.5 V direct current (DC) power supply. These aspects demonstrate that biocathode accelerates the rate of electrode reaction in BES and comparing with noble metal catalysts, biocathodes have low toxicity or non-toxic and reproducible properties, which can be widely applied in bioelectrochemical field in the future. PMID:23948224

  13. Wet oxidation of an azo dye: Lumped kinetics in batch and mixed flow reactors

    SciTech Connect

    Donlagic, J.; Levec, J.

    1999-12-01

    Oxidation of a dilute aqueous solution of a model azo dye pollutant (Orange II) was studied in batch and continuous well-mixed (CSTR) reactors. Both reactors operate at 200--250 C, and total pressures up to 50 bar and at oxygen partial pressure from 10 to 30 bar. The model pollutant concentrations were in a range between 100 and 1,000 mg/L, which may be found in industrial wastewaters. The dye oxidation undergoes parallel-consecutive reaction pathways, in which it first decomposes thermally and oxidatively to aromatic intermediates and via organic acids to the final product carbon dioxide. To develop a kinetic equation capable of predicting organic carbon reduction, all organic species present in solution were lumped by total organic carbon (TOC). The lumped oxidation rate in batch reactor exhibited second-order behavior, whereas in the CSTR is was found linearly proportional to its TOC concentration. The lump behavior in batch reactor was dominated by the refractory low molecular mass aliphatic acids formed during the oxidation.

  14. The sonochemical degradation of azobenzene and related azo dyes: Rate enhancements via Fenton's reactions

    SciTech Connect

    Joseph, J.M.; Destaillats, H.; Hung, H.M.; Hoffmann, M.R.

    2000-01-20

    The sonochemical degradation of aqueous solutions of azobenzene and related azo dyes (methyl orange, o-methyl red, and p-methyl red) was performed at 500 kHz and 50 W, under air, O{sub 2}, or Ar saturation at 288 K. Reaction products and intermediates were identified by HPLC-ES-MS. Total organic carbon (TOC) was also determined as a function of reaction time. The authors propose a reaction mechanism based on the observed species and the extent and rate of TOC depletion. The effects of the dye structures and of the background gas on the sonochemical bleaching rates were also investigated. The reaction rates for o-methyl red were approximately 30--40% faster than those for the other compounds. Saturating with Ar instead of air or O{sub 2} increased the pseudo first-order rate constants for the degradation by 10%. The acceleration of the sonochemical bleaching and the mineralization process upon addition of Fe(II) was also investigated in Ar-saturated methyl orange solutions. A 3-fold increase in the reaction rate was observed at optimal Fe(II) concentrations. This kinetic effect is quantitatively accounted for by a simple kinetic model based on the reaction of Fe(II) with sonochemically produced H{sub 2}O{sub 2} (Fenton's reaction). This latter effect illustrates a simple way of achieving a substantial improvement in the efficiency of sonochemical degradation reactions.

  15. Effect of unmodulated laser light on the nanostructure of a thin solid AD-1 azo dye film

    SciTech Connect

    Dubrovkin, A M; Ezhov, A A; Kozenkov, V M; Magnitskiy, Sergey A; Nagorskiy, Nikolay M; Panov, Vladimir I

    2010-06-23

    Exposure to light uniform in intensity and polarisation causes marked changes in the surface topography of a thin (320 nm) nanostructured AD-1 low molecular weight azo dye film. Linearly polarised incoherent light with a wavelength of 470 nm and intensity of 1 mW cm{sup -2} produces numerous teardrop-shaped hillocks of the order of 200 nm in radius over most of the film surface. (letters)

  16. A highly efficient single chambered up-flow membrane-less microbial fuel cell for treatment of azo dye Acid Orange 7-containing wastewater.

    PubMed

    Thung, Wei-Eng; Ong, Soon-An; Ho, Li-Ngee; Wong, Yee-Shian; Ridwan, Fahmi; Oon, Yoong-Ling; Oon, Yoong-Sin; Lehl, Harvinder Kaur

    2015-12-01

    Single chambered up-flow membrane-less microbial fuel cell (UFML MFC) was developed to study the feasibility of the bioreactor for decolorization of Acid Orange 7 (AO7) and electricity generation simultaneously. The performance of UFML MFC was evaluated in terms of voltage output, chemical oxygen demand (COD) and color removal efficiency by varying the concentration of AO7 in synthetic wastewater. The results shown the voltage generation and COD removal efficiency decreased as the initial AO7 concentration increased; this indicates there is electron competition between anode and azo dye. Furthermore, there was a phenomenon of further decolorization at cathode region which indicates the oxygen and azo dye are both compete as electron acceptor. Based on the UV-visible spectra analysis, the breakdown of the azo bond and naphthalene compound in AO7 were confirmed. These findings show the capability of integrated UFML MFC in azo dye wastewater treatment and simultaneous electricity generation. PMID:26342340

  17. Molecular exciton theory calculations based on experimental results for Solophenyl red 3BL azo dye-surfactants interactions

    NASA Astrophysics Data System (ADS)

    Hassanzadeh, Ali; Zeini-Isfahani, Asghar; Habibi, Mohammad Hossein

    2006-05-01

    The influence of anionic surfactant: sodium dodecyl sulfate (SDS) and cationic surfactants: cetyltrimethylammonium bormides (C 16TAB) and cetylpyridinium chloride (CPC) on the electronic spectrum of Solophenyl red 3BL azo dye (C.I. Direct 80) in aqueous solution was studied by means of UV-vis spectroscopy. Since, Solophenyl red 3BL azo dye was an anionic soluble dye, therefore, did not observed any interaction between SDS and 3BL dye. On the other hand, in the case of C 16TAB, aggregation was reflected by a hyosochromic shift of the main absorption band and dye H-aggregation was responsible for the short wavelength absorption band. Also, UV-vis spectra showed that micelle formation occurs for C 16TAB surfactant in 3BL dye aqueous solution in lower concentration in comparison with C 16TAB in aqueous solution lonely. Micelle formation was indicated by a red shift of the whole spectra with respect to monomer location. The importance of hydrophobic interactions was revealed by the dependence of aggregation on the cationic surfactant structure. Further results showed that dye H-aggregation was occurred under the cationic surfactant CPC as well, but in this case micelle formation could not occur. Addition of CPC surfactant into the J-aggregate dye solution in highly acidic aqueous solution was also caused completely disaggregating of dimer molecules, which may be related to occuring an acid-base reaction between them. Applicability of the molecular exciton (Kasha) theory in order to interpret of aggregation results and to estimate dimer structure of 3BL dye under C 16TAB and CPC surfactants addition was very poor and the calculated data based on this model showed that this simple point-dipole model could not describe our experimental results.

  18. Carcinogenicity of azo dyes: Acid Black 52 and Yellow 3 in hamsters and rats. Volume 2. Technical report (Final)

    SciTech Connect

    Plankenhorn, L.J.

    1983-09-30

    This document is an appendix to a study concerning the carcinogenicity of the azo dyes acid-black-52 and yellow-3 in male and female hamsters and rats and contains individual histopathology studies of both dyes. Histopathological features were reported in tabular form for the skin, mammary gland, muscle, salivary gland, mandibular lymph node, sciatic nerve, thymus, larynx, thyroid, parathyroid, trachea, bronchus, esophagus, adrenal, stomach, duodenum, jejunem, ileum, cecum, colon, rectum, mesenteric lymph node, lung, liver, gallbladder, spleen, pancreas, kidney, heart, urinary bladder, seminal vesicle, prostate, testis, cerebrum, cerebellum, pituitary, sternabrae, femur, bone marrow, and nasal cavity.

  19. Fish erythrocytes as biomarkers for the toxicity of sublethal doses of an azo dye, Basic Violet-1 (CI: 42535).

    PubMed

    Kaur, Kirandeep; Kaur, Arvinder

    2015-02-01

    The aim of the present study was to investigate poikilocytosis in Labeo rohita (an important food fish) as an early indicator of stress due to an azo dye, Basic Violet-1 (CI: 42535). This dye was observed to be very toxic to test fish (96 h LC50 as0.45 mg/L dye). Fish were given short-term (96 h) and subchronic (150 days) exposures to the dye, and poikilocytosis was recorded under light and scanning electron microscopy (SEM). Light microscopy helped in identification of micronuclei along with irregularities, notches, blebs, lobes, crenation, clumps, chains, spherocytes, vacuolation, and necrosis in erythrocytes. However, SEM indicated shrinkage, oozing of cytoplasm, and several new abnormal shapes including marginal foldings, discocytes, keratocytes, dacrocytes, degmacytes, acanthocytes, echinocytes, protuberances, stomatocytes, drepanocytes, holes in the membrane, stippling/spicules, crescent-shaped cells, triangular cells, and pentagonal cells. Earlier studies speculated changes in the membrane to be responsible for clumping and chaining of erythrocytes, whereas the present SEM study clearly indicates that oozing out of cytoplasm is also responsible for the formation of chains and clumps. This study also shows that erythrocytes exhibit pathological symptoms before the appearance of other external symptoms such as abnormal behavior or mortality of fish. There was a dose- and duration-dependent increase; therefore, poikilocytosis, especially echinocytes, spherocytes, and clumps, can act as a biomarker for the stress caused by azo dyes. PMID:25434363

  20. Colour removal from aqueous solutions of metal-complex azo dyes using bacterial cells of Shewanella strain J18 143.

    PubMed

    Li, Tie; Guthrie, James Thomas

    2010-06-01

    The decoloration treatment of textile dye effluents through biodegradation, using bacterial cells, has been studied as a possible means of solving some of the problems that are associated with the pollution of water sources by colorants. In this paper, the use of whole bacterial cells of Shewanella J18 143 for the reduction of aqueous solutions of selected mono-azo, metal-complex dyes, namely Irgalan Grey GLN, Irgalan Black RBLN and Irgalan Blue 3GL, was investigated. The effects of temperature, pH and dye concentration on colour removal were also investigated and shown to be important. The operative conditions for the removal of colour were 30 degrees C, at pH 6.8, with a final dye concentration of 0.12 g/L in the colour reduction system. This study provides an extension to the application of Shewanella strain J18 143 bacterial cells in the decoloration of textile wastewaters. PMID:20167478

  1. Differential expression of peroxidase and ABC transporter as the key regulatory components for degradation of azo dyes by Penicillium oxalicum SAR-3.

    PubMed

    Saroj, Samta; Kumar, Karunesh; Prasad, Manoj; Singh, R P

    2014-12-01

    Fungal species are potential dye decomposers since these secrete spectra of extracellular enzymes involved in catabolism. However, cellular mechanisms underlying azo dye catalysis and detoxification are incompletely understood and obscure. A potential strain designated as Penicillium oxalicum SAR-3 demonstrated broad-spectrum catabolic ability of different azo dyes. A forward suppression subtractive hybridization (SSH) cDNA library of P. oxalicum SAR-3 constructed in presence and absence of azo dye Acid Red 183 resulted in identification of 183 unique expressed sequence tags (ESTs) which were functionally classified into 12 functional categories. A number of novel genes that affect specifically organic azo dye degradation were discovered. Although the ABC transporters and peroxidases emerged as prominent hot spot for azo dye detoxification, we also identified a number of proteins that are more proximally related to stress-responsive gene expression. Majority of the ESTs (29.5%) were grouped as hypothetical/unknown indicating the presence of putatively novel genes. Analysis of few ESTs through quantitative real-time reverse transcription polymerase chain reaction revealed their possible role in AR183 degradation. The ESTs identified in the SSH library provide a novel insight on the transcripts that are expressed in P. oxalicum strain SAR-3 in response to AR183. PMID:25270890

  2. Batchwise dyeing of bamboo cellulose fabric with reactive dye using ultrasonic energy.

    PubMed

    Larik, Safdar Ali; Khatri, Awais; Ali, Shamshad; Kim, Seong Hun

    2015-05-01

    Bamboo is a regenerated cellulose fiber usually dyed with reactive dyes. This paper presents results of the batchwise dyeing of bamboo fabric with reactive dyes by ultrasonic (US) and conventional (CN) dyeing methods. The study was focused at comparing the two methods for dyeing results, chemicals, temperature and time, and effluent quality. Two widely used dyes, CI Reactive Black 5 (bis-sulphatoethylsulphone) and CI Reactive Red 147 (difluorochloropyrimidine) were used in the study. The US dyeing method produced around 5-6% higher color yield (K/S) in comparison to the CN dyeing method. A significant savings in terms of fixation temperature (10°C) and time (15 min), and amounts of salt (10 g/L) and alkali (0.5-1% on mass of fiber) was realized. Moreover, the dyeing effluent showed considerable reductions in the total dissolved solids content (minimum around 29%) and in the chemical oxygen demand (minimum around 13%) for the US dyebath in comparison to the CN dyebath. The analysis of colorfastness tests demonstrated similar results by US and CN dyeing methods. A microscopic examination on the field emission scanning electron microscope revealed that the US energy did not alter the surface morphology of the bamboo fibers. It was concluded that the US dyeing of bamboo fabric produces better dyeing results and is a more economical and environmentally sustainable method as compared to CN dyeing method. PMID:25575805

  3. Dyeing of Jute with Reactive Dyes: Optimisation of the Process Variables and Assessment of Colourfastness Characteristics

    NASA Astrophysics Data System (ADS)

    Samanta, A. K.; Chakraborty, Sharmistha; Guha Roy, T. K.

    2012-08-01

    This paper deals with the studies on the effect of dye concentration, electrolyte (common salt) concentration, dyeing time, dyeing temperature, soda ash concentration, pH of the dye solution and material to liquor ratio (MLR) on colour strength and other colour parameters after being dyed of jute fabrics with reactive dyes, namely, Turquoise blue, Lemon Yellow, Red CN colours. The dye absorption increases with increase in electrolyte (common salt) concentration, dyeing time, dyeing temperature, soda ash concentration, pH and decreases with increase of MLR. Colour fastness to wash, light and rubbing for the dyed samples has been studied and reported. It is observed that reactive dye gives overall good colour fastness to both washing and rubbing. But the light fastness has been found to be moderate only, due to the UV-light initiated fading of jute fibre itself change of the colour substrate, ie, undyed material. This colour fastness has been significantly resolved by post treatment with 1 % benzotriazole.

  4. Genotoxic and carcinogenic products arising from reductive transformations of the azo dye, Disperse Yellow 7.

    PubMed

    Balakrishnan, Vimal K; Shirin, Salma; Aman, Ahmed M; de Solla, Shane R; Mathieu-Denoncourt, Justine; Langlois, Valerie S

    2016-03-01

    Selected aromatic azo and benzidine based dyes are priority compounds under the Government of Canada's Chemical Management Plan (CMP) for environmental risk assessments. Organic compounds undergo chemical and biological transformations when they interact with environmental matrices and biotic species; identifying the transformation products is thus a critical component of the risk assessment process. Here, we used zero valent iron (ZVI) to initiate the reduction of the diazo compound dye Disperse Yellow 7 (DY 7). Using state-of-the-art accurate mass Liquid Chromatography-Quadrupole Time of Flight-Mass Spectroscopy (LC-QToF-MS), four transformation products were conclusively identified, while a fifth product was tentatively ascertained. The conclusively established transformation products included p-phenylenediamine (p-PDA, a known genotoxin), 4-aminoazobenzene (4-AAB, a category 2 carcinogen) and 4-aminobiphenyl (4-ABP, a category 1 human carcinogen). 4-ABP is thought to form via a benzidine rearrangement; this is the first report of DY 7 undergoing a benzidine rearrangement. Given the importance of reduction processes in the metabolism of organic contaminants by aquatic species, we used LC-MS/MS to analyze sediment samples that had been generated previously upon exposure of Western clawed frogs (Silurana tropicalis) to DY 7 (at exposure levels where cellular stress was observed in S. tropicalis). We found p-PDA, 4-AAB, and 4-ABP were present in all exposures, but not in any of the sediment controls, demonstrating that upon release of DY 7 to the aquatic environment, sediment dwelling organisms will metabolize DY 7 to generate known (and suspected) human carcinogens, including through a previously unreported in vivo benzidine rearrangement to produce 4-ABP. PMID:26735719

  5. Effect of viscosity, basicity and organic content of composite flocculant on the decolorization performance and mechanism for reactive dyeing wastewater.

    PubMed

    Wang, Yuanfang; Gao, Baoyu; Yue, Qinyan; Wang, Yan

    2011-01-01

    A coagulation/flocculation process using the composite flocculant polyaluminum chloride-epichlorohydrin dimethylamine (PAC-EPI-DMA) was employed for the treatment of an anionic azo dye (Reactive Brilliant Red K-2BP dye). The effect of viscosity (eta), basicity (B = [OH]/[Al]) and organic content (W(P)) on the flocculation performance as well as the mechanism of PAC-EPI-DMA flocculant were investigated. The eta was the key factor affecting the dye removal efficiency of PAC-EPI-DMA. PAC-EPI-DMA with an intermediate eta (2400 mPa x sec) gave higher decolorization efficiency by adsorption bridging and charge neutralization due to the co-effect of PAC and EPI-DMA polymers. The W(P) of the composite flocculant was a minor important factor for the flocculation. The adsorption bridging of PAC-EPI-DMA with eta of 300 or 4300 mPa x sec played an important role with the increase of W(P), whereas the charge neutralization of them was weaker with the increase of W(P). There was interaction between W(P) and B on the removal of reactive dye. The composite flocculant with intermediate viscosity and organic content was effective for the treatment of reactive dyeing wastewater, which could achieve high reactive dye removal efficiency with low organic dosage. PMID:22432257

  6. Ruthenium Doped ZnO Semiconductor: Synthesis, Characterization and Photodegradation of Azo Dye

    NASA Astrophysics Data System (ADS)

    Aranganayagam, K. R.; Senthilkumaar, S.; Ganapathi Subramaniam, N.; Kang, T. Wang

    2013-04-01

    Ruthenium doped zinc oxide was synthesized by a simple sol-gel method via ultrasonication. The samples were characterized by X-ray diffraction, high resolution scanning electron microscopy (HR-SEM), high resolution transmission electron microscope (HR-TEM), energy dispersive spectroscopy (EDS) and UV-visible spectroscopy techniques and tested for the feasibility as a heterogeneous photocatalyst. The photocatalytic activity of Ru doped ZnO was tested using an azo dye, congo red (CR) in an aqueous solution, as a model compound. For comparison, the photocatalytic activity of pure ZnO was also performed. The parameters studied include the effect of initial CR concentration, photocatalyst weight and charge transfer phenomenon. The observed reaction mechanism was rationalized based on the elementary chemical reaction occurring in the irradiated heterogeneous reaction mixture. Total mineralization of CR was observed for both pure and Ru doped ZnO system. However, the photocatalytic activity of Ru doped ZnO was found to be higher than that of a pure ZnO.

  7. Decolorization of azo dye Orange G by aluminum powder enhanced by ultrasonic irradiation.

    PubMed

    Cai, Mei Qiang; Wei, Xiao Qin; Song, Zhi Jun; Jin, Mi Cong

    2015-01-01

    In this work, the decolorization of azo dye Orange G (OG) in aqueous solution by aluminum powder enhanced by ultrasonic irradiation (AlP-UI) was investigated. The effects of various operating operational parameters such as the initial pH, initial OG concentration, AlP dosage, ultrasound power and added hydrogen peroxide (H2O2) concentration were studied. The results showed that the decolorization rate was enhanced when the aqueous OG was irradiated simultaneously by ultrasound in the AlP-acid systems. The decolorization rate decreased with the increase of both initial pH values of 2.0-4.0 and OG initial concentrations of 10-80mg/L, increased with the ultrasound power enhancing from 500 to 900W. An optimum value was reached at 2.0g/L of the AlP dosage in the range of 0.5-2.5g/L. The decolorization rate enhanced significantly by the addition of hydrogen peroxide in the range of 10-100mM to AlP-UI system reached an optimum value of 0.1491min(-1). The decolorization of OG appears to involve primarily oxidative steps, the cleavage of NN bond, which were verificated by the intermediate products of OG under the optimal tested degradation system, aniline and 1-amino-2-naphthol-6,8-disulfonate detected by the LC-MS. PMID:25132495

  8. Magnetically Recyclable Fe3O4@His@Cu Nanocatalyst for Degradation of Azo Dyes.

    PubMed

    Kurtan, U; Amir, Md; Baykal, A; Sözeri, H; Toprak, M S

    2016-03-01

    Fe3O4@His@Cu magnetic recyclable nanocatalyst (MRCs) was synthesized by reflux method using L-histidine as linker. The composition, structure and magnetic property of the product were characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Fourier Transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry (VSM). Powder XRD, FT-IR and EDAX results confirmed that the as-synthesized products has Fe3O4 with spinel structure and Cu nanoparticles with moderate crystallinity without any other impurities. The surface of the Fe3O4@His nanocomposite was covered by tiny Cu nanoparticles. We examine the catalytic activity of Fe3O4@His@Cu MRCs for the degradation of two azo dyes, methyl orange (MO) and methylene blue (MB) as well as their mixture. The reusability of the nanocatalyst was good and sustained even after 3 cycles. Therefore this innovated Fe3O4@His@Cu MRCs has a potential to be used for purification of waste water. PMID:27455668

  9. Can nitro groups really anchor onto TiO2? Case study of dye-to-TiO2 adsorption using azo dyes with NO2 substituents.

    PubMed

    Zhang, Lei; Cole, Jacqueline M

    2016-07-28

    The nitro group has recently been suggested as a new type of anchor for dye-sensitized solar cells (DSSCs) and has shown promising optoelectronic properties. Considering the excellent electron withdrawing ability of the nitro group and wider materials selection brought about by this substituent, it is helpful to evaluate the interfacial structures and photophysics of more organic dyes where NO2 poses as the dye-to-TiO2 anchor. A computational study on a family of azo dyes bearing a nitro group is presented, where the effect of certain side groups on their optical properties is examined. Both isolated dye molecules and dye/TiO2 nanocomposites are studied via density functional theory and time-dependent density functional theory, with complementary experimental UV/vis absorption spectroscopy and photovoltaic device testing. Results demonstrate that these nitro-containing dyes prefer a monodentate anchoring mode on a TiO2 cluster. These nitro dyes reveal weak, but non-negligible, adsorption onto TiO2; yet, very low photovoltaic performance once incorporated into a DSSC device. This poor delivery of nitro groups as DSSC anchors is ostensibly inconsistent with previous findings; but is rationalized via the "auxiliary anchor" concept. PMID:27356762

  10. A review of the genotoxicity of food, drug and cosmetic colours and other azo, triphenylmethane and xanthene dyes.

    PubMed

    Combes, R D; Haveland-Smith, R B

    1982-03-01

    The genetic toxicology of the major dyestuffs used in foods, drugs and cosmetics has been reviewed. Published data for azo, triphenylmethane and xanthene dyes from short-term assays for muta-carcinogenicity have been summarized and discussed according to usage, current and previous worldwide legislative status. Certain other synthetic food dyes, commercial mixtures, natural and polymeric colourants as well as a section on aminoazobenzene and its derivatives have been included. Genotoxicity has been discussed with reference to structural chemistry, levels of exposure, absorption and metabolism and to epidemiological information. The extent of agreement between data from different tests and correlations with animal cancer assays have been considered. Synthetic dyes from the 3 major structural classes exhibit genotoxicity, whilst only 2 natural colours have proved active. Activity may be due to the presence of certain functional groups, notably nitro- and amino-substituents which are metabolized to ultimate electrophiles that may be stabilized by electronic interaction with aryl rings. Metabolic processes such as azo-reduction may be activating or detoxifying. the low but significant correlation between animal carcinogenicity and short-term test data may be increased with further screening, especially involving chromosome assays. It is suggested that a human cancer hazard may exist where significant quantities of finished benzidine dye samples are handled. Such risks from exposures to other colours and the possibility of human germ-line mutation induction by dyestuffs cannot be meaningfully assessed. PMID:7043261

  11. Degradation process analysis of the azo dyes by catalytic wet air oxidation with catalyst CuO/γ-Al2O3.

    PubMed

    Hua, Li; Ma, Hongrui; Zhang, Lei

    2013-01-01

    Three azo dyes (Methyl Orange, Direct Brown and Direct Green) were treated by catalytic wet air oxidation (CWAO) with the catalysts CuO/γ-Al(2)O(3) prepared by consecutive impregnation. The relationship of decolorization extent, chemical oxygen demand (COD) removal extent and total organic carbon (TOC) in dye solution were investigated. The results indicated that the CuO/γ-Al(2)O(3) catalyst had excellent catalytic activity in treating azo dyes. Almost 99% of color and 70% of TOC were removed in 2h. The high removal extent of color and TOC indicated that the CWAO obtained perfect decomposition for pollutants. The degradation pathway of azo dyes was analyzed by UV-Vis, FTIR and MS. According to the examined results, the hydroxyl ((·)OH) radicals induced strong oxidizing effects in the target solution and destroyed the chromophoric groups of azo-benzene conjugated of the molecular structure. Considering characteristics of the dye structure, the azo bond (-N=N-) would first be attacked by the hydroxyl radical and other free radicals. With the continuous oxidization and the long reaction time at high temperature, these intermediates could be oxidized to the final oxidation products, such as water and carbon dioxide. PMID:22795071

  12. Ultrastructural and Metabolic Determinants of Resistance to Azo-dye and Susceptibility to Nitrosamine Carcinogenesis of the Guinea-pig

    PubMed Central

    Bryant, G. M.; Sohal, R. S.; Argus, M. F.; Arcos, J. C.

    1977-01-01

    During diethylnitrosamine (DEN) administration, a distinctive difference was observed between rats and guinea-pigs in the sequence of ultrastructural changes in the hepatic endoplasmic reticulum (ER). In DEN-induced hepatic tumour cells in the guinea-pig there was extensive proliferation of the rough ER, while the smooth ER was quite sparse; in the premalignant liver the opposite was noted. This is in contrast to the rat, in which administration of either DEN or 3′-methyl-4-dimethylaminoazobenzene (3′-Me-DAB) brings about, in both premalignant and malignant hepatic tissue, proliferation of the smooth ER and sparsity of the rough ER. Yet, as in the rat, the number of ribosomes on the outer surface of the guinea-pig liver rough ER is greatly reduced and this is paralleled by a 49% decrease of the RNA/protein ratio as early as 4 weeks of nitrosamine administration. The decrease of RNA/protein ratio and ultrastructurally observed loss of ribosomes from the ER, following nitrosamine administration, correlate with a decrease of photometric response of microsomal suspensions to the sulphydryl probe, p-chloromercuribenzoate. While azo-dye-reductase activity is higher in untreated rats than in untreated guinea-pigs, feeding 3′-Me-DAB for 6 weeks brings about a 76% decrease in the rat, but no significant decrease in the guinea-pig, which is refractory to azo-dye carcinogenesis. Thus, the ability of the liver to inactivate the dye is greatly decreased in the rat, but not in the guinea-pig, as administration progresses toward the threshold dose for tumorigenesis. On the other hand, constitutive levels of nitrosamine dealkylase are identical in the 2 species and remain essentially unchanged following administration of DEN for 10 weeks. Inasmuch as nitrosamine dealkylation represents activating metabolism, this provides a rationale for the comparable susceptibility of the rat and guinea-pig to DEN carcinogenesis. Of the 2 enzymes in the 2 species, it is only azo-dye

  13. Spectroscopic and theoretical study of the "azo"-dye E124 in condensate phase: evidence of a dominant hydrazo form.

    PubMed

    Almeida, Mariana R; Stephani, Rodrigo; Dos Santos, Hélio F; de Oliveira, Luiz Fernando C

    2010-01-14

    Spectroscopic techniques, including Raman, IR, UV/vis, and NMR were used to characterize the samples of the azo dye Ponceau 4R (also known as E124, New Coccine; Cochineal Red; C.I. no. 16255; Food Red No. 102), which is 1,3-naphthalenedisulfonic acid, 7-hydroxy-8-[(4-sulfo-1-naphthalenyl) azo] trisodium salt in aqueous solution and solid state. In addition, first principle calculations were carried out for the azo (OH) and hydrazo (NH) tautomers in order to assist in the assignment of the experimental data. The two intense bands observed in the UV/vis spectrum, centered at 332 and 507 nm, can be compared to the calculated values at 296 and 474 nm for azo and 315 and 500 nm for hydrazo isomer, with the latter in closer agreement to the experiment. The Raman spectrum is quite sensitive to tautomeric equilibrium; in solid state and aqueous solution, three bands were observed around 1574, 1515, and 1364 cm(-1), assigned to mixed modes including deltaNH + betaCH + nuCC, deltaNH + nuC horizontal lineO + nuC horizontal lineN + betaCH and nuCC vibrations, respectively. These assignments are predicted only for the NH species centered at 1606, 1554, and 1375 cm(-1). The calculated Raman spectrum for the azo (OH) tautomer showed two strong bands at 1468 (nuN = N + deltaOH) and 1324 cm(-1) (nuCC + nuC-N), which were not obtained experimentally. The (13)C NMR spectrum showed a very characteristic peak at 192 ppm assigned to the carbon bound to oxygen in the naphthol ring; the predicted values were 165 ppm for OH and 187 for NH isomer, supporting once again the predominance of NH species in solution. Therefore, all of the experimental and theoretical results strongly suggest the food dye Ponceau 4R or E124 has a major contribution of the hydrazo structure instead of the azo form as the most abundant in condensate phase. PMID:19852449

  14. Sensitization to reactive textile dyes in patients with contact dermatitis.

    PubMed

    Manzini, B M; Motolese, A; Conti, A; Ferdani, G; Seidenari, S

    1996-03-01

    Reactive dyes are used especially for colouring natural fibres (cotton, silk and wool) that are widely used in Western countries, particularly Italy, in the production of clothes. The aim of our study was to investigate sensitization to the most commonly used reactive textile dyes in patients undergoing patch tests, and to assess the clinical relevance of contact sensitization to these dyes. 1813 consecutive patients underwent patch tests with the GIRDCA standard series and an additional textile series of 12 reactive dyes. 18 of these patients were sensitized to reactive dyes (0.99%) (4 only to reactive dyes). The dyes most frequently responsible for positive patch tests were Red Cibacron CR and Violet Remazol 5R (respectively, 8 and 5 positivities). In 5 cases only was a history of intolerance to particular garments given; of 4 patch tests performed with pieces of garment, 2 were positive. In 1 occupationally-exposed patient, airborne contact dermatitis was suspected. Owing to the lack of up-to-date patch test series, some cases of allergic contact dermatitis from textile dyes are probably misdiagnosed: new colouring agents are continuously introduced to the market, so that a close relationship with textile industry is necessary to improve our diagnostic tools. PMID:8833459

  15. Decolorization and biogas production by an anaerobic consortium: effect of different azo dyes and quinoid redox mediators.

    PubMed

    Alvarez, L H; Valdez-Espinoza, R; García-Reyes, R B; Olivo-Alanis, D; Garza-González, M T; Meza-Escalante, E R; Gortáres-Moroyoqui, P

    2015-01-01

    The inhibitory effect of azo dyes and quinoid compounds on an anaerobic consortium was evaluated during a decolorization process and biogas production. In addition, the impact of quinoid compounds such as lawsone (LAW) and anthraquinone-2,6-disulfonate (AQDS) on the rate of decolorization of Direct Blue 71 (DB71) was assessed. The anaerobic consortium was not completely inhibited under all tested dye concentrations (0.1-2 mmol l(-1)), evidenced by an active decolorization process and biogas production. The presence of quinoid compounds at different concentrations (4, 8, and 12 mmol l(-1)) also inhibited biogas production compared to the control incubated without the quinoid compounds. In summary, the anaerobic consortium was affected to a greater extent by increasing the quantity of azo dyes or quinoid compounds. Nevertheless, at a lower concentration (1 mmol l(-1)) of quinoid compounds, the anaerobic consortium effectively decolorized 2 mmol l(-1) of DB71, increasing up to 5.2- and 20.4-fold the rate of decolorization with AQDS and LAW, respectively, compared to the control lacking quinoid compounds. PMID:26287839

  16. Reactive Fluorescent Dyes For Urethane Coatings

    NASA Technical Reports Server (NTRS)

    Willis, Paul B.; Cuddihy, Edward F.

    1991-01-01

    Molecules of fluorescent dyes chemically bound in urethane conformal-coating materials to enable nondestructive detection of flaws in coats through inspection under ultraviolet light, according to proposal. Dye-bonding technique prevents outgassing of dyes, making coating materials suitable for use where flaw-free coats must be assured in instrumentation or other applications in which contamination by outgassing must be minimized.

  17. Properties of the metallochromic dyes Arsenazo III, Antipyrylazo III and Azo1 in frog skeletal muscle fibres at rest.

    PubMed

    Baylor, S M; Hollingworth, S; Hui, C S; Quinta-Ferreira, M E

    1986-08-01

    Intact single twitch fibres from frog muscle were isolated and mounted in a normal Ringer solution (16 degrees C) on an optical bench apparatus for measuring fibre absorbance as a function of the wave-length and polarization of the incident light. Fibre absorbance was measured in resting fibres both in the absence and in the presence of one of three metallochromic dyes: Arsenazo III, Antipyrylazo III and Azo1. In the absence of dye, the fibre intrinsic absorbance, Ai(lambda), measured as a function of wave-length, lambda, was well described by the equation: Ai(lambda) = Ai(lambda long) (lambda long/lambda)X, where lambda long is a reference wave-length selected to lie beyond the absorbance band of the dyes and X is the exponential index. For wave-lengths between 480 and 810 nm, the average value of X was 1.1 for 0 deg polarized light (electric vector parallel to the fibre axis) and 1.3 for 90 deg polarized light (electric vector perpendicular to the fibre axis). The intrinsic absorbance at 0 deg, Ai,0(lambda), was somewhat larger than the intrinsic absorbance at 90 deg, Ai,90(lambda); for example, on average (n = 6), Ai,0 (810 nm) was 0.22, whereas Ai,90 (810 nm) was 0.016. Following dye injection, dye-related absorbance was estimated from the measured total fibre absorbance by subtracting the component attributable to the intrinsic absorbance; additionally, for comparison with in vitro calibrations as a function of wave-length, myoplasmic dye absorbance was corrected for the steady change in dye-concentration with time that was attributable to dye diffusion. In fibres injected with either Arsenazo III or Antipyrylazo III, the dye-related absorbance measured with 0 deg light, A0(lambda), was found to be significantly greater than that measured with 90 deg light, A90(lambda), indicating the presence of a resting 'dichroic' signal, A0(lambda)-A90(lambda), attributable to bound and oriented dye molecules. On average, the lower limit estimated for the percentage of

  18. Efficient treatment of azo dye containing wastewater in a hybrid acidogenic bioreactor stimulated by biocatalyzed electrolysis.

    PubMed

    Wang, Hong-Cheng; Cheng, Hao-Yi; Wang, Shu-Sen; Cui, Dan; Han, Jing-Long; Hu, Ya-Ping; Su, Shi-Gang; Wang, Ai-Jie

    2016-01-01

    In this study, a novel scaled-up hybrid acidogenic bioreactor (HAB) was designed and adopted to evaluate the performance of azo dye (acid red G, ARG) containing wastewater treatment. Principally, HAB is an acidogenic bioreactor coupled with a biocatalyzed electrolysis module. The effects of hydraulic retention time (HRT) and ARG loading rate on the performance of HAB were investigated. In addition, the influent was switched from synthetic wastewater to domestic wastewater to examine the key parameters for the application of HAB. The results showed that the introduction of the biocatalyzed electrolysis module could enhance anoxic decolorization and COD (chemical oxygen demand) removal. The combined process of HAB-CASS presented superior performance compared to a control system without biocatalyzed electrolysis (AB-CASS). When the influent was switched to domestic wastewater, with an environment having more balanced nutrients and diverse organic matters, the ARG, COD and nitrogen removal efficiencies of HAB-CASS were further improved, reaching 73.3%±2.5%, 86.2%±3.8% and 93.5%±1.6% at HRT of 6 hr, respectively, which were much higher than those of AB-CASS (61.1%±4.7%, 75.4%±5.0% and 82.1%±2.1%, respectively). Moreover, larger TCV/TV (total cathode volume/total volume) for HAB led to higher current and ARG removal. The ARG removal efficiency and current at TCV/TV of 0.15 were 39.2%±3.7% and 28.30±1.48 mA, respectively. They were significantly increased to 62.1%±2.0% and 34.55±0.83 mA at TCV/TV of 0.25. These results show that HAB system could be used to effectively treat real wastewater. PMID:26899658

  19. New 1,2,4-triazole-based azo-azomethine dyes. Part II: synthesis, characterization, electrochemical properties and computational studies.

    PubMed

    Khanmohammadi, Hamid; Erfantalab, Malihe; Bayat, Atena; Babaei, Ali; Sohrabi, Masoud

    2012-11-01

    A new series of monoiminated 1,2,4-triazole-based azo-azomethine dyes have been synthesized via condensation reaction of 4-amino-3-methyl-5-mercapto-1,2,4-triazole with various substituted azo-coupled salicylaldehyde. The dyes have been characterized by using FT-IR, UV-Vis and (1)H NMR spectroscopic methods as well as elemental analysis. The electrochemical behavior of the dyes has been investigated by cyclic voltammetry in DMSO at five different scan rates. Solvatochromic behavior of the dyes has been also investigated in four organic solvents with different polarities. Furthermore, the (1)H chemical shielding of the dyes were studied by the gauge independent atomic orbital (GIAO) method at the level of density functional theory (DFT). PMID:22902931

  20. Solvatochromism, spectral properties and antimicrobial activities of new azo-azomethine dyes with N2S2O2 donor set of atoms

    NASA Astrophysics Data System (ADS)

    Khanmohammadi, Hamid; Pass, Maryam; Rezaeian, Khatereh; Talei, Gholamreza

    2014-08-01

    Six new azo-azomethine dyes, H2Ln (n = 1-6), with N2S2O2 donor set of atoms have been prepared via condensation reaction of 1,10-diaza-4,7-dithiadecane, I, with substituted azo-coupled salicylaldehyde. The dyes were characterized by IR, UV-Vis and 1H NMR spectroscopic methods as well as elemental analysis. The solvatochromic behavior of the dyes was also probed by studying their UV-Vis spectra in four pure organic solvents of different polarities and a meaningful correlation was observed. Furthermore, all prepared dyes were assayed for their antibacterial and antifungal activities by disc diffusion method. The results indicated that all prepared dyes show good inhibition against Staphylococcus epidermidis and Bacillus cereus and did not show any antibacterial activity against Escherichia coli as compared to standard drugs.

  1. Adsorption of azo dyes using peanut hull and orange peel: a comparative study.

    PubMed

    do Nascimento, Graziele Elisandra; Duarte, Marta Maria Menezes Bezerra; Campos, Natália Ferreira; da Rocha, Otidene Rossiter Sá; da Silva, Valdinete Lins

    2014-01-01

    This work proposes the use of agro-industrial wastes, specifically peanut hull (HP) and orange peel (OP), as adsorbents for dyes, such as Remazol Golden Yellow RNL-150% (RYG), Gray Reactive BF-2R (RG) and Reactive Turquoise Q-G125 (RT). Characterization by Brunauer-Emmett-Teller indicates that the adsorbents are mesoporous, with pHzpc values of 5.0 for HP and 4.0 for OP. Fourier transform-infrared spectroscopy identified carbonyl and sulphonic groups. The initial pH of the best-adsorbing solution of the three colours was 2.0. Increasing the concentration of the adsorbent promoted an increase in the percentage of removal until saturation of the adsorbent. In a factorial design, the largest value of q was obtained with 0.25 g of the adsorbent, with a particle size of < 0.4 mm and a stirring speed of 300 rpm. Such conditions were used in kinetic studies and studies of adsorption equilibrium. The evolution kinetics were rapid in the first few minutes, and after 180 min the system reached equilibrium. The kinetic model that best fit the experimental data to a 95% confidence level for the F test was the pseudo-second-order model for RYG/HP, RG/OP and RT/OP. There was no significant difference between the kinetic models as evaluated by the F test for RYG/OP, RG/HP and RT/HP. The experimental results indicated favourable dye adsorption characteristics for the adsorbents studied. The results of the F test showed that for RYG and RG, there was no significant difference between the two evaluated models. This study suggests that HP and OP are viable alternatives for the treatment of effluents containing RYG, RG and RT dyes. PMID:24701942

  2. Decolorization and detoxification of sulfonated azo dye C.I. Remazol Red and textile effluent by isolated Lysinibacillus sp. RGS.

    PubMed

    Saratale, Rijuta G; Gandhi, Soniya S; Purankar, Madhavi V; Kurade, Mayur B; Govindwar, Sanjay P; Oh, Sang Eun; Saratale, Ganesh D

    2013-06-01

    A novel bacterium was isolated from the soil of Ichalkaranji textile industrial area. Through 16S rRNA sequence matching and morphological observation it was identified as Lysinibacillus sp. RGS. This strain has ability to decolorize various industrial dyes among which, it showed complete decolorization and degradation of toxic sulfonated azo dye C.I. Remazol Red (at 30°C, pH 7.0, under static condition) with higher chemical oxygen demand (COD) reduction (92%) within 6 h of incubation. Various parameters like agitation, pH, temperature and initial dye concentrations were optimized to develop faster decolorization process. The supplementation of cheap co-substrates (e.g., extracts of agricultural wastes) could enhance the decolorization performance of Lysinibacillus sp. RGS. Induction in oxidoreductive enzymes presumably indicates involvement of these enzymes in the decolorization/degradation process. Analytical studies of the extracted metabolites confirmed the significant degradation of Remazol Red into various metabolites. The phytotoxicity assay (with respect to plants Phaseolus mungo and Sorghum vulgare) revealed that the degradation of Remazol Red produced nontoxic metabolites. Finally Lysinibacillus sp. RGS was applied to decolorize mixture of dyes and actual industrial effluent showing 87% and 72% decolorization (in terms of decrease in ADMI value) with 69% and 62% COD reduction within 48 h and 96 h, respectively. The foregoing result increases the applicability of the strain for the treatment of industrial wastewaters containing dye pollutants. PMID:23321576

  3. Decolorization and detoxification of Synozol red HF-6BN azo dye, by Aspergillus niger and Nigrospora sp

    PubMed Central

    2013-01-01

    In the present investigation the fungi, Aspergillus niger and Nigrospora sp. were employed for decolorization of Synozol red HF-6BN. Decolorization study showed that Aspergillus niger and Nigrospora sp. were able to decolorize 88% and 96% Synozol red 6BN, respectively, in 24 days. It was also studied that 86% and 90% Synozol red containing of dye effluent was decolorized by Aspergillus niger and Nigrospora sp. after 28 days of incubation at room temperature. A fungal-based protein with relative molecular mass of 70 kDa was partially purified and examined for enzymatic characteristics. The enzyme exhibited highest activity at temperature ranging from 40-50°C and at pH=6.0. The enzyme activity was enhanced in the presence of metal cations. High performance liquid chromatography analysis confirmed that these fungal strains are capable to degrade Synozol red dye into metabolites. No zones of inhibition on agar plates and growth of Vigna radiata in the presence of dye extracted sample, indicated that the fungal degraded dye metabolites are nontoxic to beneficial micro-flora and plant growth. Aspergillus niger and Nigrospora sp. have promising potential in color removal from textile wastewater-containing azo dyes. PMID:23369298

  4. Biodecolorization of azo dye Remazol orange by Pseudomonas aeruginosa BCH and toxicity (oxidative stress) reduction in Allium cepa root cells.

    PubMed

    Jadhav, Shekhar B; Surwase, Shripad N; Kalyani, Dayanand C; Gurav, Ranjit G; Jadhav, Jyoti P

    2012-11-01

    In this report a textile azo dye Remazol orange was degraded and detoxified by bacterium Pseudomonas aeruginosa BCH in plain distilled water. This bacterial decolorization performance was found to be pH and temperature dependent with maximum decolorization observed at pH 8 and temperature 30 °C. Bacterium tolerated higher dye concentrations up to 400 mg l(-1). Effect of initial cell mass showed that higher cell mass concentration can accelerate decolorization process with maximum of 92 % decolorization observed at 2.5 g l(-1) cell mass within 6.5 h. Effect of various metal ions showed Mn has inducing effect whereas Zn strongly inhibited the decolorization process at 5 mM concentration. Analysis of biodegradation products carried out with UV-vis spectroscopy, HPTLC and FTIR confirmed the decolorization and degradation of Remazol orange. Possible route for the degradation of dye was proposed based on GC-MS analysis. During toxicological scrutiny in Allium cepa root cells, induction in the activities of superoxide dismutase (SOD), guaiacol peroxidase (GPX) and inhibition of catalase (CAT) along with raised levels of lipid peroxidation and protein oxidation in dye treated samples were detected which conclusively indicated the generation of oxidative stress. Less toxic nature of the dye degraded products was observed after bacterial treatment. PMID:22948606

  5. Photo-assisted hetero-fenton decolorization of azo dye from contaminated water by Fe-Si mixed oxide nanocomposite.

    PubMed

    Rasoulifard, M H; Monfared, H Hosseini; Masoudian, S

    2011-10-01

    An aerogel of silica gel dopeyd with 2.86 wt% Fe was prepared by an alkoxide sol-gel method and using tetraethyl orthosilicate as a precursor material. The synthesized aerogel was calcined at 500 degress C to produce nanoparticle solids, and was characterized by XRD, FT-IR and SEM. The nanosized iron-silica gel mixed oxide was tested in the photooxidation of the azo dye Acid Red 14 (AR 14) using 30% aqueous hydrogen peroxide as oxidant and UV light. The 2.86 wt% Fe-loaded SiO2 showed very good efficiency in the decolorization of AR 14. The effects of various parameters including solution pH, catalyst, oxidant and initial dye concentrations on photodegradation were investigated and the optimum conditions were determined. The catalyst was resistant to leaching and could be recycled several times without appreciable loss of activity. PMID:22329154

  6. Potential of the aquatic fern Azolla filiculoides in biodegradation of an azo dye: modeling of experimental results by artificial neural networks.

    PubMed

    Khataee, A R; Movafeghi, A; Vafaei, F; Lisar, S Y Salehi; Zarei, M

    2013-01-01

    The potential of an aquatic fern, Azolla filiculoides, in phytoremediation of a mono azo dye solution, C.I. Acid Blue 92 (AB92), was studied. The effects of operational parameters such as reaction time, initial dye concentration, fern fresh weight, pH, temperature and reusability of the fern on biodegradation efficiency were investigated. The intermediate compounds produced by biodegradation process were analyzed using GC-MS analysis. An artificial neural network (ANN) model was developed to predict the biodegradation efficiency. The findings indicated that ANN provides reasonable predictive performance (R2 = 0.961). The effects of AB92 solutions (10 and 20 mg L(-1)) on growth, chlorophylls and carotenoids content, activity of antioxidant enzymes such as superoxide dismutase, peroxidase and catalase and formation of malondialdehyde were analyzed. AB92 generally showed inhibitory effects on the growth. Moreover, photosynthetic pigments in the fronds significantly decreased in the treatments. An increase was detected for lipid peroxidation and antioxidant enzymes activity, suggesting that AB92 caused reactive oxygen species production in Azolla fronds, which were scavenged by induced activities of antioxidant enzymes. PMID:23819271

  7. Remediation of textile azo dye acid red 114 by hairy roots of Ipomoea carnea Jacq. and assessment of degraded dye toxicity with human keratinocyte cell line.

    PubMed

    Jha, Pamela; Jobby, Renitta; Desai, N S

    2016-07-01

    Bioremediation has proven to be the most desirable and cost effective method to counter textile dye pollution. Hairy roots (HRs) of Ipomoea carnea J. were tested for decolourization of 25 textile azo dyes, out of which >90% decolourization was observed in 15 dyes. A diazo dye, Acid Red 114 was decolourized to >98% and hence, was chosen as the model dye. A significant increase in the activities of oxidoreductive enzymes was observed during decolourization of AR114. The phytodegradation of AR114 was confirmed by HPLC, UV-vis and FTIR spectroscopy. The possible metabolites were identified by GCMS as 4- aminobenzene sulfonic acid 2-methylaniline and 4- aminophenyl 4-ethyl benzene sulfonate and a probable pathway for the biodegradation of AR114 has been proposed. The nontoxic nature of the metabolites and toxicity of AR114 was confirmed by cytotoxicity tests on human keratinocyte cell line (HaCaT). When HaCaT cells were treated separately with 150 μg mL(-1) of AR114 and metabolites, MTT assay showed 50% and ≈100% viability respectively. Furthermore, flow cytometry data showed that, as compared to control, the cells in G2-M and death phase increased by 2.4 and 3.6 folds respectively on treatment with AR114 but remained unaltered in cells treated with metabolites. PMID:26971029

  8. Acute and subchronic toxicity of metal complex azo acid dye and anionic surfactant oil on fish Oreochromis niloticus.

    PubMed

    Amwele, Hilma Rantilla; Papirom, Pittaya; Chukanhom, Kanit; Beamish, Fredrick Henry William; Petkam, Rakpong

    2015-01-01

    The acute toxicity study of metal complex dark green azo acid dye, anionic surfactant oil and their mixture determined the 96 hr LC50, and fish behaviours. Subchronic toxicity determined haematology parameters and concentrations of copper and chromium in blood. The 96 hr LC50 was determined by probit analysis and subchronic toxicity was conducted in 90 days. No mortalities were observed in control and anionic surfactant oil treatments. The 96 hr LC50 value of mixture was 26.7 mg I(-1) (95% CL = 20.7 - 46.8) and that of metal complex dark green azo acid dye was not met as the percentage of dead was below 50% of tested organisms. In a treatment of anionic surfactant oil and that of mixture observed behaviours were respiration response, uncoordinated movement, loss of equilibrium, erratic posture and loss of responsiveness. Subchronic toxicity indicated fluctuations in number of erythrocytes, leukocytes and thrombocytes in all chemical treatments. Erythrocyte morphology such as anisocytosis, erythrocytes hypertrophy, karyolysis, cytoplasm vacuolation, ghost cell were observed in fish blood in all chemical treatments. An inverse relation was observed between total copper and chromium concentration in blood. However, the toxicity effect was chemical dose dependent and length of exposure. PMID:26536793

  9. Efficient azo dye decolorization in a continuous stirred tank reactor (CSTR) with built-in bioelectrochemical system.

    PubMed

    Cui, Min-Hua; Cui, Dan; Gao, Lei; Cheng, Hao-Yi; Wang, Ai-Jie

    2016-10-01

    A continuous stirred tank reactor with built-in bioelectrochemical system (CSTR-BES) was developed for azo dye Alizarin Yellow R (AYR) containing wastewater treatment. The decolorization efficiency (DE) of the CSTR-BES was 97.04±0.06% for 7h with sludge concentration of 3000mg/L and initial AYR concentration of 100mg/L, which was superior to that of the sole CSTR mode (open circuit: 54.87±4.34%) and the sole BES mode (without sludge addition: 91.37±0.44%). The effects of sludge concentration and sodium acetate (NaAc) concentration on azo dye decolorization were investigated. The highest DE of CSTR-BES for 4h was 87.66±2.93% with sludge concentration of 12,000mg/L, NaAc concentration of 2000mg/L and initial AYR concentration of 100mg/L. The results in this study indicated that CSTR-BES could be a practical strategy for upgrading conventional anaerobic facilities against refractory wastewater treatment. PMID:27497830

  10. Degradation of a model azo dye in submerged anaerobic membrane bioreactor (SAMBR) operated with powdered activated carbon (PAC).

    PubMed

    Baêta, B E L; Luna, H J; Sanson, A L; Silva, S Q; Aquino, S F

    2013-10-15

    This work investigated the anaerobic degradation of the model azo dye Remazol Yellow Gold RNL in an upflow anaerobic sludge blanket reactor (UASB) and two submerged anaerobic membrane (SAMBR) bioreactors, one of which (SAMBR-1) was operated with powdered activated carbon (PAC) in its interior. The reactors were operated at 35 °C with a hydraulic retention time of 24 h in three operational phases, aimed to assess the effect of external sources of carbon (glucose) or redox mediator (yeast extract) on the removal or color and organic matter. The results showed that removal efficiencies of COD (73-94%) and color (90-94%) were higher for SAMBR-1 when compared to SAMBR-2 (operated without PAC) and UASB reactors. In addition, the presence of PAC in SAMBR-1 increased reactor stability, thereby leading to a lower accumulation of volatile fatty acids (VFA). The microfiltration membrane was responsible for an additional removal of ~50% of soluble residual COD in the form of VFA, thus improving permeate quality. On its turn, PAC exhibited the ability to adsorb byproducts (aromatic amines) of azo dye degradation as well as to act as source of immobilized redox mediator (quinone groups on its surface), thereby enhancing color removal. PMID:23810998

  11. Synthesis, spectral characterization, molecular modeling and antimicrobial studies of tridentate azo-dye Schiff base metal complexes

    NASA Astrophysics Data System (ADS)

    Alaghaz, Abdel-Nasser M. A.; Zayed, Mohamed E.; Alharbi, Suliman A.

    2015-03-01

    Nine mononuclear Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pt(IV) complexes of azo-dye Schiff's base ligand were synthesized and determined by different physical techniques. All the nine metal complexes are reported using elemental analysis, molar conductance, magnetic susceptibility, IR, UV-Vis, thermal analysis and 1H NMR, 13C NMR, mass, SEM, TEM, EDX, XRD spectral studies. The molar conductance measurements of all the complexes in DMF solution correspond to non-electrolytic nature. All complexes were of the high-spin type and found to have six-coordinate octahedral geometry except the Cu(II) complex which was four coordinate, square planar. Quantum chemical calculations were performed with semi-empirical method to find the optimum geometry of the ligand and its complexes. In molecular modeling the geometries of azo-dye Schiff base ligand HL and its metal (II/III/IV) complexes were fully optimized with respect to the energy using the 6-31G basis set. These ligand and its metal complexes have also been screened for their in vitro antimicrobial activities.

  12. Response surface-optimized removal of Reactive Red 120 dye from its aqueous solutions using polyethyleneimine enhanced ultrafiltration.

    PubMed

    Dasgupta, J; Singh, M; Sikder, J; Padarthi, V; Chakraborty, S; Curcio, S

    2015-11-01

    Retention of toxic dyes with molecular weights lower than the molecular weight cut-off (MWCO) of the ultrafiltration membranes can be improved through selective binding of the target dyes to a water-soluble polymer, followed by ultrafiltration of the macromolecular complexes formed. This method, often referred to as polymer enhanced ultrafiltration (PEUF), was investigated in the present study, using polyethyleneimine (PEI) as the chelating agent. Model azo dye Reactive Red 120 was selected as the poorly biodegradable, target contaminant, because of its frequent recalcitrant presence in colored effluents, and its eventual ecotoxicological impacts on the environment. The effects of the governing process factors, namely, cross flow rate, transmembrane pressure polymer to dye ratio and pH, on target dye rejection efficiency were meticulously examined. Additionally, each parameter level was statistically optimized using central composite design (CCD) from the response surface methodology (RSM) toolkit, with an objective to maximize performance efficiency. The results revealed high dye retention efficiency over 99%, accompanied with reasonable permeate flux over 100L/m(2)h under optimal process conditions. The estimated results were elucidated graphically through response surface (RS) plots and validated experimentally. The analyses clearly established PEUF as a novel, reasonably efficient and economical route for recalcitrant dye treatment. PMID:25575914

  13. Polar Glass Structure for Second-Order Nonlinear Optics Prepared by the Langmuir-Blodgett Method Using Amorphous Polymers with an Azo-Dye

    NASA Astrophysics Data System (ADS)

    Okada, Shuji; Matsuda, Hiro; Masaki, Atsushi; Nakanishi, Hachiro; Abe, Takashi; Ito, Hiroshi

    1992-02-01

    In order to obtain Langmuir-Blodgett (LB) films for second-order nonlinear optics, LB films of the amorphous copolymers synthesized from methyl methacrylate and 2-(N-ethyl-N-(4-(4-nitrophenyl)azo)phenyl)aminoethyl acrylate were investigated. From the measurement of F-A isotherms and UV and visible spectra of the Langmuir (L) film, it was estimated that the azo-dye moiety was squeezed out from the air-water interface into the subphase, and the dipoles of azo-dye align uniaxially in the direction perpendicular to the interface. The L film could be deposited into X-type multilayers by the horizontal lifting method, resulting in the formation of “polar glass.”

  14. Creation of second-order nonlinear optical effects by photoisomerization of polar azo dyes in polymeric films: theoretical study of steady-state and transient properties

    NASA Astrophysics Data System (ADS)

    Sekkat, Zouheir; Knoll, Wolfgang

    1995-10-01

    It was shown recently that the application of a dc field across a polymer film containing polar azo dye chromophores at a temperature far below that of its glass transition leads to an appreciable polar order when the azo dyes undergo cis \\left-right-double-arrow trans isomerization. We present a detailed theoretical study of this phenomenon based on the enhanced mobility of the azo chromophores during the isomerization process. The equations representing this phenomenological theory are solved by recurrence relations of Legendre polynomials, and both the steady state and the dynamics are investigated. Analytical expressions are derived for the photoinduced polar order and its related anisotropy for both cis and trans molecular distributions.

  15. Identification of non-regulated aromatic amines of toxicological concern which can be cleaved from azo dyes used in clothing textiles.

    PubMed

    Brüschweiler, Beat J; Küng, Simon; Bürgi, Daniel; Muralt, Lorenz; Nyfeler, Erich

    2014-07-01

    Azo dyes in textiles may release aromatic amines after enzymatic cleavage by skin bacteria or after dermal absorption and metabolism in the human body. From the 896 azo dyes with known chemical structure in the available textile dyes database, 426 azo dyes (48%) can generate one or more of the 22 regulated aromatic amines in the European Union in Annex XVII of REACH. Another 470 azo dyes (52%) can be cleaved into exclusively non-regulated aromatic amines. In this study, a search for publicly available toxicity data on non-regulated aromatic amines was performed. For a considerable percentage of non-regulated aromatic amines, the toxicity database was found to be insufficient or non-existent. 62 non-regulated aromatic amines with available toxicity data were prioritized by expert judgment with objective criteria according to their potential for carcinogenicity, genotoxicity, and/or skin sensitization. To investigate the occurrence of azo dye cleavage products, 153 random samples of clothing textiles were taken from Swiss retail outlets and analyzed for 22 high priority non-regulated aromatic amines of toxicological concern. Eight of these 22 non-regulated aromatic amines of concern could be detected in 17% of the textile samples. In 9% of the samples, one or more of the aromatic amines of concern could be detected in concentrations >30 mg/kg, in 8% of the samples between 5 and 30 mg/kg. The highest measured concentration was 622 mg/kg textile. There is an obvious need to assess consumer health risks for these non-regulated aromatic amines and to fill this gap in the regulation of clothing textiles. PMID:24793261

  16. COD and color removal of reactive orange 16 dye solution by electrochemical oxidation and adsorption method

    NASA Astrophysics Data System (ADS)

    Zakaria, Zuhailie; Ahmad, Wan Yaacob Wan; Yusop, Muhammad Rahimi; Othman, Mohamed Rozali

    2015-09-01

    Degradation of Reactive Orange 16 (RO16) dye was investigated using electrochemical oxidation and adsorption (batch method) using mixture of coconut trunk charcoal-graphite-tin-polyvinyl chloride(PVC). In batch studies for adsorbents pellet and powder form of the charcoal mixture were used. RO16 was chosen as the model dye because of its high resistance towards conventional treatment methods. NaCl and RO16 concentration, treatment duration, weight of electrode and adsorbent and volume of solution were kept constant for both methods. The effectiveness of the treatments were compared and evaluated by percentage of RO16 decolorization and chemical oxygen demand (COD) removal and results indicated that electrochemical oxidation method ables to decolorized RO16 dye up to 98.5% after 20 minutes electrolysis time while pellet and powder in batch method only removed 17.1 and 33.6% of RO16 color respectively. However, only 45.6% of COD can be removed using electrochemical oxidation method while pellet and powder in batch method removed 47.8 and 49.6% of COD respectively. The decolorization and COD removal of RO16 was determined using UV-Vis spectrophotometer (by the changes of absorption spectrum intensity of azo chromophore (-N=N-) at λ=388 and 492.50 nm and Hach spectrophotometer respectively. FTIR was used to determine functional groups present in the coconut trunk charcoal.

  17. Genotoxicity assessment of reactive and disperse textile dyes using human dermal equivalent (3D cell culture system).

    PubMed

    Leme, Daniela Morais; Primo, Fernando Lucas; Gobo, Graciely Gomides; da Costa, Cleber Rafael Vieira; Tedesco, Antonio Claudio; de Oliveira, Danielle Palma

    2015-01-01

    Thousands of dyes are marketed daily for different purposes, including textile dyeing. However, there are several studies reporting attributing to dyes deleterious human effects such as DNA damage. Humans may be exposed to toxic dyes through either ingestion of contaminated waters or dermal contact with colored garments. With respect to dermal exposure, human skin equivalents are promising tools to assess in vitro genotoxicity of dermally applied chemicals using a three-dimensional (3D) model to mimic tissue behavior. This study investigated the sensitivity of an in-house human dermal equivalent (DE) for detecting genotoxicity of textile dyes. Two azo (reactive green 19 [RG19] and disperse red 1[DR1]) dyes and one anthraquinone (reactive blue 2 [RB2]) dye were analyzed. RG19 was genotoxic for DE in a dose-responsive manner, whereas RB2 and DR1 were nongenotoxic under the conditions tested. These findings are not in agreement with previous genotoxicological assessment of these dyes carried out using two-dimensional (2D) cell cultures, which showed that DR1 was genotoxic in human hepatoma cells (HepG2) and RG19 was nongenotoxic for normal human dermal fibroblasts (NHDF). These discrepant results probably may be due to differences between metabolic activities of each cell type (organ-specific genotoxicity, HepG2 and fibroblasts) and the test setup systems used in each study (fibroblasts cultured at 2D and three-dimensional [3D] culture systems). Genotoxicological assessment of textile dyes in context of organ-specific genotoxicity and using in vitro models that more closely resemble in vivo tissue architecture and physiology may provide more reliable estimates of genotoxic potential of these chemicals. PMID:25785560

  18. Batch and fixed-bed adsorption of tartrazine azo-dye onto activated carbon prepared from apricot stones

    NASA Astrophysics Data System (ADS)

    Albroomi, H. I.; Elsayed, M. A.; Baraka, A.; Abdelmaged, M. A.

    2016-02-01

    This work describes the potential of utilizing prepared activated carbon from apricot stones as an efficient adsorbent material for tartrazine (TZ) azo-dye removal in a batch and dynamic adsorption system. The results revealed that activated carbons with well-developed surface area (774 m2/g) and pore volume (1.26 cm3/g) can be manufactured from apricot stones by H3PO4 activation. In batch experiments, effects of the parameters such as initial dye concentration and temperature on the removal of the dye were studied. Equilibrium was achieved in 120 min. Adsorption capacity was found to be dependent on the initial concentration of dye solution, and maximum adsorption was found to be 76 mg/g at 100 mg/L of TZ. The adsorption capacity at equilibrium (q e) increased from 22.6 to 76 mg/g with an increase in the initial dye concentrations from 25 to 100 mg/L. The thermodynamic parameters such as change in free energy (ΔG 0), enthalpy (ΔH 0) and entropy (ΔS 0) were determined and the positive value of (ΔH) 78.1 (K J mol-1) revealed that adsorption efficiency increased with an increase in the process temperature. In fixed-bed column experiments, the effect of selected operating parameters such as bed depth, flow rate and initial dye concentration on the adsorption capacity was evaluated. Increase in bed height of adsorption columns leads to an extension of breakthrough point as well as the exhaustion time of adsorbent. However, the maximum adsorption capacities decrease with increases of flow rate. The breakthrough data fitted well to bed depth service time and Thomas models with high coefficient of determination, R 2 ≥ 94.

  19. EPR and LC-MS studies on the mechanism of industrial dye decolorization by versatile peroxidase from Bjerkandera adusta.

    PubMed

    Baratto, Maria Camilla; Juarez-Moreno, Karla; Pogni, Rebecca; Basosi, Riccardo; Vazquez-Duhalt, Rafael

    2015-06-01

    The mechanisms of industrial dye transformation by versatile peroxidase were elucidated. Purified versatile peroxidase from Bjerkandera adusta was able to decolorize different classes of dyes including azo and phthalocyanines, but unable to transform any of the anthraquinones tested. Kinetic constants for selected dyes were determined and the transformation products were analyzed by EPR spectroscopy and mass spectrometry. The EPR and MS analyses of the enzymatic decolorization products showed the cleavage of the azo bond in azo dyes and the total disruption of the phthalocyaninic ring in phthalocyanine dyes. The EPR analysis on two copper-containing dyes, reactive violet 5 (azo) and reactive blue 72 (phthalocyanine), showed that the transformation can or not break the metal-ion coordination bond according the dye nature. The role of the catalytic Trp172 in the dye transformation by a long-range electron transfer pathway was confirmed and the oxidation mechanisms are proposed and discussed. PMID:25567062

  20. Synthesis, spectral characterization, thermal analysis, molecular modeling and antimicrobial activity of new potentially N2O2 azo-dye Schiff base complexes

    NASA Astrophysics Data System (ADS)

    Alaghaz, Abdel-Nasser M. A.; Ammar, Yousry A.; Bayoumi, Hoda A.; Aldhlmani, Sharah A.

    2014-09-01

    The azo-dye Schiff's base of N2O2 dibasic ligand, H2L [N,N‧-bis(5-(4-sulfanilamidophenylazosalicylidene)ethylenediamine] was prepared by the condensation of ethylenediamine with [5-(4-sulfanilamidophenylazo-salicylaldehyde] in ethanol. New complexes of with metal ions Cu(II), Ni(II), Co(II), Mn(II), Zn(II), Cd(II), Pt(IV), Fe(III) and Cr(III) are synthesized. Elemental, spectroscopic and thermal analyses as well as conductivity and magnetic susceptibility measurements are used to elucidate the structure of the newly prepared metal complexes. The azo-dye Schiff's base behaves as a di-negative N2O2 tetradentate ligand. The metal complexes exhibited square planar, tetrahedral and octahedral geometrical arrangements, the molar conductivity data indicates that all complexes are neutral. The thermogravimetry (TG) and differential thermoanalysis (DTA) of the Cu(II), Mn(II), Cr(III) and Co(II) complexes were carried out in the range of 30-800 °C. The complexes were decomposed in one and two stages of the Cu(II), Mn(II), Cr(III) and Co(II) complexes, respectively. Also, decomposition of the synthesized complexes is related to the Schiff's base characteristics. The thermal decomposition of the studied reactions was first order. The kinetic parameters for the decomposition steps in Cu(II), Mn(II), Cr(III) and Co(II) complexes thermograms have been calculated using Broido's method. In molecular modeling the geometries of azo-dye Schiff base ligand H2L and its metal(II/III/IV) complexes were fully optimized with respect to the energy using the 6-31G basis set. Antimicrobial activities of the azo-dye Schiff's base ligand and its corresponding metal complexes were screened against various organisms. The azo-dye Schiff's base ligand and some of its complexes were found to be biologically inactive.

  1. Azo dye load-shock on relative behavior of biofilm and suspended growth configured periodic discontinuous batch mode operations: critical evaluation with enzymatic and bio-electrocatalytic analysis.

    PubMed

    Naresh Kumar, A; Nagendranatha Reddy, C; Hari Prasad, R; Venkata Mohan, S

    2014-09-01

    Effect of dye (C.I.Acid Black 10B) load-shock was comparatively evaluated in biofilm (self-immobilized) and suspended growth systems operated in periodic discontinuous batch mode (PDBR, anoxic-aerobic-anoxic) was investigated. At higher dye load (1250 mg dye/l), biofilm system showed relatively higher dye (74.5%) and COD (46%) removal efficiencies than the corresponding suspended mode operation (dye/COD removal efficiency, 42%/65%). Increment in dye load showed increment in azo reductase and dehydrogenase enzyme activities. Voltammograms (cyclic) showed higher reduction currents (RC) with increment in dye load specifically in biofilm system. Derivative cyclic voltammograms analysis depicted the involvement of mediators (NAD (+), FAD(+), etc.) which presumably played a major role in electron transport chain and dye degradation. Disappearance of peak (1612 cm(-1)) specific to azo group in FTIR spectrum, at higher loading rate in both the systems indicates the non-inhibitory and robust nature of PDBR operation. PMID:24859232

  2. Low-temperature-fabricated ZnO, AZO, and SnO2 nanoparticle-based dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Kim, Hong Hee; Park, Cheolmin; Choi, WonKook; Cho, Sungjae; Moon, ByungJoon; Son, Dong Ick

    2014-11-01

    The authors investigated the microstructural and the electrical properties of ZnO, AZO, and SnO2 based dye-sensitized solar cells (DSSCs) fabricated using a low-temperature-processed (200 °C) dye-sensitized ZnO, AZO, and SnO2 nanoparticle thin film and a Pt catalyst deposited on ITO/glass by RF magnetron sputtering. A hydropolymer containing PEG (poly ethylene glycol) and PEO (poly ethylene oxide) is used to make uniformly-distributed ZnO, AZO, and SnO2 nanoparticle layer which forms a nano porous ZnO, AZO, and SnO2 network after heat treatment. The layer is then dye sensitized and sandwiched between two electrodes in an electrolyte to make a DSSC device. The highest measured parameters, the short-circuit current density ( J sc ), the open circuit potential ( V oc ), the fill factor (FF), and power conversion efficiency ( η), of the DSSC fabricated wander optimized conditions were observed to be 5.10 mA/cm2, 0.61 V, 0.46, and 1.43%, respectively.

  3. Subcritical water and dynamic sonication-assisted solvent extraction of fluorescent whitening agents and azo dyes in paper samples.

    PubMed

    de los Santos, Mario; Batlle, Ramón; Salafranca, Jesús; Nerín, Cristina

    2005-02-01

    Two low-volume solvent continuous extraction methods are applied to the extraction of paper matrices. In the methods reported here, a complex mixture of fluorescent whitening agents (FWAs) and azo dyes (AZOs) used in paper materials intended to come into contact with foodstuffs was extracted by using subcritical water extraction (SWE) and dynamic sonication-assisted solvent extraction (DSASE). Rationale for the work is based upon migration concerns of these groups of analytes from the packaging to the packaged items, thus compromising their subjective and/or objective quality. In SWE, sample was extracted in 21 min with 0.5 mL of water, whereas the DSASE method required 11 min and used 7 mL of water. DSASE was further developed by incorporating an organic modifier in order to change water polarity, thus improving extraction of moderately polar analytes. This way, modified-DSASE used a total organic volume of 0.9 mL which represents a reduction of 200 times in organic solvent consumption (200 mL versus approximately 1.0 mL) and 11 times in extraction time (2h versus 11 min) compared to the existing methods. SWE was able to extract only 9 out of 12 test analytes with average recoveries between 10 and 25% whereas modified-DSASE succeed in extracting all the target analytes with an average recovery of 89%. Complete discussion and explanation concerning these differences are provided in the text. PMID:15739881

  4. Synthesis and evaluation of simple naked-eye colorimetric chemosensors for anions based on azo dye-thiosemicarbazones

    NASA Astrophysics Data System (ADS)

    Radchatawedchakoon, Widchaya; Sangsuwan, Withsakorn; Kruanetr, Senee; Sakee, Uthai

    2014-03-01

    A series of novel, highly selective azo dye-thiosemicarbazones based anion sensors (3e-f) have been synthesized from the condensation reaction between thiosemicarbazide and six different azo salicylaldehydes. The structure of the sensors was confirmed by spectroscopic methods. The selectivity and sensitivity in the recognition for acetate anion over other anions such as fluoride, chloride, iodide and dihydrogenphosphate anions were determined by naked-eyes and UV-vis spectra. The color of the solution containing sensor had an obvious change from light yellow to orange only after the addition of acetate anion in aqueous solution (water/dimethylsulfoxide, 7:3, v/v) while other anions did not cause obvious color change. The anion recognition property of the receptor via proton-transfer is monitored by UV-vis titration and 1H NMR spectroscopy. Under condition in aqueous solution of sensor 3e (water/dimethylsulfoxide, 7:3, v/v), linearity range for the quantification of acetate anion was 1-22 μM and limit of detection (LOD) of acetate anion was 0.71 μM.

  5. ANALYSIS OF ANIONIC METALLIZED AZO AND FORMAZAN DYES BY CAPILLARY ELECTROPHORESIS/MASS SPECTROMETRY

    EPA Science Inventory

    Capillary electrophoresis-mass spectrometry was applied to the separation of several anionic dyes containing copper(II), chromium(III), or cobalt(III) as part of the dye molecule. The dyes were separated using a 110 cmX50 mu m uncoated fused-silica capillary and a 5 mM ammonium a...

  6. EVALUATION OF AN AZO AND TWO ANTHRAQUINONE DYES FOR ALLERGIC POTENTIAL

    EPA Science Inventory

    Two dye mixtures and the individual component dyes were evaluated for the potential to Induce contact or pulmonary hypersensitivity. hese dye mixtures were suspect because of anecdotal reports of both pulmonary and contact hypersensitivity in assembly workers, and because the com...

  7. Rapid isolation of a facultative anaerobic electrochemically active bacterium capable of oxidizing acetate for electrogenesis and azo dyes reduction.

    PubMed

    Shen, Nan; Yuan, Shi-Jie; Wu, Chao; Cheng, Yuan-Yuan; Song, Xiang-Ning; Li, Wen-Wei; Tong, Zhong-Hua; Yu, Han-Qing

    2014-05-01

    In this study, 27 strains of electrochemically active bacteria (EAB) were rapidly isolated and their capabilities of extracellular electron transfer were identified using a photometric method based on WO3 nanoclusters. These strains caused color change of WO3 from white to blue in a 24-well agar plate within 40 h. Most of the isolated EAB strains belonged to the genera of Aeromonas and Shewanella. One isolate, Pantoea agglomerans S5-44, was identified as an EAB that can utilize acetate as the carbon source to produce electricity and reduce azo dyes under anaerobic conditions. The results confirmed the capability of P. agglomerans S5-44 for extracellular electron transfer. The isolation of this acetate-utilizing, facultative EBA reveals the metabolic diversity of environmental bacteria. Such strains have great potential for environmental applications, especially at interfaces of aerobic and anaerobic environments, where acetate is the main available carbon source. PMID:24648142

  8. Removal of azo dye by a highly graphitized and heteroatom doped carbon derived from fish waste: Adsorption equilibrium and kinetics.

    PubMed

    Liu, Zhengang; Zhang, Fang; Liu, Tingting; Peng, Nana; Gai, Chao

    2016-11-01

    A highly graphitized and heteroatom doped porous carbon was prepared from fish waste in the present study. The morphology and chemical composition of the resultant porous carbon were characterized by SEM-EDS, TEM, BET, XRD and Raman measurement. The prepared porous carbon was employed as an adsorbent for acid orange 7, a typical azo dye, removal from aqueous solution. The results showed that the porous carbon had ultrahigh surface area of 2146 m(2)/g, a high degree of graphitization structure and naturally doped with nitrogen and phosphorous. The maximum adsorption capacity of acid orange 7 reached 285.71 mg/g due to unique property of the prepared porous carbon. In addition, acid orange 7 adsorption onto the porous carbon well followed pseudo-second-order kinetics model and acid orange 7 diffusion in micropores was the potential rate controlling step. PMID:27526082

  9. Spectrophotometric determination of sildenafil citrate in pure form and in pharmaceutical formulation using some chromotropic acid azo dyes

    NASA Astrophysics Data System (ADS)

    Issa, Y. M.; El-Hawary, W. F.; Youssef, A. F. A.; Senosy, A. R.

    2010-04-01

    Two simple and highly sensitive spectrophotometric methods were developed for the quantitative determination of the drug sildenafil citrate (SC), Viagra, in pure form and in pharmaceutical formulations, through ion-associate formation reactions (method A) with mono-chromotropic acid azo dyes, chromotrope 2B (I) and chromotrope 2R (II) and ion-pair reactions (method B) with bi-chromotropic acid azo dyes, 3-phenylazo-6-o-carboxyphenylazo-chromotropic acid (III), bis-3,6-(o-hydroxyphenylazo)-chromotropic acid (IV), bis-3,6-(p-N,N-dimethylphenylazo)-chromotropic acid (V) and 3-phenylazo-6-o-hydroxyphenylazo-chromotorpic acid (VI). The reaction products, extractable in methylene chloride, were quantitatively measured at 540, 520, 540, 570, 600 and 575 nm using reagents, I-VI, respectively. The reaction conditions were studied and optimized. Beer's plots were linear in the concentration ranges 3.3-87.0, 3.3-96.0, 5.0-115.0, 2.5-125.0, 8.3-166.7 and 0.8-15.0 μg mL -1 with corresponding molar absorptivities 1.02 × 10 4, 8.34 × 10 3, 6.86 × 10 3, 5.42 × 10 3, 3.35 × 10 3 and 2.32 × 10 4 L mol -1 cm -1 using reagents I-VI, respectively. The limits of detection and Sandell's sensitivities were calculated. The methods were successfully applied to the analysis of commercial tablets (Vigoran) and the recovery study reveals that there is no interference from the common excipients that are present in tablets. Statistical comparison of the results was performed with regard to accuracy and precision using Student's t- and F-tests at 95% confidence level. There is no significant difference between the reported and proposed methods with regard to accuracy and precision.

  10. Decolorization and mineralization of Allura Red AC azo dye by solar photoelectro-Fenton: Identification of intermediates.

    PubMed

    Thiam, Abdoulaye; Sirés, Ignasi; Centellas, Francesc; Cabot, Pere Lluís; Brillas, Enric

    2015-10-01

    The degradation of 2.5L of Allura Red AC solutions in sulfate medium containing 0.50mM Fe(2+) has been studied by solar photoelectro-Fenton (SPEF) using a flow plant equipped with a Pt/air-diffusion cell and a solar photoreactor. Comparative electro-Fenton treatment yielded rapid total decolorization but poor mineralization, since most products were slowly destroyed by OH formed from Fenton's reaction between Fe(2+) and H2O2 generated at the air-diffusion cathode. In contrast, the potent action of UV radiation from sunlight in SPEF allowed the rapid photolysis of recalcitrant intermediates, thus giving rise to a quick mineralization. Sulfate and nitrate ions, along with a large proportion of volatile N-derivatives, were always released. The increase in current density and decrease in azo dye concentration accelerated the decolorization and mineralization in SPEF, although lower current efficiency and greater specific energy consumption were obtained. The most cost-effective SPEF treatment was found for 460 mg L(-1) azo dye in 0.05 M Na2SO4 at 50 mA cm(-2), which yielded 95% mineralization with 81% current efficiency and 8.50 kW h m(-3). No significant effect of sulfate concentration was found. Up to 16 aromatic intermediates and 11 short-chain carboxylic acids, including oxalic and oxamic as the most persistent ones, were detected by GC-MS and HPLC. The large oxidation ability of SPEF can be explained by the quick photolysis of Fe(III)-oxalate complexes and other undetected intermediates. PMID:25880813

  11. Role of surfactant derived intermediates in the efficacy and mechanism for radiation chemical degradation of a hydrophobic azo dye, 1-phenylazo-2-naphthol.

    PubMed

    Das, Laboni; Chatterjee, Suchandra; Naik, Devidas B; Adhikari, Soumyakanti

    2015-11-15

    A combined methodology involving gamma and pulse radiolysis, product analysis and toxicity studies has been adopted to comprehend the degradation process of a model hydrophobic azo dye, 1-phenylazo-2-naphthol, emphasizing the role of the surfactant, which is an integral part of textile waste. Two new and important findings are underlined in this article. The first is the direct attestation of the hydrazyl radical-parent adduct, formed in the reaction of the dye with e(-)aq followed by protonation and subsequent addition to the unreacted dye molecule. This has been confirmed from concentration dependent studies. Secondly, we have clearly shown that in the reaction of hydroxyl radical with the dye in Triton X-100 media, the initially produced TX radicals cause reductive degradation of the dye. Identification and detailed analysis of HPLC and GCMS data reveals that similar products are formed in both the reactions of e(-)aq and OH radicals. Moreover, the cytotoxicity of 10(-4)moldm(-3) dye was found to be reduced significantly after irradiation. Thus, the present study not only depicts new pathways for the degradation of hydrophobic azo dye, but also demonstrates the role of a surfactant in the entire process. PMID:26001620

  12. Decolorization and biodegradation of reactive dyes and dye wastewater by a developed bacterial consortium.

    PubMed

    Saratale, R G; Saratale, G D; Chang, J S; Govindwar, S P

    2010-11-01

    A bacterial consortium (consortium GR) consisting of Proteus vulgaris NCIM-2027 and Micrococcus glutamicus NCIM-2168 could rapidly decolorize and degrade commonly-used sulfonated reactive dye Green HE4BD and many other reactive dyes. Consortium GR shows markedly higher decolorization activity than that of the individual strains. The preferable physicochemical parameters were identified to achieve higher dye degradation and decolorization efficiency. The supplementation of cheap co-substrates (e.g., extracts of agricultural wastes) could enhance the decolorization performance of consortium GR. Extent of mineralization was determined with TOC and COD measurements, showing nearly complete mineralization of Green HE4BD by consortium GR (up to 90% TOC and COD reduction) within 24 h. Oxidoreductive enzymes seemed to be involved in fast decolorization/degradation process with the evidence of enzymes induction in the bacterial consortium. Phytotoxicity and microbial toxicity studies confirm that the biodegraded products of Green HE4BD by consortium GR are non-toxic. Consortium GR also shows significant biodegradation and decolorization activities for mixture of reactive dyes as well as the effluent from actual dye manufacturing industry. This confers the possibility of applying consortium GR for the treatment of industrial wastewaters containing dye pollutants. PMID:20407917

  13. Spectral studies and molecular orbital PPP-calculations of some azo-dyes

    NASA Astrophysics Data System (ADS)

    Shalabi, A. S.; Dessouki, H. A.; Issa, Y. M.; Ahmed, I. S.

    2002-10-01

    The UV, IR and 1H-NMR spectra of some 4-( R-phenyl azo) 1-hydroxy 2-naphthoic acid derivatives are studied. The effects of substituent groups and the solvent polarity on electronic spectral, IR bands and 1H-NMR proton chemical shifts are considered, the molecular orbital calculations obtained are rationalized quantitatively with that obtained practically using the PPP-model with configuration interaction (CI).

  14. Effect of electrode position on azo dye removal in an up-flow hybrid anaerobic digestion reactor with built-in bioelectrochemical system

    PubMed Central

    Cui, Min-Hua; Cui, Dan; Lee, Hyung-Sool; Liang, Bin; Wang, Ai-Jie; Cheng, Hao-Yi

    2016-01-01

    In this study, two modes of hybrid anaerobic digestion (AD) bioreactor with built-in BESs (electrodes installed in liquid phase (R1) and sludge phase (R2)) were tested for identifying the effect of electrodes position on azo dye wastewater treatment. Alizarin yellow R (AYR) was used as a model dye. Decolorization efficiency of R1 was 90.41 ± 6.20% at influent loading rate of 800 g-AYR/ m3·d, which was 39% higher than that of R2. The contribution of bioelectrochemical reduction to AYR decolorization (16.23 ± 1.86% for R1 versus 22.24 ± 2.14% for R2) implied that although azo dye was mainly removed in sludge zone, BES further improved the effluent quality, especially for R1 where electrodes were installed in liquid phase. The microbial communities in the electrode biofilms (dominant by Enterobacter) and sludge (dominant by Enterococcus) were well distinguished in R1, but they were similar in R2. These results suggest that electrodes installed in liquid phase in the anaerobic hybrid system are more efficient than that in sludge phase for azo dye removal, which give great inspirations for the application of AD-BES hybrid process for various refractory wastewaters treatment. PMID:27121278

  15. Effect of electrode position on azo dye removal in an up-flow hybrid anaerobic digestion reactor with built-in bioelectrochemical system.

    PubMed

    Cui, Min-Hua; Cui, Dan; Lee, Hyung-Sool; Liang, Bin; Wang, Ai-Jie; Cheng, Hao-Yi

    2016-01-01

    In this study, two modes of hybrid anaerobic digestion (AD) bioreactor with built-in BESs (electrodes installed in liquid phase (R1) and sludge phase (R2)) were tested for identifying the effect of electrodes position on azo dye wastewater treatment. Alizarin yellow R (AYR) was used as a model dye. Decolorization efficiency of R1 was 90.41 ± 6.20% at influent loading rate of 800 g-AYR/ m(3)·d, which was 39% higher than that of R2. The contribution of bioelectrochemical reduction to AYR decolorization (16.23 ± 1.86% for R1 versus 22.24 ± 2.14% for R2) implied that although azo dye was mainly removed in sludge zone, BES further improved the effluent quality, especially for R1 where electrodes were installed in liquid phase. The microbial communities in the electrode biofilms (dominant by Enterobacter) and sludge (dominant by Enterococcus) were well distinguished in R1, but they were similar in R2. These results suggest that electrodes installed in liquid phase in the anaerobic hybrid system are more efficient than that in sludge phase for azo dye removal, which give great inspirations for the application of AD-BES hybrid process for various refractory wastewaters treatment. PMID:27121278

  16. Bioelectricity Generation and Bioremediation of an Azo-Dye in a Microbial Fuel Cell Coupled Activated Sludge Process.

    PubMed

    Khan, Mohammad Danish; Abdulateif, Huda; Ismail, Iqbal M; Sabir, Suhail; Khan, Mohammad Zain

    2015-01-01

    Simultaneous bioelectricity generation and dye degradation was achieved in the present study by using a combined anaerobic-aerobic process. The anaerobic system was a typical single chambered microbial fuel cell (SMFC) which utilizes acid navy blue r (ANB) dye along with glucose as growth substrate to generate electricity. Four different concentrations of ANB (50, 100, 200 and 400 ppm) were tested in the SMFC and the degradation products were further treated in an activated sludge post treatment process. The dye decolorization followed pseudo first order kinetics while the negative values of the thermodynamic parameter ∆G (change in Gibbs free energy) shows that the reaction proceeds with a net decrease in the free energy of the system. The coulombic efficiency (CE) and power density (PD) attained peak values at 10.36% and 2,236 mW/m2 respectively for 200 ppm of ANB. A further increase in ANB concentrations results in lowering of cell potential (and PD) values owing to microbial inhibition at higher concentrations of toxic substrates. Cyclic voltammetry studies revealed a perfect redox reaction was taking place in the SMFC. The pH, temperature and conductivity remain 7.5-8.0, 27(±2°C and 10.6-18.2 mS/cm throughout the operation. The biodegradation pathway was studied by the gas chromatography coupled with mass spectroscopy technique, suggested the preferential cleavage of the azo bond as the initial step resulting in to aromatic amines. Thus, a combined anaerobic-aerobic process using SMFC coupled with activated sludge process can be a viable option for effective degradation of complex dye substrates along with energy (bioelectricity) recovery. PMID:26496083

  17. Bioelectricity Generation and Bioremediation of an Azo-Dye in a Microbial Fuel Cell Coupled Activated Sludge Process

    PubMed Central

    Khan, Mohammad Danish; Abdulateif, Huda; Ismail, Iqbal M.; Sabir, Suhail; Khan, Mohammad Zain

    2015-01-01

    Simultaneous bioelectricity generation and dye degradation was achieved in the present study by using a combined anaerobic-aerobic process. The anaerobic system was a typical single chambered microbial fuel cell (SMFC) which utilizes acid navy blue r (ANB) dye along with glucose as growth substrate to generate electricity. Four different concentrations of ANB (50, 100, 200 and 400 ppm) were tested in the SMFC and the degradation products were further treated in an activated sludge post treatment process. The dye decolorization followed pseudo first order kinetics while the negative values of the thermodynamic parameter ∆G (change in Gibbs free energy) shows that the reaction proceeds with a net decrease in the free energy of the system. The coulombic efficiency (CE) and power density (PD) attained peak values at 10.36% and 2,236 mW/m2 respectively for 200 ppm of ANB. A further increase in ANB concentrations results in lowering of cell potential (and PD) values owing to microbial inhibition at higher concentrations of toxic substrates. Cyclic voltammetry studies revealed a perfect redox reaction was taking place in the SMFC. The pH, temperature and conductivity remain 7.5–8.0, 27(±2°C and 10.6–18.2 mS/cm throughout the operation. The biodegradation pathway was studied by the gas chromatography coupled with mass spectroscopy technique, suggested the preferential cleavage of the azo bond as the initial step resulting in to aromatic amines. Thus, a combined anaerobic-aerobic process using SMFC coupled with activated sludge process can be a viable option for effective degradation of complex dye substrates along with energy (bioelectricity) recovery. PMID:26496083

  18. Bacterial Decolorization of Textile Azo Dye Acid Orange by Staphylococcus hominis RMLRT03

    PubMed Central

    Singh, Rajat Pratap; Singh, Pradeep Kumar; Singh, Ram Lakhan

    2014-01-01

    A bacterial strain RMLRT03 with ability to decolorize textile dye Acid Orange dye was isolated from textile effluent contaminated soil of Tanda, Ambedkar Nagar, Uttar Pradesh (India). The decolorization studies were performed in Bushnell and Haas medium (BHM) amended with Acid Orange dye. The bacterial strain was identified as Staphylococcus hominis on the basis of 16S rDNA sequence. The bacterial strain exhibited good decolorization ability with glucose and yeast extract supplementation as cosubstrate in static conditions. The optimal condition for the decolorization of Acid Orange dye by Staphylococcus hominis RMLRT03 strain were at pH 7.0 and 35°C in 60 h of incubation. The bacterial strain could tolerate high concentrations of Acid Orange dye up to 600 mg l-1. The high decolorizing activity under natural environmental conditions indicates that the bacterial strain has practical application in the treatment of dye containing wastewaters. PMID:25253925

  19. Enhanced degradation of azo dye by nanoporous-copper-decorated Mg-Cu-Y metallic glass powder through dealloying pretreatment

    NASA Astrophysics Data System (ADS)

    Luo, Xuekun; Li, Ran; Zong, Jingzhen; Zhang, Ying; Li, Haifei; Zhang, Tao

    2014-06-01

    A controllable uniform nanoporous copper (NPC) layer was synthesized on the surface of the ball-milled powder of Mg65Cu25Y10 metallic glass by dealloying. The morphology, the elemental surface composition and the phase structure of the powders were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffractometry, respectively. The composite powder with a core-shell structure shows higher degradation efficiency of the azo dye of Direct Blue 6 than the untreated powder and the pure NPC. The improved performance can be attributed to the strong synergistic effect between the NPC layer and the metallic glass matrix, because the nanoporous structure provides large surface area for the adsorption of the dye molecules and three-dimensional diffusion channels of reaction masses, as well as the dissolution acceleration of the active atoms through local galvanic cell reaction. This tunable pretreatment is a promising surface activation method for novel chemical applications of metallic glasses.

  20. Remediation of Water Contaminated with an Azo Dye: An Undergraduate Laboratory Experiment Utilizing an Inexpensive Photocatalytic Reactor

    NASA Astrophysics Data System (ADS)

    Bumpus, John A.; Tricker, Jennifer; Andrzejewski, Ken; Rhoads, Heather; Tatarko, Matthew

    1999-12-01

    The construction and use of an inexpensive photocatalytic reactor that utilizes titanium dioxide as the photocatalyst for wastewater treatment is described. In these experiments and in supplementary material, students are made aware that a variety of techniques have been developed to treat wastewaters, including those generated by the chemical industry. Water contaminated with the azo dye Congo Red was selected as an example of how one might treat contaminated water from a textile manufacturing facility. These experiments emphasize that, in addition to product development, chemists must also be concerned with waste treatment. A summary of the theory of titanium dioxide-mediated photocatalysis is provided. The phenomenon of photosensitization is also discussed. The usefulness of Congo Red is summarized and a brief history of this dye is given. In addition to being inexpensive, the photocatalytic reactor described is easy to construct and uses a readily available low-wattage fluorescent light. An important feature of this reactor is that the heat generated by the light source is readily dissipated by the water undergoing treatment. Thus no special cooling apparatus is required. One of the most important aspects of this work is that it provides a wide variety of continuing research suggestions that would be suitable and readily accomplished in undergraduate departments and high school laboratories; even those where budgetary priorities are a major concern. Use of this reactor would also enable students to design systems to treat "real-world" wastes, including some that are generated in instructional laboratories.

  1. Decolorization of sulfonated azo dye Metanil Yellow by newly isolated bacterial strains: Bacillus sp. strain AK1 and Lysinibacillus sp. strain AK2.

    PubMed

    Anjaneya, O; Souche, S Yogesh; Santoshkumar, M; Karegoudar, T B

    2011-06-15

    Two different bacterial strains capable of decolorizing a highly water soluble azo dye Metanil Yellow were isolated from dye contaminated soil sample collected from Atul Dyeing Industry, Bellary, India. The individual bacterial strains Bacillus sp. AK1 and Lysinibacillus sp. AK2 decolorized Metanil Yellow (200 mg L(-1)) completely within 27 and 12h respectively. Various parameters like pH, temperature, NaCl and initial dye concentrations were optimized to develop an economically feasible decolorization process. The maximum concentration of Metanil Yellow (1000 mg L(-1)) was decolorized by strains AK2 and AK1 within 78 and 84 h respectively. These strains could decolorize Metanil Yellow over a broad pH range 5.5-9.0; the optimum pH was 7.2. The decolorization of Metanil Yellow was most efficient at 40°C and confirmed by UV-visible spectroscopy, TLC, HPLC and GC/MS analysis. Further, both the strains showed the involvement of azoreductase in the decolorization process. Phytotoxicity studies of catabolic products of Metanil Yellow on the seeds of chick pea and pigeon pea revealed much reduction in the toxicity of metabolites as compared to the parent dye. These results indicating the effectiveness of strains AK1 and AK2 for the treatment of textile effluents containing azo dyes. PMID:21470774

  2. Synthesis and characterization of Copper(II) complexes of an azo dye derived from 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one

    NASA Astrophysics Data System (ADS)

    Kumar, V. G. Viju; Rajan, Nidhy Mary

    2014-10-01

    Azo dye based metal complexes have been found potential applications for molecular memory storage and nonlinear optical elements. Copper(II) complexes with azo dye derived from 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one with p-cresol, m-cresol and o-cresol having the composition [CuL2Cl2] were synthesized. The Complexes were characterized by elemental analysis, electrical conductance, magnetic susceptibility, mass spectroscopy, 1H-NMR, ESR, IR, UV-Vis spectroscopy and TG-DTG technique. The IR spectra suggest the ligand act as neutral bidentate ligand and complexes are monomeric and non-electrolytes. A distorted octahedral geometry was suggested for all the three complexes. The thermal decomposition characteristics have been studied and kinetic parameters were calculated using Coats-Redfern equation. The biological activity of complex was investigated.

  3. A comparative study of selected disperse azo dye derivatives based on spectroscopic (FT-IR, NMR and UV-Vis) and nonlinear optical behaviors.

    PubMed

    Cinar, Mehmet; Coruh, Ali; Karabacak, Mehmet

    2014-03-25

    In the present work, a combined experimental and quantum chemical study on ground state equilibrium structure, spectroscopic and nonlinear optical properties of selected disperse azo dye molecules are reported. The vibrational transitions were identified based on the recorded FT-IR spectra in the range of 4000-400 cm(-1) for solid state, simulated IR spectra and total energy distribution (TED) of vibrational modes. The chemical shifts were determined from the results of observed (1)H and (13)C NMR spectra in chloroform and dimethylsulfoxide solution. The DFT/gauge-invariant atomic orbital (GIAO) methodology was applied to predict the magnetic properties. Electronic properties were carried out by UV-Vis spectroscopy and TD-DFT/CIS approach. The nonlinear optical (NLO) features were addressed theoretically. A detailed description of spectroscopic and NLO behaviors of studied disperse azo dyes was reported with the help of comparison of experimental measurements and theoretical calculations. PMID:24345608

  4. A comparative study of selected disperse azo dye derivatives based on spectroscopic (FT-IR, NMR and UV-Vis) and nonlinear optical behaviors

    NASA Astrophysics Data System (ADS)

    Cinar, Mehmet; Coruh, Ali; Karabacak, Mehmet

    2014-03-01

    In the present work, a combined experimental and quantum chemical study on ground state equilibrium structure, spectroscopic and nonlinear optical properties of selected disperse azo dye molecules are reported. The vibrational transitions were identified based on the recorded FT-IR spectra in the range of 4000-400 cm-1 for solid state, simulated IR spectra and total energy distribution (TED) of vibrational modes. The chemical shifts were determined from the results of observed 1H and 13C NMR spectra in chloroform and dimethylsulfoxide solution. The DFT/gauge-invariant atomic orbital (GIAO) methodology was applied to predict the magnetic properties. Electronic properties were carried out by UV-Vis spectroscopy and TD-DFT/CIS approach. The nonlinear optical (NLO) features were addressed theoretically. A detailed description of spectroscopic and NLO behaviors of studied disperse azo dyes was reported with the help of comparison of experimental measurements and theoretical calculations.

  5. In situ homeotropic alignment of nematic liquid crystals based on photoisomerization of azo-dye, physical adsorption of aggregates, and consequent topographical modification.

    PubMed

    Kundu, Sudarshan; Lee, Myong-Hoon; Lee, Seung Hee; Kang, Shin-Woong

    2013-06-25

    In situ homeotropic alignment is achieved by photochromic trans- to cis-isomerization of an azo-dye doped in a nematic host. The augmented dipole moment of the cis-isomer formed under UV-irradiation expedites molecular assembly into crystalline aggregates. Subsequent deposition of the aggregates creates a roughened surface and induces an anchoring transition from the initial planar to a homeotropic alignment of the LCs. PMID:23666876

  6. Highly selective and sensitive colorimetric probe for hydrogen sulfide by a copper (II) complex of azo-dye based on chemosensing ensemble approach

    NASA Astrophysics Data System (ADS)

    Zhang, Dengqing; Jin, Wusong

    2012-05-01

    A copper (II) complex of azo-dye (Cu-1) has been synthesized by the reaction of 1-(2-pyridylazo)-2-naphthol (1) with copper (II) chloride. The complex Cu-1 is able to selectively sense hydrogen sulfide over other anions followed by the release of compound 1 to give a remarkable change of UV-vis absorption at neutral pH in aqueous solution.

  7. Bioremoval of the azo dye Congo Red by the microalga Chlorella vulgaris.

    PubMed

    Hernández-Zamora, Miriam; Cristiani-Urbina, Eliseo; Martínez-Jerónimo, Fernando; Perales-Vela, Hugo Virgilio; Ponce-Noyola, Teresa; Montes-Horcasitas, María del Carmen; Cañizares-Villanueva, Rosa Olivia

    2015-07-01

    Discharge of dye-containing wastewater by the textile industry can adversely affect aquatic ecosystems and human health. Bioremoval is an alternative to industrial processes for detoxifying water contaminated with dyes. In this work, active and inactive biomass of the microalga Chlorella vulgaris was assayed for the ability to remove Congo Red (CR) dye from aqueous solutions. Through biosorption and biodegradation processes, Chlorella vulgaris was able to remove 83 and 58 % of dye at concentrations of 5 and 25 mg L(-1), respectively. The maximum adsorption capacity at equilibrium was 200 mg g(-1). The Langmuir model best described the experimental equilibrium data. The acute toxicity test (48 h) with two species of cladocerans indicated that the toxicity of the dye in the effluent was significantly decreased compared to the initial concentrations in the influent. Daphnia magna was the species less sensitive to dye (EC50 = 17.0 mg L(-1)), followed by Ceriodaphnia dubia (EC50 = 3.32 mg L(-1)). These results show that Chlorella vulgaris significantly reduced the dye concentration and toxicity. Therefore, this method may be a viable option for the treatment of this type of effluent. PMID:25772869

  8. Photoinduced reordering in thin azo-dye films and light-induced reorientation dynamics of the nematic liquid-crystal easy axis.

    PubMed

    Kiselev, Alexei D; Chigrinov, V G; Pasechnik, S V; Dubtsov, A V

    2012-07-01

    We theoretically study the kinetics of photoinduced reordering triggered by linearly polarized (LP) reorienting light in thin azo-dye films that were initially illuminated with LP ultraviolet pumping beam. The process of reordering is treated as a rotational diffusion of molecules in the light intensity-dependent mean-field potential. The two-dimensional diffusion model which is based on the free energy rotational Fokker-Planck equation and describes the regime of in-plane reorientation is generalized to analyze the dynamics of the azo-dye order parameter tensor at varying polarization azimuth of the reorienting light. It is found that, in the photosteady state, the intensity of LP reorienting light determines the scalar order parameter (the largest eigenvalue of the order parameter tensor), whereas the steady state orientation of the corresponding eigenvector (the in-plane principal axis) depends solely on the polarization azimuth. We show that, under certain conditions, reorientation takes place only if the reorienting light intensity exceeds its critical value. Such threshold behavior is predicted to occur in the bistability region provided that the initial principal axis lies in the polarization plane of reorienting light. The model is used to interpret the experimental data on the light-induced azimuthal gliding of the liquid-crystal easy axis on photoaligned azo-dye substrates. PMID:23005436

  9. Sequential decolorization of azo dye and mineralization of decolorization liquid coupled with bioelectricity generation using a pH self-neutralized photobioelectrochemical system operated with polarity reversion.

    PubMed

    Sun, Jian; Hu, Yongyou; Li, Wanjun; Zhang, Yaping; Chen, Jie; Deng, Feng

    2015-05-30

    A novel photobioelectrochemical system (PBES) was developed by acclimating algal-bacterial biofilm in both anode and cathode using Chlorella vulgaris and indigenous wastewater bacteria as inoculums. The PBES was operated in polarity reversion mode depend on dark/light alternate reaction to achieve simultaneous pH self-neutralization, azo dye degradation (Congo red) and bioelectricity generation. The anodic accumulated acidity and cathodic accumulated alkalinity were self-neutralized after polarity reversion and hence eliminate the membrane pH gradient. The Congo red was first decolored in the dark anode and the resultant decolorization liquid was subsequently mineralized after the dark anode changing to the photo-biocathode. The presence of C. vulgaris significantly enhanced the two-stage degradation of Congo red, with 93% increases in decolorization rates and 8% increases in mineralization compared to the algae-free BES. The PBES continuously generated stable voltage output over four months under repeatedly reversion of polarity. The maximum power density produced before and after polarity reversion was 78 and 61 mW/m(2), respectively. The synergy between C. vulgaris and mixed bacteria was responsible for the successful operation of the PBES which can be potentially applied to treat wastewater containing azo dye with benefits of enhanced azo dye degradation, high net power output and buffer minimization. PMID:25723885

  10. An interesting coordination complex formed between the azo dye Sudan Red G and cobalt ion

    NASA Astrophysics Data System (ADS)

    Garcia, Humberto C.; Ferreira, Gilson Rodrigues; de Oliveira, Luiz Fernando C.

    2014-03-01

    In this study, the synthesis, spectroscopic analysis (Raman and infrared) and crystal structure of compound denominated [Co(SRG)2]·CH3CH2OH have been investigated, were SRG is 1-(2-methoxyphenyl-azo)-2-naphthol or simply Sudan Red G and CH3CH2OH is one molecule of ethanol. The repeating unit is formed by the presence of an adduct complex constituted by two SRG ligands coordinated to the cobalt ion in a slightly distorted octahedral geometry. The other building block consists of a molecule of ethanol, which was used as the reaction solvent. The spectroscopic analysis provided important information related to coordination and formation of molecular complex through its mains bands. In the Raman spectrum the presence of marker bands as in at 1224 cm-1 ascribed to the binder SRG [δ(NH) + ν(COC) + δ(CH) + ν(CC)] were displaced in the complex formed to 1232 cm-1 due to the loss of the proton from the azo group and the formation of a bond between the oxygen of the ether group with the metal ion. In the infrared spectrum the bands at 653/489 cm-1 and 622/528 cm-1 were attributed to [ν(CoO) + νCC)] and [νCoN + νCC] characteristic of the metal-ligand bond.

  11. Studies on Dyeing Process Variables for Salt Free Reactive Dyeing of Glycine Modified Cationized Cotton Muslin Fabric

    NASA Astrophysics Data System (ADS)

    Samanta, Ashis Kumar; Kar, Tapas Ranjan; Mukhopadhyay, Asis; Shome, Debashis; Konar, Adwaita

    2015-04-01

    Bleached cotton muslin fabric with or without pre-oxidized with NaIO4 (oxy-cotton) was chemically modified with glycine (amino acid) by pad dry calendar process to investigate the changes in textile properties and its dyeability with reactive dye. This glycine modified cotton incorporates new functional groups producing -NH3 + or -C=NH+ -ion (cationic groups) in acid bath to obtain cationized cotton making it amenable to a newer route of salt free reactive dyeing in acid bath. In the present work the process variables of reactive dyeing in the salt free acid bath for dyeing of amine (glycine) modified cationized cotton were studied and optimized. The present study also includes thorough investigation of changes in important textile related properties and dyeability with reactive dye after such chemical modifications. Between oxidized and unoxidized cotton muslin fabric, unoxidized cotton fabric shows better reactive dye uptake in both conventional alkaline bath dyeing and nonconventional salt free acid bath dyeing particularly for high exhaustion class of reactive dye with acceptable level of colour fastness and overall balance of other textile related properties. Moreover, application of dye fixing agent further improves surface colour depth (K/S) of the glycine treated cotton fabric for HE brand of reactive dyes. Corresponding reaction mechanisms for such modifications were supported by FTIR spectroscopy. Finally unoxidized cotton and pre-oxidized cotton further treated with glycine (amino acid) provide a new route of acid bath salt free reactive dyeing showing much higher dye uptake and higher degree of surface cover with amino acid residue anchored to modified cotton.

  12. Comparison of three combined sequencing batch reactor followed by enhanced Fenton process for an azo dye degradation: Bio-decolorization kinetics study.

    PubMed

    Azizi, A; Alavi Moghaddam, M R; Maknoon, R; Kowsari, E

    2015-12-15

    The purpose of this research was to compare three combined sequencing batch reactor (SBR) - Fenton processes as post-treatment for the treatment of azo dye Acid Red 18 (AR18). Three combined treatment systems (CTS1, CTS2 and CTS3) were operated to investigate the biomass concentration, COD removal, AR18 dye decolorization and kinetics study. The MLSS concentration of CTS2 reached 7200 mg/L due to the use of external feeding in the SBR reactor of CTS2. The COD concentration remained 273 mg/L and 95 mg/L (initial COD=3270 mg/L) at the end of alternating anaerobic-aerobic SBR with external feeding (An-A MSBR) and CTS2, respectively, resulting in almost 65% of Fenton process efficiency. The dye concentration of 500 mg/L was finally reduced to less than 10mg/L in all systems indicating almost complete AR18 decolorization, which was also confirmed by UV-vis analysis. The dye was removed following two successive parts as parts 1 and 2 with pseudo zero-order and pseudo first-order kinetics, respectively, in all CTSs. Higher intermediate metabolites degradation was obtained using HPLC analysis in CTS2. Accordingly, a combined treatment system can be proposed as an appropriate and environmentally-friendly system for the treatment of the azo dye AR18 in wastewater. PMID:26143197

  13. Removal of COD and color from hydrolyzed textile azo dye by combined ozonation and biological treatment.

    PubMed

    de Souza, Selene Maria de Arruda Guelli Ulson; Bonilla, Karin Angela Santos; de Souza, Antônio Augusto Ulson

    2010-07-15

    The application of ozonation has been increasing in recent years, the main disadvantage of this type of treatment being related to the by-products, which can have toxic and carcinogenic properties, and therefore should be studied further. In this study, the combined treatment of ozonation and subsequent biological degradation with a biofilm, to reduce the color and chemical oxygen demand (COD), was investigated. The experimental part of the study consisted of two phases. The first phase was the ozonation process, the results obtained demonstrated that the ozonation of Remazol Black B dye at pH values of 3-11, was effective, partially oxidizing and completely decolorizing the effluent, even at relatively high concentrations of the dye (500 mg/L). Color removal efficiencies greater than 96% were obtained in all cases. The degradation kinetics of ozone is a pseudo-first-order reaction with respect to the dye concentration. It was possible to verify that the ozonation process as a pre-treatment increases the dye degradation efficiency. For the biological treatment, an increase in ozonization time increased the dye concentration reduction in hydrolyzed dye synthetic effluent. The toxicological results of the tests with Daphnia Magna showed that there is an increase in toxicity after ozonization and a decrease after submitting the ozonized synthetic wastewater to biological treatment with a biofilm. PMID:20227826

  14. Biodecolourisation of reactive red an industrial dye by Phlebia spp. .

    PubMed

    Chander, Mukesh; Singh, Daljit; Kaur, Ramandeep

    2014-11-01

    Four white rot fungi namely Phanerochaete chrysosporium, Phlebia floridensis, P. radiata and P. brevispora were selected for their ligninolytic enzymes viz., lignin peroxidase, manganese peroxidase and laccase. Cell free enzyme extracts (as such and concentrated) obtained from these fungi were tested for their ability to decolourise reactive red 28 (Congo red), an industrial dye. The use of cell free enzyme extracts helped to overcome the problem of adsorption of dye to mycelia. Laccase production was best expressed in P. brevispora. Increase in decolourisation percentage by concentrated culture extract was comparable to increase in enzyme activity. P. floridensis proved to be a better dye decolouriser in comparison to Pha. chrysosporium, thus showing its potential for biocleaning of industrial wastes and wastewaters. PMID:25522502

  15. WASTES FROM MANUFACTURE OF DYES AND PIGMENTS: VOLUME 1. AZO DYES AND PIGMENTS (BENZIDINE AND ITS CONGENERS SUBSECTOR)

    EPA Science Inventory

    In a study of the manufacture of dyes and pigments based on benzidine and its congeners, several solid waste streams that could contain hazardous material were identified. The solid residues included filter cake from clarifying operations, intermediates on discarded shipping cont...

  16. Synthesis of some transition metal complexes with new heterocyclic thiazolyl azo dye and their uses as sensitizers in photo reactions

    NASA Astrophysics Data System (ADS)

    AL-Adilee, Khalid J.; Abass, Ahmed K.; Taher, Ali M.

    2016-03-01

    A new heterocyclic thiazolylazo dye ligand, 2- [bar2-(4, 5- dimethyl thiazolyl) azo ] -4-Ethoxy Phenol (DMeTAEP), (LH) was synthesized by the diazotization of 4.5-dimethyl thiazolylazonium chloride and coupling with 4- Ethoxy phenol in alkaline alcoholic solution under suitable optimized experimental conditions to yield a new azo dye ligand. The structure of ligand and its complexes was prepared from Co(III), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), Ag (I) and Au(III) ions. They confirmed by XRD, SEM, (TG-DTG) thermal analysis, 1H-NMR,UV-visb, mass and FT-IR spectroscopic methods, elemental analysis, atomic absorption, magnetic susceptibility and molar conductance. The mole ratio [M: L], it was also studied which was 1:1 for Ag (I) and Au (III) complexes and 1:2 The rest of the metal complexes. The isolated solid complexes are found to have the general formula [M (L)2 ] Cln.mH2O, where n = 1, m = 0 when M = Co (III) and n = 0, m = 1 when M = Ni (II), and Hg(II) while n = 0 and m = 0 when M = Cu (II), Zn (II), Cd (II) and ]ML (H2O)] of Ag(I) - complex but Au(III)-complex structural formula was [Au(L)Cl] Cl conductivity measurements for prepared complexes showed 1:1 electrolyte for Co(III(and Au(III) complexes and non - electrolyte the rest of complexes. The spectral and analytical data revealed that this ligand behaves as a tridentate chelating agent and coordination number of all metal ions were found to be six except for Ag (I) and Au (III) which was four. The activities of complexes were examined as sensitizers in the photocatalytic reaction of p-nitro aniline (PNA) which is used as a model of water pollutants.

  17. Biodegradable hollow zein nanoparticles for removal of reactive dyes from wastewater.

    PubMed

    Xu, Helan; Zhang, Yue; Jiang, Qiuran; Reddy, Narendra; Yang, Yiqi

    2013-08-15

    In this study, biodegradable hollow zein nanoparticles with diameters less than 100 nm were developed to remove reactive dyes from simulated post-dyeing wastewater with remarkably high efficiency. Reactive dyes are widely used to color cellulosic materials, such as cotton and rayon. Wastewater from reactive dyeing process contains up to 50% dye and electrolytes with concentrations up to 100 g L(-1). Current methods to remove reactive dyes from wastewater are suffering from low adsorption capacities or low biodegradability of the sorbents. In this research, biodegradable zein nanoparticles showed high adsorption capacities for dyes. Hollow zein nanoparticles showed higher adsorption for Reactive Blue 19 than solid structures, and the adsorption amount increased as temperature decreased, pH decreased or initial dye concentration increased. At pH 6.5 and pH 9.0, increasing electrolyte concentration could improve dye adsorption significantly. Under simulated post-dyeing condition with 50.0 g L(-1) salt and pH 9.0, maximum adsorption of 1016.0 mg dye per gram zein nanoparticles could be obtained. The adsorption capacity was much higher than that of various biodegradable adsorbents developed to remove reactive dye. It is suggested that the hollow zein nanoparticles are good candidates to remove reactive dye immediately after dyeing process. PMID:23643969

  18. Effect of an azo dye on the performance of an aerobic granular sludge sequencing batch reactor treating a simulated textile wastewater.

    PubMed

    Franca, Rita D G; Vieira, Anabela; Mata, Ana M T; Carvalho, Gilda S; Pinheiro, Helena M; Lourenço, Nídia D

    2015-11-15

    This study analyzed the effect of an azo dye (Acid Red 14) on the performance of an aerobic granular sludge (AGS) sequencing batch reactor (SBR) system operated with 6-h anaerobic-aerobic cycles for the treatment of a synthetic textile wastewater. In this sense, two SBRs inoculated with AGS from a domestic wastewater treatment plant were run in parallel, being one supplied with the dye and the other used as a dye-free control. The AGS successfully adapted to the new hydrodynamic conditions forming smaller, denser granules in both reactors, with optimal sludge volume index values of 19 and 17 mL g(-1) after 5-min and 30-min settling, respectively. As a result, high biomass concentration levels and sludge age values were registered, up to 13 gTSS L(-1) and 40 days, respectively, when deliberate biomass wastage was limited to the sampling needs. Stable dye removal yields above 90% were attained during the anaerobic reaction phase, confirmed by the formation of one of the aromatic amines arising from azo bond reduction. The control of the sludge retention time (SRT) to 15 days triggered a 30% reduction in the biodecolorization yield. However, the increase of the SRT values back to levels above 25 days reverted this effect and also promoted the complete bioconversion of the identified aromatic amine during the aerobic reaction phase. The dye and its breakdown products did not negatively affect the treatment performance, as organic load removal yields higher than 80% were attained in both reactors, up to 77% occurring in the anaerobic phase. These high anaerobic organic removal levels were correlated to an increase of Defluviicoccus-related glycogen accumulating organisms in the biomass. Also, the capacity of the system to deal with shocks of high dye concentration and organic load was successfully demonstrated. Granule breakup after long-term operation only occurred in the dye-free control SBR, suggesting that the azo dye plays an important role in improving granule

  19. Use of RSM modeling for optimizing decolorization of simulated textile wastewater by Pseudomonas aeruginosa strain ZM130 capable of simultaneous removal of reactive dyes and hexavalent chromium.

    PubMed

    Maqbool, Zahid; Hussain, Sabir; Ahmad, Tanvir; Nadeem, Habibullah; Imran, Muhammad; Khalid, Azeem; Abid, Muhammad; Martin-Laurent, Fabrice

    2016-06-01

    Remediation of colored wastewater loaded with dyes and metal ions is a matter of interest nowadays. In this study, 220 bacteria isolated from textile wastewater were tested for their potential to decolorize each of the four reactive dyes (reactive red-120, reactive black-5, reactive yellow-2, and reactive orange-16) in the presence of a mixture of four different heavy metals (Cr, Zn, Pb, Cd) commonly found in textile effluents. Among the tested bacteria, the isolate ZM130 was found to be the most efficient in decolorizing reactive dyes in the presence of the mixture of heavy metals and was identified as Pseudomonas aeruginosa strain ZM130 by 16S rRNA gene analysis. The strain ZM130 was highly effective in simultaneously removing hexavalent chromium (25 mg L(-1)) and the azo dyes (100 mg L(-1)) from the simulated wastewater even in the presence of other three heavy metals (Zn, Pb, Cd). Simultaneous removal of chromium and azo dyes ranged as 76.6-98.7 % and 51.9-91.1 %, respectively, after 180 h incubation. On the basis of quadratic polynomial equation and response surfaces given by the response surface methodology (RSM), optimal salt content, pH, carbon co-substrate content, and level of multi-metal mixtures for decolorization of reactive red-120 in a simulated textile wastewater by the strain ZM130 were predicted to be 19.8, 7.8, and 6.33 g L(-1) and a multi-metal mixture (Cr 13.10 mg L(-1), Pb 26.21 mg L(-1), Cd 13.10 mg L(-1), Zn 26.21 mg L(-1)), respectively. Moreover, the strain ZM130 also exhibited laccase and nicotinamide adenine dinucleotide (reduced)-dichlorophenolindophenol reductase (NADH-DCIP reductase) activity during the decolorization of reactive red-120. However, the laccase activity was found to be maximum in the presence of 300 mg L(-1) of the dye as compared to other concentrations. Hence, the isolation of this strain might serve as a potential bio-resource required for developing the strategies aiming at bioremediation of the

  20. Investigation on substituent effect in novel azo-naphthol dyes containing polymethacrylates for nonlinear optical studies

    NASA Astrophysics Data System (ADS)

    Shalini Rosalyn, P. Delphia; Senthil, S.; Kannan, P.; Vinitha, G.; Ramalingam, A.

    2007-09-01

    A novel structurally isomeric and free-radically polymerizable methacrylates bearing azo-naphthol group in the side chain spaced away from the backbone by a hexamethylene spacer and substituted in 4-position with electron-withdrawing and donating substituent were synthesized for NLO applications. These polymers were characterized by UV, IR, 1H-NMR and 13C-NMR spectroscopy. The photoisomerization properties of all the polymers were studied. The glass transition temperature and thermal stability of the polymers were investigated by DSC and TGA, respectively. The third-order nonlinear optical properties of the polymer film were measured by the Z-scan technique using Ar-ion laser and exhibits negative optical nonlinearity. The results revealed that these polymers possess potential applications in nonlinear optics.

  1. Comparative study of toxicity of azo dye Procion Red MX-5B following biosorption and biodegradation treatments with the fungi Aspergillus niger and Aspergillus terreus.

    PubMed

    Almeida, E J R; Corso, C R

    2014-10-01

    Azo dyes are an important class of environmental contaminants and are characterized by the presence of one or more azo bonds (-N=N-) in their molecular structure. Effluents containing these compounds resist many types of treatments due to their molecular complexity. Therefore, alternative treatments, such as biosorption and biodegradation, have been widely studied to solve the problems caused by these substances, such as their harmful effects on the environment and organisms. The aim of the present study was to evaluate biosorption and biodegradation of the azo dye Procion Red MX-5B in solutions with the filamentous fungi Aspergillus niger and Aspergillus terreus. Decolorization tests were performed, followed by acute toxicity tests using Lactuca sativa seeds and Artemia salina larvae. Thirty percent dye removal of the solutions was achieved after 3 h of biosorption. UV-Vis spectroscopy revealed that removal of the dye molecules occurred without major molecular changes. The acute toxicity tests confirmed lack of molecular degradation following biosorption with A. niger, as toxicity to L. sativa seed reduced from 5% to 0%. For A. salina larvae, the solutions were nontoxic before and after treatment. In the biodegradation study with the fungus A. terreus, UV-Vis and FTIR spectroscopy revealed molecular degradation and the formation of secondary metabolites, such as primary and secondary amines. The biodegradation of the dye molecules was evaluated after 24, 240 and 336 h of treatment. The fungal biomass demonstrated considerable affinity for Procion Red MX-5B, achieving approximately 100% decolorization of the solutions by the end of treatment. However, the solutions resulting from this treatment exhibited a significant increase in toxicity, inhibiting the growth of L. sativa seeds by 43% and leading to a 100% mortality rate among the A. salina larvae. Based on the present findings, biodegradation was effective in the decolorization of the samples, but generated

  2. Characterization of azo dyes on Pt and Pt/polyaniline/dispersed Pt electrodes

    NASA Astrophysics Data System (ADS)

    Molina, J.; Fernández, J.; del Río, A. I.; Bonastre, J.; Cases, F.

    2012-06-01

    The electrochemical characterization of two organic dyes (amaranth and procion orange MX-2R) has been performed on Pt electrodes and Pt electrodes coated with polyaniline and dispersed Pt. Electrodes with different Pt loads have been synthesized and characterized obtaining that a load of 300 μg cm-2 was the optimum one. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) was employed to observe the distribution and morphology of the Pt nanoparticles. The electroactivity of the electrodes has also been characterized by means of scanning electrochemical microscopy (SECM). The chemical characterization of Pt dispersed Pani coated Pt electrodes (Pt-Pani-Pt) was performed by means of X-ray photoelectron spectroscopy (XPS). The electrochemical characterization of the dyes has been performed by means of cyclic voltammetry. Voltammograms have shown that the presence of the dyes diminishes characteristic Pt oxidation and reduction peaks. However, redox processes due to the dyes, appeared in the voltammograms. The different species responsible of these redox processes were generated in the vicinity of the electrode and were not adsorbed on the electrode surface since after stirring, the different redox processes disappeared. Characterization with different scan rates showed that redox processes of both dyes were controlled by diffusion.

  3. Graphene oxide supported copper oxide nanoneedles: An efficient hybrid material for removal of toxic azo dyes.

    PubMed

    Rajesh, Rajendiran; Iyer, Sahithya S; Ezhilan, Jayabal; Kumar, S Senthil; Venkatesan, Rengarajan

    2016-09-01

    Herein, we report a simple, one step synthesis of hybrid copper oxide nanoneedles on graphene oxide sheets (GO-CuONNs) through sonochemical method. The present method affords a facile mean for controlling effective concentration of the active CuO nanoneedles on the graphene oxide sheets, and also offers the necessary stability to the resulting GO-CuONNs structure for adsorption transformations.Furthermore, this hybrid GO-CuONNs is successfully employed in the removal of a series of hazardous ionic organic dyes namely coomassie brilliant blue, methylene blue, congo red and amidoblack 10B. Through careful investigation of the material, we found that the synergetic effect between CuONNs and GO play a significant role in the adsorption of all the dyes studied. The prepared hybrid material contains both hydrophobic and hydrophilic environment which is expected to enhance the electrostatic interaction between the adsorbent and the dye molecules, consequently favouring the adsorption process. PMID:27208759

  4. Graphene oxide supported copper oxide nanoneedles: An efficient hybrid material for removal of toxic azo dyes

    NASA Astrophysics Data System (ADS)

    Rajesh, Rajendiran; Iyer, Sahithya S.; Ezhilan, Jayabal; Kumar, S. Senthil; Venkatesan, Rengarajan

    2016-09-01

    Herein, we report a simple, one step synthesis of hybrid copper oxide nanoneedles on graphene oxide sheets (GO-CuONNs) through sonochemical method. The present method affords a facile mean for controlling effective concentration of the active CuO nanoneedles on the graphene oxide sheets, and also offers the necessary stability to the resulting GO-CuONNs structure for adsorption transformations.Furthermore, this hybrid GO-CuONNs is successfully employed in the removal of a series of hazardous ionic organic dyes namely coomassie brilliant blue, methylene blue, congo red and amidoblack 10B. Through careful investigation of the material, we found that the synergetic effect between CuONNs and GO play a significant role in the adsorption of all the dyes studied. The prepared hybrid material contains both hydrophobic and hydrophilic environment which is expected to enhance the electrostatic interaction between the adsorbent and the dye molecules, consequently favouring the adsorption process.

  5. Azo Dyes and Their Interfacial Activity: Implications for Multiphase Flow Experiments

    SciTech Connect

    Tuck, D.M.

    1999-04-21

    Interfacial effects play an important role in governing multiphase fluid behavior in porous media (Neustadter 1984; Tuck et al. 1988). For instance, several dimensionless numbers have been developed to express important force ratios applicable to multiphase flow in porous media (Morrow and Songkran 1981; Chatzis and Morrow 1984; Wardlaw 1988; Pennell et al. 1996; Dawson and Roberts 1997). These force ratios emphasize the importance of interfacial properties. Our objectives are to provide chemical information regarding the dyes commonly used in multiphase flow visualization studies and to show the surface chemistry effects of the most commonly used dye, Sudan IV, in the tetrachloroethylene (PCE)-water-glass system

  6. Decolourization of the azo dye Orange G in aqueous solution via a heterogeneous Fenton-like reaction catalysed by goethite.

    PubMed

    Wu, Honghai; Dou, Xiaowen; Deng, Dayi; Guan, Yufeng; Zhang, Liguo; He, Guangping

    2012-01-01

    Decolourization of the azo dye Orange G (OG) was investigated by using goethite/H2O2 as a heterogeneous Fenton-like reagent. Five principle operational parameters, namely pH, ion strength, concentrations ofgoethite (alpha-FeOOH) and hydrogen peroxide (H2O2), and reaction temperature, were taken into account to investigate how these controlling factors mediated OG decolourization. Goethite surfaces catalysed a Fenton-like reaction responsible for decolourizing OG following pseudo-first-order kinetics (R2 > 0.964). This process was effective but seriously impacted by the medium pH and the dosages of both alpha-FeOOH and H2O2. The decolourization efficiencies of OG increased with the decrease of solution pH and NaCl (chloride ion) concentration and/or the increase of H2O2. The acidic aqueous medium conditions were likely favourable due to the surface adsorption of the negatively charged OG leading to the promotion of decolourizing OG. The apparent activation energy (E) for this reaction was 42.18 kJ mol(-1), a relatively low value. This is consistent with the OG decolourization being enhanced with the reaction temperature increase. PMID:22988614

  7. Optical bistability in a silicon nitride microring resonator with azo dye-doped liquid crystal as cladding material.

    PubMed

    Wang, Chun-Ta; Tseng, Chih-Wei; Yu, Jui-Hao; Li, Yuan-Cheng; Lee, Chun-Hong; Jau, Hung-Chang; Lee, Ming-Chang; Chen, Yung-Jui; Lin, Tsung-Hsien

    2013-05-01

    This investigation reports observations of optical bistability in a silicon nitride (SiN) micro-ring resonator with azo dye-doped liquid crystal cladding. The refractive index of the cladding can be changed by switching the liquid crystal between nematic (NLC) and photo-induced isotropic (PHI) states by. Both the NLC and the PHI states can be maintained for many hours, and can be rapidly switched from one state to the other by photo-induced isomerization using 532 nm and 408 nm addressing light, respectively. The proposed device exhibits optical bistable switching of the resonance wavelength without sustained use of a power source. It has a 1.9 nm maximum spectral shift with a Q-factor of over 10000. The hybrid SiN- LC micro-ring resonator possesses easy switching, long memory, and low power consumption. It therefore has the potential to be used in signal processing elements and switching elements in optically integrated circuits. PMID:23669955

  8. Optimized matching modes of bioelectrochemical module and anaerobic sludge in the integrated system for azo dye treatment.

    PubMed

    Kong, Fanying; Wang, Aijie; Ren, Hong-Yu

    2015-09-01

    In this work, three matching modes (relative positions, catholyte flow sequences, and flow regimes) of bioelectrochemical module and anaerobic sludge were evaluated and optimized for azo dye treatment in the integrated system with embedding modular bioelectrochemical system into anaerobic sludge reactor. Results showed that it was favorable to operate this integrated system under the condition of 1/4 cathode soaking into sludge with spiral distributor in down-flow direction. Current, electrochemical impedance spectroscopy and pH clearly demonstrated the important role of 1/4 soaking in electron/proton transfer. The down-flow direction flowed through electrode zone and then sludge zone could benefit to the efficient use of cathode and improve AO7 treatment. Furthermore, the positive effect of spiral catholyte distributor might be due to its promoting role in mixing and creating a spiral flow channel around the cathode electrode-microbes-solution interface. These results exhibited great potential for matching modular bioelectrochemical system with anaerobic treatment process. PMID:26080106

  9. Enhancement of azo dye Acid Orange 7 removal in newly developed horizontal subsurface-flow constructed wetland.

    PubMed

    Tee, Heng-Chong; Lim, Poh-Eng; Seng, Chye-Eng; Mohd Nawi, Mohd Asri; Adnan, Rohana

    2015-01-01

    Horizontal subsurface-flow (HSF) constructed wetland incorporating baffles was developed to facilitate upflow and downflow conditions so that the treatment of pollutants could be achieved under multiple aerobic, anoxic and anaerobic conditions sequentially in the same wetland bed. The performances of the baffled and conventional HSF constructed wetlands, planted and unplanted, in the removal of azo dye Acid Orange 7 (AO7) were compared at the hydraulic retention times (HRT) of 5, 3 and 2 days when treating domestic wastewater spiked with AO7 concentration of 300 mg/L. The planted baffled unit was found to achieve 100%, 83% and 69% AO7 removal against 73%, 46% and 30% for the conventional unit at HRT of 5, 3 and 2 days, respectively. Longer flow path provided by baffled wetland units allowed more contact of the wastewater with the rhizomes, microbes and micro-aerobic zones resulting in relatively higher oxidation reduction potential (ORP) and enhanced performance as kinetic studies revealed faster AO7 biodegradation rate under aerobic condition. In addition, complete mineralization of AO7 was achieved in planted baffled wetland unit due to the availability of a combination of aerobic, anoxic and anaerobic conditions. PMID:25284799

  10. NaNO(2)/FeCl(3) catalyzed wet oxidation of the azo dye Acid Orange 7.

    PubMed

    Peng, Yanrong; Fu, Dongmei; Liu, Renhua; Zhang, Feifang; Liang, Xinmiao

    2008-03-01

    A combination of ferric chloride and sodium nitrite significantly improved the wet oxidation of the azo dye Acid Orange 7 (AO7) in acid aqueous media (pH 2.6) under moderate conditions (T=150 degrees C; oxygen pressure=0.5 MPa). To evaluate the catalytic system, wet oxidation of AO7 was carried out at temperatures between 90 and 150 degrees C and oxygen pressures ranging from 0.1 to 0.5 MPa. The effect of initial solution pH from 2.6 to 11.4 and the amount of catalyst on the degradation of AO7 were also investigated. AO7 initial concentration was kept 200 mg L(-1). The degradation process was monitored by UV-visible spectroscopy, HPLC, IC (ion chromatography), GC-MS and TOC analysis. At 150 degrees C and 0.5 MPa oxygen pressure, 56% TOC was removed after 4h of treatment, while no obvious TOC removal were achieved without catalyst at the same experimental condition. The main degradation products were some small organic acids: formic acid, acetic acid, pyruvic acid, oxalic acid, succinic acid (identified and quantified by IC) and phthalic acid (identified by GC-MS). PMID:18177919

  11. Unveiling characteristics of a bioelectrochemical system with polarity reversion for simultaneous azo dye treatment and bioelectricity generation.

    PubMed

    Sun, Jian; Zhang, Yaping; Liu, Guoguang; Ning, Xunan; Wang, Yujie; Liu, Jingyong

    2015-09-01

    A novel bioelectrochemical system (BES) operated with polarity reversion was explored for simultaneous anaerobic/aerobic treatment of azo dye and production of bioelectricity under extremely low buffer. The Congo red was first decolorized in anode, with completed color removal in 35 h. The resultant decolorization intermediates were then mineralized after the anode reversed to aerobic biocathode, evidenced by 55 % chemical oxygen demand (COD) removal in 200 h. The mineralization efficiency was further increased to 70 % when the period of the half-cycle was prolonged to 375 h. Meanwhile, the BES produced a continuous stable positive/negative alternate voltage output under 5 mM phosphate buffer because of the self-neutralization of the accumulated protons and hydroxyl ions in electrolyte. The electrode performance was significantly improved, which was indicated by alleviated electrode polarization, due to in situ use of accumulated protons and hydroxyl ions and enhanced electron transfer in the presence of Congo red and its degradation intermediates, which resulted in 1.05-fold increases in maximum power density (67.5 vs. 32.9 mW/m(2)). An analysis of the microbial diversity in the biofilm revealed that the biofilm was dominated by facultative bacteria with functional roles in contaminant degradation and electricity generation. PMID:25957151

  12. AZO DYES ARE MAJOR CONTRIBUTORS TO THE MUTAGENIC ACTIVITY DETECTED IN THE CRISTAIS RIVER WATERS

    EPA Science Inventory

    To determine if compounds from a dye processing plant were contributing to the mutagenicity repeatedly found in the Cristais River, Sao Paulo, Brazil, we chemically characterized the treated industrial effluent, raw and treated water, and the sludge produced by a Drinking Water T...

  13. THE CONTRIBUTION OF AZO DYES TO THE MUTAGENIC ACTIVITY OF THE CRISTAIS RIVER

    EPA Science Inventory

    To verify if compounds within the discharge of a dye processing plant were contributing to the mutagenicity repeatedly found in the Cristais River, Sao Paulo, Brazil, we chemically characterized the treated industrial effluent, raw and treated water, and the sludge produced by a ...

  14. Plant-mediated synthesis of silver-nanocomposite as novel effective azo dye adsorbent

    NASA Astrophysics Data System (ADS)

    Satapathy, Mantosh Kumar; Banerjee, Priya; Das, Papita

    2015-01-01

    Toxicity of textile effluent is a globally alarming issue nowadays. In order to address this problem, a cost-effective and environment-friendly technique for adsorption of toxic dyes has been introduced in this research. Firstly in this study, green synthesis of silver nanoparticles (AgNPs) having antibacterial efficacy, had been carried out using leaf extracts of Azadirachta indica as reducing as well as capping agent. This research idea was further extended for the development and application of a novel method of preparation of silver-nanocomposite using synthesized microwave-assisted AgNPs with soil as a novel nanocomposite to adsorb hazardous dyes. However, this nanocomposite was found to possess higher efficiency and adsorption capacity in comparison to soil as adsorbent for the removal of crystal violet dye under same experimental conditions. Additionally, it was also observed that use of this Ag-nanocomposite as adsorbent helped in achieving about 97.2 % removal of crystal violet dye from the effluent solution.

  15. Synthesis, structural elucidation, solvatochromism and spectroscopic properties of some azo dyes derived from 6-chloro-4-hydroxyquinoline-2(1H)-one

    NASA Astrophysics Data System (ADS)

    Rufchahi, E. O. Moradi; Gilani, A. Ghanadzadeh; Taghvaei, V.; Karimi, R.; Ramezanzade, N.

    2016-03-01

    Malondianilide (I) derived from p-chloroaniline was cyclized to 6-chloro-4-hydroxyquinoline-2(1H)-one (II) in moderately good yield using polyphosphoric acid as catalyst. This compound was then coupled with some diazotized aromatic amines to give the corresponding azo disperse dyes 1-12. A systematic study of the effect of solvent, acid, base and pH upon the electronic absorption spectra of the dyes 1-12 was carried out. In DMSO, DMF, CH3CN, CHCl3, EtOH and acidic media (CH3COOH, acidified EtOH) these dyes that theoretically may be involved in azo-hydrazone tautomerism have been detected only as hydrazone tautomers T1 and T2. The acidic dissociation constants of the dyes were measured in 80 vol% ethanol-water solution at room temperature and ionic strength of 0.1. The results were correlated by the Hammett-type equation using the substituent constants σx.

  16. Optimization and modelling of synthetic azo dye wastewater treatment using Graphene oxide nanoplatelets: Characterization toxicity evaluation and optimization using Artificial Neural Network.

    PubMed

    Banerjee, Priya; Sau, Shubhra; Das, Papita; Mukhopadhayay, Aniruddha

    2015-09-01

    Azo dyes pose a major threat to current civilization by appearing in almost all streams of wastewater. The present investigation was carried out to examine the potential of Graphene oxide (GO) nanoplatelets as an efficient, cost-effective and non-toxic azo dye adsorbent for efficient wastewater treatment. The treatment process was optimized using Artificial Neural Network for maximum percentage dye removal and evaluated in terms of varying operational parameters, process kinetics and thermodynamics. A brief toxicity assay was also designed using fresh water snail Bellamya benghalensis to analyze the quality of the treated solution. 97.78% removal of safranin dye was obtained using GO as adsorbent. Characterization of GO nanoplatelets (using SEM, TEM, AFM and FTIR) reported the changes in its structure as well as surface morphology before and after use and explained its prospective as a good and environmentally benign adsorbent in very low quantities. The data recorded when subjected to different isotherms best fitted the Temkin isotherm. Further analysis revealed the process to be endothermic and chemisorption in nature. The verdict of the toxicity assay rendered the treated permeate as biologically safe for discharge or reuse in industrial and domestic purposes. PMID:25966335

  17. Thermal, optical and photoinduced properties of a series of homo and co-polyimides with two kinds of covalently bonded azo-dyes and their supramolecular counterparts

    NASA Astrophysics Data System (ADS)

    Konieczkowska, Jolanta; Wojtowicz, Magdalena; Sobolewska, Anna; Noga, Joanna; Jarczyk-Jedryka, Anna; Kozanecka-Szmigiel, Anna; Schab-Balcerzak, Ewa

    2015-10-01

    The paper describes the synthesis and characterization of new aromatic polyimides with one or two different moieties of the azo-dyes covalently attached to the polymer backbone and their supramolecular analogues. Azo-functionalized polyimides were prepared using post-polymerization method including the introduction of Disperse Red 13 and/or 4-[4-(6-hydroxyhexyloxy)phenylazo]pyridine to homo and co-polyimides containing hydroxyl groups via Mitsunobu reaction. The degree of functionalization of polymers with chromophores was estimated by UV-Vis spectroscopy. Polyimides containing hydroxyl groups were applied as matrixes to create supramolecular systems based on hydrogen bonds. Hydrogen-bond interactions in azosystems were studied by FTIR spectroscopy. The polymers were characterized by 1H NMR, FTIR, X-ray, UV-Vis, DSC and TGA methods. The photoisomerization process was investigated in supramolecular systems. The light-induced anisotropy was studied in a holographic gratings recording experiment and by photoinduced birefringence measurements. The polymer films were investigated by atomic force microscopy (AFM) after the diffraction grating recording to confirm formation of surface relief gratings (SRGs). To the best of our knowledge, that the first time photoinduced anisotropy has been studied by birefringence measurements in polyimides containing two different azo-dyes.

  18. Salt-free reactive dyeing of cotton hosiery fabrics by exhaust application of cationic agent.

    PubMed

    Nallathambi, Arivithamani; Venkateshwarapuram Rengaswami, Giri Dev

    2016-11-01

    Reactive dyes are most preferred dyes for dyeing of cellulosic fibres as they are chemically bonded to the fibre which is being dyed and also inexpensive to apply. But the application of reactive dyes onto the cellulosic materials requires a very high concentration of salt since fibre and dyes are anionic in nature. Even with required amount of salt only 65-70% of reactive dyes are exhausted, remaining 25-30% of dyes are removed as a coloured effluent after dyeing. The present work aims to eliminate salt usage in the reactive dyeing of cellulosic material, especially in cotton hosiery fabrics dyeing industry. In this study, the cationization of cotton fabric was carried out by varying concentration of cationic agent from 20 to 60g/L by an exhaust method with the goal to achieve 100% dye utilization and fixation during the salt-free reactive dyeing process. All the dyes taken for the study showed excellent dye exhaustion, fixation and colour strength properties on the cotton fabrics. PMID:27516243

  19. Ultrasound energy to accelerate dye uptake and dye-fiber interaction of reactive dye on knitted cotton fabric at low temperatures.

    PubMed

    Tissera, Nadeeka D; Wijesena, Ruchira N; de Silva, K M Nalin

    2016-03-01

    Acoustic cavitation formed due to propagation of ultrasound wave inside a dye bath was successfully used to dye cotton fabric with a reactive dye at lower temperatures. The energy input to the system during sonication was 0.7 W/cm(2). This was within the energy range that contributes towards forming cavitation during ultra-sonication. The influence of ultrasound treatment on dye particle size and fiber morphology is discussed. Particle size analysis of the dye bath revealed ultra-sonication energy was capable of de-agglomeration of hydrolyzed dye molecules during dyeing. SEM micrograph and AFM topographical image of the fiber surface revealed fiber morphology remains unchanged after the sonication. The study was extended in understanding the contribution of ultrasound method of dyeing towards achieving good color strength on the fabric, compared to the normal heating method of dyeing. Study showed color strength obtained using ultra sound method of dyeing is higher compared to normal heating dyeing. Ultrasound energy was able to achieve the good color strength on cotton fabric at very low temperature such as 30 °C, which was approximately 230% more than the color strength achieved in normal heating method of dyeing. This indicates that energy input to the system using ultrasound was capable of acting as an effective alternative method of dyeing knitted cotton fabrics with reactive dye. PMID:26585007

  20. Mineralization and Detoxification of the Carcinogenic Azo Dye Congo Red and Real Textile Effluent by a Polyurethane Foam Immobilized Microbial Consortium in an Upflow Column Bioreactor.

    PubMed

    Lade, Harshad; Govindwar, Sanjay; Paul, Diby

    2015-06-01

    A microbial consortium that is able to grow in wheat bran (WB) medium and decolorize the carcinogenic azo dye Congo red (CR) was developed. The microbial consortium was immobilized on polyurethane foam (PUF). Batch studies with the PUF-immobilized microbial consortium showed complete removal of CR dye (100 mg·L-1) within 12 h at pH 7.5 and temperature 30 ± 0.2 °C under microaerophilic conditions. Additionally, 92% American Dye Manufactureing Institute (ADMI) removal for real textile effluent (RTE, 50%) was also observed within 20 h under the same conditions. An upflow column reactor containing PUF-immobilized microbial consortium achieved 99% CR dye (100 mg·L-1) and 92% ADMI removal of RTE (50%) at 35 and 20 mL·h-l flow rates, respectively. Consequent reduction in TOC (83 and 79%), COD (85 and 83%) and BOD (79 and 78%) of CR dye and RTE were also observed, which suggested mineralization. The decolorization process was traced to be enzymatic as treated samples showed significant induction of oxidoreductive enzymes. The proposed biodegradation pathway of the dye revealed the formation of lower molecular weight compounds. Toxicity studies with a plant bioassay and acute tests indicated that the PUF-immobilized microbial consortium favors detoxification of the dye and textile effluents. PMID:26086710

  1. Application of acidic treated pumice as an adsorbent for the removal of azo dye from aqueous solutions: kinetic, equilibrium and thermodynamic studies

    PubMed Central

    2012-01-01

    Colored effluents are one of the important environment pollution sources since they contain unused dye compounds which are toxic and less-biodegradable. In this work removal of Acid Red 14 and Acid Red 18 azo dyes was investigated by acidic treated pumice stone as an efficient adsorbent at various experimental conditions. Removal of dye increased with increase in contact time and initial dye concentration, while decreased for increment in solution temperature and pH. Results of the equilibrium study showed that the removal of AR14 and AR18 followed Freundlich (r2>0.99) and Langmuir (r2>0.99) isotherm models. Maximum sorption capacities were 3.1 and 29.7 mg/g for AR 14 and AR18, namely significantly higher than those reported in the literature, even for activated carbon. Fitting of experimental data onto kinetic models showed the relevance of the pseudo-second order (r2>0.99) and intra-particle diffusion (r2>0.98) models for AR14 and AR18, respectively. For both dyes, the values of external mass transfer coefficient decreased for increasing initial dye concentrations, showing increasing external mass transfer resistance at solid/liquid layer. Desorption experiments confirmed the relevance of pumice stone for dye removal, since the pH regeneration method showed 86% and 89% regeneration for AR14 and AR18, respectively. PMID:23369579

  2. Mineralization and Detoxification of the Carcinogenic Azo Dye Congo Red and Real Textile Effluent by a Polyurethane Foam Immobilized Microbial Consortium in an Upflow Column Bioreactor

    PubMed Central

    Lade, Harshad; Govindwar, Sanjay; Paul, Diby

    2015-01-01

    A microbial consortium that is able to grow in wheat bran (WB) medium and decolorize the carcinogenic azo dye Congo red (CR) was developed. The microbial consortium was immobilized on polyurethane foam (PUF). Batch studies with the PUF-immobilized microbial consortium showed complete removal of CR dye (100 mg·L−1) within 12 h at pH 7.5 and temperature 30 ± 0.2 °C under microaerophilic conditions. Additionally, 92% American Dye Manufactureing Institute (ADMI) removal for real textile effluent (RTE, 50%) was also observed within 20 h under the same conditions. An upflow column reactor containing PUF-immobilized microbial consortium achieved 99% CR dye (100 mg·L−1) and 92% ADMI removal of RTE (50%) at 35 and 20 mL·h−l flow rates, respectively. Consequent reduction in TOC (83 and 79%), COD (85 and 83%) and BOD (79 and 78%) of CR dye and RTE were also observed, which suggested mineralization. The decolorization process was traced to be enzymatic as treated samples showed significant induction of oxidoreductive enzymes. The proposed biodegradation pathway of the dye revealed the formation of lower molecular weight compounds. Toxicity studies with a plant bioassay and acute tests indicated that the PUF-immobilized microbial consortium favors detoxification of the dye and textile effluents. PMID:26086710

  3. Application of acidic treated pumice as an adsorbent for the removal of azo dye from aqueous solutions: kinetic, equilibrium and thermodynamic studies.

    PubMed

    Samarghandi, Mohammad Reza; Zarrabi, Mansur; Sepehr, Mohammad Noori; Amrane, Abdeltif; Safari, Gholam Hossein; Bashiri, Saied

    2012-01-01

    Colored effluents are one of the important environment pollution sources since they contain unused dye compounds which are toxic and less-biodegradable. In this work removal of Acid Red 14 and Acid Red 18 azo dyes was investigated by acidic treated pumice stone as an efficient adsorbent at various experimental conditions. Removal of dye increased with increase in contact time and initial dye concentration, while decreased for increment in solution temperature and pH. Results of the equilibrium study showed that the removal of AR14 and AR18 followed Freundlich (r2>0.99) and Langmuir (r2>0.99) isotherm models. Maximum sorption capacities were 3.1 and 29.7 mg/g for AR 14 and AR18, namely significantly higher than those reported in the literature, even for activated carbon. Fitting of experimental data onto kinetic models showed the relevance of the pseudo-second order (r2>0.99) and intra-particle diffusion (r2>0.98) models for AR14 and AR18, respectively. For both dyes, the values of external mass transfer coefficient decreased for increasing initial dye concentrations, showing increasing external mass transfer resistance at solid/liquid layer. Desorption experiments confirmed the relevance of pumice stone for dye removal, since the pH regeneration method showed 86% and 89% regeneration for AR14 and AR18, respectively. PMID:23369579

  4. Occurrence and risk assessment of an azo dye - The case of Disperse Red 1.

    PubMed

    Vacchi, Francine Inforçato; Von der Ohe, Peter Carsten; Albuquerque, Anjaína Fernandes de; Vendemiatti, Josiane Aparecida de Souza; Azevedo, Carina Cristina Jesus; Honório, Jaqueline Gonçalves; Silva, Bianca Ferreira da; Zanoni, Maria Valnice Boldrin; Henry, Theodore B; Nogueira, Antonio J; Umbuzeiro, Gisela de Aragão

    2016-08-01

    Water quality criteria to protect aquatic life are not available for most disperse dyes which are often used as commercial mixtures in textile coloration. In this study, the acute and chronic toxicity of the commercial dye Disperse Red 1 (DR1) to eight aquatic organisms from four trophic levels was evaluated. A safety threshold, i.e. Predicted No-Effect Concentration (PNEC), was derived based on the toxicity information of the commercial product and the purified dye. This approach was possible because the toxicity of DR1 was accounting for most of the toxicity of the commercial mixture. A long-term PNEC of 60 ng L(-1) was proposed, based on the most sensitive chronic endpoint for Daphnia similis. A short-term PNEC of 1800 ng L(-1) was proposed based on the most sensitive acute endpoint also for Daphnia similis. Both key studies have been evaluated with the new "Criteria for Reporting and Evaluating ecotoxicity Data" (CRED) methodology, applying more objective criteria to assess the quality of toxicity tests, resulting in two reliable and relevant endpoints with only minor restrictions. HPLC-MS/MS was used to quantify the occurrence of DR1 in river waters of three sites, influenced by textile industry discharges, resulting in a concentration range of 50-500 ng L(-1). The risk quotients for DR1 obtained in this work suggest that this dye can pose a potential risk to freshwater biota. To reduce uncertainty of the derived PNEC, a fish partial or full lifecycle study should be performed. PMID:27174821

  5. Decolorization and detoxification of sulfonated azo dye methyl orange by Kocuria rosea MTCC 1532.

    PubMed

    Parshetti, G K; Telke, A A; Kalyani, D C; Govindwar, S P

    2010-04-15

    Kocuria rosea (MTCC 1532) showed 100% decolorization of methyl orange (50 mg l(-1)) under static condition. The optimum pH and temperature for dye decolorization was 6.8 and 30 degrees C, respectively. The K. rosea (MTCC 1532) showed maximum decolorization of methyl orange when growth medium containing yeast extract as compared to other substrates. The culture exhibited significant ability to decolorize repeated additions of dye, with reduction in time up to 12 h at eighth dye aliquot addition. Significant induction of reductases (NADH-DCIP reductase and azoreductase) suggests its involvement in decolorization of methyl orange. The metabolites formed after decolorization of methyl orange, such as 4-amino sulfonic acid and N,N'-dimethyl p-phenyldiamine were characterized using FTIR and MS. Phytotoxicity and microbial toxicity study showed the methyl orange was toxic and metabolites obtained after its decolorization was nontoxic for experimental plants (Triticum aestivum and Phaseolus mungo) and bacteria (K. rosea, Pseudomonas aurugenosa and Azatobacter vinelandii). PMID:19969416

  6. Wet oxidative regeneration of activated carbon loaded with reactive dye.

    PubMed

    Shende, R V; Mahajani, V V

    2002-01-01

    Wet Oxidative Regeneration (WOR) of powdered activated carbon (PAC) and granular activated carbon (GAC) loaded with the reactive dyes, namely chemictive brilliant blue R and cibacron turquoise blue G, was studied. Attempts were made to regenerate the loaded carbons designated now as spent carbon. A slurry (10% w/v) of spent carbon in distilled water was oxidized by wet oxidation in the temperature range of 150-250 degrees C using oxygen partial pressures between 0.69-1.38 MPa in an 1 1 SS 316 autoclave. The percent regeneration was determined from a ratio, X(RC)/X(VC), corresponding to an equilibrium adsorption capacity of regenerated carbon/equilibrium adsorption capacity of virgin carbon from an initial adsorption period of 3 h. It was observed that the regeneration mainly occurred due to the oxidation of the adsorbates taking place on the surface of carbon. It was possible to regenerate the spent GAC and PAC to the extent of more than 98% (approximately X(RC)/X(VC) > 0.98) by wet oxidation. After four consecutive cycles of adsorption and regeneration using the same stocks of GAC, carbon weight loss observed at 200 degrees C was about 40%. SEM studies of the regenerated carbon showed widening of the pores and loss of structure between the adjacent pores as compared with the virgin carbon. PAC was found to be more suitable as compared with GAC for the adsorption and wet oxidative regeneration processes to treat the aqueous solution containing lower concentration of unhydrolyzed reactive dye. The suitability of wet oxidative regeneration is demonstrated at a bench scale to treat the synthetic reactive dye solution. PMID:11942707

  7. Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor.

    PubMed

    Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying; Lee, Hyung-Sool; Wang, Ai-Jie

    2012-11-15

    Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8±1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 gm(-3) d(-1)) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 gm(-3) d(-1) (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China. PMID:23009797

  8. Predictive modeling of an azo metal complex dye sorption by pumpkin husk.

    PubMed

    Çelekli, Abuzer; Bozkurt, Hüseyin

    2013-10-01

    Effective disposal of pumpkin husk (PH) as a redundant waste is a significant work for environmental protection and full utilization of resource. Predictive modeling of sorption of Lanaset Red (LR) G on PH was investigated in a batch system as functions of particle size, adsorbent dose, pH, temperature, and initial dye concentration. Fourier transform infrared spectroscopy attenuated total reflectance spectra of PH powders before and after the sorption of LR G were determined. Sorption process was found to be dependent on particle size, adsorbent dose, pH, temperature, initial dye concentration, and contact time. Amine and amide groups of PH had significant effect on the sorption process. The pHzpc of PH was found as 6.4. Sorption process was very fast initially and reached equilibrium within 60 min. Dynamic behavior of sorption was well represented by logistic and Avrami models. The sorption of LR G on PH was excellently described by Langmuir model, indicating a homogeneous phenomenon. Monolayer sorption capacity decreased from 440.78 to 436.28 mg g(-1) with increasing temperature. Activation energy, thermodynamic, and desorption studies showed that this process was physical character, exothermic, and spontaneous. This study confirmed that PH as an effective and low-cost adsorbent had a great potential for the removal of LR G as an alternative eco-friendly process. PMID:23625123

  9. Adsorption of an azo dye in an aqueous solution using hydroxyl-terminated polybutadiene (HTPB).

    PubMed

    Olya, Mohammad Ebrahim; Pirkarami, Azam; Mirzaie, Mohammad

    2013-05-01

    This paper reports an investigation into the effect of a number of operating factors on the removal of Acid Blue 92 (AB92) from an aqueous solution using hydroxyl-terminated polybutadiene (HTPB) as an adsorbent. The optimum values of adsorbent dose and pH were found to be 35mgL(-1) and 6, respectively. Temperature showed a significant effect, with maximum dye removal being observed at 45°C. Stirring the solution during the treatment process resulted in significant removal improvement. The Langmuir adsorption model was used to quantify the amount of AB92 adsorbed on the surface of HTPB. FT-IR spectrometry results for HTPB, AB92, and HTPB-AB92 verified the efficiency of the treatment. Further, the adsorbent was characterized using SEM and H NMR techniques. PMID:23484459

  10. Organic acids enhanced decoloration of azo dye in gas phase surface discharge plasma system.

    PubMed

    Wang, Tiecheng; Qu, Guangzhou; Ren, Jingyu; Sun, Qiuhong; Liang, Dongli; Hu, Shibin

    2016-01-25

    A gas phase surface discharge plasma combined with organic acids system was developed to enhance active species mass transfer and dye-containing wastewater treatment efficacy, with Acid Orange II (AO7) as the model pollutant. The effects of discharge voltage and various organic acid additives (acetic acid, lactic acid and nonoic acid) on AO7 decoloration efficiency were evaluated. The experimental results showed that an AO7 decoloration efficiency of approximately 69.0% was obtained within 4 min of discharge plasma treatment without organic acid addition, which was improved to 82.8%, 83.5% and 88.6% within the same treatment time with the addition of acetic acid, lactic acid and nonoic acid, respectively. The enhancement effects on AO7 decoloration efficiency could be attributed to the decrease in aqueous surface tension, improvement in bubble distribution and shape, and increase in ozone equivalent concentration. The AO7 wastewater was biodegradable after discharge plasma treatment with the addition of organic acid. AO7 decomposition intermediates were analyzed by UV-vis spectrometry and GC-MS; 2-naphthol, 1,4-benzoquinone, phthalic anhydride, coumarin, 1,2-naphthoquinone, and 2-formyl-benzoic acid were detected. A possible pathway for AO7 decomposition in this system was proposed. PMID:26444488

  11. Highly efficient visible light mediated azo dye degradation through barium titanate decorated reduced graphene oxide sheets

    NASA Astrophysics Data System (ADS)

    Rastogi, Monisha; Kushwaha, H. S.; Vaish, Rahul

    2016-03-01

    This study investigates BaTiO3 decorated reduced graphene oxide sheets as a potential visible light active catalyst for dye degradation (Rhodamine B). The composites were prepared through conventional hydrothermal synthesis technique using hydrazine as a reducing agent. A number of techniques have been employed to affirm the morphology, composition and photocatalytic properties of the composites; these include UV-visible spectrophotoscopy that assisted in quantifying the concentration difference of Rhodamine B. The phase homogeneity of the composites was examined through x-ray powder diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) was employed to confirm the orientation of the BaTiO3 particles over the reduced graphene oxide sheets. Photoluminescence (PL) emission spectra assisted in determining the surface structure and excited state of the catalyst. Fourier transformed-infrared (FTIR) spectra investigated the vibrations and adsorption peak of the composites, thereby ascertaining the formation of reduced graphene oxide. In addition, diffuse reflectance spectroscopy (DRS) demonstrated an enhanced absorption in the visible region. The experimental investigations revealed that graphene oxide acted as charge collector and simultaneously facilitated surface adsorption and photo-sensitization. It could be deduced that BaTiO3-reduced graphene oxide composites are of significant interest the field of water purification through solar photocatalysis. [Figure not available: see fulltext.

  12. THE FINE STRUCTURE OF PROLIFERATING CELLS IN PRENEOPLASTIC RAT LIVERS DURING AZO-DYE CARCINOGENESIS

    PubMed Central

    Karasaki, Shuichi

    1969-01-01

    The continuous feeding of the carcinogenic aminoazo dye DAB to rats produces hyperbasophilic foci in the preneoplastic livers. After injections of thymidine-3H into the rats, such foci were isolated from the livers and studied by radioautography with the phase-contrast and electron microscopes. In these foci, the only cells found to be proliferating, as determined by the uptake of thymidine-3H into their nuclei, were a poorly differentiated type; well differentiated hepatocytes in the same regions were not labeled with the isotope. The labeled cells had an irregular cell outline and a high nucleocytoplasmic ratio; the cytoplasm had almost completely lost the specialized elements characteristic of hepatocytes; the irregular nuclei with prominent nucleoli, the altered mitochondria, and the increased free ribosomes noted in these cells are features which are characteristic of neoplastic cells induced by DAB. Thus, it seems likely that the hyperbasophilic foci represent the sites of extensive dedifferentiation of hepatocytes followed by rapid cellular proliferation, leading to neoplastic growth. PMID:4302683

  13. Evaluation of the treatment performance of lab-scaled vertical flow constructed wetlands in removal of organic compounds, color and nutrients in azo dye-containing wastewater.

    PubMed

    Dogdu, Gamze; Yalcuk, Arda

    2016-01-01

    The objective of this study is to examine the treatment performance of vertical flow intermittent feeding constructed wetland (VFCW) in removal of organic pollution, nutrients and color in azo-dye containing wastewater. The systems consisted of PVC reactors, some filling materials such as gravel, sand and zeolite and wetland plants including Typha angustifolia and Canna indica. The average treatment efficiency of the systems for COD, color, sulphate, NH4-N, and PO4-P were in the range of 57-63%, 94-99%, 44-48%, 39-44%, and 84-88%, respectively among the VFCW reactors. It is concluded that VFCW reactor system can effectively be used in the treatment of dye-rich wastewater, especially for the removal of color and in the reduction of COD. Biofilm formation and cleavage of azo bonds could be observed by SEM and FTIR results, respectively. Almost similar NH4-N and PO4-P removal were obtained in all reactors by using same amount of zeolite media. PMID:26248021

  14. Microextraction by packed sorbent and salting-out-assisted liquid-liquid extraction for the determination of aromatic amines formed from azo dyes in textiles.

    PubMed

    Sánchez, Miguel del Nogal; Santos, Patricia Martín; Sappó, Cristina Pérez; Pavón, José Luis Pérez; Cordero, Bernardo Moreno

    2014-02-01

    EU legislation prohibits the use of certain azo dyes which, on reduction, form any of 22 aromatic amines listed in Regulation (EC) 1907/2006 at concentrations above the threshold limit of 30 mg Kg(-1). Two different extraction techniques for the determination of aromatic amines formed from azo dyes in textiles in combination with gas chromatography-mass spectrometry (GC-MS) are described. The first one is based on microextraction by packed sorbent (MEPS) and the other approach involves salting-out-assisted liquid-liquid extraction (SALLE). The influence of several parameters on the efficiency of the extraction using MEPS (sorbent material, sample volume, elution solvent, elution volume and washing steps, among others) and SALLE (extraction volume and amount of salt) were investigated. In addition, chromatographic separation was optimized and quadrupole mass spectrometry was evaluated using the synchronous SIM/scan data acquisition mode. The repeatability (n=8, S/N=3) of the methods, calculated as the relative standard deviation (RSD) was below 15 and 11% for all compounds when MEPS and SALLE were used, respectively. Standard additions procedure was used to quantify the aromatic amines in the textil samples. The detection limits in the samples for both methods were lower than the maximum value allowed by legislation. The results obtained in the analysis of textiles revealed the presence of o-anisidine, p-chloroaniline, 4-chloro-o-toluidine, 2-naphthylamine and 3,3'-dimethoxybenzidine in some of them. PMID:24401428

  15. Removal of anionic azo dye from aqueous solution via an adsorption-photosensitized regeneration process on a TiO2 surface.

    PubMed

    Bao, Nan; Li, Yuan; Yu, Xiao-Hong; Niu, Jun-Jian; Wu, Guo-Lin; Xu, Xiao-Hong

    2013-02-01

    Textile dye effluents are typically characterized by strong color and recalcitrance, even at very low concentration. The process of enrichment of anionic azo dye on the surface of TiO(2) fibers followed by photosensitization degradation under ambient air conditions was extensively investigated. Adsorption isotherms and zeta potentials were used to describe the "dye/TiO(2) surface" interface, taking into account the effects of pH on the nature and population of the surface groups on the TiO(2) fibers. The extent of the photocatalytic degradation of dye on TiO(2) surface was determined by FTIR. N(2) adsorption isotherms and optical spectra were employed to investigate the effect of photosensitization. The adsorption of dyes on the TiO(2) surface occurs via electrostatic attraction through the formation of single- or multidentate-coordinated surface complexes. Almost complete photobleaching of the absorption band at 534 nm is achieved in ~4 h. Dye-sensitized TiO(2) fiber could absorb part of the visible light spectrum (λ < 600 nm). Interfacial electron transfer can potentially alter the degradation efficiency. The regenerated TiO(2) fiber could be reused for subsequent decolorization without a decline in adsorption efficiency compared with freshly prepared TiO(2) samples, which may be attributed to preservation of the hierarchical pore structure and restoration of the original surface properties. In summary, we propose an efficient "adsorption-photoregeneration-reuse" process applying TiO(2) fibers for the degradation of dyes in water. PMID:22544602

  16. Synthesis and characterization of BiFeO{sub 3} for photocatalytic degradation of azo dye

    SciTech Connect

    Kaur, Manpreet Uniyal, Poonam

    2015-08-28

    A novel approach is reported to synthesize single phase BiFeO{sub 3} via. sol-gel auto combustion method using glycine as fuel. Synthesized powder was subjected to annealing at different temperatures, i.e. 400 °C, 450 °C, 500 °C, 550 °C, and 600°C. Crystal structure of BiFeO{sub 3} samples examined by X-ray diffraction indicates that the samples were single-phased with different particle sizes, as particle sizes are temperature dependent and crystallized in rhombohedral structure. As the temperature was increased, the diffraction peak intensity of BiFeO3 in the XRD spectra gradually enhanced and the diffraction peaks became sharper. The optical properties of the resultant BiFeO{sub 3} were characterized using UV-Vis spectrophotometer over the range of 350-800 nm. UV-vis spectra of all the samples indicate that optical band gap lies in the visible region in the range of 2.2-2.07 eV at all temperatures. Moreover, photocatalytic properties of the BiFeO{sub 3} powders were investigated by the photodegradation of Reactive Black-5 (RB-5)

  17. Synthesis and characterization of BiFeO3 for photocatalytic degradation of azo dye

    NASA Astrophysics Data System (ADS)

    Kaur, Manpreet; Uniyal, Poonam

    2015-08-01

    A novel approach is reported to synthesize single phase BiFeO3 via. sol-gel auto combustion method using glycine as fuel. Synthesized powder was subjected to annealing at different temperatures, i.e. 400 °C, 450 °C, 500 °C, 550 °C, and 600°C. Crystal structure of BiFeO3 samples examined by X-ray diffraction indicates that the samples were single-phased with different particle sizes, as particle sizes are temperature dependent and crystallized in rhombohedral structure. As the temperature was increased, the diffraction peak intensity of BiFeO3 in the XRD spectra gradually enhanced and the diffraction peaks became sharper. The optical properties of the resultant BiFeO3 were characterized using UV-Vis spectrophotometer over the range of 350-800 nm. UV-vis spectra of all the samples indicate that optical band gap lies in the visible region in the range of 2.2-2.07 eV at all temperatures. Moreover, photocatalytic properties of the BiFeO3 powders were investigated by the photodegradation of Reactive Black-5 (RB-5).

  18. The UV and Laser Aging for PMMA/BDK/Azo-dye Polymer Blend Cured by UV Light Beams

    NASA Astrophysics Data System (ADS)

    Ahmad, A. A.; Omari, A. M.

    2015-10-01

    A polymeric-based solution blend composed of Azo-dye methyl red (MR) doped with polymethelmethacrelate (PMMA) solution, in addition, to the BenzylDimethylKetal (BDK) photoinitiator was made with optimum molar ratios and deposited on glass substrate by spin coating technique. The samples were then exposed to UV light beams in order to assist the layers polymerization by the proper exposure process. The photo chemical reaction occurred during the UV light polymerization process induces photo refractive changes which were presented as a function of wavelength or photon energy. Two main strong absorption peaks were observed in the films at around 330 nm (3.75 eV) and 500 nm (2.48 eV) for different curing time periods. This phenomenon enhances the films usage for optical data storage media at these two wavelengths. Since the deposited films were then useful as based layers for Read/Write optical data storage media, they were then tested by UV or laser Read/Write beams independently. The optical properties of the films were investigated while exposed to each beam. Finally, their optical properties were investigated as a function of aging time in order to relate the temporary and/or permanent light-exposure effect on the films compared to their optical properties before the light exposure. The films show a low absorbance at 630 nm (1.97 eV) and high absorbance at 480 nm (2.58 eV). This fact makes it possible to record holographic gratings in the polymeric film upon light exposure. In all cases the optical properties were evaluated by using the very sensitive, non destructive surface testing spectroscopic ellipsometry technique. The films were characterized in the spectral range of 300 to 1000 nm using Lorentz oscillator model with one oscillator centred at 4.15 eV. This study has been supported by the SEM and EDAX results to investigate the effect of the UV and visible beams on their optical properties. The results of this research determined the proper conditions for

  19. Biosorption of synthetic dyes (Direct Red 89 and Reactive Green 12) as an ecological refining step in textile effluent treatment.

    PubMed

    Guendouz, Samira; Khellaf, Nabila; Zerdaoui, Mostefa; Ouchefoun, Moussa

    2013-06-01

    With the use of cost-effective natural materials, biosorption is considered as an ecological tool that is applied worldwide for the remediation of pollution. In this study, we proposed Lemna gibba biomass (LGB), a lignocellulosic sorbent material, for the removal of two textile dyes, Direct Red 89 (DR-89) and Reactive Green 12 (RG-12). These azo dyes commonly used in dying operations of natural and synthetic fibres are the most important pollutants produced in textile industry effluents. For this purpose, batch biosorption experiments were carried out to assess the efficacy of LGB on dye treatment by evaluating the effect of contact time, biomass dosage, and initial dye concentration. The results indicated that the bioremoval efficiency of 5 mg L(-1) DR-89 and RG-12 reached approximately 100 % after 20 min of the exposure time; however, the maximum biosorption of 50 mg L(-1) DR-89 and 15 mg L(-1) RG-12 was determined to be about 60 and 47 %, respectively. Fourier transform infrared spectroscopy used to explain the sorption mechanism showed that the functional groups of carboxylic acid and hydroxyl played a major role in the retention of these pollutants on the biomass surface. The modelling results using Freundlich, Langmuir, Temkin, Elovich, and Dubini Radushkevich (D-R) isotherms demonstrated that the DR-89 biosorption process was better described with the Langmuir theory (R (2) =0.992) while the RG-12 biosorption process fitted well by the D-R isotherm equation (R (2) =0.988). The maximum biosorption capacity was found to be 20.0 and 115.5 mg g(-1) for DR-89 and RG-12, respectively, showing a higher ability of duckweed biomass for the bioremoval of the green dye. The thermodynamic study showed that the dye biosorption was a spontaneous and endothermic process. The efficacy of using duckweed biomass for the bioremoval of the two dyes was limited to concentrations ≤50 mg L(-1), indicating that L. gibba biomass may be suitable in the refining step

  20. Synthesis, characterization and antimicrobial studies of 2-{(E)-[(2-hydroxy-5-methylphenyl)imino]methyl}-4-[(E)-phenyldiazenyl]phenol as a novel azo-azomethine dye

    NASA Astrophysics Data System (ADS)

    Köse, Muhammet; Kurtoglu, Nurcan; Gümüşsu, Özkan; Tutak, Mustafa; McKee, Vickie; Karakaş, Duran; Kurtoglu, Mukerrem

    2013-12-01

    A novel dye, 2-{(E)-[(2-hydroxy-5-methylphenyl)imino]methyl}-4-[(E)-phenyldiazenyl]phenol dye was synthesized by the condensation reaction of 2-hydroxy-5-[(E)-phenyldiazenyl]benzaldehyde with 2-amino-4-methylphenol in methanol. The title dye was characterized by its melting point, elemental analysis, FT-IR, 1H, 13C NMR and mass spectroscopic studies. Molecular structure of the title dye was determined by single crystal X-ray diffraction study. X-ray data showed that the dye crystallizes in the monoclinic space group P21/c with cell parameters a = 18.541(2) Å, b = 4.7091(5) Å, c = 20.586(2) Å, V = 1761.5(3) Å3 and Z = 4. The title dye adopts azo-enamine tautomer in the solid state. The molecules crystallises as dimers assembled by two molecules of methanol via intermolecular hydrogen bonding resulting in R64(18) hydrogen bonding motif. Additionally, there is an intramolecular keto-amine hydrogen bond (NH⋯O) with a distance of 2.6172(17) Å. Optimized structures of the three possible tautomers of the compound were obtained using B3LYP method with 6-311++G(d,p), 6-31G and 3-21G basis sets in the gas phase. Thermal properties of the prepared dye were examined by thermogravimetric analysis and results indicated that the framework of the dye is stable up to 172 °C. Furthermore, the pathogenic activities of the synthesized dye were tested in vitro against the sensitive organisms, Bacillus cereous (ATCC 33019) and Staphylococcus aureus (ATCC 25923) as gram positive bacteria, Escherichia coli (ATCC 11229), and Klebsiella pneumoniae (ATCC 13883) as gram negative bacteria and the results are discussed. The results indicated that the prepared dye had antibacterial activities against gram-positive bacteria (S. aureus and Bacillus cereuss), but it exhibited no activity against gram-negative bacteria (E. coli and K. pneumoniae).

  1. Structure and absorption of Co(III) azo complex dyes based on pyrrolinone esters: DFT and TD DFT study

    NASA Astrophysics Data System (ADS)

    Luňák, Stanislav; Aysha, Tarek; Lyčka, Antonín; Machalický, Oldřich; Hrdina, Radim

    2014-07-01

    The relation between structure and absorption of three symmetrical 2:1 octahedral Co(III) azo complexes was studied. Quantum chemical calculations based on density functional theory (DFT) relate well with E-azo configuration of ligands with coordinated nitrogen atoms coming solely from phenolic residues. DFT calculations estimate the mer stereoisomer as remarkably preferred with respect to any fac arrangement. Time dependent DFT calculations using B3LYP and CAM-B3LYP functionals were successfully used to interpret the absorption spectra in a visible range.

  2. One-step purification of phosphinothricin acetyltransferase using reactive dye-affinity chromatography.

    PubMed

    Wang, Cunxi; Lee, Thomas C; Crowley, Kathleen S; Bell, Erin

    2015-01-01

    Reactive dye purification is an affinity purification technique offering unique selectivity and high purification potential. Historically, purification of phosphinothricin acetyltransferase (PAT) has involved several steps of precipitation and column chromatography. Here, we describe a novel purification method that is simple, time-saving, inexpensive, and reproducible. The novel method employs a single chromatography step using a reactive dye resin, Reactive brown 10-agarose. Reactive brown 10 preferentially binds the PAT protein, which can then be specifically released by one of its substrates, acetyl-CoA. Using Reactive brown 10-agarose, PAT protein can be purified to homogeneity from E. coli or plant tissue with high recovery efficiency. PMID:25749943

  3. Thermal modification of activated carbon surface chemistry improves its capacity as redox mediator for azo dye reduction.

    PubMed

    Pereira, L; Pereira, R; Pereira, M F R; van der Zee, F P; Cervantes, F J; Alves, M M

    2010-11-15

    The surface chemistry of a commercial AC (AC(0)) was selectively modified, without changing significantly its textural properties, by chemical oxidation with HNO(3) (AC(HNO3)) and O(2) (AC(O2)), and thermal treatments under H(2) (AC(H2)) or N(2) (AC(N2)) flow. The effect of modified AC on anaerobic chemical dye reduction was assayed with sulphide at different pH values 5, 7 and 9. Four dyes were tested: Acid Orange 7, Reactive Red 2, Mordant Yellow 10 and Direct Blue 71. Batch experiments with low amounts of AC (0.1 g L(-1)) demonstrated an increase of the first-order reduction rate constants, up to 9-fold, as compared with assays without AC. Optimum rates were obtained at pH 5 except for MY10, higher at pH 7. In general, rates increased with increasing the pH of point zero charge (pH(pzc)), following the trend AC(HNO3) < AC(O2) < AC(0) < AC(N2) < AC(H2). The highest reduction rate was obtained for MY10 with AC(H2) at pH 7, which corresponded to the double, as compared with non-modified AC. In a biological system using granular biomass, AC(H2) also duplicated and increase 4.5-fold the decolourisation rates of MY10 and RR2, respectively. In this last experiment, reaction rate was independent of AC concentration in the tested range 0.1-0.6 g L(-1). PMID:20800966

  4. Adsorption of reactive dyes from aqueous solutions by fly ash: kinetic and equilibrium studies.

    PubMed

    Dizge, N; Aydiner, C; Demirbas, E; Kobya, M; Kara, S

    2008-02-11

    Adsorption kinetic and equilibrium studies of three reactive dyes namely, Remazol Brillant Blue (RB), Remazol Red 133 (RR) and Rifacion Yellow HED (RY) from aqueous solutions at various initial dye concentration (100-500 mg/l), pH (2-8), particle size (45-112.5 microm) and temperature (293-323 K) on fly ash (FA) were studied in a batch mode operation. The adsorbent was characterized with using several methods such as SEM, XRD and FTIR. Adsorption of RB reactive dye was found to be pH dependent but both RR and RY reactive dyes were not. The result showed that the amount adsorbed of the reactive dyes increased with increasing initial dye concentration and contact time. Batch kinetic data from experimental investigations on the removal of reactive dyes from aqueous solutions using FA have been well described by external mass transfer and intraparticle diffusion models. It was found that external mass transfer and intraparticle diffusion had rate limiting affects on the removal process. This was attributed to the relatively simple macropore structure of FA particles. The adsorption data fitted well with Langmuir and Freundlich isotherm models. The optimum conditions for removal of the reactive dyes were 100mg/l initial dye concentration, 0.6g/100ml adsorbent dose, temperature of 293 K, 45 microm particle size, pH 6 and agitation speed of 250 rpm, respectively. The values of Langmuir and Freundlich constants were found to increase with increasing temperature in the range 135-180 and 15-34 mg/g for RB, 47-86 and 1.9-3.7 mg/g for RR and 37-61 and 3.0-3.6 mg/g for RY reactive dyes, respectively. Different thermodynamic parameters viz., changes in standard free energy, enthalpy and entropy were evaluated and it was found that the reaction was spontaneous and endothermic in nature. PMID:17574338

  5. Preparation and Photovoltaic Properties of Dye Sensitized Solar Cells Using ZnO Nanorods Stacking Films on AZO Substrate as Photoanode.

    PubMed

    Xu, Yang; Wang, Xina; Liu, Rong; Wang, Hao

    2016-04-01

    Three-dimensional stacking of ZnO nanorods on conducting aluminum-doped ZnO (AZO) glass were studied as efficient photoanodes of dye sensitized solar cells (DSSCs). By changing hydrothermal growth time and cycle times, the thickness of ZnO nanorods stacking films varied from 30 µm to 64 µm, and its influence on the energetic conversion efficiency of the DSSCs based on the stacking films photoanodes was investigated. The loading density of N719 on the surface of ZnO nanorods was studied to increase the efficiency of the cells. Annealing experiments showed that the AZO substrates remained good conductors until heated above 350 °C. A photoelectric conversion efficiency as high as ~2.0% together with ISC of ~9.5 mA/cm2, VOC of ~0.5 V and FF of ~41.4% was achieved for the DSSC using 50 µm-thick film stacking by ZnO nanorods as photoanode and N719 as sensitizer under illumination of AM1.5G solar light (power density of 100 mW/cm2). A charge separation and transfer mechanism was proposed for the ZnO nanorods stacking electrode-based DSSCs. PMID:27451677

  6. An integrated (electro- and bio-oxidation) approach for remediation of industrial wastewater containing azo-dyes: Understanding the degradation mechanism and toxicity assessment.

    PubMed

    Aravind, Priyadharshini; Selvaraj, Hosimin; Ferro, Sergio; Sundaram, Maruthamuthu

    2016-11-15

    A hybrid approach for the remediation of recalcitrant dye wastewater is proposed. The chlorine-mediated electrochemical oxidation of real textile effluents and synthetic samples (using Ti/IrO2-RuO2-TiO2 anodes), lead to discoloration by 92% and 89%, respectively, in 100min, without significant mineralization. The remediation was obtained through biodegradation, after removing the residual bio-toxic active chlorine species via sunlight exposition. Results show that the electrochemical discoloration enhances the effluent biodegradability with about 90% COD removal employing acclimatized naphthalene-degrading bacterial consortia, within 144h. Based on results obtained through FT-IR and GC-MS, it is likely that azo group stripping and oxidative cleavage of dyes occur due to the nucleophilic attack of active chlorine species during electro-oxidation. This leads to generation of aromatic intermediates which are further desulfonated, deaminated or oxidized only at their functional groups. These aromatic intermediates were mineralized into simpler organic acids and aldehydes by bacterial consortia. Phyto-toxicity trials on Vigna radiata confirmed the toxic nature of the untreated dye solutions. An increase in root and shoot development was observed with the electrochemically treated solutions, the same was higher in case of bio-treated solutions. Overall, obtained results confirm the capability of the proposed hybrid oxidation scheme for the remediation of textile wastewater. PMID:27427887

  7. Degradation of Amaranth azo dye in water by heterogeneous photo-Fenton process using FeWO4 catalyst prepared by microwave irradiation.

    PubMed

    da Cruz Severo, Eric; Anchieta, Chayene Gonçalves; Foletto, Vitória Segabinazzi; Kuhn, Raquel Cristine; Collazzo, Gabriela Carvalho; Mazutti, Marcio Antonio; Foletto, Edson Luiz

    2016-01-01

    FeWO4 particles were synthesized by a simple, rapid and facile microwave technique and their catalytic properties in heterogeneous photo-Fenton reaction were evaluated. This material was employed in the degradation of Amaranth azo dye. Individual and interactive effects of operational parameters such as pH, dye concentration and H2O2 dosage on the decolorization efficiency of Amaranth dye were evaluated by 2(3) central composite design. According to characterization techniques, a porous material and a well-crystallized phase of FeWO4 oxide were obtained. Regarding the photo-Fenton reaction assays, up to 97% color and 58% organic carbon removal were achieved in the best experimental conditions. In addition, the photo-Fenton process maintained treatment efficiency over five catalyst reuse cycles to indicate the durability of the FeWO4 catalyst. In summary, the results reveal that the synthesized FeWO4 material is a promising catalyst for wastewater treatment by heterogeneous photo-Fenton process. PMID:26744938

  8. New 1,2,4-triazole-based azo-azomethine dye. Part III: Synthesis, characterization, thermal property, spectrophotometric and computational studies

    NASA Astrophysics Data System (ADS)

    Erfantalab, Malihe; Khanmohammadi, Hamid

    A new 1,2,4-triazole-based azo-azomethine compound, H2L, has been prepared by condensation reaction of 1-(3-formyl-4-hydroxyphenylazo)-4-ethylbenzene with prepared triazole-based diamine. The structure of H2L was characterized by using FT-IR, UV-Vis and 1H NMR spectroscopic methods as well as elemental analysis. Hard model chemometrics method has been used to determine the formation constants of zinc(II), copper(II), nickel(II) and cobalt(II) complexes of H2L in DMSO by UV-Vis spectrophotometric method. Solvatochromic behavior of the dye has been also investigated in some organic solvents with different polarities. Thermal properties of the prepared dye was examined by thermogravimetric analysis. Results indicated that the framework of the dye was stable up to 245 °C. Furthermore,1H chemical shifts and UV-Vis of H2L were studied by the gauge independent atomic orbital (GIAO), continuous set of gauge transformations (CSGT) and time-dependent density functional theory (TD-DFT) methods respectively at the level of density functional theory using B3LYP/6-311+G(d) basis sets in DMSO. The computational data are in reasonably good agreement with the experimental data.

  9. New 1,2,4-triazole-based azo-azomethine dye. Part III: Synthesis, characterization, thermal property, spectrophotometric and computational studies.

    PubMed

    Erfantalab, Malihe; Khanmohammadi, Hamid

    2014-05-01

    A new 1,2,4-triazole-based azo-azomethine compound, H2L, has been prepared by condensation reaction of 1-(3-formyl-4-hydroxyphenylazo)-4-ethylbenzene with prepared triazole-based diamine. The structure of H2L was characterized by using FT-IR, UV-Vis and (1)H NMR spectroscopic methods as well as elemental analysis. Hard model chemometrics method has been used to determine the formation constants of zinc(II), copper(II), nickel(II) and cobalt(II) complexes of H2L in DMSO by UV-Vis spectrophotometric method. Solvatochromic behavior of the dye has been also investigated in some organic solvents with different polarities. Thermal properties of the prepared dye was examined by thermogravimetric analysis. Results indicated that the framework of the dye was stable up to 245 °C. Furthermore,(1)H chemical shifts and UV-Vis of H2L were studied by the gauge independent atomic orbital (GIAO), continuous set of gauge transformations (CSGT) and time-dependent density functional theory (TD-DFT) methods respectively at the level of density functional theory using B3LYP/6-311+G(d) basis sets in DMSO. The computational data are in reasonably good agreement with the experimental data. PMID:24577255

  10. Decolorization of reactive textile dyes using water falling film dielectric barrier discharge.

    PubMed

    Dojčinović, Biljana P; Roglić, Goran M; Obradović, Bratislav M; Kuraica, Milorad M; Kostić, Mirjana M; Nešić, Jelena; Manojlović, Dragan D

    2011-08-30

    Decolorization of reactive textile dyes Reactive Black 5, Reactive Blue 52, Reactive Yellow 125 and Reactive Green 15 was studied using advanced oxidation processes (AOPs) in a non-thermal plasma reactor, based on coaxial water falling film dielectric barrier discharge (DBD). Used initial dye concentrations in the solution were 40.0 and 80.0mg/L. The effects of different initial pH of dye solutions, and addition of homogeneous catalysts (H(2)O(2), Fe(2+) and Cu(2+)) on the decolorization during subsequent recirculation of dye solution through the DBD reactor, i.e. applied energy density (45-315kJ/L) were studied. Influence of residence time was investigated over a period of 24h. Change of pH values and effect of pH adjustments of dye solution after each recirculation on the decolorization was also tested. It was found that the initial pH of dye solutions and pH adjustments of dye solution after each recirculation did not influence the decolorization. The most effective decolorization of 97% was obtained with addition of 10mM H(2)O(2) in a system of 80.0mg/L Reactive Black 5 with applied energy density of 45kJ/L, after residence time of 24h from plasma treatment. Toxicity was evaluated using the brine shrimp Artemia salina as a test organism. PMID:21703757

  11. Cationic starch (Q-TAC) pre-treatment of cotton fabric: influence on dyeing with reactive dye.

    PubMed

    Ali, Shamshad; Mughal, Mohsin Ali; Shoukat, Umair; Baloch, Mansoor Ali; Kim, Seong Hun

    2015-03-01

    Reactive dyes require high concentrations of an electrolyte to improve dye-fiber interaction, leading to the discharge of harmful effluent. One approach to reduce this unsafe release is treatment of the cotton fabric with cationic chemical reagents. This paper reports on the treatment of cotton fabric with cationic starch (Q-TAC), a commercial product, by batchwise method and pad batch method for the first time prior to reactive dyeing process. Furthermore,three commercial reactive dyes, based on monochloro triazine, vinyl sulfone and monochlorotriazine + vinyl sulfonechemistry, was applied on the cotton fabrics by continuous (pad-dry-cure) method. The treated cotton fabric by batchwise method produced 70% higher color yield (K/S) and 20% enhanced dye fixation (%F) than the untreated cotton fabric. X-ray photoelectron spectrometer (XPS) analysis revealed the presence of N1s peaks in the treated cotton fabrics. The crystallinity of treated cotton fabrics was reduced in comparison to untreated cotton fabric as revealed by wide angle X-ray diffraction (WAXD) measurements. Field Emission Scanning Electron Microscopy (FE-SEM) showed that the surface of treated cotton fabrics was rougher than untreated cotton fabric due to the deposition of cationic starch. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum confirmed the existence of quaternary ammonium groups, N(+)(CH3)3, in the treated cotton fabrics. The analysis of color fastness tests demonstrated good to excellent ratings for treated cotton fabrics. In this way, cationic starch treatment of cotton fabric before reactive dyeing process has been proven potentially a more environmentally sustainable method than conventional dyeing method. PMID:25498635

  12. Color removal from acid and reactive dye solutions by electrocoagulation and electrocoagulation/adsorption processes.

    PubMed

    Bellebia, S; Kacha, S; Bouberka, Z; Bouyakoub, A Z; Derriche, Z

    2009-04-01

    In this study, electrocoagulation of Marine Blue Erionyl MR (acid dye) and electrocoagulation followed by adsorption of Brilliant Blue Levafix E-BRA (reactive dye) from aqueous solutions were investigated, using aluminum electrodes and granular activated carbon (GAC). In the electrocoagulation and adsorption of dyestuff solutions, the effects of current density, loading charge, pH, conductivity, stirring velocity, contact time, and GAC concentration were examined. The optimum conditions for the electrocoagulation process were identified as loading charges 7.46 and 1.49 F/m3, for a maximum abatement of 200 mg/L reactive and acid dye, respectively. The residual reactive dye concentration was completely removed with 700 mg/L GAC. The results of this investigation provide important data for the development of a combined process to remove significant concentrations of recalcitrant dyes from water, using moderate activated carbon energy and aluminum consumption, and thereby lowering the cost of treatment. PMID:19445327

  13. Decoloration and mineralization of reactive dyes using electron beam irradiation, Part I: Effect of the dye structure, concentration and absorbed dose (single, binary and ternary systems)

    NASA Astrophysics Data System (ADS)

    Vahdat, Ali; Bahrami, S. Hajir; Arami, M.; Bahjat, A.; Tabakh, F.; Khairkhah, M.

    2012-07-01

    In this study, three different reactive dyes (C.I. Reactive Red 4, C.I. Reactive Blue 2 and C.I. Reactive Yellow 4) and their blend solutions were irradiated with 10 MeV electron beam. Effect of absorbed dose, dye structure and primary solution concentrations on the pH value changes, degree of decoloration and chemical oxygen demand (COD) removal of solutions were investigated. Results show that this method is effective in decomposition and decoloration of the dyes solutions. This method can be applied in mineralization of wastewater containing different dyes.

  14. IDENTIFICATION OF REACTIVE DYES IN SPENT DYEBATHS AND WASTEWATER BY CAPILLARY ELECTROPHORESIS/MASS SPECTROMETRY

    EPA Science Inventory

    Capillary electrophoresis with diode array detection and mass spectrometry combined with solid-phase extraction were employed for the identification of reactive vinylsulfone and chlorotriazine dyes and their hydrolysis products in spent dyebaths and raw and treated wastewater. Re...

  15. Fabrication of a TiO2-BDD heterojunction and its application as a photocatalyst for the simultaneous oxidation of an azo dye and reduction of Cr(VI).

    PubMed

    Yu, Hongbin; Chen, Shuo; Quan, Xie; Zhao, Huimin; Zhang, Yaobin

    2008-05-15

    A TiO2-boron doped diamond (TiO2-BDD) heterojunction was employed as a photocatalyst to simultaneously oxidize an azo dye C.I. reactive yellow 15 (RY15) and reduce hexavalent chromium (Cr(VI)). This heterojunction was fabricated first by depositing a BDD film on a Ti sheet in a hot filament chemical vapor deposition reactor, followed by covering a layer of TiO2 in a metal-organic chemical vapor deposition system. The morphology of this heterojunction was characterized by using a scanning electron microscope (SEM). X-ray diffraction (XRD), Raman spectroscopy, and current-voltage (I-V) measurement were used to characterize its structures. Additionally, the characterization of surface photovoltage showed that the TiO2-BDD heterojunction exhibited a higher photovoltage response and a better ability for charge separation than the photocatalyst of TiO2 directly deposited on a Ti sheet (TiO2-Ti). The photocatalytic experiments revealed that the kinetic constants for the oxidation of RY15 and the reduction of Cr(VI) were, respectively, increased by 85 and 71% when the photocatalyst of TiO2-Ti was replaced by the TiO2-BDD heterojunction. Meanwhile, a significant synergy was confirmed in the simultaneous oxidation of RY15 and reduction of Cr(VI). The enhanced photocatalytic ability of the TiO2-BDD composite could be attributed to the heterojunction. The possible photocatalytic mechanism was also discussed. PMID:18546724

  16. Hydrogen bonding intermolecular effect on electro-optical response of doped 6PCH nematic liquid crystal with some azo dyes

    NASA Astrophysics Data System (ADS)

    Kiani, S.; Zakerhamidi, M. S.; Tajalli, H.

    2016-05-01

    Previous studies on the electro-optical responses of dye-doped liquid crystal have shown that dopant material have a considerable effect on their electro-optical responses. Despite the studies carried out on electro-optical properties of dye-doped liquid crystal, no attention has been paid to study of the interaction and structural effects in this procedure. In this paper, linear dyes and with similar structure were selected as dopants. The only difference in used dyes is the functional groups in their tails. So, doping of these dyes into liquid crystals determines the influence of interaction type on electro-optical behaviours of the doped systems. Therefore, in this work, two aminoazobenzene ("A-dye": hydrogen bond donor) and dimethyl-aminoazobenzene ("B-dye") dyes with different compositional percentages in liquid crystal host were used. Electro-optical Kerr behaviour, the pre-transition temperature and third order nonlinear susceptibility were investigated. The obtained results effectively revealed that type of interactions between the dye and liquid crystal is determinative of behavioral difference of doped system, compared to pure liquid crystal. Also, pre-transitional behaviour and thereupon Kerr electro-optical responses were affected by formed interactions into doped systems. In other words, it will be shown that addition of any dopants in liquid crystal, regardless of the nature of interactions, cannot cause appropriate electro-optical responses. In fact, type of dye, nature of interactions between dopant and liquid crystalline host as well as concentration of dye are the key factors in selecting the appropriate liquid crystal and dopant dye.

  17. Kinetic modelling and simulation of laccase catalyzed degradation of reactive textile dyes.

    PubMed

    Cristóvão, Raquel O; Tavares, Ana P M; Ribeiro, Adriano S; Loureiro, José M; Boaventura, Rui A R; Macedo, Eugénia A

    2008-07-01

    A kinetic model based on Michaelis-Menten equation was developed to simulate the dye decolourisation of Reactive Black 5 (RB5), Reactive Blue 114 (RB114), Reactive Yellow 15 (RY15), Reactive Red 239 (RR239) and Reactive Red 180 (RR180) dyes by commercial laccase. The unusual kinetic behavior of some of these reactions suggests that the kinetic model must consider the activation of the laccase-mediator system. Several reactions at different concentrations of each dye were performed in batch reactors and time courses were obtained. A LSODE code to solve the differential equation obtained from the batch reactor was combined with an optimization Fortran program to obtain the theoretical time courses. The time courses obtained from the developed program were compared with the experimentally obtained ones to estimate the kinetic constants that minimized the difference between them. The close correlation between the predicted and the experimental results seems to support the reliability of the established models. PMID:17986393

  18. Bioaccumulation of Cu-complex reactive dye by growing pellets of Penicillium oxalicum and its mechanism.

    PubMed

    Xin, Baoping; Chen, Gang; Zheng, Wenchai

    2010-06-01

    In this paper bioaccumulation of Cu-complex reactive dye by growing pellets of Penicillium oxalicum and its mechanism was investigated. Shaking flasks experiment showed that 99.7% of dye removal at 400 mg/l was attained after 48 h contact. Column reactor experiment showed that air lift ferment tower was a suitable reactor for both pellets formation and dye bioaccumulation. Repeated inoculation of the dye-loaded pellets accelerated dye bioaccumulation, leading to complete dye removal within 12 h. Dye initially was adsorbed on surface of cell, followed by penetration into cytoplasm. During bioaccumulation, mycelium expanded unevenly and thickened locally in diameter, generating a chain of spindles along the mycelium. In addition, the cell walls grew loose and thickened remarkably, being 4-5 folds as thick as the control one. The loose cell wall may offer both dye accumulation space and route way for dye to enter cytoplasm. There were certain unknown active matters in cytoplasm, which played an important role in dye accumulation. Desorption experiments suggested that electrostatic attraction was mainly attributed to the dye bioaccumulation. PMID:20421123

  19. Simultaneous decolorization of reactive Orange M2R dye and reduction of chromate by Lysinibacillus sp. KMK-A.

    PubMed

    Chaudhari, Ashvini U; Tapase, Savita R; Markad, Vijaykumar L; Kodam, Kisan M

    2013-11-15

    Azo dyes constitute the largest and diverse group of dyes, widely used in number of industries that are contributing toward organic and inorganic load of effluent treatment. In the present study, Lysinibacillus sp. KMK-A was able to effectively decolorize Orange M2R dye up to 2000 mg l(-1) (Vmax of 19.6 mg l(-1) h(-1) and Km of 439 mg l(-1)) and reduce Cr(VI) up to 250 mg l(-1) (Vmax of 3.6 mg l(-1) h(-1) and Km 28.3 mg l(-1)). It also has an ability of simultaneous decolorization of Orange M2R dye (200-1000 mg l(-1)) with reduction of Cr(VI) (50-200 mg l(-1)). Significant reduction in total organic carbon content, chemical and biological oxygen demand along with spectroscopic and chromatographic analysis confirmed the biotransformation of Orange M2R. Involvement of enzymes namely azoreductase and chromate reductase was observed during biotransformation. The phyto and geno toxicity studies demonstrated that metabolites of dye degradation were non-toxic. Higher tolerance with simultaneous decolorization and detoxification of azo dyes in presence of Cr(VI) makes Lysinibacillus sp. KMK-A, a potential candidate for eco-friendly remediation of metal contaminated dye effluents. PMID:24095998

  20. Enhanced accumulation and visible light-assisted degradation of azo dyes in poly(allylamine hydrochloride)-modified mesoporous silica spheres

    SciTech Connect

    Tao Xia Liu Bing; Hou Qian; Xu Hui; Chen Jianfeng

    2009-02-04

    A new route for the economic and efficient treatment of azo dye pollutants is reported, in which surface-modified organic-inorganic hybrid mesoporous silica (MS) spheres were chosen as microreactors for the accumulation and subsequent photodegradation of pollutants in defined regions. The surface-modified silica materials were prepared by anchoring the polycationic species such as poly(allylamine hydrochloride) on MS spheres via a simple wet impregnation method. The as-synthesized spheres with well-defined porous structures exhibited 15 times of accumulating capacity for orange II and Congo red compared to that of the pure MS spheres. Diffuse reflectance UV-vis spectroscopy and confocal laser scanning microscopy demonstrated that the accumulated orange II and CR in defined MS spheres were rapidly degraded in the presence of Fenton reagent under visible radiation. Kinetics analysis in recycling degradation showed that the as-synthesized materials might be utilized as environment-friendly preconcentrators/microreactors for the remediation of dye wastewater.

  1. Photo-electrochemical studies of chemically deposited nanocrystalline meso-porous n-type TiO2 thin films for dye-sensitized solar cell (DSSC) using simple synthesized azo dye

    NASA Astrophysics Data System (ADS)

    Ezema, C. G.; Nwanya, A. C.; Ezema, B. E.; Patil, B. H.; Bulakhe, R. N.; Ukoha, P. O.; Lokhande, C. D.; Maaza, Malik; Ezema, Fabian I.

    2016-04-01

    Nanocrystalline titanium dioxide (TiO2) thin films were deposited by successive ionic layer adsorption and reaction method onto fluorine doped tin oxide coated glass substrate at room temperature (300 K). Titanium trichloride and sodium hydroxide were used as cationic and anionic sources, respectively. The as-deposited and annealed films were characterized for structural, morphological, optical, electrical and wettability properties. The photoelectrochemical study of TiO2 sensitized with a laboratory synthesized organic dye (azo) was evaluated in the polyiodide electrolyte at 40 mW cm-2 light illumination intensity. The photovoltaic characteristics show a fill factor of 0.24 and solar conversion efficiency value of 0.032 % for a TiO2 thickness of 0.96 µm as compared to efficiency of 0.014 % for rose Bengal of the same thickness.

  2. THE EFFECTS OF PRENATAL ADMINISTRATION OF AZO DYES ON TESTICULAR FUNCTION IN THE MOUSE: A STRUCTURE ACTIVITY PROFILE OF DYES DERIVED FROM BENZIDINE, DIMETHYLBENZIDINE OR DIMETHOXYBENZIDINE

    EPA Science Inventory

    Prenatal exposure to the dye Congo red causes a reduction in the number of germ cells in male and female offspring (Gray et al., in press; Gray and Kavlock, 1984). In the current investigation nine other dyes structurally related to Congo red were evaluated for developmental test...

  3. Genotoxicological assessment of two reactive dyes extracted from cotton fibres using artificial sweat.

    PubMed

    Leme, Daniela Morais; de Oliveira, Gisele Augusto Rodrigues; Meireles, Gabriela; dos Santos, Tuane Cristina; Zanoni, Maria Valnice Boldrin; de Oliveira, Danielle Palma

    2014-02-01

    Human eyes have a remarkable ability to recognize hundreds of colour shades, which has stimulated the use of colorants, especially for clothing, but toxicological studies have shown that some textile dyes can be hazardous to human health. Under conditions of intense perspiration, dyes can migrate from coloured clothes and penetrate into human skin. Garments made from cotton fabrics are the most common clothing in tropical countries, due to their high temperatures. Aiming to identify safe textile dyes for dyeing cotton fabrics, the genotoxicity [in vitro Comet assay with normal human dermal fibroblasts (NHDF), Tail Intensity] and mutagenicity [Salmonella/microsome preincubation assay (30min), tester strains TA98, TA100, YG1041 and YG1042] of Reactive Blue 2 (RB2, CAS No. 12236-82-7, C.I. 61211) and Reactive Green 19 (RG19, CAS No. 61931-49-5, C.I. 205075) were evaluated both in the formulated form and as extracted from cotton fibres using different artificial sweats. Both the dyes could migrate from cotton fibres to sweat solutions, the sweat composition and pH being important factors during this extraction. However, the dye sweat solutions showed no genotoxic/mutagenic effects, whereas a weak mutagenic potential was detected by the Ames test for both dyes in their formulated form. These findings emphasize the relevance of textile dyes assessment under conditions that more closely resemble human exposure, in order to recognize any hazard. PMID:23811265

  4. Torsionally Responsive C[subscript 3]-Symmetric Azo Dyes: Azo−Hydrazone Tautomerism, Conformational Switching, and Application for Chemical Sensing

    SciTech Connect

    Lee, Ho Yong; Song, Xinli; Park, Hyunsoo; Baik, Mu-Hyun; Lee, Dongwhan

    2010-12-07

    An efficient triple azo coupling reaction between anilines and phloroglucinol furnished a series of C{sub 3}-symmetric molecules 7-9 supporting multiple conjugation pathways that converge at the molecular core. A combination of {sup 1}H/{sup 13}C NMR spectroscopy, X-ray crystallography, and density functional theory computational studies provided a coherent picture of the [n,{pi}]-conjugated molecular core, which is best described as the tris(hydrazone) [rather than tris(azo)] tautomer stabilized by resonance-assisted hydrogen bonding. For a homologous series of compounds, an increase in the torsional angles between the planar molecular core and the peripheral aryl groups results in a systematic blue shift in the low-energy electronic transitions (7, 523 nm; 8, 505 nm; 9, 445 nm in CHCl{sub 3}) that qualitatively correlates with the shrinkage of effective conjugation through structural distortion. Similar spectral shifts could also be induced by amine substrates that interact with the intramolecular hydrogen-bonding network to trigger bond-twisting motions. Specifically, a brief exposure of a thin film of 7 to vapor samples of butyl-, hexyl-, diethyl-, and diisopropylamine resulted in a rapid and reversible color change from pink to dark-orange. Under similar conditions, however, triethylamine did not elicit any detectable color change, despite the fact that it has a significantly higher vapor pressure than n-hexylamine. These findings implicate that the hydrogen-bonding donor ability is a key requirement for the binding-induced conformational switching, which allows for direct naked-eye detection of volatile amines under ambient conditions.

  5. Skin testing of gallic acid-based hair dye in paraphenylenediamine/paratoluenediamine-reactive patients.

    PubMed

    Choi, Yunseok; Lee, Joon Ho; Kwon, Hyok Bu; An, Susun; Lee, Ai-Young

    2016-07-01

    Incidence of allergic contact dermatitis (ACD) to para-phenylenediamine (PPD)/paratoluenediamine (PTD) hair dyes is increasing. Hair dyes utilizing gallic acid (GA) may be a safe alternative. However, pretesting is recommended. We investigated the contact sensitivity to ingredients of a dye product; GA, monoethanolamine thioglycolate (MT), l-cystein and ferrous sulfate, and an appropriate pretest method in 31 patients reactive to PPD and/or PTD. An open test was performed with the test dye following the patch test. Subsequently, a use test was performed twice, with a 4-week interval. One subject showed a positive reaction to ferrous sulfate in the patch test. Another subject reacted to the first compound alone in the open test. Thirteen subjects manifesting cutaneous lesions from previous regular hair dyeing, showed reactions at the first use of the test dye; and six had reactions with reduced severity at the second test. GA and MT are safe for use in ACD patients reactive to PPD and/or PTD. For predicting contact allergy to hair dyes, the open test appeared to be a better pretest method than the patch test. PMID:26663148

  6. Different molecular complexity of linear-isomaltomegalosaccharides and β-cyclodextrin on enhancing solubility of azo dye ethyl red: towards dye biodegradation.

    PubMed

    Lang, Weeranuch; Kumagai, Yuya; Sadahiro, Juri; Maneesan, Janjira; Okuyama, Masayuki; Mori, Haruhide; Sakairi, Nobuo; Kimura, Atsuo

    2014-10-01

    Intermolecular interaction of linear-type α-(1 → 6)-glucosyl megalosaccharide rich (L-IMS) and water-insoluble anionic ethyl red was firstly characterized in a comparison with inclusion complexation by cyclodextrins (CDs) to overcome the problem of poor solubility and bioavailability. Phase solubility studies indicated an enhancement of 3- and 9-fold over the solubility in water upon the presence of L-IMS and β-CD, respectively. (1)H NMR and circular dichrosim spectra revealed the dye forms consisted of 1:1 stoichiometric inclusion complex within the β-CD cavity, whereas they exhibited non-specific hydrophobic interaction, identified by solvent polarity changes, with L-IMS. The inclusion complex delivered by β-CD showed an uncompetitive inhibitory-type effect to azoreductase, particularly with high water content that did not promote dye liberation. Addition of the solid dye dispersed into coupled-enzyme reaction system supplied by L-IMS as the dye solubilizer provided usual degradation rate. The dye intermission in series exhibited successful removal with at least 5 cycles was economically feasible. PMID:25087215

  7. Optimization of working cathode position in sleeve-type bioelectrochemical system with inner chamber/outer chamber for azo dye treatment.

    PubMed

    Kong, Fanying; Wang, Aijie; Ren, Hong-Yu

    2015-12-01

    In this study, the optimization of working cathode position in sleeve-type bioelectrochemical system (BES) was evaluated with inner/outer chamber for azo dye decolorization. Results showed that the working position in outer chamber performed better with decolorization efficiencies of 97.8 ± 2.1% (7h) and 94.0 ± 2.3% (16 h) than that in inner chamber as the volume ratio Vcathode:Vanode=1:1 and 3:1, respectively. The current and electrochemical impedance spectroscopy (EIS) analysis indicated that the proton/electron transfer and anolyte diffusion could be improved using outer chamber as working position. The decolorization with increased volume ratio could be further improved through the strategy of increasing substrate concentration, which would provide enough electrons and decrease diffusion resistance, further improving the whole performance with increased outer cathode volume. It has the great potential in sleeve-type configuration application and would create more challenges for process optimization and maintenance. PMID:26409856

  8. Induction of NAD(P)H:quinone reductase in murine hepatoma cells by phenolic antioxidants, azo dyes, and other chemoprotectors: a model system for the study of anticarcinogens

    SciTech Connect

    De Long, M.J.; Prochaska, H.J.; Talalay, P.

    1986-02-01

    Exposure of murine hepatoma (Hepa 1c1c7) cells to a variety of chemical agents known to protect animals against the neoplastic, mutagenic, and other toxic effects of chemical carcinogens results in dose- and time-dependent inductions of NAD(P)H:quinone reductase (EC 1.6.99.2). This enzyme protects against quinone toxicity by promoting obligatory two-electron reductions that divert quinones from oxidative cycling or direct interactions with critical nucleophiles. Quinone reductase levels are stable in culture, are easily measured, and are useful markers for the inductive effects of chemoprotective agents. The Hepa 1c1c7 system responds to chemoprotective compounds such as phenolic antioxidants /e.g., BHA (3(2)-tert-butyl-4-hydroxyanisole), BHT (3,5-di-tert-butyl-4-hydroxytoluene), and tert-butylhydroquinone/, lipophilic azo dyes belonging to the 1,1'-azonaphthalene, Sudan I (1-phenylazo-2-naphthol), and Sudan III (1-(4-phenylazophenylazo)-2-naphthol) families, polycyclic aromatic hydrocarbons, coumarin and various other lactones, flavonoids, and certain sulfur compounds (e.g., benzylisothiocyanate, dithiolthiones, and dithiocarbamates), all of which are recognized enzyme inducers and chemoprotectors in vivo. Quinone reductase induction in Hepa 1c1c7 cells therefore provides a simple, versatile, and reliable system for the evaluation of the potency, kinetics, and mechanism of action of anticarcinogens.

  9. Novel determination of nabumetone, a cox-2 inhibitor precursor via its 4-carboxyl-2,6-dinitrobenzene diazonium (CDNBD) derived AZO dye.

    PubMed

    Adegoke, A O; Idowu, S O; Olaniyi, A A

    2007-09-01

    A novel colorimetric determination ofnabumetone in tablets has been developed. The assay is based on chemical derivatization (aromatic ring derivatization technique) using newly developed 4-carboxyl-2,6-dinitrobenzene diazonium (CDNBD) ion as the chromogenic derivatizing reagent and resultant formation of azo dye.Optimization studies established an optimal reaction time of 10 minutes at 30 degrees C after mixing the drug/reagent mixture in a vortex mixer for 10 sec. A new absorption maximum (ë(max)) was found at 470 nm, which was selected as analytical wavelength. The assays were linear over 1-6 microg/ml of nabumetone and the optimal reaction required a 2:1 reagent/drug stoichiometric ratio. The developed method has a low limit of detection of 0.39 microg/ml, and is reproducible (1.81% RSD). It has been applied successfully to the assay of nabumetone tablets and is of equivalent accuracy (p > 0.05) with the official (B.P) HPLC method. The new method is simple, has the main advantage of employing a more affordable instrumentation and could find application in routine in-process quality control of nabumetone tablets. PMID:18390065

  10. Multi-scale biomarker evaluation of the toxicity of a commercial azo dye (Disperse Red 1) in an animal model, the freshwater cnidarian Hydra attenuata.

    PubMed

    de Jong, Laetitia; Pech, Nicolas; de Aragão Umbuzeiro, Gisela; Moreau, Xavier

    2016-06-01

    Acute (24 h, 48 h, 72 h) and chronic (7 days) tests have been performed to evaluate the effects of the commercial azo dye Disperse Red 1 (DR1) using various biomarkers in the freshwater invertebrate Hydra attenuata. Morphological changes have been selected to calculate ecotoxicological thresholds for sublethal and lethal DR1 concentrations. A multinomial logistic model showed that the probability of each morphological stage occurrence was function of concentration, time and interaction between both. Results of oxidative balance parameter measurements (72 h and 7 days) suggest that polyps set up defense mechanisms to limit lipid peroxidation caused by DR1. DR1 exposure at hormetic concentrations induces increase of asexual reproductive rates. This result suggests (1) an impact on the fitness-related phenotypical traits and (2) trade-offs between reproduction and maintenance to allow the population to survive harsher conditions. Changes in serotonin immuno-labeling in polyps showing alterations in feeding behavior suggest that chronic DR1 exposure impaired neuronal processes related to ingesting behavior in H. attenuata. This ecotoxicity study sheds light on the possible serotonin function in Hydra model and reports for the first time that serotonin could play a significant role in feeding behavior. This study used a multi-scale biomarker approach investigating biochemical, morphological, reproductive and behavioral endpoints in Hydra attenuata. This organism is proposed for a pertinent animal model to assess ecotoxicological impact of pollutant mixtures in freshwater environment. PMID:27019466

  11. Characterization and performance of carbonaceous materials obtained from exhausted sludges for the anaerobic biodecolorization of the azo dye Acid Orange II.

    PubMed

    Athalathil, S; Stüber, F; Bengoa, C; Font, J; Fortuny, A; Fabregat, A

    2014-02-28

    This work presents the preliminary study of new carbonaceous materials (CMs) obtained from exhausted sludge, their use in the heterogeneous anaerobic process of biodecolorization of azo dyes and the comparison of their performance with one commercial active carbon. The preparation of carbonaceous materials was conducted through chemical activation and carbonization. Chemical activation was carried out through impregnation of sludge-exhausted materials with ZnCl2 and the activation by means of carbonization at different temperatures (400, 600 and 800°C). Their physicochemical and surface characteristics were also investigated. Sludge based carbonaceous (SBC) materials SBC400, SBC600 and SBC800 present values of 13.0, 111.3 and 202.0m(2)/g of surface area. Biodecolorization levels of 76% were achieved for SBC600 and 86% for SBC800 at space time (τ) of 1.0min, similar to that obtained with commercial activated carbons in the continuous anaerobic up-flow packed bed reactor (UPBR). The experimental data fit well to the first order kinetic model and equilibrium data are well represented by the Langmuir isotherm model. Carbonaceous materials show high level of biodecolorization even at very short space times. Results indicate that carbonaceous materials prepared from sludge-exhausted materials have outstanding textural properties and significant degradation capacity for treating textile effluents. PMID:24413048

  12. [Characterization of cases contravening of regulations regarding primary aromatic amines originating from azo dyes in commercial textile products and leather products in European Union].

    PubMed

    Kawakami, Tsuyoshi; Isama, Kazuo; Ikarashi, Yoshiaki

    2013-01-01

    Contraventions of regulations regarding primary aromatic amines (PAAs) originating from azo dyes in commercial textile products and leather products in European Union (EU), notified in the period between 2006 and 2012 were collected from the Rapid Alert System for non-food consumer products (RAPEX), were characterized. Various types of products (clothes, footwear, bedding, etc.) and their raw materials (cotton, silk, viscose, leather, etc.) were reported to have contravened the regulations. The contravention frequencies for products made in China and India were higher than those for other countries. Ten percentage of the country in which the reported products were produced was unknown. The notification frequencies for benzidine and 4-aminoazobenzene were higher than those for other PAAs. Contravention of regulations regarding benzidine, 4-aminoazobenzene, and 3,3'-dimethoxybenzidine were notified every year. Contraventions of regulations regarding five PAAs--classified as IARC group 1--were notified one or several times. Since the scale of the survey conducted in Japan were small compared with RAPEX, it is necessary that many kinds and number of products should be surveyed in Japan. In addition, it is also necessary to pay attention to 4-aminoazobenzene, while it has not been detected in the previous studies conducted in Japan. PMID:24340672

  13. Large electro-optic effect in sol-gel-processed poled TiO II/SiO II films doped with organic azo dye

    NASA Astrophysics Data System (ADS)

    Hou, Alin; Liu, Hongfei; Liu, Shaolin; Gao, Weinan; Sun, Jie; Zhang, Daming; Yi, Maobin

    2007-01-01

    Highly transparent TiO II/SiO II films prepared using sol-gel technique doped with organic azo dye, Disperse Red 1(DR1) have been investigated. Processing parameters such as spin speed, spin time, and ambient atmosphere, and solution synthesis parameters such as catalysis method, alcohol dilution ratio, and component molar percentages, may affect the film formation. The refractive index increases follow along with the raising of the molar ratio between TiO II and SiO II. When the molar ratio between TiO II and SiO II is zero, i.e. no titania precursor in the initial solution, the refractive index is minimum 1.49 at 1300nm, whereas when there is no TEOS in the initial solution, the refractive index is maximum 1.81 at 1300nm. The sol-gel thin film is spin-coated on ITO glass substrate with better uniformity. The electric-optic coefficient γ 33=42pm/V was measured by simple reflection technique at a fundamental wavelength of 1300nm. The hybrid organic-inorganic sol-gel film is well balanced material in its simplicity for film formation, nonlinearity, and thermal stability sufficient for device fabrication. Moreover, the measurement system was calibrated and the measured electric-optic coefficient of the gallium arsenide crystal is in excellent agreement with the known value.

  14. GONADAL EFFECTS OF FETAL EXPOSURE TO THE AZO DYE CONGO RED IN MICE: INFERTILITY IN FEMALE BUT NOT MALE OFFSPRING

    EPA Science Inventory

    The present study describes the relationship between gonadal genesis and fertility in male and female mice exposed in utero to the diazo dye Congo red (CR). aternal CR treatment inhibited testicular and ovarian function in the offspring after oral administration of I or 0.5 g/kg/...

  15. [Transporting models of reactive X-3B red dye in water-soil-crop continuums].

    PubMed

    Zhou, Qixing

    2002-02-01

    Reactive X-3B red dye entering into environment is a typical persistent organic pollutant(POPs). Transport of the dye from water to soil and from soil to crop compartment is a continuous ecological process. According to the cognitionm, the quantitative depiction of the process using mathematical models was theoretically discussed. Some of the mathematical models were also verified using burozem-soybean, cinnamon soil-wheat, krasnozem-radish, aquorizem-rice systems. In particular, transference of the dye from water compartment to soil compartment by way of adsorbent mechanisms was accorded with the Langmuir model, and movement of the dye from soil compartment to crop compartment on the basis of root-absorbing mechanisms could be expressed using logarithmic crop-soil accumulation factor(CSAF) models. PMID:11993110

  16. Adsorption of reactive blue BF-5G dye by soybean hulls: kinetics, equilibrium and influencing factors.

    PubMed

    Honorio, Jacqueline Ferandin; Veit, Márcia Teresinha; Gonçalves, Gilberto da Cunha; de Campos, Élvio Antonio; Fagundes-Klen, Márcia Regina

    2016-01-01

    The textile industry is known for the high use of chemicals, such as dyes, and large volumes of effluent that contaminate waters, a fact that has encouraged research and improved treatment techniques. In this study, we used unprocessed soybean hulls for the removal of reactive blue BF-5G dye. The point of zero charge of soybean hulls was 6.76. Regarding the speed of agitation in the adsorption process, the resistance to mass transfer that occurs in the boundary layer was eliminated at 100 rpm. Kinetics showed an experimental amount of dye adsorbed at equilibrium of 57.473 mg g(-1) obtained under the following conditions: dye initial concentration = 400 mg L(-1); diameter of particle = 0.725 mm; dosage = 6 g L(-1); pH 2; 100 rpm; temperature = 30 °C; and duration of 24 hours. The pseudo-second order best showed the dye removal kinetics. The adsorption isotherms performed at different temperatures (20, 30, 40 and 50 °C) showed little variation in the concentration range assessed, being properly adjusted by the Langmuir isotherm model. The maximum capacity of dye adsorption was 72.427 mg g(-1) at 30 °C. Since soybean hull is a low-cost industrial byproduct, it proved to be a potential adsorbent for the removal of the textile dye assessed. PMID:26942540

  17. Polymer complexes. LVII. Supramolecular assemblies of novel polymer complexes of dioxouranium(VI) with some substituted allyl azo dye compounds

    NASA Astrophysics Data System (ADS)

    Diab, M. A.; El-Sonbati, A. Z.; El-Bindary, A. A.; Balboula, M. Z.

    2013-05-01

    A novel method to synthesize some dioxouranium(VI) polymer complexes of the general formula [UO2(Ln)2(OAc)2] (where HLn = azo allyl rhodanine). The structure of the novel mononuclear dioxoutranium(VI) polymer complexes was characterized using elemental analysis, spectral (electronic, infrared, 1H &13C NMR) studies, magnetic susceptibility measurements and thermal analysis. The molar conductivities show that all the polymer complexes are non-electrolytes. The IR showed that the ligand HLn act as bidentate neutral through carbonyl group and imine group nitrogen atom forming thereby a six-membered chelating ring and concomitant formation of an intramolecular hydrogen bond. The υ3 frequency of UO2+2 has been shown to be an excellent molecular probe for studying the coordinating power of the ligands. The values of υ3 of the prepared complexes containing UO2+2 were successfully used to calculate the force constant, FUO (10-8 N/Å) and the bond length RUO (Å) of the Usbnd O bond. A strategy based upon both theoretical and experimental investigations has been adopted. The theoretical aspects are described in terms of the well-known theory of 5d-4f transitions. Wilson's, matrix method, Badger's formula, and Jones and El-Sonbati equations were used to calculate the Usbnd O bond distances from the values of the stretching and interaction force constants. The most probable correlation between Usbnd O force constant to Usbnd O bond distance were satisfactorily discussed in term of Badger's rule and the equations suggested by Jones and El-Sonbati. The effect of Hammet constant is also discussed.

  18. Reactive dye house wastewater treatment. Use of hybrid technology: Membrane, sonication followed by wet oxidation

    SciTech Connect

    Dhale, A.D.; Mahajani, V.V.

    1999-05-01

    To address problems associated with treatment of an aqueous waste stream from a reactive dye house, a model dye, turquoise blue CI25, was studied. A hybrid technology, membrane separation followed by sonication and wet oxidation, has been demonstrated to treat the wastewater for reuse and discharge. Experiments were first performed with the reactive dye solution in water. A nanofiltration membrane (MPT 30) was found to be suitable to concentrate the dye. The concentrate was then treated with a wet oxidation process. Kinetics studies were performed with and without catalyst, in the temperature range of 170--215 C. The color destruction achieved was > 99%. After process parameters were fixed, studies were conducted with the actual dye waste stream. The actual waste stream was found to be refractory for wet oxidation under the above conditions. Sonication of the concentrate obtained after membrane filtration, in the presence of CuSO{sub 4}, made the waste stream amenable to wet oxidation. Sonication followed by wet oxidation was found to be more effective at near neutral conditions as compared to basic conditions.

  19. Decolorization characteristics of a newly isolated salt-tolerant Bacillus sp. strain and its application for azo dye-containing wastewater in immobilized form.

    PubMed

    Yu, Lei; Zhang, Xiao-Yu; Tang, Qing-Wen; Li, Jia; Xie, Tian; Liu, Chang; Cao, Ming-Yue; Zhang, Rui-Chang; Wang, Shi; Hu, Jin-Mei; Qiao, Wei-Chuan; Li, Wen-Wei; Ruan, Hong-Hua

    2015-11-01

    Strain CICC 23870 capable of decolorization of various azo dyes under high saline conditions was isolated from saline-alkali soil. The oxygen-insensitive azoreductase in crude extracts exhibited a wide substrate adaptively in the presence of NADH as a cofactor. The decolorization process by free cells followed first-order kinetics, with a high Methyl Orange (MO) tolerance concentration up to 100 mg l(-1) estimated by Haldane model. The average decolorization rate of free cell system was 26.30 mg g(-1) h(-1) at initial MO concentration of 32.7 mg l(-1). However, the values for the systems of immobilized cells (4 mm) in alginate, alginate and nano-TiO2, and alginate and powered activated carbon (PAC) were 6.83, 4.64, and 11.34 mg g(-1) h(-1), respectively. The effective diffusion factors in the tree different matrices were calculated by diffusion-based mathematic model. The diffusion step controls the overall decolorization rate, and the effective diffusion coefficients varied with internal structure of the bead matrices. The diffusion coefficients were increased from 4.98 × 10(-9) to 2.25 × 10(-8) cm(2) s(-1) when PAC was added, but decreased to 6.62 × 10(-10) cm(2) s(-1) when nano-TiO2 was added. The immobilized matrices could be reused for at least three cycles but with a decreased decolorization rate, possibly due to the breakage of beads at the end of each cycle, which led to the loss of immobilized bacteria. PMID:26175104

  20. Assessment of the functionality of a pilot-scale reactor and its potential for electrochemical degradation of calmagite, a sulfonated azo-dye.

    PubMed

    Agarwal, Shirish; Cluxton, Phillip; Kemper, Mark; Dionysiou, Dionysios D; Al-Abed, Souhail R

    2008-10-01

    Electrochemical degradation (ECD) is a promising technology for in situ remediation of diversely contaminated environmental matrices by application of a low level electric potential gradient. This investigation, prompted by successful bench-scale ECD of trichloroethylene, involved development, parametric characterization and evaluation of a pilot-scale electrochemical reactor for degradation of calmagite, a sulfonated azo-dye used as a model contaminant. The reactor has two chambers filled with granulated graphite for electrodes. The system has electrical potential, current, conductivity, pH, temperature, water-level and flow sensors for automated monitoring. The reactor supports outdoor and fail-safe venting, argon purging, temperature regulation and auto-shutdown for safety. Treatment involves recirculating the contaminated solution through the electrode beds at small flow velocities mimicking low fluid-flux in groundwater and submarine sediments. The first phase of the investigation involved testing of the reactor components, its parametric probes and the automated data acquisition system for performance as designed. The results showed hydraulic stability, consistent pH behavior, marginal temperature rise (<5 degrees C) and overall safe and predictable performance under diverse conditions. Near complete removal of calmagite was seen at 3-10V of applied voltage in 8-10h. The effects of voltage and strength of electrolyte on degradation kinetics have been presented. Further, it was observed from the absorption spectra that as calmagite degrades over time, new peaks appear. These peaks were associated with degradation products identified using electrospray ionization mass spectrometry. A reaction mechanism for ECD of calmagite has also been proposed. PMID:18676003

  1. Enhanced degradation of azo dye in wastewater by pulsed discharge plasma coupled with MWCNTs-TiO2/γ-Al2O3 composite photocatalyst.

    PubMed

    Li, Xin; Wang, Tiecheng; Qu, Guangzhou; Liang, Dongli; Hu, Shibin

    2016-05-01

    In order to improve the photocatalytic performance of TiO2 in pulsed discharge plasma systems, easily recycled multi-walled carbon nanotubes (MWCNTs)-TiO2 supported on γ-Al2O3 (MWCNTs-TiO2/γ-Al2O3) composite photocatalyst were prepared. The morphology and physicochemical properties of the prepared catalysts were investigated using XRD, SEM, FTIR and UV-vis spectroscopy. The photocatalytic activity was evaluated by degradation of azo dye acid orange II (AO7) in wastewater under pulsed discharge plasma. The results indicate that the MWCNTs-TiO2/γ-Al2O3 composite catalyst possesses enhanced photocatalytic activity facilitating the decomposition of AO7 compared with TiO2/γ-Al2O3 composite in pulsed discharge plasma systems. Under pulsed discharge plasma, almost 100% AO7 is degraded by the MWCNTs-TiO2/γ-Al2O3 composite after 60 min at optimal conditions. The degradation efficiency of AO7 is also affected by the dosage of the composite catalyst and pulsed discharge peak voltage. As the amount of MWCNTs-TiO2/γ-Al2O3 composite and pulsed discharge peak voltage increases, the degradation efficiency of AO7 increases. The photocatalyst was implemented for 6 cycles and the degradation efficiency of AO7 remains higher than 85% under pulsed discharge plasma. Results indicate that the catalyst displays easy separation and minimal deactivation after several uses. Possible decomposition mechanisms were also investigated. MWCNTs are capable of improving the photocatalytic activity of TiO2/γ-Al2O3 composite in pulsed discharge plasma systems primarily due to the photo-induced-electron absorption effect and the electron trap effect of MWCNTs. The results of this study establish the feasibility and potential implementation of MWCNTs-TiO2/γ-Al2O3 composites in pulsed discharge plasma systems for the degradation of dye wastewater. PMID:26946167

  2. Environmental assessment of the degradation potential of mushroom fruit bodies of Pleurotus ostreatus (Jacq.: Fr.) P. Kumm. towards synthetic azo dyes and contaminating effluents collected from textile industries in Karnataka, India.

    PubMed

    Skariyachan, Sinosh; Prasanna, Apoorva; Manjunath, Sirisha P; Karanth, Soujanya S; Nazre, Ambika

    2016-02-01

    Pleurotus ostreatus (Jacq.: Fr.) P. Kumm. is one of the edible mushrooms currently gaining attention as environmental restorer. The present study explores the potential of P. ostreatus (Jacq.: Fr.) P. Kumm. in degradation of textile dyes and effluents. The mushroom cultivation was carried out using paddy bed as substrate. The fully grown mushroom fruit bodies were used as a bioremediation agent against two industrially important azo dyes such as nylon blue and cotton yellow and few effluents collected from various textile industries in Karnataka, India. The ideal growth parameters such as temperature, pH, and dye concentrations for effective degradation were carried out. One of the main enzymes, laccase, responsible for biodegradation, was partially characterized. The degradation was found to be ideal at pH 3.0 and temperature at 26-28 °C. This study demonstrated a percentage degradation of 78.10, 90.81, 82.5, and 64.88 for dye samples such as nylon blue (50 ppm), cotton yellow (350 ppm), KSIC effluents, and Ramanagar effluents at 28 °C within 15th days respectively in comparison with other temperature conditions. Similarly, a percentage degradation of 35.99, 33.33, 76.13 and 25.8 for nylon blue (50 ppm), cotton yellow (350 ppm), Karnataka Silk Industries Corporation (KSIC) effluents and Ramnagar effluents were observed at pH 3.0 within 15 days, respectively (p < 0.05). Thus, the current study concluded that the utilization of P. ostreatus (Jacq.: Fr.) P. Kumm. at ideal environmental conditions is a cost-effective and eco-friendly approach for the degradation of various azo dyes and textile effluents which are harmful to the ecosystem. PMID:26818015

  3. New pathway for degradation of sulfonated azo dyes by microbial peroxidases of Phanerochaete chrysosporium and Streptomyces chromofuscus.

    PubMed Central

    Goszczynski, S; Paszczynski, A; Pasti-Grigsby, M B; Crawford, R L; Crawford, D L

    1994-01-01

    Pathways for the degradation of 3,5-dimethyl-4-hydroxy-azobenzene-4'-sulfonic acid (I) and 3-methoxy-4-hydroxyazobenzene-4'-sulfonamide (II) by the manganese peroxidase and ligninase of Phanerochaete chrysosporium and by the peroxidase of Streptomyces chromofuscus have been proposed. Twelve metabolic products were found, and their mechanisms of formation were explained. Preliminary oxidative activation of the dyes resulted in the formation of cationic species, making the molecules vulnerable to the nucleophilic attack of water. Two types of hydrolytic cleavage were observed. Asymmetric splitting gave rise to quinone and diazene derivatives, while symmetric splitting resulted in the formation of quinone monoimine and nitroso derivatives. These unstable intermediates underwent further redox, oxidation, and hydrolytic transformation, eventually furnishing 11 organic products and ammonia. PMID:8113173

  4. Removal of reactive dyes from wastewater by adsorption on coir pith activated carbon.

    PubMed

    Santhy, K; Selvapathy, P

    2006-07-01

    The removal efficiency of activated carbon prepared from coir pith towards three highly used reactive dyes in textile industry was investigated. Batch experiments showed that the adsorption of dyes increased with an increase in contact time and carbon dose. Maximum de-colorisation of all the dyes was observed at acidic pH. Adsorption of dyes was found to follow the Freundlich model. Kinetic studies indicated that the adsorption followed first order and the values of the Lagergren rate constants of the dyes were in the range of 1.77 x 10(-2)-2.69 x 10(-2)min(-1). The column experiments using granular form of the carbon (obtained by agglomeration with polyvinyl acetate) showed that adsorption efficiency increased with an increase in bed depth and decrease of flow rate. The bed depth service time (BDST) analysis carried out for the dyes indicated a linear relationship between bed depth and service time. The exhausted carbon could be completely regenerated and put to repeated use by elution with 1.0M NaOH. The coir pith activated carbon was not only effective in removal of colour but also significantly reduced COD levels of the textile wastewater. PMID:16040240

  5. Review of experimental additions of rhodamine wt dye into reactive aquatic environments

    SciTech Connect

    Bencala, K.E.; Zellweger, G.W. )

    1988-09-01

    The fluorescent dye rhodamine WT is routinely used in hydrologic studies. It is also being used in field studies of the potential addition or loss of other chemical components to aquatic systems; for example, the determination of atmospheric oxygen transfer to streams or the study of solute transport in an acidic and metal-rich stream. Although rhodamine WT is considered appropriate environmentally as a tracer, toxicological concerns have been raised as the result of laboratory experiments. Smart (1984) placed these concerns in the environmental perspective. Steinheimer and Johnson (1986) have shown that an environmental hazard does not exist when following customary dye-study practices. Additional work by Abidi et al (1986) also has lessened the concerns regarding potential environmental hazards. Because this dye is generally considered effective and nonhazardous, it has been tested in environments in which its stability may be questioned a priori. An appreciable body of knowledge is now growing regarding the chemical fate of rhodamine WT dye in aquatic systems. Smart and Laidlaw (1977) previously presented an extensive evaluation of fluorescent dye properties in natural waters. Their survey included consideration of the impact of temperature, pH, salinity, chlorine, photochemical decay, chemical decay, and biodegradation. This presentation is a review of selected recent evaluations of rhodamine WT in reactive environments that were acidic or that presented significant opportunity for dye sorption onto solids.

  6. Fabrication of nanospinel ZnCr2O4 using sol-gel method and its application on removal of azo dye from aqueous solution.

    PubMed

    Yazdanbakhsh, Mohammad; Khosravi, Iman; Goharshadi, Elaheh K; Youssefi, Abbas

    2010-12-15

    For the first time, nanoparticles of zinc chromite, spinel ZnCr(2)O(4) have been fabricated by the thermal decomposition of Zn-Cr gel prepared by sol-gel method in the presence of oxalic acid as a chelating agent. It was shown that the well-crystallized spinel structure is formed after calcination at 450°C. The nanospinel has been characterized by differential thermal analysis (DTA), X-ray powder diffraction (XRD), infrared spectroscopy (IR), and transmission electron microscope (TEM). The average particle size is approximately 13 nm according to the TEM image. The nanoparticles of zinc chromites showed excellent adsorption properties towards reactive dye, reactive blue 5 (RB5). The adsorption studies have been carried out for contact time, different pH values, different temperatures, and adsorbent doses. The investigation of removal kinetics of RB5 indicates that the removal process obeys the rate of second-order kinetic equation. The results indicate that the Langmuir adsorption isotherm fitted the data better than the Freundlich. Also, the photocatalytic degradation of RB5 using spinel ZnCr(2)O(4) under UV irradiation at pH=1 has been also examined. The results showed that the degradation of RB5 dye follows merely an adsorption process. PMID:20863619

  7. Cationic-cellulose nanofibers: preparation and dyeability with anionic reactive dyes for apparel application.

    PubMed

    Khatri, Zeeshan; Mayakrishnan, Gopiraman; Hirata, Yuichi; Wei, Kai; Kim, Ick-Soo

    2013-01-01

    Continuous effort in research and development of nanofibers for apparel usage has been focused within their functional properties only. We investigated esthetic properties by producing colored cationic-cellulose nanofibers for the very first time for the potential application of apparel use. The cellulose acetate nanofibers were electrospun followed by deacetylation and cationization to produce functional cationic-cellulose nanofibers and then dyed with anionic reactive dyes. The spectrophotometric measurement of dyed samples was carried out to determine color coordinates and color yield values. The cationic-cellulose nanofibers showed enhanced color yield and dye fixation without addition of an electrolyte in comparison to cellulose nanofibers. The cationization of cellulose nanofibers significantly enhanced the color yield values of around 76% at dye concentrations of 5%. Excellent color fastness results demonstrate that these new colored and breathable materials can potentially be considered as future apparel for casual or fashion. PMID:23044154

  8. Kinetic studies of the liquid-phase adsorption of a reactive dye onto activated lignite

    SciTech Connect

    Petrolekas, P.D.; Maggenakis, G.

    2007-02-14

    The kinetics of batch adsorption of a commercial reactive dye onto activated lignite has been investigated at temperatures of 26, 40, and 55{sup o}C, using aqueous solutions with initial dye concentrations in the range of 15-60 mg/L. An empirical single parameter relationship of the adsorbent loading versus the square root of contact time was proposed, which was determined to provide a very good description of the batch adsorption transients up to equilibrium. The data were also examined by means of the Elovich equation. The effect of the temperature and the initial dye concentration on the adsorption kinetics was analyzed, and the results were discussed by considering that intraparticle diffusion is the dominant mechanism.

  9. Removal of azo dye C.I. acid red 14 from contaminated water using Fenton, UV/H(2)O(2), UV/H(2)O(2)/Fe(II), UV/H(2)O(2)/Fe(III) and UV/H(2)O(2)/Fe(III)/oxalate processes: a comparative study.

    PubMed

    Daneshvar, N; Khataee, A R

    2006-01-01

    The decolorization of the solution containing a common textile and leather dye, C.I. Acid Red 14 (AR14), at pH 3 by hydrogen peroxide photolysis, Fenton, Fenton-like and photo-Fenton processes was studied. The dark and light reactions were carried out in stirred batch photoreactor equipped with an UV-C lamp (30 W) as UV light source. The experiments showed that the dye was resistant to the UV illumination, but was oxidized when one of Fe(II), Fe(III) and H(2)O(2) compounds was present. It was also found that UV light irradiation can accelerate significantly the rate of AR14 decolorization in the presence of Fe(III)/H(2)O(2) or Fe(II)/H(2)O(2), comparing to that in the dark. The effect of different system variables like initial concentration of the azo dye, effect of UV light irradiation, initial concentration of Fe(II) or Fe(III) and added oxalate ion has been investigated. The results showed that the decolorization efficiency of AR14 at the reaction time of 2 min follows the decreasing order: UV/H(2)O(2)/Fe(III)/oxalate > UV/H(2)O(2)/Fe(III) > UV/H(2)O(2)/Fe(II) > UV/H(2)O(2). Our results also showed that the UV/H(2)O(2)/Fe(III)/oxalate process was appropriate as the effective treatment method for decolorization of a real dyeing and finishing. The mechanism for each process is also discussed and linked together for understanding the observed differences in reactivity. PMID:16484066

  10. Process development for the batch and bulk removal and recovery of a hazardous, water-soluble azo dye (Metanil Yellow) by adsorption over waste materials (Bottom Ash and De-Oiled Soya).

    PubMed

    Mittal, Alok; Gupta, V K; Malviya, Arti; Mittal, Jyoti

    2008-03-01

    Bottom Ash and De-Oiled Soya have been used as adsorbents for the removal of a hazardous azo dye-Metanil Yellow from its aqueous solutions. Adsorption of Metanil Yellow on these adsorbents has been studied as function of time, temperature, concentration and pH. Batch adsorption studies, kinetic studies and column operations enabled extraction of lethal dye from wastewaters. Adsorption equilibrium data confirms both Langmuir and Freundlich isotherm models and monolayer coverage of dye over adsorbents. Kinetic data have been employed to calculate specific rate constants, indicating thereby involvement of first order kinetics in the on-going adsorption and activation energy was determined as 0.813 and 1.060 kJ mol(-1) for Bottom Ash and De-Oiled Soya, respectively. For both adsorbents, the adsorption process has been found governing by film diffusion, over the entire concentration range. Column operations have also been performed for the bulk removal of the dye and also to examine the practical utilization of fixed bed adsorption technique in elimination of dangerous effluent. Saturation factors for Bottom Ash and De-Oiled Soya columns have been calculated as 99.15 and 99.38%, respectively. Attempts have also been made to regenerate the dye from the exhausted columns using aqueous sodium hydroxide as eluent. PMID:17659833

  11. Complete degradation of the azo dye Acid Orange-7 and bioelectricity generation in an integrated microbial fuel cell, aerobic two-stage bioreactor system in continuous flow mode at ambient temperature.

    PubMed

    Fernando, Eustace; Keshavarz, Taj; Kyazze, Godfrey

    2014-03-01

    In this study, the commercially used model azo dye Acid Orange-7 (AO-7) was fully degraded into less toxic intermediates using an integrated microbial fuel cell (MFC) and aerobic bioreactor system. The integrated bioreactor system was operated at ambient temperature and continuous-flow mode. AO-7 loading rate was varied during experiments from 70gm(-3)day(-1) to 210gm(-3)day(-1). Colour and soluble COD removal rates reached>90% under all AO-7 loading rates. The MFC treatment stage prompted AO-7 to undergo reductive degradation into its constituent aromatic amines. HPLC-MS analysis of metabolite extracts from the aerobic stage of the bioreactor system indicated further oxidative degradation of the resulting aromatic amines into simpler compounds. Bioluminescence based Vibrio fischeri ecotoxicity testing demonstrated that aerobic stage effluent exhibited toxicity reductions of approximately fivefold and ten-fold respectively compared to the dye wastewater influent and MFC-stage effluent. PMID:24495541

  12. Kinetics of heterogeneous photocatalytic degradation of reactive dyes in an immobilized TiO2 photocatalytic reactor.

    PubMed

    Mahmoodi, Niyaz Mohammad; Arami, Mokhtar; Limaee, Nargess Yousefi; Tabrizi, Nooshin Salman

    2006-03-01

    The photocatalytic degradation of two reactive dyes has been investigated by UV/TiO2/H2O2 using an immobilized TiO2 photocatalytic reactor. Reactive Blue 8 (RB 8) and Reactive Blue 220 (RB 220) textile dyes were used as model compounds. Photocatalytic degradation processes were performed using a 5-L solution containing dyes. The initial concentrations of dyes were 50 mg/L. The radiation source was two 15 W UV-C lamps. A batch mode immersion photocatalytic reactor was utilized. UV-vis and ion chromatography (IC) analyses were employed to obtain the details of the photodegradation of the selected dyes. Colored synthetic waters were completely decolorized in relatively short time after UV irradiation in the presence of various concentrations of hydrogen peroxide. Formate, acetate, oxalate, and glyoxylate anions were detected as dominant aliphatic intermediates where they were further oxidized slowly to CO2. The UV/TiO2/H2O2 process was able to oxidize the dyes with partial mineralization of carbon, nitrogen, and sulfur heteroatoms into CO2, NO3-, and SO4(2-), respectively. Kinetics analysis indicates that the photocatalytic decolorization rates of the dye can be approximated by a pseudo-first-order model. The UV/TiO2/H2O2 process proved to be capable of decolorization and mineralization of the reactive dyes (RB 8 and RB 220). PMID:16181631

  13. Enzymatic reduction of azo and indigoid compounds.

    PubMed

    Pricelius, S; Held, C; Murkovic, M; Bozic, M; Kokol, V; Cavaco-Paulo, A; Guebitz, G M

    2007-11-01

    A customer- and environment-friendly method for the decolorization azo dyes was developed. Azoreductases could be used both to bleach hair dyed with azo dyes and to reduce dyes in vat dyeing of textiles. A new reduced nicotinamide adenine dinucleotide-dependent azoreductase of Bacillus cereus, which showed high potential for reduction of these dyes, was purified using a combination of ammonium sulfate precipitation and chromatography and had a molecular mass of 21.5 kDa. The optimum pH of the azoreductase depended on the substrate and was within the range of pH 6 to 7, while the maximum temperature was reached at 40 degrees C. Oxygen was shown to be an alternative electron acceptor to azo compounds and must therefore be excluded during enzymatic dye reduction. Biotransformation of the azo dyes Flame Orange and Ruby Red was studied in more detail using UV-visible spectroscopy, high-performance liquid chromatography, and mass spectrometry (MS). Reduction of the azo bonds leads to cleavage of the dyes resulting in the cleavage product 2-amino-1,3 dimethylimidazolium and N approximately 1 approximately ,N approximately 1 approximately -dimethyl-1,4-benzenediamine for Ruby Red, while only the first was detected for Flame Orange because of MS instability of the expected 1,4-benzenediamine. The azoreductase was also found to reduce vat dyes like Indigo Carmine (C.I. Acid Blue 74). Hydrogen peroxide (H(2)O(2)) as an oxidizing agent was used to reoxidize the dye into the initial form. The reduction and oxidation mechanism of Indigo Carmine was studied using UV-visible spectroscopy. PMID:17891390

  14. Degradation of reactive, acid and basic textile dyes in the presence of ultrasound and rare earths [Lanthanum and Praseodymium].

    PubMed

    Srivastava, Pankaj; Goyal, Shikha; Patnala, Prem Kishore

    2014-11-01

    Degradation of five textile dyes, namely Reactive Red 141 (RR 141), Reactive Blue 21 (RB 21), Acid Red 114 (AR 114), Acid Blue 113 (AB 113) and Basic Violet 16 (BV 16) in aqueous solution has been carried out with ultrasound (US) and in combination with rare earth ions (La(3+) and Pr(3+)). Kinetic analysis of the data showed a pseudo-first order degradation reaction for all the dyes. The rate constant (k), half life (t1/2) and the process efficiency (φ) for various processes in degradation of dyes under different experimental conditions have been calculated. The influence of concentrations of dyes (16-40mg/L), pH (5, 7 and 9) and rare earth ion concentration (4, 12 and 20mg/L) on the degradation of dyes have also been studied. The degradation percentage increased with increasing rare earth amount and decreased with increasing concentration of dyes. Both horn and bath type sonicators were used at 20kHz and 250W for degradation. The sonochemical degradation rate of dyes in the presence of rare earths was related to the type of chromophoric groups in the dye molecule. Degradation sequence of dyes was further examined through LCMS and Raman spectroscopic techniques, which confirmed the sonochemical degradation of dyes to non-toxic end products. PMID:24491599

  15. Electricity production from Azo dye wastewater using a microbial fuel cell coupled constructed wetland operating under different operating conditions.

    PubMed

    Fang, Zhou; Song, Hai-liang; Cang, Ning; Li, Xian-ning

    2015-06-15

    Microbial fuel cells (MFCs) have got tremendous attention for their capability to enhance the degradation of some recalcitrant pollutants and simultaneous electricity production. A microbial fuel cell coupled constructed wetland (CW-MFC) is a new device to treat the wastewater and produce energy which has more wastewater treatment volume and more easily to maintenance than others MFCs. The studies on the performance of CW-MFCs are necessary. In this work, the effects of hydraulic residence time (HRT), reactive brilliant red X-3B (ABRX3) proportion and COD concentration on the electricity production of CW-MFC and the degradation characteristics of ABRX3 were investigated. The decolorization rate and the electricity production increased to a peak before slowing down with the elongation of HRT. The highest decolorization rate and electricity production were obtained when HRT was 3 days. The ABRX3 proportion (calculated as COD) in the wastewater played an important role in decolorization and electricity production, which may influence the distribution of electrons in the system. The power density of CW-MFC and the decolorization rate decreased concomitantly with an increasing ABRX3 proportion. The COD concentration influenced the CW-MFC performance slightly. The highest decolorization rate and power density reached 95.6% and 0.852 W/m(3), respectively, when the COD concentration was 300 mg/L while the ABRX3 proportion was 30%. The coulombic efficiency of the CW-MFC depended on glucose and ABRX3 proportions in the wastewater. ABRX3 acquired more electrons than the anode. Further investigations are needed to optimize CW-MFC performance and explain the mechanism of biorefractory compounds degradation and electron motion in CW-MFCs. PMID:25562740

  16. Biodegradation of C.I. Reactive Red 195 by Enterococcus faecalis strain YZ66.

    PubMed

    Mate, Madhuri Sahasrabudhe; Pathade, Girish

    2012-03-01

    Synthetic dyes are extensively used in textile dyeing, paper, printing, colour photography, pharmaceutics, cosmetics and other industries. Among these, azodyes represents the largest and most versatile class of synthetic dyes. As high as 50% of the dyes are released into the environment during manufacture and usage. Traditional methods of treatment are found to be expensive and have operational problems. Biological decolourization has been investigated as a method to transform, degrade or mineralize azo dyes. In the present studies bacteria from soil from dye waste area, dye waste, sewage and dung were subjected to acclimatization with C.I. Reactive Red 195 an azo dye, in the basal nutrient media. The most promising bacterial isolate was used for further dye degradation studies. The 16s rRNA gene sequencing and biochemical characteristics revealed the isolated organism as Enterococcus faecalis strain YZ66. The strain showed 99.5% decolourization of the selected dye (Reactive Red 195-50 mg/l) within one and half hour in static anoxic condition. The optimum pH and temperature for the decolourization was 5.0 and 40°C respectively. The biodegradation was monitored by UV-Vis, FTIR, TLC and HPLC. The final products were characterized by Gas chromatography and Mass Spectrophotometry. Toxicity study demonstrated no toxicity of the biodegradation product. The results suggest that the isolated organism E. faecalis strain YZ 66 can be used as a useful tool to treat waste water containing reactive dyes. PMID:22805800

  17. Decolorization of a reactive copper-phthalocyanine dye under methanogenic conditions.

    PubMed

    Beydili, M I; Matthews, R D; Pavlostathis, S G

    2001-01-01

    The objective of this research was to assess the biological decolorization of the copper-phthalocyanine dye Reactive Blue 7 (RB7) under methanogenic conditions using a mixed, methanogenic culture in a repetitive dye addition batch assay. The initial rate of decolorization was 13.2 mg/L-d and 5.7 mg/L-d for the first and second dye addition, respectively. For an initial RB7 concentration of ca. 300 mg/L, the extent of decolorization remained constant (about 62%) for each repetitive RB7 addition and resulted in a residual color build up. Declining absorbance ratio values (A664/A620) with increasing incubation time confirmed that the observed color removal was due to transformation as opposed to adsorption on the biomass. Chemical decolorization assays using sodium dithionite as the reducing agent resulted in similar absorbance spectra to that obtained after biological decolorization. In addition, in both the chemical and biological decolorization assays, partial oxidation of the reduced dye solution upon exposure to air resulted in higher residual color, indicating that the reduction and decolorization of RB7 are partially reversible. These results also suggest that RB7 reduction and decolorization both chemically and biologically most likely followed a similar reduction mechanism. PMID:11380199

  18. Decolorization of salt-alkaline effluent with industrial reactive dyes by laccase-producing Basidiomycetes strains.

    PubMed

    Moreira-Neto, S L; Mussatto, S I; Machado, K M G; Milagres, A M F

    2013-04-01

    The discharge of highly coloured synthetic dye effluents into rivers and lakes is harmful to the water bodies, and therefore, intensive researches have been focussed on the decolorization of wastewater by biological, physical or chemical treatments. In the present study, 12 basidiomycetes strains from the genus Pleurotus, Trametes, Lentinus, Peniophora, Pycnoporus, Rigidoporus, Hygrocybe and Psilocybe were evaluated for decolorization of the reactive dyes Cibacron Brilliant Blue H-GR and Cibacron Red FN-2BL, both in solid and liquid media. Among the evaluated fungi, seven showed great ability to decolorize the synthetic textile effluent, both in vivo (74-77%) or in vitro (60-74%), and laccase was the main ligninolytic enzyme involved on dyes decolorization. Pleurotus ostreatus, Trametes villosa and Peniophora cinerea reduced near to 60% of the effluent colour after only 1 h of treatment. The decolorization results were still improved by establishing the nitrogen source and amount to be used during the fungal strains cultivation in synthetic medium previous their action on the textile effluent, with yeast extract being a better nitrogen source than ammonium tartarate. These results contribute for the development of an effective microbiological process for decolorization of dye effluents with reduced time of treatment. PMID:23350659

  19. Simple one-pot preparation of water-soluble, cysteine-reactive cyanine and merocyanine dyes for biological imaging.

    PubMed

    Toutchkine, Alexei; Nguyen, Dan-Vinh; Hahn, Klaus M

    2007-01-01

    A simple one-pot-procedure for preparation of protein-reactive, water-soluble merocyanine and cyanine dyes has been developed. The 1-(3-ammoniopropyl)-2,3,3-trimethyl-3H-indolium-5-sulfonate bromide (1) was used as a common starting intermediate. The method allows easy preparation of dyes with chloro- and iodoacetamide side chains for covalent attachment to cysteine. By placing a sulfonato group directly on the dye fluorophore system, dyes with high fluorescence quantum yields in water were generated. Both iodo- and chloroacetamido derivatives were shown to be useful in protein labeling. Less reactive chloroacetamides will be preferential for selective labeling of the most reactive cysteines. PMID:17542551

  20. Decolorization and biodegradation of reactive blue 220 textile dye by Lentinus crinitus extracellular extract.

    PubMed

    Niebisch, Carolina Heyse; Malinowski, Alexandre Knoll; Schadeck, Ruth; Mitchell, David A; Kava-Cordeiro, Vanessa; Paba, Jaime

    2010-08-15

    Studies were carried on the decolorization of the textile dye reactive blue 220 (RB220) by a novel isolate of Lentinus crinitus fungi. The optimal conditions for the production of destaining activity were obtained in media containing intermediate concentrations of ammonium oxalate and glucose (10 g L(-1)) as nitrogen and carbon sources, respectively, at 28 degrees C and pH 5.5. Maximum decolorization efficiency against RB220 achieved in this study was around 95%. Ultra-violet and visible (UV-vis) spectrophotometric analyses, before and after decolorization, suggest that decolorization was due to biodegradation. This effect was associated with a putative low molecular weight laccase (41 kDa) displaying good tolerance to a wide range of pH values, salt concentrations and temperatures, suggesting a potential role for this organism in the remediation of real dye containing effluents. PMID:20452721

  1. UV-Vis microspectrophotometry as a method of differentiation between cotton fibre evidence coloured with reactive dyes

    NASA Astrophysics Data System (ADS)

    Was-Gubala, Jolanta; Starczak, Roza

    2015-05-01

    The main purposes of this study was to assess the usefulness of microspectrophotometry (MSP), both in the ultraviolet (UV) and visible (Vis) range for discriminating single cotton fibres dyed with reactive dyes coming from the same manufacturer, as well as the possibility of evaluation of the concentration of dye in an examine fibre. This study utilised woven cotton fabrics dyed with different concentrations of one-compound reactive dyes with the commercial name Cibacron® (at present Novacron®) as the focus of the MSP analysis. The spectra were recorded in the UV-Vis range between 200 and 800 nm, in transmission mode. The results from this study illustrated that all of the analysed cotton samples dyed with reactive dyes were distinguishable between each other with the use of MSP, mostly in the visible, and also in ultraviolet range. The limit for applied MSP techniques was 0.18% of the concentration of a dye in the textile sample. The results indicate that based on the absorbance measurements for fibres constituting e.g. forensic traces it was not possible to estimate the concentration of the dye in the fibre because Beer's law did not obey. The intra-sample, and inter- sample variation, as well as dichroism effect in a case of a cotton fibres dyed with reactive dye were observed. On the basis of the results obtained for each analysed cotton sample, it was concluded that there was no correlation between colour uniformity in cotton fabric (changes in lightness, red/green and yellow/blue colour) and concentration of the reactive dye.

  2. UV-Vis microspectrophotometry as a method of differentiation between cotton fibre evidence coloured with reactive dyes.

    PubMed

    Was-Gubala, Jolanta; Starczak, Roza

    2015-05-01

    The main purposes of this study was to assess the usefulness of microspectrophotometry (MSP), both in the ultraviolet (UV) and visible (Vis) range for discriminating single cotton fibres dyed with reactive dyes coming from the same manufacturer, as well as the possibility of evaluation of the concentration of dye in an examine fibre. This study utilised woven cotton fabrics dyed with different concentrations of one-compound reactive dyes with the commercial name Cibacron® (at present Novacron®) as the focus of the MSP analysis. The spectra were recorded in the UV-Vis range between 200 and 800nm, in transmission mode. The results from this study illustrated that all of the analysed cotton samples dyed with reactive dyes were distinguishable between each other with the use of MSP, mostly in the visible, and also in ultraviolet range. The limit for applied MSP techniques was 0.18% of the concentration of a dye in the textile sample. The results indicate that based on the absorbance measurements for fibres constituting e.g. forensic traces it was not possible to estimate the concentration of the dye in the fibre because Beer's law did not obey. The intra-sample, and inter- sample variation, as well as dichroism effect in a case of a cotton fibres dyed with reactive dye were observed. On the basis of the results obtained for each analysed cotton sample, it was concluded that there was no correlation between colour uniformity in cotton fabric (changes in lightness, red/green and yellow/blue colour) and concentration of the reactive dye. PMID:25699701

  3. A novel ammonia-assisted method for the direct synthesis of Mn3O4 nanoparticles at room temperature and their catalytic activity during the rapid degradation of azo dyes

    NASA Astrophysics Data System (ADS)

    Mansournia, Mohammadreza; Azizi, Fatemeh; Rakhshan, Narges

    2015-05-01

    In this study, we prepared trimanganese tetroxide nanoparticles from MnCl2 solution in an ammonia atmosphere using a new surfactant-free method at room temperature. We analyzed and characterized the effects of different processing conditions, such as the concentrations of manganese and the ammonia source, as well as the reaction time, on the structure, purity, and morphology of the products using powder X-ray diffraction (XRD), scanning electron microscopy, and Fourier transformation infrared spectroscopy (FTIR) techniques. The XRD and FTIR analyses confirmed that the prepared products comprised single phase Mn3O4. At room temperature, the paramagnetic characteristics were also verified by vibrating sample magnetometry. Furthermore, we tested the catalytic activity of the nanoparticles during the degradation of methyl orange and Congo red, which are organic pollutants. Our experiments demonstrated the rapid color removal and reduction in the chemical oxygen demand (>70% and >50% within 10 min, respectively) using aqueous solutions of azo dyes.

  4. Nanostructured semiconductor films for photocatalysis. Photoelectrochemical behavior of SnO{sub 2}/TiO{sub 2} composite systems and its role in photocatalytic degradation of a textile azo dye

    SciTech Connect

    Vinodgopal, K.; Bedja, I.; Kamat, P.V.

    1996-08-01

    Nanostructured semiconductor films of SnO{sub 2}, TiO{sub 2}, and SnO{sub 2}/TiO{sub 2} have been employed for electrochemically assisted photocatalytic degradation of a textile azo dye naphthol blue black (NBB). The degradation rate is significantly higher for SnO{sub 2}/TiO{sub 2} composite films than SnO{sub 2} and TiO{sub 2} films alone. An effort has been made to correlate the photoelectrochemical behavior of these films to the rate of photocatalytic degradation of NBB. The enhanced degradation rate of NBB using composite semiconductor films is attributed to increased charge separation in these systems. Photoelectrochemical and photocatalytic degradation experiments carried out in both nitrogen- and oxygen-saturated solutions with an externally applied electrochemical bias provide useful information in optimizing semiconductor concentrations in a composite film. 83 refs., 9 figs., 1 tab.

  5. Quantitative structure-activity relationship analysis of substituted arylazo pyridone dyes in photocatalytic system: Experimental and theoretical study.

    PubMed

    Dostanić, J; Lončarević, D; Zlatar, M; Vlahović, F; Jovanović, D M

    2016-10-01

    A series of arylazo pyridone dyes was synthesized by changing the type of the substituent group in the diazo moiety, ranging from strong electron-donating to strong electron-withdrawing groups. The structural and electronic properties of the investigated dyes was calculated at the M062X/6-31+G(d,p) level of theory. The observed good linear correlations between atomic charges and Hammett σp constants provided a basis to discuss the transmission of electronic substituent effects through a dye framework. The reactivity of synthesized dyes was tested through their decolorization efficiency in TiO2 photocatalytic system (Degussa P-25). Quantitative structure-activity relationship analysis revealed a strong correlation between reactivity of investigated dyes and Hammett substituent constants. The reaction was facilitated by electron-withdrawing groups, and retarded by electron-donating ones. Quantum mechanical calculations was used in order to describe the mechanism of the photocatalytic oxidation reactions of investigated dyes and interpret their reactivities within the framework of the Density Functional Theory (DFT). According to DFT based reactivity descriptors, i.e. Fukui functions and local softness, the active site moves from azo nitrogen atom linked to benzene ring to pyridone carbon atom linked to azo bond, going from dyes with electron-donating groups to dyes with electron-withdrawing groups. PMID:27209516

  6. Degradation of Anthraquinone Dye Reactive Blue 4 in Pyrite Ash Catalyzed Fenton Reaction

    PubMed Central

    Becelic-Tomin, Milena; Dalmacija, Bozo; Rajic, Ljiljana; Tomasevic, Dragana; Kerkez, Djurdja; Watson, Malcolm; Prica, Miljana

    2014-01-01

    Pyrite ash (PA) is created by burning pyrite in the chemical production of sulphuric acid. The high concentration of iron oxide, mostly hematite, present in pyrite ash, gives the basis for its application as a source of catalytic iron in a modified Fenton process for anthraquinone dye reactive blue 4 (RB4) degradation. The effect of various operating variables such as catalyst and oxidant concentration, initial pH and RB4 concentration on the abatement of total organic carbon, and dye has been assessed in this study. Here we show that degradation of RB4 in the modified Fenton reaction was efficient under the following conditions: pH = 2.5; [PA]0 = 0.2 g L−1; [H2O2]0 = 5 mM and initial RB4 concentration up to 100 mg L−1. The pyrite ash Fenton reaction can overcome limitations observed from the classic Fenton reaction, such as the early termination of the Fenton reaction. Metal (Pb, Zn, and Cu) content of the solution after the process suggests that an additional treatment step is necessary to remove the remaining metals from the water. These results provide basic knowledge to better understand the modified, heterogeneous Fenton process and apply the PA Fenton reaction for the treatment of wastewaters which contains anthraquinone dyes. PMID:24526885

  7. Removal of reactive blue 19 dye by sono, photo and sonophotocatalytic oxidation using visible light.

    PubMed

    Khan, Muhammad Abdul Nasir; Siddique, Maria; Wahid, Fazli; Khan, Romana

    2015-09-01

    An efficient sonophotocatalytic degradation of reactive blue 19 (RB 19) dye was successfully carried out using sulfur-doped TiO2 (S-TiO2) nanoparticles. The effect of various treatment processes that is sonolysis, photolysis, catalysis, sonocatalysis, photocatalysis, and sonophotocatalysis were investigated for RB 19 removal. S-TiO2 were synthesized in 1, 3 and 5 wt.% of sulfur by sol-gel process and characterized by X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive X-ray (SEM-EDX), UV-Visible diffuse reflectance spectra (DRS). The results confirm anatase phase of TiO2, porous agglomerate structure, and a red shift in the absorbance spectra of S-TiO2. The dye degradation was studied by using UV-Vis spectrophotometer at λ max=594 nm. The reaction parameters such as pH, catalyst dosage, initial dye concentration, ultrasonic power and effect of sulfur doping in different weight percent were studied to find out the optimum degradation conditions. Optimum conditions were found as: S-TiO2=5 wt.%, catalyst (S-TiO2 5 wt.%)=50mg, RB 19 solution concentration=20 mg L(-1), pH=3, ultrasound power=100 and operating temperature=25°C. The response of 5 wt.% S-TiO2 was found better than 1 and 3 wt.% S-TiO2 and other forms TiO2. The sonophotocatalysis process was superior to other methods. During this process the ultrasound cavitation and photocatalysis water splitting takes place which leads to the generation of OH. As reveled by the GCMS results the reactive blue 19 (20 mg L(-1)) was degraded to 90% within 120 min. The S-TiO2 sonophotocatalysis system was studied for the first time for dye degradation and was found practicable, efficient and cost effective for the degradation of complex and resistant dyes such as RB19. PMID:25899438

  8. Delaminated montmorillonite with iron(III)-TiO₂ species as a photocatalyst for removal of a textile azo-dye from aqueous solution.

    PubMed

    Torres-Luna, Juan A; Carriazo, José G; Sanabria, Nancy R

    2016-01-01

    A set of mesoporous delaminated montmorillonites containing iron(III)-titanium oxide species was synthesized using two minerals: a bentonite as support and an ilmenite as source of Fe-TiO2 species. Several values of both sulphuric acid concentration and temperature were employed to extract Fe-TiO2 species from an ilmenite. Analyses by X-ray fluorescence, X-ray diffraction, scanning electron microscopy and nitrogen adsorption-desorption confirmed the successful formation of delaminated (or exfoliated) mesoporous structures. Optical properties of solids were determined by UV-Vis diffuse reflectance spectroscopy, and their band gap energy values were also calculated. A small UV-shift of band gap values regarding that of commercial photo-active TiO2 was detected as consequence of the quantum size effect, suggesting that photocatalytic experiments should be performed under UV-radiation assistance. The synthesized solids showed good activity in the photocatalytic oxidation of a textile dye (reactive yellow 145: RY 145), achieving conversions higher than 70% and chemical oxygen demand removal between 60% and 80%. PMID:26586178

  9. Activation of waste MDF sawdust charcoal and its reactive dye adsorption characteristics.

    PubMed

    Gan, Q; Allen, S J; Matthews, R

    2004-01-01

    This paper reports an experimental investigation of converting waste medium density fibreboard (MDF) sawdust into chars and activated carbon using chemical activation and thermal carbonisation processes. The MDF sawdust generated during the production of architectural mouldings was characterised and found to have unique properties in terms of fine particle size and high particle density. It also has a high content of urea formaldehyde resin used as a binder in the manufacturing of MDF board. Direct thermal carbonisation and chemical activation of the sawdust by metal impregnation and acid (phosphoric acid) treatment prior to pyrolysis treatment were carried out. The surface morphology of the raw dust, its chars and activated carbon were examined using scanning electron microscopy (SEM). Adsorptive properties and total pore volume of the materials were also analysed using the BET nitrogen adsorption method. Liquid adsorption of a reactive dye (Levafix Brilliant red E-4BA) by the derived sawdust carbon was investigated in batch isothermal adsorption process and the results compared to adsorption on to a commercial activated carbon (Filtrasorb F400). The MDF sawdust carbon exhibited in general a very low adsorption capacity towards the reactive dye, and physical characterisation of the carbon revealed that the conventional chemical activation and thermal carbonisation process were ineffective in developing a microporous structure in the dust particles. The small size of the powdery dust, the high particle density, and the presence of the urea formaldehyde resin all contributed to the difficulty of developing a proper porous structure during the thermal and chemical activation process. Finally, activation of the dust material in a consolidated form (cylindrical pellet) only achieved very limited improvement in the dye adsorption capacity. This original study, reporting some unexpected outcomes, may serve as a stepping-stone for future investigations of recycle and

  10. Degradation of reactive dyes in wastewater from the textile industry by ozone: analysis of the products by accurate masses.

    PubMed

    Constapel, Marc; Schellenträger, Marc; Marzinkowski, Joachim Michael; Gäb, Siegmar

    2009-02-01

    The present work describes the use of ozone to degrade selected reactive dyes from the textile industry and the analysis of the resulting complex mixture by liquid chromatography/mass spectrometry (LC-MS). To allow certain identification of the substances detected in the wastewater, the original dyes were also investigated either separately or in a synthetic mixture of three dyes (trichromie). Since the reactive dyes are hydrolyzed during the dyeing process, procedures for the hydrolysis were worked out first for the individual dyes. The ozonated solutions were concentrated by solid-phase extraction, which separated very polar or ionic substances from moderately polar degradation products. The latter, which are the primary degradation products, were investigated by liquid chromatography/mass spectrometry with a tandem quadrupole time-of-flight mass analyzer. Accurate masses, which in most cases could be determined with a deviation of dyes, plausible structures could be proposed for most of the components of the moderately polar fraction. These structures were confirmed by 1H NMR in cases where it was practical to isolate the degradation products by preparative HPLC. PMID:19110293

  11. Organic solvent-free air-assisted liquid-liquid microextraction for optimized extraction of illegal azo-based dyes and their main metabolite from spices, cosmetics and human bio-fluid samples in one step.

    PubMed

    Barfi, Behruz; Asghari, Alireza; Rajabi, Maryam; Sabzalian, Sedigheh

    2015-08-15

    Air-assisted liquid-liquid microextraction (AALLME) has unique capabilities to develop as an organic solvent-free and one-step microextraction method, applying ionic-liquids as extraction solvent and avoiding centrifugation step. Herein, a novel and simple eco-friendly method, termed one-step air-assisted liquid-liquid microextraction (OS-AALLME), was developed to extract some illegal azo-based dyes (including Sudan I to IV, and Orange G) from food and cosmetic products. A series of experiments were investigated to achieve the most favorable conditions (including extraction solvent: 77μL of 1-Hexyl-3-methylimidazolium hexafluorophosphate; sample pH 6.3, without salt addition; and extraction cycles: 25 during 100s of sonication) using a central composite design strategy. Under these conditions, limits of detection, linear dynamic ranges, enrichment factors and consumptive indices were in the range of 3.9-84.8ngmL(-1), 0.013-3.1μgmL(-1), 33-39, and 0.13-0.15, respectively. The results showed that -as well as its simplicity, fastness, and use of no hazardous disperser and extraction solvents- OS-AALLME is an enough sensitive and efficient method for the extraction of these dyes from complex matrices. After optimization and validation, OS-AALLME was applied to estimate the concentration of 1-amino-2-naphthol in human bio-fluids as a main reductive metabolite of selected dyes. Levels of 1-amino-2-naphthol in plasma and urinary excretion suggested that this compound may be used as a new potential biomarker of these dyes in human body. PMID:26149246

  12. Evaluation of integrated anaerobic/aerobic fixed-bed sequencing batch biofilm reactor for decolorization and biodegradation of azo dye acid red 18: comparison of using two types of packing media.

    PubMed

    Hosseini Koupaie, E; Alavi Moghaddam, M R; Hashemi, S H

    2013-01-01

    Two integrated anaerobic/aerobic fixed-bed sequencing batch biofilm reactor (FB-SBBR) were operated to evaluate decolorization and biodegradation of azo dye Acid Red 18 (AR18). Volcanic pumice stones and a type of plastic media made of polyethylene were used as packing media in FB-SBBR1 and FB-SBBR2, respectively. Decolorization of AR18 in both reactors followed first-order kinetic with respect to dye concentration. More than 63.7% and 71.3% of anaerobically formed 1-naphthylamine-4-sulfonate (1N-4S), as one of the main sulfonated aromatic constituents of AR18 was removed during the aerobic reaction phase in FB-SBBR1 and FB-SBBR2, respectively. Based on statistical analysis, performance of FB-SBBR2 in terms of COD removal as well as biodegradation of 1N-4S was significantly higher than that of FB-SBBR1. Spherical and rod shaped bacteria were the dominant species of bacteria in the biofilm grown on the pumice stones surfaces, while, the biofilm grown on surfaces of the polyethylene media had a fluffy structure. PMID:23138064

  13. Studies on decolorization of reactive blue 19 textile dye by Coprinus plicatilis

    PubMed Central

    2014-01-01

    Background Studies were carried on the decolorization of the textile dye reactive blue 19 (RB 19) by a novel isolate of Coprinus plicatilis (C. plicatilis) fungi. We describe an in vitro optimization process for decolorization and its behavior under different conditions of carbon and nitrogen sources, pH, temperature and substrate concentration. Results The optimal conditions for decolorization were obtained in media containing intermediate concentrations of ammonium oxalate and glucose (10 g/L) as nitrogen and carbon sources, respectively, at 26°C and pH = 5.5. Maximum decolorization efficiency against RB 19 achieved in this study was around 99%. Ultra-violet and visible (UV-vis) spectrophotometric analyses, before and after decolorization, suggest that decolorization was due to biodegradation. Conclusions This effect was associated with laccase enzyme displaying good tolerance to a wide range of pH values, salt concentrations and temperatures, suggesting a potential role for this organism in the remediation of real dye containing effluents. In conclusion, laccase activity in C. plicatilis was firstly described in this study. PMID:24565535

  14. Chitosan/Graphene Oxide Composite as an Effective Adsorbent for Reactive Red Dye Removal.

    PubMed

    Guo, Xiaoqing; Qu, Lijun; Tian, Mingwei; Zhu, Shifeng; Zhang, Xiansheng; Tang, Xiaoning; Sun, Kaikai

    2016-07-01

    Chitosan, modified with different dosages of graphene oxide (GO) and reduced graphene oxide (rGO), was first prepared, and its adsorption capacity for reactive red (RR) dye in aqueous solutions was investigated, in this paper. The structure and morphology of the adsorbents were characterized by FT-IR, XRD, SEM, EDX, BET, and TGA. The effect of varying parameters (pH, temperature, adsorbent loading, and contact time) was also investigated. The maximum adsorption capacity based on the Langmuir model was found to be 32.16 mg/g. In addition, experimental kinetic data were analyzed by the psuedo-first order and psuedo-second order equation models. The psuedo-second order model proved to be the best model for the adsorption system, which suggested that adsorption might be controlled by the chemical rate-limiting step through sharing of electrons or by covalent forces. PMID:27329054

  15. Selective removal and recovery of Black B reactive dye from simulated textile wastewater using the supported liquid membrane process.

    PubMed

    Harruddin, Norlisa; Othman, Norasikin; Ee Sin, Andeline Lim; Raja Sulaiman, Raja Norimie

    2015-01-01

    Effluent containing colour/dyes, especially reactive dyes, becomes a great concern of wastewater treatment because it is toxic to human life and aquatic life. In this study, reactive dye of Black B was separated using the supported liquid membrane process. Commercial polypropylene membrane was used as a support of the kerosene-tridodecylamine liquid membrane. Several parameters were tested and the result showed that almost 100% of 70 ppm Black B was removed and 99% of 70 ppm Black B was recovered at pH 2 of the feed phase containing 0.00001 M Na2SiO3, flow rate of 150 ml/min and 0.2 M NaOH. The membrane support also remained stable for up to 36 hours under an optimum condition. PMID:25514128

  16. Low frequency sonochemical synthesis of nanoporous amorphous manganese dioxide (MnO2) and adsorption of remazol reactive dye

    NASA Astrophysics Data System (ADS)

    Hasan, Siti Zubaidah; Yusop, Muhammad Rahimi; Othman, Mohamed Rozali

    2015-09-01

    Nanoporous amorphous-MnO2 was synthesized by sonochemical process (sonication) on the solid manganese (II) acetate tetrahydrate (Mn(CH3COO)2.4H2O) in 0.1 M KMnO4. The product was characterized by X-ray diffraction (XRD), morphology of the material was scanned by Field Emission Scanning Electron Microscopy (FE-SEM) and absorptions of MnO2 bonding was characterized by Fourier Transform Infra-Red Spectrometer (FT-IR). Remazol reactive dye or Red 3BS, was used in the adsorption study using nanoporous amorphous-MnO2. In batch experiment, 10 ppm of Remazol reactive dye was used and experiment was carried out at room temperature. Adsorption of Remazol dye on 0.2g synthesized nanoporous amorphous-MnO2 showed 99 - 100% decolorization.

  17. Low frequency sonochemical synthesis of nanoporous amorphous manganese dioxide (MnO{sub 2}) and adsorption of remazol reactive dye

    SciTech Connect

    Hasan, Siti Zubaidah; Yusop, Muhammad Rahimi; Othman, Mohamed Rozali

    2015-09-25

    Nanoporous amorphous-MnO{sub 2} was synthesized by sonochemical process (sonication) on the solid manganese (II) acetate tetrahydrate (Mn(CH{sub 3}COO){sub 2}.4H{sub 2}O) in 0.1 M KMnO{sub 4}. The product was characterized by X-ray diffraction (XRD), morphology of the material was scanned by Field Emission Scanning Electron Microscopy (FE-SEM) and absorptions of MnO{sub 2} bonding was characterized by Fourier Transform Infra-Red Spectrometer (FT-IR). Remazol reactive dye or Red 3BS, was used in the adsorption study using nanoporous amorphous-MnO{sub 2}. In batch experiment, 10 ppm of Remazol reactive dye was used and experiment was carried out at room temperature. Adsorption of Remazol dye on 0.2g synthesized nanoporous amorphous-MnO{sub 2} showed 99 – 100% decolorization.

  18. Kinetic studies on degradation of Reactive Red 120 dye in immobilized packed bed reactor by Bacillus cohnii RAPT1.

    PubMed

    Padmanaban, V C; Geed, Sachin RameshRao; Achary, Anant; Singh, R S

    2016-08-01

    The degradation of Reactive Red 120 using Bacillus cohnii RAPT1 immobilized on polyurethane was studied. Initial experiments indicated that the percentage removal of dye in immobilized batch was significantly higher than batch (without immobilization). The optimum process parameters such as effect of dye concentration, time of immobilization on Poly Urethane Foam, initial inoculum size, pH and temperature for removal of dye were investigated and was found as 200ppm, 36h, 300*10(6) colony forming units/ml, 8.0 and 35°C respectively. Under optimum conditions, 100% removal of dye was obtained within 4h. The kinetics of biodegradation for the batch with free cells and immobilised packed batch was found to be IInd order with kinetic constant and initial rate of reaction as 0.0408, 0.084L/(mgday) and 1632, 3360 (mg/Lday) respectively. PMID:26968121

  19. Comparison of color removal from reactive dye contaminated water by systems containing fungal biosorbent, active carbon and their mixture.

    PubMed

    Gül, Ulküye Dudu; Silah, Hülya

    2014-01-01

    The adsorption of Everzol Black (EB) from synthetic aqueous solution onto active carbon (AC) and dried fungal biosorbent (Rhizopus arrhizus) was studied under the same experimental conditions. The effects of initial dye concentration, adsorbent dosage and contact time were examined at a batch-scale level. As an alternative to AC, fungus was investigated as a low-cost adsorbent for dye removal. The amount of EB adsorbed onto AC was lower compared with fungal biosorbent; dye adsorption capacity of AC and fungal biosorbent were 94.48 and 106.61 mg/g, respectively. The adsorbent dosage experiments showed that 4 g/L biosorbent removed 100% of EB (Co: 114.39 mg/L) after 2 hours. The results obtained from this study showed that biosorbent effectively removed reactive dye from dye-containing water in a short time period. Langmuir and Freundlich adsorption isotherm models were used for mathematical description of the biosorption equilibrium data; the Freundlich model was found to exhibit good fits to the experimental data. According to the Freundlich isotherm, the maximum dye adsorption capacities of AC and biosorbent were calculated as 344.82 and 357.14 mg/g, respectively. The Fourier transform infrared spectroscopy spectral analysis showed the involvement of functional groups for dye bindings. PMID:25325540

  20. A constructed wetland model for synthetic reactive dye wastewater treatment by narrow-leaved cattails (Typha angustifolia Linn.).

    PubMed

    Nilratnisakorn, S; Thiravetyan, P; Nakbanpote, W

    2009-01-01

    Textile wastewater is contaminated by reactive dye causing unattractive levels of wastewater color, high pH and high salt content when discharged into public water systems. Decolorization of textile wastewater by plant, phytoremediation, is an alternative, sustainable method which is suitable for long term operation. Narrow-leaved cattails are one species of wetland plant with efficiency for decolorizing and remediating textile wastewater. In addition, chemical oxygen demand (COD) can be lowered and dye residue can be removed. The plant also showed a good salt tolerance even after being exposed to a salt solution for 15 days. The narrow-leaved cattails were set up in a constructed wetland model with a vertical flow system operating from bottom to top for synthetic reactive dye wastewater (SRDW) removal. Narrow-leaved cattails could achieve the removal of SRDW at approximately 0.8 g(SRDW) m(-2) day(-1). Decolorization of SRDW by this plant was approximately 60%. The advantage of this method is that it is suitable for textile wastewater management and improvement of wetland. These plants could lower COD, remove dye, sodium and total dissolved solids (TDS) whereas other biological and chemical methods could not remove TDS and dye in the same time. These results suggested that the spongy cell structure of this plant has the ability to absorb large amounts of water and nutrients. Physico-chemical analysis revealed increasing amounts of sulfur, silicon, iron and calcium in the plant leafs and roots after exposure to wastewater. Proteins or amide groups in the plant might help in textile dye removal. Regarding decolorization, this plant accumulates dye in the intercellular space and still grows in this SRDW condition. Hence, it can be noted here that narrow-leaved cattails are efficient for textile dye wastewater treatment. PMID:19759459

  1. Diffraction efficiency and phase stability of poly(N-vinylcarbazole)-based photorefractive polymer composites as a function of azo-dye concentration

    NASA Astrophysics Data System (ADS)

    Smiley, E. J.; McGee, D. J.; Salter, C.; Carlen, C. R.

    2000-10-01

    Diffraction efficiency and phase stability of photorefractive polymer composites doped with alkylether-substituted azobenzene dyes are studied as a function of dye concentration. Composites doped with 2,5-dimethyl-4-(4'-nitrophenylazo)phenyl benzyl ether (DMNPAPBE) are phase stable at all concentrations studied while composites doped with 2,5-dimethyl-4-(4'-nitrophenylazo)phenyl octyl ether (DMNPAPOE) exhibit a critical concentration of 47% above which the composite rapidly degrades due to dye crystallization. The glass transition temperatures Tg of DMNPAPBE- and DMNPAPOE-doped composites are approximately 67 and 57 °C, respectively. Diffraction efficiency measurements of DMNPAPOE-doped composites show a threefold increase at 100 V/μm over DMNPAPBE-doped composites at the same dye concentration and applied field.

  2. Decolorization potential of some reactive dyes with crude laccase and laccase-mediated system.

    PubMed

    Saşmaz, Samet; Gedikli, Serap; Aytar, Pınar; Güngörmedi, Gökhan; Cabuk, Ahmet; Hür, Evrim; Unal, Arzu; Kolankaya, Nazif

    2011-02-01

    In this study, decolorization of dyestuffs, such as Reactive Red 198, Rem Blue RR, Dylon Navy 17, Rem Red RR, and Rem Yellow RR was studied using laccase and laccase-mediated system. The laccases are known to have an important potential for remediation of pollutants. Among these dyestuffs, decolorization of Rem Blue RR and Dylon Navy 17 was performed with crude laccase under optimized conditions. Vanillin was selected as laccase mediator after screening six different compounds with Rem Yellow RR, Reactive Red 198, and Rem Red RR as substrates. However, Rem Yellow RR was not decolorized by either laccase or laccase-mediated system. It is observed that the culture supernatant contained high laccase activity after treatment with catalase that was responsible for the decolorization. Besides, culture supernatant with high laccase activity as enzyme source was treated with catalase; in this way, the hypothesis that laccase was the enzyme responsible for decolorization was supported. The Rem Blue RR was decolorized with 64.84% under the optimum conditions and Dylon Navy 17 with 75.43% with crude laccase. However, using the laccase and vanillin, the decolorization of Reactive Red 198 and Rem Red RR was found to be 62% and 68%, respectively. Our study demonstrated that the decolorization abilities of laccase and/or laccase mediator systems were based on the types of mediator, the dye structure, and the standard experimental conditions. Also, the electrochemical behaviors of some samples were studied. The redox potentials of these samples were determined using cyclic voltammetry on glassy carbon electrode in phosphate buffer (pH 6) solution. PMID:20669054

  3. Degradation of reactive orange 4 dye using hydrodynamic cavitation based hybrid techniques.

    PubMed

    Gore, Mohan M; Saharan, Virendra Kumar; Pinjari, Dipak V; Chavan, Prakash V; Pandit, Aniruddha B

    2014-05-01

    In the present work, degradation of reactive orange 4 dye (RO4) has been investigated using hydrodynamic cavitation (HC) and in combination with other AOP's. In the hybrid techniques, combination of hydrodynamic cavitation and other oxidizing agents such as H2O2 and ozone have been used to get the enhanced degradation efficiency through HC device. The hydrodynamic cavitation was first optimized in terms of different operating parameters such as operating inlet pressure, cavitation number and pH of the operating medium to get the maximum degradation of RO4. Following the optimization of HC parameters, the degradation of RO4 was carried out using the combination of HC with H2O2 and ozone. It has been found that the efficiency of the HC can be improved significantly by combining it with H2O2 and ozone. The mineralization rate of RO4 increases considerably with 14.67% mineralization taking place using HC alone increases to 31.90% by combining it with H2O2 and further increases to 76.25% through the combination of HC and ozone. The synergetic coefficient of greater than one for the hybrid processes of HC+H2O2 and HC+Ozone has suggested that the combination of HC with other oxidizing agents is better than the individual processes for the degradation of dye effluent containing RO4. The combination of HC with ozone proves to be the most energy efficient method for the degradation of RO4 as compared to HC alone and the hybrid process of HC and H2O2. PMID:24360991

  4. Removal of reactive dyes from textile wastewater by immobilized chitosan upon grafted Jute fibers with acrylic acid by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Hassan, Mahmoud S.

    2015-10-01

    Jute fibers were grafted with acrylic acid by gamma irradiation technique. Chitosan was immobilized upon the grafted Jute fibers to be used as an adsorbent for waste reactive dye. The treated Jute fibers were characterized by using of Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effect of Jute treatment on its thermal stability by using thermogravimetric analysis (TGA) and its mechanical properties were investigated. The adsorption isotherm and the different factors affecting the dye adsorption such as pH and contact time were also studied. It was found that the dye adsorption was enhanced in the low pH range and increased with increasing of the contact time, regardless of temperature change.

  5. Enhanced decolorization of azo dye in a small pilot-scale anaerobic baffled reactor coupled with biocatalyzed electrolysis system (ABR-BES): a design suitable for scaling-up.

    PubMed

    Cui, Dan; Guo, Yu-Qi; Lee, Hyung-Sool; Wu, Wei-Min; Liang, Bin; Wang, Ai-Jie; Cheng, Hao-Yi

    2014-07-01

    A four-compartment anaerobic baffled reactor (ABR) incorporated with membrane-less biocatalyzed electrolysis system (BES) was tested for the treatment of azo dye (alizarin yellow R, AYR) wastewater (AYR, 200 mg L(-1); glucose, 1000 mg L(-1)). The ABR-BES was operated without and with external power supply to examine AYR reduction process and reductive intermediates with different external voltages (0.3, 0.5 and 0.7 V) and hydraulic retention times (HRT: 8, 6 and 4h). The decolorization efficiency in the ABR-BES (8h HRT, 0.5 V) was higher than that in ABR-BES without electrolysis, i.e. 95.1 ± 1.5% versus 86.9 ± 6.3%. Incorporation of BES with ABR accelerated the consumption of VFAs (mainly acetate) and attenuated biogas (methane) production. Higher power supply (0.7 V) enhanced AYR decolorization efficiency (96.4 ± 1.8%), VFAs removal, and current density (24.1 Am(-3) TCV). Shorter HRT increased volumetric AYR decolorization rates, but decreased AYR decolorization efficiency. PMID:24821204

  6. Adsorption of phenol and reactive dye from aqueous solution on activated carbons derived from solid wastes.

    PubMed

    Nakagawa, Kyuya; Namba, Akio; Mukai, Shin R; Tamon, Hajime; Ariyadejwanich, Pisit; Tanthapanichakoon, Wiwut

    2004-04-01

    Activated carbons were produced from several solid wastes, namely, waste PET, waste tires, refuse derived fuel and wastes generated during lactic acid fermentation from garbage. Activated carbons having various pore size distributions were obtained by the conventional steam-activation method and via the pre-treatment method (i.e., mixture of raw materials with a metal salt, carbonization and acid treatment prior to steam-activation) that was proposed by the authors. The liquid-phase adsorption characteristics of organic compounds from aqueous solution on the activated carbons were determined to confirm the applicability of these carbons, where phenol and a reactive dye, Black5, were employed as representative adsorbates. The hydrophobic surface of the carbons prepared was also confirmed by water vapor adsorption. The characteristics of a typical commercial activated carbon were also measured and compared. It was found that the activated carbons with plentiful mesopores prepared from PET and waste tires had quite high adsorption capacity for large molecules. Therefore they are useful for wastewater treatment, especially, for removal of bulky adsorbates. PMID:15026233

  7. The application of textile sludge adsorbents for the removal of Reactive Red 2 dye.

    PubMed

    Sonai, Gabriela G; de Souza, Selene M A Guelli U; de Oliveira, Débora; de Souza, Antônio Augusto U

    2016-03-01

    Sludge from the textile industry was used as a low-cost adsorbent to remove the dye Reactive Red 2 from an aqueous solution. Adsorbents were prepared through the thermal and chemical treatment of sludge originating from physical-chemical (PC) and biological (BIO) effluent treatment processes. The adsorbent characterization was carried out through physical-chemical analysis, X-ray fluorescence (XRF) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, pHPZC determination, Boehm titration method, Brunauer-Emmett-Teller (BET) surface area analysis and scanning electron microscopy (SEM). Batch kinetic experiments and adsorption isotherm modeling were conducted under different pH and temperature conditions. The results for the kinetic studies indicate that the adsorption processes associated with these systems can be described by a pseudo-second-order model and for the equilibrium data the Langmuir model provided the best fit. The adsorption was strongly dependent on the pH but not on the temperature within the ranges studied. The maxima adsorption capacities were 159.3 mg g(-1) for the BIO adsorbent and 213.9 mg g(-1) for PC adsorbent at pH of 2 and 25 °C. PMID:26706227

  8. Synthesis of magnetically recyclable MnFe2O4@SiO2@Ag nanocatalyst: Its high catalytic performances for azo dyes and nitro compounds reduction

    NASA Astrophysics Data System (ADS)

    Kurtan, U.; Amir, Md.; Yıldız, A.; Baykal, A.

    2016-07-01

    In this study, magnetically recycable MnFe2O4@SiO2@Ag nanocatalyst (MnFe2O4@SiO2@Ag MRCs) has been synthesized through co-precipition and chemical reduction method. XRD analysis confirmed the synthesis of single phase nanoproduct with crystallite size of 10 nm. VSM measurements showed the superparamagnetic property of the product. Catalytic studies showed that MnFe2O4@SiO2@Ag MRC could catalyze the reduction of the various azo compounds like methyl orange (MO), methylene blue (MB), eosin Y (EY), and rhodamine B (RhB) and also aromatic nitro compounds such as 4-nitrophenol (4-NP), 4-nitroaniline (4-NA) and 2-nitroaniline (2-NA). Moreover, the magnetic nanocatalyst showed an excellent reusability properties that remained unchanged after several cycles. Therefore, MnFe2O4@SiO2@Ag is the potential candidate for the application of organic pollutants for wastewater treatment.

  9. Interaction of toxic azo dyes with heme protein: biophysical insights into the binding aspect of the food additive amaranth with human hemoglobin.

    PubMed

    Basu, Anirban; Kumar, Gopinatha Suresh

    2015-05-30

    A biophysical study on the interaction of the food colorant amaranth with hemoglobin was undertaken. Spectrophotometric and spectrofluorimetric studies proposed for an intimate binding interaction between the dye and the protein. The dye quenched the fluorescence of the protein remarkably and the mechanism of quenching was found to be static in nature. Synchronous fluorescence studies suggested that the polarity around the tryptophan residues was altered in the presence of amaranth whereas the polarity around tyrosine residues remained largely unaltered. 3D fluorescence, FTIR and circular dichroism results suggested that the binding reaction caused conformational changes in hemoglobin. The negative far-UV CD bands exhibited a significantly large decrease in magnitude in the presence of amaranth. From calorimetry studies it was established that the binding was driven by a large positive entropic contribution and a small but favorable enthalpy change. PMID:25725343

  10. The investigation of sonocatalytic activity of Er3+:YAlO3/TiO2-ZnO composite in azo dyes degradation.

    PubMed

    Gao, Jingqun; Jiang, Renzheng; Wang, Jun; Kang, Pingli; Wang, Baoxin; Li, Ying; Li, Kai; Zhang, Xiangdong

    2011-03-01

    In this work, the emphasis was mainly placed on investigating the sonocatalytic activity of TiO(2)-ZnO mixed with Er(3+):YAlO(3), namely, Er(3+):YAlO(3)/TiO(2)-ZnO composite. It is able to utilize the sonoluminescence light to improve the sonocatalytic degradation of organic dyes. The Er(3+):YAlO(3) as up-conversion luminescence agent was synthesized by sol-gel and auto-combustion method, and then Er(3+):YAlO(3)/TiO(2)-ZnO composite as sonocatalyst were prepared by ultrasonic dispersion and liquids boil method. The prepared up-conversion luminescence agent and composites were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Acid Red B dye was selected to examine the sonocatalytic activity of Er(3+):YAlO(3)/TiO(2)-ZnO composite. The degradation reaction processes were monitored by UV-vis spectrophotometer and ion chromatogram. The influences on the activity of the Er(3+):YAlO(3)/TiO(2)-ZnO such as Ti/Zn molar ratio, heat-treated temperature and heat-treated time were studied. The results showed that the Er(3+):YAlO(3)/TiO(2)-ZnO composite exhibited a significantly high sonocatalytic activity compared with other catalysts in the degradation of Acid Red B. And the sonocatalyst with 1:1 Ti/Zn molar ratio heat-treated at 550°C for 60min showed the highest sonocatalytic activity. At last, the experiment also indicated that it has a good sonocatalytic activity to degrade other organic dyes. PMID:20980186

  11. Reactive clays for the fixation and stabilization of dye precursors in interactive papers

    NASA Astrophysics Data System (ADS)

    Dominguez, Jose M.

    1997-08-01

    individual absorption spectra rather than the conjugated spectrum. In this view, swelling clays may be used to host reactive molecules for optical, thermal or electrical recording in paper. Most of the clays that are introduced already into the composition of paper, i.e. kaolin paper clays, can host molecules externally and are potentially useful for the design of interactive papers. In this work, the interaction of dyes and clays was investigated, based on the reactive forms of spiropyrans, which are sensitive materials for recording optical and electrical signals.

  12. Biodecolorization of recalcitrant dye as the sole sourceof nutrition using Curvularia clavata NZ2 and decolorization ability of its crude enzymes.

    PubMed

    Neoh, Chin Hong; Lam, Chi Yong; Lim, Chi Kim; Yahya, Adibah; Bay, Hui Han; Ibrahim, Zaharah; Noor, Zainura Zainon

    2015-08-01

    Extensive use of recalcitrant azo dyes in textile and paper industries poses a direct threat to the environment due to the carcinogenicity of their degradation products. The aim of this study was to investigate the efficiency of Curvularia clavata NZ2 in decolorization of azo dyes. The ability of the fungus to decolorize azo dyes can be evaluated as an important outcome as existing effluent treatment is unable to remove the dyes effectively. C. clavata has the ability to decolorize Reactive Black 5 (RB5), Acid Orange 7 (AO7), and Congo Red azo dyes, utilizing these as sole sources of carbon and nitrogen. Ultraviolet-visible (UV-vis) spectroscopy and Fourier infrared spectroscopy (FTIR) analysis of the extracted RB5's metabolites along with desorption tests confirmed that the decolorization process occurred due to degradation and not merely by adsorption. Enzyme activities of extracellular enzymes such as carboxymethylcellulase (CMCase), xylanase, laccase, and manganese peroxidase (MnP) were also detected during the decolorization process. Toxicity expressed as inhibition of germination was reduced significantly in fungal-treated azo dye solution when compared with the control. The cultivation of C. clavata under sequential batch system also recorded a decolorization efficiency of above 90%. The crude enzyme secreted by C. clavata also showed excellent ability to decolorize RB5 solutions with concentrations of 100 ppm (88-92%) and 1000 ppm (70-77%) without redox mediator. This proved that extracellular enzymes produced by C. clavata played a major role in decolorization of RB5. PMID:25850745

  13. Synthesis of Ni nanoparticles decorated SiO2/TiO2 magnetic spheres for enhanced photocatalytic activity towards the degradation of azo dye

    NASA Astrophysics Data System (ADS)

    Mahesh, K. P. O.; Kuo, Dong-Hau

    2015-12-01

    Highly photocatalytic active Ni magnetic nanoparticles-decorated SiO2 core/TiO2 shell (Ni-SiO2/TiO2) particles have been prepared by the simultaneous hydrolysis and condensation of titanium tetra-isopropoxide on SiO2 sphere of ∼300 nm in size followed by the reduction of nickel chloride using hydrazine hydrate as a reducing agent. The crystalline nature, surface morphology, electrochemical impedance spectra and UV-vis diffuse reflectance spectra of the Ni-SiO2/TiO2 magnetic spheres were characterized by PXRD, FE-SEM, TEM, EIS and UV-vis DRS. The Ni-SiO2/TiO2 magnetic photocatalyst was used for the degradation of Acid Black 1 (AB 1) dye under UV irradiation. The effects of different concentrations of the Ni nanoparticles deposited on the SiO2/TiO2 composite spheres for the photo-mineralization of AB 1 dye were analyzed. The results showed the Ni-SiO2/TiO2 magnetic photocatalyst to be efficient and reusable.

  14. Adsorption of Reactive Red M-2BE dye from water solutions by multi-walled carbon nanotubes and activated carbon.

    PubMed

    Machado, Fernando M; Bergmann, Carlos P; Fernandes, Thais H M; Lima, Eder C; Royer, Betina; Calvete, Tatiana; Fagan, Solange B

    2011-09-15

    Multi-walled carbon nanotubes and powdered activated carbon were used as adsorbents for the successful removal of Reactive Red M-2BE textile dye from aqueous solutions. The adsorbents were characterised by infrared spectroscopy, N(2) adsorption/desorption isotherms and scanning electron microscopy. The effects of pH, shaking time and temperature on adsorption capacity were studied. In the acidic pH region (pH 2.0), the adsorption of the dye was favourable using both adsorbents. The contact time to obtain equilibrium at 298K was fixed at 1h for both adsorbents. The activation energy of the adsorption process was evaluated from 298 to 323K for both adsorbents. The Avrami fractional-order kinetic model provided the best fit to the experimental data compared with pseudo-first-order or pseudo-second-order kinetic adsorption models. For Reactive Red M-2BE dye, the equilibrium data were best fitted to the Liu isotherm model. Simulated dyehouse effluents were used to check the applicability of the proposed adsorbents for effluent treatment. PMID:21724329

  15. Biodecolorization and biodegradation of reactive Levafix Blue E-RA granulate dye by the white rot fungus Irpex lacteus.

    PubMed

    Kalpana, Duraisamy; Velmurugan, Natarajan; Shim, Jae Hong; Oh, Byung-Taek; Senthil, Kalaiselvi; Lee, Yang Soo

    2012-11-30

    The treatment of effluents from textile industry with microorganisms, especially bacteria and fungi, has recently gained attention. The present study was conducted using white rot fungi Irpex lacteus, Trametes hirsuta, Trametes sp., and Lentinula edodes for the decolorization of reactive textile Levafix Blue E-RA granulate dye. I. lacteus resulted in the best decolorization and degradation of the dye within four days. Therefore, more detailed studies were carried out using I. lacteus. The decolorization was evaluated at various concentration, pH values, and temperatures. The activities of laccase, manganese peroxidase, and lignin peroxidase enzymes were estimated to reveal the roles of enzymes in decolorization. The colorless nature of the fungal cells revealed that decolorization occurred through degradation, and confirmed by analysis of the metabolites by UV-visible spectroscopy and High Performance Liquid Chromatography after decolorization. The metabolites were identified by Gas Chromatography-Mass Spectrometry, and functional group analysis was performed by Fourier Transform Infrared Spectroscopy. The degraded dye metabolites were assessed for phytotoxicity using Vigna radiata and Brassica juncea, which demonstrated nontoxic nature of the metabolites formed after degradation of dye. PMID:22846889

  16. Rapid degradation of azo dye Direct Black BN by magnetic MgFe2O4-SiC under microwave radiation

    NASA Astrophysics Data System (ADS)

    Gao, Jia; Yang, Shaogui; Li, Na; Meng, Lingjun; Wang, Fei; He, Huan; Sun, Cheng

    2016-08-01

    A novel microwave (MW) catalyst, MgFe2O4 loaded on SiC (MgFe2O4-SiC), was successfully synthesized by sol-gel method, and pure MgFe2O4 was used as reference. The MgFe2O4 and MgFe2O4-SiC catalysts were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), N2 adsorption analyzer (BET specific surface area), X-ray photoelectron spectroscopy (XPS). The electromagnetic parameters of the prepared catalysts were measured by vector network analyzer. The reflection loss (RL) based on the electromagnetic parameters calculated in Matlab showed MgFe2O4-SiC attained the maximum absorbing value of 13.32 dB at 2.57 GHz, which reached extremely high RL value at low frequency range, revealing the excellent MW absorption property of MgFe2O4-SiC. MW-induced degradation of Direct Black BN (DB BN) over as-synthesized MgFe2O4-SiC indicated that degradation efficiency of DB BN (20 mg L-1) in 5 min reached 96.5%, the corresponding TOC removal was 65%, and the toxicity of DB BN after degradation by MgFe2O4-SiC obviously decreased. The good stability and applicability of MgFe2O4-SiC on the degradation process were also discovered. Moreover, the ionic chromatogram during degradation of DB BN demonstrated that the C-S, C-N and azo bonds in the DB BN molecule were destroyed gradually. MW-induced rad OH and holes could be responsible for the efficient removal involved in the system. These findings make MgFe2O4-SiC become an excellent MW absorbent as well as an effective MW catalyst with rapid degradation of DB BN. Therefore, it may be promising for MgFe2O4-SiC under MW radiation to deal with various dyestuffs and other toxic organic pollutants.

  17. Food intolerance in rheumatoid arthritis. I. A double blind, controlled trial of the clinical effects of elimination of milk allergens and azo dyes.

    PubMed Central

    van de Laar, M A; van der Korst, J K

    1992-01-01

    The hypothetically negative influence of food on the clinical activity of seropositive rheumatoid arthritis was studied using two types of artificial elementary food. One diet was allergen free, the other allergen restricted, containing only lactoproteins and yellow dyes. Ninety four patients entered the study, which lasted 12 weeks. During the second four week period they were randomly assigned to one of the two artificial foods. Comparison between baseline and subsequent periods showed only subjective improvements. No differences were seen between the clinical effects of the two tested diets. Nine patients (three in the allergen restricted group, six in the allergen free group) showed favourable responses, followed by marked disease exacerbation during rechallenge. Dietary manipulation also brought about changes in objective disease activity parameters in these patients. The existence of a subgroup of patients in whom food intolerance influences the activity of rheumatoid factor seropositive rheumatoid arthritis deserves serious consideration. PMID:1575571

  18. Synthesis and spectral study of new azo dye and its iron complexes derived from 2-naphthol and 2-amino-3-hydroxypyridine

    NASA Astrophysics Data System (ADS)

    G, Vidya V.; Sadasivan, V.; Meena, S. S.; Bhatt, Pramod

    2014-10-01

    An azodye C5H12N3O2 [LH] is synthesised by coupling diazotised 2-amino-3-hydroxy pyridine with 2-naphthol in ice cold condition. The Fe(II)and Fe(III) complexes were prepared by mixing ethanol solution of metal salt and azodye in 1:2 molar ratio. The dye and metal complexes are structurally characterised by elemental analysis, molar conductance, magnetic susceptibility measurements and spectral techniques like IR, UV-Vis, and Mössbauer analysis. Analytical data suggests the stoichiometry as [FeL2Cl(H2O)] for Fe(III) complex and [FeL2(H2O)] for Fe(II) complex. The IR spectral data suggests that [L-] is acting as a uninegative bidentate ligand. A high spin octahedral geometry is tentatively proposed for both the complexes with respect to the above studies.

  19. Effect of air plasma treatment on the dyeing of Tencel fabric with C.I. Reactive Black 5

    NASA Astrophysics Data System (ADS)

    Zhang, L. S.; Liu, H. L.; Yu, W. D.

    2015-02-01

    The Tencel fabrics were treated by the atmospheric pressure plasma with air for different length of time and dyed with the C.I. Reactive Black 5 at 1%, 5% and 10% o.m.f. The effect of the prolonged plasma treatment time was characterized by both the weight loss and the whiteness index analyses, which implied that with the increase of the plasma treatment time, the treated fabrics were lighter and yellower than the untreated ones. The contact angle decreased dramatically from 139° to instantly spread. The results of SEM showed that, with the prolonged treatment time, more significant crater-like surface morphology on the fiber of Tencel samples was formed. Compared with untreated samples, the values of dye bath exhaustion and total fixation effect were higher. But they did not increase with the prolonged plasma treatment time. With the prolonged storage time after the plasma treatment, the result to ageing effect indicated that the values of dye bath exhaustion and total fixation effect reduced. The Integ values for characterizing the coloring effect were evaluated by the CIE system of color measurement. In most cases, the Integ values reached the highest ones when the plasma treatment time was 10 or 20 min. When the concentration of the dye bath was low (at 1% o.m.f.), the longer plasma treatment time was, the higher the Integ value was. However, if the fabrics after plasma treatment were stored for 21 days, the longer plasma treatment time did not cause the larger Integ value. When the concentration was 1%, the Integ value increased with the weight loss increasing, which was different from the values of fabrics with 5% and 10% concentration. If the dyeing concentration was low, the fixation had a more significant effect on the color fastness to wet rubbing; in contrast, if the dyeing concentration was high, the surface roughness had a more important effect on it.

  20. Polar red-emitting rhodamine dyes with reactive groups: synthesis, photophysical properties, and two-color STED nanoscopy applications.

    PubMed

    Kolmakov, Kirill; Wurm, Christian A; Meineke, Dirk N H; Göttfert, Fabian; Boyarskiy, Vadim P; Belov, Vladimir N; Hell, Stefan W

    2014-01-01

    The synthesis, reactivity, and photophysical properties of new rhodamines with intense red fluorescence, two polar residues (hydroxyls, primary phosphates, or sulfonic acid groups), and improved hydrolytic stability of the amino-reactive sites (NHS esters or mixed N-succinimidyl carbonates) are reported. All fluorophores contain an N-alkyl-1,2-dihydro-2,2,4-trimethylquinoline fragment, and most of them bear a fully substituted tetrafluoro phenyl ring with a secondary carboxamide group. The absorption and emission maxima in water are in the range of 635-639 and 655-659 nm, respectively. A vastly simplified approach to red-emitting rhodamines with two phosphate groups that are compatible with diverse functional linkers was developed. As an example, a phosphorylated dye with an azide residue was prepared and was used in a click reaction with a strained alkyne bearing an N-hydroxysuccinimid (NHS) ester group. This method bypasses the undesired activation of phosphate groups, and gives an amphiphilic amino-reactive dye, the solubility and distribution of which between aqueous and organic phases can be controlled by varying the pH. The presence of two hydroxyl groups and a phenyl ring with two carboxyl residues in the dyes with another substitution pattern is sufficient for providing the hydrophilic properties. Selective formation of a mono-N-hydroxysuccinimidyl ester from 5-carboxy isomer of this rhodamine is reported. The fluorescence quantum yields varied from 58 to 92% for free fluorophores, and amounted to 18-64% for antibody conjugates in aqueous buffers. The brightness and photostability of these fluorophores facilitated two-color stimulated emission depletion (STED) fluorescence nanoscopy of biological samples with high contrast and minimal background. Selecting a pair of fluorophores with absorption/emission bands at 579/609 and 635/655 nm enabled two-color channels with low cross-talk and negligible background at approximately 40 nm resolution. PMID:24338798

  1. Enhanced photocatalytic efficiency of NiS/TiO{sub 2} composite catalysts using sunset yellow, an azo dye under day light illumination

    SciTech Connect

    Rajamanickam, D.; Dhatshanamurthi, P.; Shanthi, M.

    2015-01-15

    Highlights: • NiS/TiO{sub 2} was successfully synthesized by sol–gel method. • This new method of preparation gives a homogeneous dispersion of NiS on TiO{sub 2}. • Degradation activity of NiS/TiO{sub 2} is found to be more efficient than other catalysts. • Addition of oxidants enhances the degradation efficiency significantly. • COD measurements reveal the complete mineralization of dye molecules. • The catalyst is found to be reusable. - Abstract: To improve the solar light induced photocatalytic application performances of TiO{sub 2}, in this study, the NiS modified TiO{sub 2} composite photocatalysts with various ratios of NiS to TiO{sub 2} were prepared by sol–gel method. The catalyst was characterized by X-ray diffraction (XRD), high resolution scanning electron microscope (HR-SEM), high resolution transmission electron microscope (HR-TEM), energy dispersive spectra (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (B–E–T) surface area measurement methods. The photocatalytic activity of NiS/TiO{sub 2} was investigated for the degradation of sunset yellow (SY) in aqueous solution using solar light. The NiS/TiO{sub 2} is found to be more efficient than prepared TiO{sub 2} and TiO{sub 2}–P25 at pH 7 for the mineralization of SY. The effects of operational parameters such as the amount of photocatalyst, dye concentration and initial pH on photo mineralization of SY have been analyzed. The degradation was strongly enhanced in the presence of oxidants such as H{sub 3}K{sub 5}O{sub 18}S{sub 4} (Oxone), KIO{sub 4}, and KBrO{sub 3}. The mineralization of SY has been identified by COD measurements. The catalyst is found to be reusable.

  2. PHOTOLYSIS OF SMOKE DYES ON SOILS

    EPA Science Inventory

    Photolysis of an azo, a quinophthalone, and several anthraquinone smoke dyes was studied on soil surfaces. nitially, rapid photodegradation of each dye occurred, followed by a period of much slower rate of loss, indicating that the remaining fraction of the dye was photochemicall...

  3. Preparation and characterization of SeO2/TiO2 composite photocatalyst with excellent performance for sunset yellow azo dye degradation under natural sunlight illumination.

    PubMed

    Rajamanickam, D; Dhatshanamurthi, P; Shanthi, M

    2015-03-01

    To improve the solar light induced photocatalytic application performances of TiO2, in this study, the SeO2 modified TiO2 composite photocatalysts with various ratios of SeO2 to TiO2 were prepared by sol-gel method. The catalyst was characterized by X-ray diffraction (XRD), high resolution scanning electron microscope (HR-SEM), energy dispersive spectra (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area measurement methods. The photocatalytic activity of SeO2/TiO2 was investigated for the degradation of sunset yellow (SY) in aqueous solution using solar light. The SeO2/TiO2 is found to be more efficient than prepared TiO2 and TiO2-P25 at pH 7 for the mineralization of SY. The effects of operational parameters such as the amount of photocatalyst, dye concentration and initial pH on photo mineralization of SY have been analyzed. The degradation was strongly enhanced in the presence of electron acceptors such as oxone, KIO4 and KBrO3. The kinetics of SY photodegradation was found to follow the pseudo-first order rate law and could be described in terms of Langmuir-Hinshelwood model. The mineralization of SY has been confirmed by COD measurements. The catalyst is found to be reusable. PMID:25528508

  4. Photocatalytic degradation of an azo dye Sunset Yellow under UV-A light using TiO2/CAC composite catalysts

    NASA Astrophysics Data System (ADS)

    Rajamanickam, D.; Shanthi, M.

    2014-07-01

    The photocatalytic activity and the promoting effect of titania (TiO2) by commercial activated carbon (CAC) for removing the pollutant in wastewater were investigated. The TiO2/CAC composite photocatalysts with various ratios of CAC to TiO2 were prepared by sol-gel method. The catalyst was characterized by X-ray diffraction (XRD), high resolution scanning electron microscope (HR-SEM), energy dispersive spectra (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area measurement methods. The photocatalytic activity of TiO2/CAC was investigated for the degradation of Sunset Yellow (SY) in aqueous solution using UV-A light. The TiO2/CAC is found to be more efficient than prepared TiO2 and TiO2-P25 at pH 7 for the mineralization of SY. The synergism between TiO2 and CAC may increase the catalytic activity. The effects of operational parameters such as the amount of photocatalyst, dye concentration and initial pH on photo mineralization of SY have been analyzed. The mineralization of SY has been confirmed by COD measurements. The catalyst is found to be reusable.

  5. Preparation and characterization of SeO2/TiO2 composite photocatalyst with excellent performance for sunset yellow azo dye degradation under natural sunlight illumination

    NASA Astrophysics Data System (ADS)

    Rajamanickam, D.; Dhatshanamurthi, P.; Shanthi, M.

    2015-03-01

    To improve the solar light induced photocatalytic application performances of TiO2, in this study, the SeO2 modified TiO2 composite photocatalysts with various ratios of SeO2 to TiO2 were prepared by sol-gel method. The catalyst was characterized by X-ray diffraction (XRD), high resolution scanning electron microscope (HR-SEM), energy dispersive spectra (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area measurement methods. The photocatalytic activity of SeO2/TiO2 was investigated for the degradation of sunset yellow (SY) in aqueous solution using solar light. The SeO2/TiO2 is found to be more efficient than prepared TiO2 and TiO2-P25 at pH 7 for the mineralization of SY. The effects of operational parameters such as the amount of photocatalyst, dye concentration and initial pH on photo mineralization of SY have been analyzed. The degradation was strongly enhanced in the presence of electron acceptors such as oxone, KIO4 and KBrO3. The kinetics of SY photodegradation was found to follow the pseudo-first order rate law and could be described in terms of Langmuir-Hinshelwood model. The mineralization of SY has been confirmed by COD measurements. The catalyst is found to be reusable.

  6. Synthesis and spectral study of new azo dye and its iron complexes derived from 2-naphthol and 2-amino-3-hydroxypyridine

    SciTech Connect

    G, Vidya V. Sadasivan, V.; Meena, S. S. Bhatt, Pramod

    2014-10-15

    An azodye C{sub 5}H{sub 12}N{sub 3}O{sub 2} [LH] is synthesised by coupling diazotised 2-amino-3-hydroxy pyridine with 2-naphthol in ice cold condition. The Fe(II)and Fe(III) complexes were prepared by mixing ethanol solution of metal salt and azodye in 1:2 molar ratio. The dye and metal complexes are structurally characterised by elemental analysis, molar conductance, magnetic susceptibility measurements and spectral techniques like IR, UV-Vis, and Mössbauer analysis. Analytical data suggests the stoichiometry as [FeL{sub 2}Cl(H{sub 2}O)] for Fe(III) complex and [FeL{sub 2}(H{sub 2}O)] for Fe(II) complex. The IR spectral data suggests that [L{sup −}] is acting as a uninegative bidentate ligand. A high spin octahedral geometry is tentatively proposed for both the complexes with respect to the above studies.

  7. Optimisation of decolourisation and degradation of Reactive Black 5 dye under electro-Fenton process using Fe alginate gel beads.

    PubMed

    Iglesias, O; Fernández de Dios, M A; Rosales, E; Pazos, M; Sanromán, M A

    2013-04-01

    The aim of this work was to improve the ability of the electro-Fenton process using Fe alginate gel beads for the remediation of wastewater contaminated with synthetic dyes and using a model diazo dye such as Reactive Black 5 (RB5). Batch experiments were conducted to study the effects of main parameters, such as voltage, pH and iron concentration. Dye decolourisation, reduction of chemical oxygen demand (COD) and energy consumption were studied. Central composite face-centred experimental design matrix and response surface methodology were applied to design the experiments and to evaluate the interactive effects of the three studied parameters. A total of 20 experimental runs were set, and the kinetic data were analysed using first-order and second-order models. In all cases, the experimental data were fitted to the empirical second-order model with a suitable degree for the maximum decolourisation of RB5, COD reduction and energy consumption by electro-Fenton-Fe alginate gel beads treatment. Working with the obtained empirical model, the optimisation of the process was carried out. The second-order polynomial regression model suggests that the optimum conditions for attaining maximum decolourisation, COD reduction and energy consumption are voltage, 5.69 V; pH 2.24 and iron concentration, 2.68 mM. Moreover, the fixation of iron on alginate beads suggests that the degradation process can be developed under this electro-Fenton process in repeated batches and in a continuous mode. PMID:22733554

  8. Synthesis, characterization, and reactivity of cellulose modified nano zero-valent iron for dye discoloration

    NASA Astrophysics Data System (ADS)

    Wang, Xiangyu; Wang, Pei; Ma, Jun; Liu, Huiling; Ning, Ping

    2015-08-01

    Nano zero-valent iron (NZVI) was innovatively and successfully modified by using hydroxyethyl cellulose (HEC) and hydroxypropylmethyl cellulose (HPMC) as dispersants. The systematic characterization observations (including XRD, SEM and TEM) illustrate that, compared with bare nano zero-valent iron particles (BNZVI), the particle sizes of hydroxyethyl cellulose modified (ENZVI) and hydroxypropylmethyl cellulose modified (PNZVI) were decreased, while the dispersity and antioxidizability of ENZVI and PNZVI particles were increased. The discoloration efficiencies of ENZVI, PNZVI, and BNZVI were compared by using dyes (including orange II, methyl orange, methyl blue, and methylene blue) as target pollutant. The results show that both the discoloration efficiency and reaction rate of ENZVI and PNZVI are higher than that of BNZVI. In addition, effects of dispersant content, dye type, pH value, initial dye concentration, iron dosage, and reaction temperature on discoloration efficiencies were studied. The results show that discoloration efficiency was decreased by increasing initial pH value and dye concentration, and it was increased with the increase the iron dosage and reaction temperature. Under optimized NZVI addition of 0.7 g L-1, the discoloration efficiencies of ENZVI and PNZVI were increased to 96.33% and 98.62%, respectively. And the possible discoloration pathway and dispersant modification mechanism of NZVI were discussed. This study suggests hydroxyethyl cellulose and hydroxypropylmethyl cellulose dispersed NZVI can be utilized as a promising modified nano-material for degradation of dye wastewater.

  9. The anisotropic nanomovement of azo-polymers.

    PubMed

    Ishitobi, H; Tanabe, M; Sekkat, Z; Kawata, S

    2007-01-22

    Nanoscale polymer movement is induced by a tightly focused laser beam in an azo-polymer film just at the diffraction limit of light. The deformation pattern that is produced by photoisomerization of the azo dye is strongly dependent on the incident laser polarization and the longitudinal focus position of the laser beam along the optical axis. The anisotropic photo-fluidity of the polymer film and the optical gradient force played important roles in the light induced polymer movement. We also explored the limits of the size of the photo-induced deformation, and we found that the deformation depends on the laser intensity and the exposure time. The smallest deformation size achieved was 200 nm in full width of half maximum; a value which is nearly equal to the size of the diffraction limited laser spot. PMID:19532288

  10. Degradation characteristic of monoazo, diazo and anthraquinone dye by UV / H2O2 process

    NASA Astrophysics Data System (ADS)

    Abidin, Che Zulzikrami Azner; Fahmi, Muhammad Ridwan; Fazara, Md Ali Umi; Nadhirah, Siti Nurfatin

    2014-10-01

    In this study, the degradation characteristic of monoazo, diazo and anthraquinone dye by UV / H2O2 process was evaluated based on the trend of color, chemical oxygen demand (COD) and total organic carbon (TOC) removal. Three types of dyes consist of monoazo, diazo and anthraquinone dyes were used to compare the degradation mechanism of the dyes. The UV / H2O2 experiments were conducted in a laboratory scale cylindrical glass reactor operated in semi-batch mode. The UV/Vis characterization of monoazo, diazo and anthraquinone dye indicated that the rapid degradation of the dyes by UV / H2O2 process is meaningful with respect to decolourization, as a result of the azo bonds and substitute antraquinone chromophore degradation. However, this process is not efficient for aromatic amines removal. The monoazo MO was difficult to be decolorized than diazo RR120 dye, which imply that number of sulphonic groups in the dye molecules determines the reactivity with hydroxyl radical. The increased in COD removal is the evidence for oxidation and decreased in carbon content of dye molecules. TOC removal analysis shows that low TOC removal of monoazo MO and diazo RR120, as compared to anthraquinone RB19 may indicate an accumulation of by-products that are resistant to the H2O2 photolysis.

  11. Removal of C.I. Reactive Red 2 by low pressure UV/chlorine advanced oxidation.

    PubMed

    Wu, Qianyuan; Li, Yue; Wang, Wenlong; Wang, Ting; Hu, Hongying

    2016-03-01

    Azo dyes are commonly found as pollutants in wastewater from the textile industry, and can cause environmental problems because of their color and toxicity. The removal of a typical azo dye named C.I. Reactive Red 2 (RR2) during low pressure ultraviolet (UV)/chlorine oxidation was investigated in this study. UV irradiation at 254nm and addition of free chlorine provided much higher removal rates of RR2 and color than UV irradiation or chlorination alone. Increasing the free chlorine dose enhanced the removal efficiency of RR2 and color by UV/chlorine oxidation. Experiments performed with nitrobenzene (NB) or benzoic acid (BA) as scavengers showed that radicals (especially OH) formed during UV/chlorine oxidation are important in the RR2 removal. Addition of HCO3(-) and Cl(-) to the RR2 solution did not inhibit the removal of RR2 during UV/chlorine oxidation. PMID:26969069

  12. Ultrasonic dyeing of cellulose nanofibers.

    PubMed

    Khatri, Muzamil; Ahmed, Farooq; Jatoi, Abdul Wahab; Mahar, Rasool Bux; Khatri, Zeeshan; Kim, Ick Soo

    2016-07-01

    Textile dyeing assisted by ultrasonic energy has attained a greater interest in recent years. We report ultrasonic dyeing of nanofibers for the very first time. We chose cellulose nanofibers and dyed with two reactive dyes, CI reactive black 5 and CI reactive red 195. The cellulose nanofibers were prepared by electrospinning of cellulose acetate (CA) followed by deacetylation. The FTIR results confirmed complete conversion of CA into cellulose nanofibers. Dyeing parameters optimized were dyeing temperature, dyeing time and dye concentrations for each class of the dye used. Results revealed that the ultrasonic dyeing produced higher color yield (K/S values) than the conventional dyeing. The color fastness test results depicted good dye fixation. SEM analysis evidenced that ultrasonic energy during dyeing do not affect surface morphology of nanofibers. The results conclude successful dyeing of cellulose nanofibers using ultrasonic energy with better color yield and color fastness results than conventional dyeing. PMID:26964959

  13. Bifunctional core-shell nanocomposite Mn-doped ZnO/Fe3O4 for photodegradation of reactive blue 198 dye

    NASA Astrophysics Data System (ADS)

    Nguyen, Van Cuong

    2014-09-01

    Magnetic nanoparticles of manganese doped ZnO have been prepared by co-precipitation method. Photocatalytic activity results show that 9% of Mn in Mn-doped ZnO exhibited the highest photodegradation efficiency of reactive blue 198 dye. Additionally, excellent photocatalytic activity was observed when the molar ratio of Mn-doped ZnO/Fe3O4 was 1:1. The photodegradation of reactive blue 198 (RB198) dye was carried out with different illumination times, initial concentrations of dye, amounts of photocatalyst and pH of medium. The results reveal that the degradation efficiency of reactive blue 198 were 99% at the concentration of 30 ppm for 25 min when the amount of catalyst was 5 g L-1. The photodegradation of dye increased with increasing catalyst load. Furthermore, the prepared magnetic nanoparticles could also serve as convenient recyclable photocatalysts because of their magnetic properties. As a result, the removal of dye was still 90% after three times recycling.

  14. The Hydractinia echinata test-system. III: Structure-toxicity relationship study of some azo-, azo-anilide, and diazonium salt derivatives.

    PubMed

    Chicu, Sergiu Adrian; Munteanu, Melania; Cîtu, Ioana; Soica, Codruta; Dehelean, Cristina; Trandafirescu, Cristina; Funar-Timofei, Simona; Ionescu, Daniela; Simu, Georgeta Maria

    2014-01-01

    Structure-toxicity relationships for a series of 75 azo and azo-anilide dyes and five diazonium salts were developed using Hydractinia echinata (H. echinata) as model species. In addition, based on these relationships, predictions for 58 other azo-dyes were made. The experimental results showed that the measured effectiveness Mlog(1/MRC50) does not depend on the number of azo groups or the ones corresponding to metobolites, but it is influenced by the number of anilide groups, as well as by the substituents' positions within molecules. The conformational analysis pointed out the intramolecular hydrogen bonds, especially the simple tautomerization of quinoidic (STOH) or aminoidic (STNH2) type. The effectiveness is strongly influenced by the "push-pull" electronic effect, specific to two hydroxy or amino groups separated by an azo moiety (double alternate tautomery, (DAT), to the -COOH or -SO3H groups which are located in ortho or para position with respect to the azo group. The levels of the lipophylic/hydrophilic, electronic and steric equilibriums, pointed out by the Mlog(1/MRC50) values, enabled the calculation of their average values Clog(1/MRC50) ("Köln model"), characteristic to one derivative class (class isotoxicity). The azo group reduction and the hydrolysis of the amido/peptidic group are two concurrent enzymatic reactions, which occur with different reaction rates and mechanisms. The products of the partial biodegradation are aromatic amines. No additive or synergic effects are noticed among them. PMID:25006787

  15. Retarded hydrolysis-condensing reactivity of tetrabutyl titanate by acetylacetone and the application in dye-sensitized solar cells

    SciTech Connect

    Zhou, Conghua Ouyang, Jun; Yang, Bingchu

    2013-10-15

    Graphical abstract: - Highlights: • Effect of acetone acetyl on coarsening rate of TiO{sub 2} nanocrystallites was studied. • Hydrolysis reactivity of alkoxide was retarded with addition of acetone acetyl. • Coarsening rate of TiO{sub 2} nanocrystallites is retarded with addition of acetone acetyl. • The synthesized TiO{sub 2} sols were utilized in dye sensitized solar cells. • Small particles formed by Ti-complexes were beneficial for device performance. - Abstract: TiO{sub 2} nanocrystallites have been synthesized by hydrothermal reaction using tetrabutyl titanate as source material. Acetylacetone was utilized to modify hydrolysis-condensation behavior of the alkoxide and thus coarsening dynamics of TiO{sub 2} nanocrystallites in the reaction. With assistance of Fourier transformation infrared spectrum, transmission electron microscopy, selected area electron diffraction and X-ray diffraction, interaction between acetylacetone and tetrabutyltitanate was explored, crystallographic and morphological properties of TiO{sub 2} nanocrystallites were monitored. Less hydrolysable complex was formed by “method of chelating” as tetrabutyltitanate was mixed with acetylacetone, leading to retarded coarsening rate of nanocrystallites. The obtained TiO{sub 2} nanocrystallites were applied to fabricate nanoporous photoanode of dye sensitized solar cells. Improvement of 18% has been achieved for photo-to-electric energy conversion efficiency of the devices due to both upgraded open circuit voltage and photocurrent density.

  16. Reactively sputtered nickel nitride as electrocatalytic counter electrode for dye- and quantum dot-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Soo Kang, Jin; Park, Min-Ah; Kim, Jae-Yup; Ha Park, Sun; Young Chung, Dong; Yu, Seung-Ho; Kim, Jin; Park, Jongwoo; Choi, Jung-Woo; Jae Lee, Kyung; Jeong, Juwon; Jae Ko, Min; Ahn, Kwang-Soon; Sung, Yung-Eun

    2015-05-01

    Nickel nitride electrodes were prepared by reactive sputtering of nickel under a N2 atmosphere at room temperature for application in mesoscopic dye- or quantum dot- sensitized solar cells. This facile and reliable method led to the formation of a Ni2N film with a cauliflower-like nanostructure and tetrahedral crystal lattice. The prepared nickel nitride electrodes exhibited an excellent chemical stability toward both iodide and polysulfide redox electrolytes. Compared to conventional Pt electrodes, the nickel nitride electrodes showed an inferior electrocatalytic activity for the iodide redox electrolyte; however, it displayed a considerably superior electrocatalytic activity for the polysulfide redox electrolyte. As a result, compared to dye-sensitized solar cells (DSCs), with a conversion efficiency (η) = 7.62%, and CdSe-based quantum dot-sensitized solar cells (QDSCs, η = 2.01%) employing Pt counter electrodes (CEs), the nickel nitride CEs exhibited a lower conversion efficiency (η = 3.75%) when applied to DSCs, but an enhanced conversion efficiency (η = 2.80%) when applied to CdSe-based QDSCs.

  17. Obtention of plant peroxidase and its potential for the decolorization of the reactive dye Remazol Turquoise G 133%.

    PubMed

    Silva, Maria Cristina; Torres, Juliana Arriel; Corrêa, Angelita Duarte; Junqueira, Allana Maria Bernardes; Amorim, Maria Teresa Pessoa; dos Santos, Custódio Donizete

    2012-01-01

    Peroxidases can be used in the decolorization process. There is a growing interest for new sources of this enzyme and for obtaining economically viable processes. In this work, a low-cost vegetable peroxidase extraction process is proposed; the resulting enzyme is characterized to determine its optimum pH, temperature, and stability conditions, and it is then applied in the decolorization of reactive dye Remazol Turquoise G 133%. The turnip peroxidase (TP) was utilized as an enzymatic source. This enzyme exhibited maximum activity at pH 7.0, and it was active in the temperature range of 30 to 50 °C, which favors its use in industrial processes. Acetone was the most efficient solvent to induce precipitation. The removal of Remazol Turquoise G 133% was 56.0% complete after 50 min, while 41.0% of the same dye was removed with the commercial horseradish peroxidase enzyme in 50 min. TP presents potential as a viable alternative in the decolorization of textile wastewaters. PMID:22277225

  18. Second-order nonlinear optical Langmuir-Blodgett films based on a series of azo rare-earth coordination compounds

    SciTech Connect

    Gao, L.H.; Wang, K.Z.; Huang, C.H.

    1995-06-01

    A series of novel azo dyes composed of a lanthanide complex anion and an azo cation, in which strongly electron-donating (dihexadecylamino)phenyl and electron-accepting pyridinium groups are separated by an azo group, was designed as second-order nonlinear optical Langmuir-Blodgett (LB) film materials. The compounds are of good film-forming properties. The values of second-order molecular hyperpolarizability {beta} were determined to be (1.20-3.03) x 10{sup {minus}27} esu, comparable to the largest value known for azo LB materials. The compounds studied may be attactive in the application in future optical devices. 13 refs., 5 figs., 1 tab.

  19. The Use of HRP in Decolorization of Reactive Dyes and Toxicological Evaluation of Their Products

    PubMed Central

    da Silva, Michelle Reis; de Sá, Lívian Ribeiro Vasconcelos; Russo, Carlos; Scio, Elita; Ferreira-Leitão, Viridiana Santana

    2010-01-01

    This work studied the potential use of horseradish peroxidase (HRP) in the decolorization of the following textile dyes: Drimarene Blue X-3LR (DMBLR), Drimarene Blue X-BLN (DMBBLN), Drimarene Rubinol X-3LR (DMR), and Drimarene Blue CL-R (RBBR). Dyes were individually tested in the reaction media containing 120 mg·L−1, considering the following parameters: temperature (20–45°C), H2O2 concentration (0–4.44 mmol·L−1), and reaction time (5 minutes, 1 and 24 h). The following conditions: 35°C, 0.55 mmol·L−1, and 1h, provided the best set of results of color removal for DMBLR (99%), DMBBLN (77%), DMR (94%), and RBBR (97%). It should be mentioned that only 5 minutes of reaction was enough to obtain 96% of decolorization for DMBLR and RBBR. After the decolorization reactions of DMBLR, DMR, and RBBR, it was possible to observe the reduction of Artemia salina mortality and the no significant increase in toxicity for the products generated from DMBBLN. PMID:21318147

  20. Synergic adsorption of Pb2 + and reactive dye — RB5 on two series of organomodified bentonites

    NASA Astrophysics Data System (ADS)

    Jović-Jovičić, N. P.; Milutinović-Nikolić, A. D.; Žunić, M. J.; Mojović, Z. D.; Banković, P. T.; Gržetić, I. A.; Jovanović, D. M.

    2013-07-01

    Two series of organobentonites (OBs) were synthesized from Na+-exchanged bentonite clay from Bogovina, Serbia. In the first series the starting material was modified using hexadecyltrimethylammonium (HDTMA+) ion in the amounts corresponding to 0.2, 0.5, 1.0 and 2.0 of the CEC value. The second series was obtained using quaternary alkyl ammonium cations (QAACs) with different alkyl chain lengths: hexadecyltrimethylammonium (HDTMA+), dodecyltrimethylammonium (DDTMA+) and tetramethylammonium (TMA+) ions. The synthesized OBs were characterized. The adsorption of anionic reactive dye Reactive Black 5 (RB5) and Pb2 + from single component solutions and their bi-component solution was investigated for both series of OBs. The adsorptive properties of the OBs were correlated to the amount and type of incorporated QAACs. The correlation was tested using different mathematical models and best fits were found. Experimental results showed that simultaneous adsorption of RB5 and Pb2 + exhibited synergic effect. The adsorption capacity for both RB5 and Pb2 + was higher in their bi-component solution than in single-component solutions. These results indicate the creation of new adsorption sites during the simultaneous adsorption.

  1. Combined strategy to realize efficient photoelectrodes for low temperature fabrication of dye solar cells.

    PubMed

    Alberti, A; De Marco, L; Pellegrino, G; Condorelli, G G; Giannuzzi, R; Scarfiello, R; Manca, M; Spinella, C; Gigli, G; La Magna, A

    2014-05-14

    We implemented a low-temperature approach to fabricate efficient photoanodes for dye-sensitized solar cells, which combines three different nanoarchitectures, namely, a highly conductive and highly transparent AZO film, a thin TiO2-blocking layer, and a mesoporous TiO2 nanorod-based working electrode. All the components were processed at T≤200°C. Both the AZO and the TiO2 blocking layers were deposited by reactive sputtering, whereas the TiO2 nanorods were synthesized by surfactant-assisted wet-chemical routes and processed into photoelectrodes in which the native geometric features assured uniform mesoporous structure with effective nanocrystal interconnectivity suitable to maximize light harvesting and electron diffusion. Because of the optimized structure of the TiO2-blocking/AZO bilayer, and thanks to the good adhesion of the TiO2 nanorods over it, a significant enhancement of the charge recombination resistance was demonstrated, this laying on the basis of the outstanding power conversion efficiency achievable through the use of this photoanode's architecture: a value of 4.6% (N719) was achieved with a 4-μm-thick electrode processed at T=200°C. This value noticeably overcomes the current literature limit got on AZO-based cells (N719), which instead use Nb-doped and thicker blocking layers, and thicker nanostructured photoanodes, which have been even sintered at higher temperatures (450-500°C). PMID:24694230

  2. Preparation and application of cellulose acetate/Fe films in the degradation of Reactive Black 5 dye through photo-Fenton reaction.

    PubMed

    Ribeiro, Karine; de Andrade, Tamara Maria; Fujiwara, Sérgio Toshio

    2016-07-01

    In this study, the Reactive Black 5 dye degradation and textile effluent were investigated using the photo-Fenton process employing immobilized Fe(3+) in acetate cellulose films. The films prepared were characterized through Fourier transform infrared spectroscopy, atomic absorption spectroscopy, scanning electron microscopy - energy-dispersive spectroscopy and ultraviolet visible spectroscopy. The factorial design revealed that the best conditions for the Reactive Black 5 dye degradation were obtained using the film containing 5% Fe (w/w), 100 mg L(-1) H2O2 and pH 4.0. In studies using artificial light, the dye degradation was 99.29% and the chemical oxygen demand (COD) reduction was 90% after 45 min of treatment. In the process assisted by sunlight, the degradation was 86% and the COD reduction was 70% considering the same time of treatment. At pH 6.0 and artificial light, the dye degradation was 98.90% and the COD reduction was 78%, indicating that the material prepared can be used at pH values greater than 3 without the occurrence of hydrated ferric oxides precipitation. It was also observed that the material can be reused seven consecutive times without substantial loss of efficacy in dye degradation. Furthermore, the proposed material reduces the COD of a textile effluent by 72% after 300 min of treatment. PMID:26675986

  3. The triazine-based azo-azomethine dyes; synthesis, characterization, spectroscopy, solvatochromism and biological properties of 2,2‧-(((6-methoxy-1,3,5-triazine-2,4-diyl)bis(sulfanediyl)bis(2,1-phenylene))bis(azanylylidene)bis(methanylylidene))bis(4-(phenyldiazenyl)phenol)

    NASA Astrophysics Data System (ADS)

    Ghasemian, Motaleb; Kakanejadifard, Ali; Azarbani, Farideh; Zabardasti, Abedin; Shirali, Somayeh; Saki, Zeinab; Kakanejadifard, Sahar

    2015-03-01

    The macrocyclic azo-azomethine dyes 2,2‧-(((6-methoxy-1,3,5-triazine-2,4-diyl)bis(sulfanediyl)bis(2,1-phenylene))bis(azanylylidene)bis(methanylylidene))bis(4-(phenyldiazenyl)phenol) and its derivatives were synthesized and characterized by elemental analysis, mass, FT-IR, UV-vis and NMR spectroscopy. The solvatochromism as well as effects of substitutions on the electronic absorption of these compounds have been studied in the DMSO, DMF, THF, CH3CN, CH3OH and CH3COOH as solvents. Also they positive solvatochromism behaviors are explained on the basis of intramolecular hydrogen bonding, enol-keto tautomeric and dipole moment changes. Compounds having electron donating substituent on the phenyl ring showed good antioxidant activity. However, none of them has a considerable antibacterial activity.

  4. Degradation characteristic of monoazo, diazo and anthraquinone dye by UV/H{sub 2}O{sub 2} process

    SciTech Connect

    Abidin, Che Zulzikrami Azner E-mail: drfahmi@unimap.edu.my E-mail: fatinnadhirah89@gmail.com; Fahmi, Muhammad Ridwan E-mail: drfahmi@unimap.edu.my E-mail: fatinnadhirah89@gmail.com; Fazara, Md Ali Umi E-mail: drfahmi@unimap.edu.my E-mail: fatinnadhirah89@gmail.com; Nadhirah, Siti Nurfatin E-mail: drfahmi@unimap.edu.my E-mail: fatinnadhirah89@gmail.com

    2014-10-24

    In this study, the degradation characteristic of monoazo, diazo and anthraquinone dye by UV/H{sub 2}O{sub 2} process was evaluated based on the trend of color, chemical oxygen demand (COD) and total organic carbon (TOC) removal. Three types of dyes consist of monoazo, diazo and anthraquinone dyes were used to compare the degradation mechanism of the dyes. The UV/H{sub 2}O{sub 2} experiments were conducted in a laboratory scale cylindrical glass reactor operated in semi-batch mode. The UV/Vis characterization of monoazo, diazo and anthraquinone dye indicated that the rapid degradation of the dyes by UV/H{sub 2}O{sub 2} process is meaningful with respect to decolourization, as a result of the azo bonds and substitute antraquinone chromophore degradation. However, this process is not efficient for aromatic amines removal. The monoazo MO was difficult to be decolorized than diazo RR120 dye, which imply that number of sulphonic groups in the dye molecules determines the reactivity with hydroxyl radical. The increased in COD removal is the evidence for oxidation and decreased in carbon content of dye molecules. TOC removal analysis shows that low TOC removal of monoazo MO and diazo RR120, as compared to anthraquinone RB19 may indicate an accumulation of by-products that are resistant to the H{sub 2}O{sub 2} photolysis.

  5. Aggregation and adsorption of reactive dyes in the presence of an anionic surfactant on mesoporous aminopropyl silica.

    PubMed

    Cestari, Antonio R; Vieira, Eunice F S; Vieira, Gláucia S; Almeida, Luis E

    2007-05-15

    A surface tension technique was used to determine the critical aggregation concentration (cac) of a yellow and a red dye in relation to the presence of the anionic surfactant sodium dodecylbenzene sulfonate (DBS) and to temperature changes in buffered aqueous solutions. The cac values of the yellow dye increase from 25 to 45 degrees C (from 41.37 to 50.32 mg L-1) and decrease from 45 to 55 degrees C (from 50.32 to 38.72 mg L-1). The cac values for the red dye/DBS aggregates decrease (from 124.52 to 88.50 mg L-1) from 25 to 55 degrees C. Adsorption of the two dyes onto a mesoporous aminopropyl silica (Sil-NH2) was also studied. The adsorption of the yellow dye increases with an increase in temperature from 25 to 55 degrees C. In the presence of DBS the adsorption on Sil-NH2 for the yellow dye decreases, and for the red dye increases from 25 to 55 degrees C. Adsorptions occurred below and above the cac of the anionic dyes/DBS aggregates. Adsorption of the dyes onto Sil-NH2 fitted well to the Langmuir, Freundlich, and Redlich-Peterson adsorption models. However, in the presence of DBS, only the Freundlich model fit the experimental adsorption data at low dye concentrations (less than 400 mg L-1). In this case, the Redlich-Peterson model was only fitted to the red dye adsorption data. The magnitude of the Dubinin-Radushkevich energetic parameters (E, from 7.00 to 15.00 kJ mol-1) indicates that the adsorption of the dyes onto Sil-NH2, in the absence and in the presence of DBS, is controlled by water adsorbed/dye in solution ion-exchange interactions. It is observed that the values of DeltaadsH are positive for both dyes and the values are quite similar to each other. The exception is the adsorption of the yellow dye in the presence of DBS, which is slightly exothermic. The DeltaadsG values are all negative. However, the interactions of the dyes with Sil-NH2 silica are more spontaneous in the presence of the surfactant. The positive adsorption entropy values (Deltaads

  6. Study of chemical reactivity in relation to experimental parameters of efficiency in coumarin derivatives for dye sensitized solar cells using DFT.

    PubMed

    Soto-Rojo, Rody; Baldenebro-López, Jesús; Glossman-Mitnik, Daniel

    2015-06-01

    A group of dyes derived from coumarin was studied, which consisted of nine molecules using a very similar manufacturing process of dye sensitized solar cells (DSSCs). Optimized geometries, energy levels of the highest occupied molecular orbital and the lowest unoccupied molecular orbital, and ultraviolet-visible spectra were obtained using theoretical calculations, and they were also compared with experimental conversion efficiencies of the DSSC. The representation of an excited state in terms of natural transition orbitals (NTOs) was studied. Chemical reactivity parameters were calculated and correlated with the experimental data linked to the efficiency of the DSSC. A new proposal was obtained to design new molecular systems and to predict their potential use as a dye in DSSCs. PMID:25959071

  7. Rapid dye degradation with reactive oxidants generated by chloride-induced peroxymonosulfate activation.

    PubMed

    Lou, Xiao-Yi; Guo, Yao-Guang; Xiao, Dong-Xue; Wang, Zhao-Hui; Lu, Shu-Yu; Liu, Jian-She

    2013-09-01

    Transition-metal is known to catalyze peroxymonosulfate (PMS) decomposition to produce sulfate radicals. Here we report reactions between PMS and chloride, without a need of transition metals, also can be used to degrade organic dye pollutant (Rhodamine B, (RhB)). Some important operating parameters, such as dosages of PMS and Cl(-), pH of solution, temperature, ionic strength, and several common cations, were systematically investigated. Almost complete decoloration of RhB was achieved within 5 min ([PMS] = 0.5 mM, [Cl(-)] = 120 mM, and pH 3.0), and RhB bleaching rate increased with the increased dosages of both PMS and chloride ion, following the pseudo-first-order kinetic model. However, the total organic carbon (TOC) removal results demonstrated that the decoloration of RhB was due to the destruction of chromophore rather than complete degradation. RhB decoloration could be significantly accelerated due to the high ionic strength. Increasing of the reaction temperature from 273 K to 333 K was beneficial to the RhB degradation, and the activation energy was determined to be 32.996 kJ/mol. Bleaching rate of RhB with the examined cations increased with the order of NH4 (+) < Na(+) < K(+) < Al(3+) < Ca(2+) < Mg(2+). Some major degradation products of RhB were identified by GC-MS. The present study may have active technical implications for the treatment of dyestuff wastewater in practice. PMID:23589259

  8. Relaxation phenomena in optically activated azo-materials

    NASA Astrophysics Data System (ADS)

    Prasuhn, Kai; Draude, Ansgar; Franke, Hilmar; Lessard, Roger A.

    2004-10-01

    The photo-isomerisation of azo-compounds is used to record reversible holographic volume phase gratings in films of guest-host polymers. In situ recording of the diffraction efficiency has been performed for different azo-dyes in the non-polar Poly-methylmethacrylate (PMMA) and the polar Poly-α-methyl-styrene (PαMS) as a matrix. Within an exposure energy of 100 mJ/cm2 a pronounced maximum is observed for s-polarised light. With the light pattern still on this is then reduced to a lower level. In case of the polar matrix, this process can be identified as an interaction of the dye molecules with the polymer matrix.

  9. Degradation of C.I. Reactive Red 2 through photocatalysis coupled with water jet cavitation.

    PubMed

    Wang, Xiaoning; Jia, Jinping; Wang, Yalin

    2011-01-15

    The decolorization of an azo dye, C.I. Reactive Red 2 was investigated using TiO(2) photocatalysis coupled with water jet cavitation. Experiments were performed in a 4.0 L solution under ultraviolet power of 9 W. The effects of TiO(2) loading, initial dye concentration, solution pH, geometry of cavitation tube, and the addition of anions on the degradation of the dye were evaluated. Degradation of the dye followed a pseudo-first order reaction. The photocatalysis coupled with water jet cavitation elevated degradation of the dye by about 136%, showing a synergistic effect compared to the individual photocatalysis and water jet cavitation. The enhancement of photocatalysis by water jet cavitation could be due to the deagglomeration of catalyst particles as well as the better contact between the catalyst surfaces and the reactants. Venturi tube with smaller diameter and shorter length of throat tube favored the dye decolorization. The degradation efficiency was found to increase with decreasing initial concentration and pH. The presence of NO(3)(-) and SO(4)(2-) enhanced the degradation of RR2, while Cl(-), and especially HCO(3)(-) significantly reduced dye decolorization. The results of this study indicated that the coupled photocatalysis and water jet cavitation is effective in degrading dye in wastewater and provides a promising alternative for treatment of dye wastewater at a large scale. PMID:20940086

  10. Sequential study on reactive blue 29 dye removal from aqueous solution by peroxy acid and single wall carbon nanotubes: experiment and theory

    PubMed Central

    2013-01-01

    The majority of anthraquinone dye released to the environment come from antrapogenic sources. Several techniques are available for dyes' removal. In this study removal of reactive blue 29 (RB29) by an advanced oxidation process sequenced with single wall carbon nanotubes was investigated. Advanced oxidation process was optimized over a period of 60 minutes by changing the ratio of acetic acid to hydrogen peroxide, the compounds which form peroxy acid. Reduction of 20.2% -56.4% of reactive blue 29 was observed when the ratio of hydrogen peroxide/acetic acid/dye changed from 344/344/1 to 344/344/0.08 at different times (60, 120 and 180 min). The optimum ratio of acetic acid/hydrogen peroxide/dye was found to be 344/344/0.16 over 60 min. The resultant then was introduced for further removal by single wall carbon nanotubes(SWCNTs) as adsorbent. The adsorption of reactive blue 29 onto SWCNTs was also investigated. Langmuir, Freundlich and BET isotherms were determined and the results revealed that the adsorption of RB29 onto SWCNTs was well explained by BET model and changed to Freundlich isotherm when SWCNTs was used after the application of peroxy acid. Kinetic study showed that the equilibrium time for adsorption of RB 29 on to SWCNT is 4 h. Experiments were carried out to investigate adsorption kinetics, adsorbent capacity and the effect of solution pH on the removal of reactive blue29. The pseudo-second order kinetic equation could best describe the sorption kinetics. The most efficient pH for color removal (amongst pH=3, 5 and 8) was pH= 5. Further studies are needed to identify the peroxy acid degradation intermediates and to investigate their effects on SWCNTs. PMID:23369540

  11. Soybean peroxidase-mediated degradation of an azo dye– a detailed mechanistic study

    PubMed Central

    2013-01-01

    Background Peroxidases are emerging as an important class of enzymes that can be used for the efficient degradation of organic pollutants. However, detailed studies identifying the various intermediates produced and the mechanisms involved in the enzyme-mediated pollutant degradation are not widely published. Results In the present study, the enzymatic degradation of an azo dye (Crystal Ponceau 6R, CP6R) was studied using commercially available soybean peroxidase (SBP) enzyme. Several operational parameters affecting the enzymatic degradation of dye were evaluated and optimized, such as initial dye concentration, H2O2 dosage, mediator amount and pH of the solution. Under optimized conditions, 40 ppm dye solution could be completely degraded in under one minute by SBP in the presence of H2O2 and a redox mediator. Dye degradation was also confirmed using HPLC and TOC analyses, which showed that most of the dye was being mineralized to CO2 in the process. Conclusions Detailed analysis of metabolites, based on LC/MS results, showed that the enzyme-based degradation of the CP6R dye proceeded in two different reaction pathways- via symmetric azo bond cleavage as well as asymmetric azo bond breakage in the dye molecule. In addition, various critical transformative and oxidative steps such as deamination, desulfonation, keto-oxidation are explained on an electronic level. Furthermore, LC/MS/MS analyses confirmed that the end products in both pathways were small chain aliphatic carboxylic acids. PMID:24308857

  12. Decolorization of acid and basic dyes: understanding the metabolic degradation and cell-induced adsorption/precipitation by Escherichia coli.

    PubMed

    Cerboneschi, Matteo; Corsi, Massimo; Bianchini, Roberto; Bonanni, Marco; Tegli, Stefania

    2015-10-01

    Escherichia coli strain DH5α was successfully employed in the decolorization of commercial anthraquinone and azo dyes, belonging to the general classes of acid or basic dyes. The bacteria showed an aptitude to survive at different pH values on any dye solution tested, and a rapid decolorization was obtained under aerobic conditions for the whole collection of dyes. A deep investigation about the mode of action of E. coli was carried out to demonstrate that dye decolorization mainly occurred via three different pathways, specifically bacterial induced precipitation, cell wall adsorption, and metabolism, whose weight was correlated with the chemical nature of the dye. In the case of basic azo dyes, an unexpected fast decolorization was observed after just 2-h postinoculation under aerobic conditions, suggesting that metabolism was the main mechanism involved in basic azo dye degradation, as unequivocally demonstrated by mass spectrometric analysis. The reductive cleavage of the azo group by E. coli on basic azo dyes was also further demonstrated by the inhibition of decolorization occurring when glucose was added to the dye solution. Moreover, no residual toxicity was found in the E. coli-treated basic azo dye solutions by performing Daphnia magna acute toxicity assays. The results of the present study demonstrated that E. coli can be simply exploited for its natural metabolic pathways, without applying any recombinant technology. The high versatility and adaptability of this bacterium could encourage its involvement in industrial bioremediation of textile and leather dyeing wastewaters. PMID:26062529

  13. 40 CFR 721.9538 - Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Lithium salt of sulfophenyl azo phenyl... Significant New Uses for Specific Chemical Substances § 721.9538 Lithium salt of sulfophenyl azo phenyl azo... substance identified generically as lithium salt of sulfophenyl azo phenyl azo disulfostilbene (PMN...

  14. 40 CFR 721.9538 - Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Lithium salt of sulfophenyl azo phenyl... Significant New Uses for Specific Chemical Substances § 721.9538 Lithium salt of sulfophenyl azo phenyl azo... substance identified generically as lithium salt of sulfophenyl azo phenyl azo disulfostilbene (PMN...

  15. 40 CFR 721.9538 - Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Lithium salt of sulfophenyl azo phenyl... Significant New Uses for Specific Chemical Substances § 721.9538 Lithium salt of sulfophenyl azo phenyl azo... substance identified generically as lithium salt of sulfophenyl azo phenyl azo disulfostilbene (PMN...

  16. 40 CFR 721.9538 - Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Lithium salt of sulfophenyl azo phenyl... Significant New Uses for Specific Chemical Substances § 721.9538 Lithium salt of sulfophenyl azo phenyl azo... substance identified generically as lithium salt of sulfophenyl azo phenyl azo disulfostilbene (PMN...

  17. 40 CFR 721.9538 - Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Lithium salt of sulfophenyl azo phenyl... Significant New Uses for Specific Chemical Substances § 721.9538 Lithium salt of sulfophenyl azo phenyl azo... substance identified generically as lithium salt of sulfophenyl azo phenyl azo disulfostilbene (PMN...

  18. 40 CFR 721.10488 - Cuprate, [[[[[[[ (sulfonaphthalenyl)]azo]-(substitutedphenyl)]azo]-(substitutedsulfonaphthalenyl...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Cuprate, azo]-(substitutedphenyl)]azo]-(substitutedsulfonaphthalenyl)] azo] - substituted phenyl - substituted heteromonocycle], sodium salts (generic). 721.10488... Substances § 721.10488 Cuprate, azo]-(substitutedphenyl)]azo]-(substitutedsulfonaphthalenyl)]...

  19. 40 CFR 721.10488 - Cuprate, [[[[[[[ (sulfonaphthalenyl)]azo]- (substitutedphenyl)]azo...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Cuprate, azo]- (substitutedphenyl)]azo]- (substitutedsulfonaphthalenyl)] azo]- substituted phenyl- substituted heteromonocycle], sodium salts (generic). 721.10488... Substances § 721.10488 Cuprate, azo]- (substitutedphenyl)]azo]- (substitutedsulfonaphthalenyl)]...

  20. Biodegradation potential of pure and mixed bacterial cultures for removal of 4-nitroaniline from textile dye wastewater.

    PubMed

    Khalid, Azeem; Arshad, Muhammad; Crowley, David E

    2009-03-01

    Environmentally toxic aromatic amines including nitroanilines are commonly generated in dye contaminated wastewater in which azo dyes undergo degradation under anaerobic conditions. The aim of this study was to develop a process for biological treatment of 4-nitroaniline. Three bacteria identified as Acinetobacter sp., Citrobacter freundii and Klebsiella oxytoca were isolated from enrichment cultures of activated sludge on 4-nitroaniline, after which the isolates and the mixed culture were studied to determine optimal conditions for biodegradation. HPLC analyses showed the mixed culture was capable of complete removal of 100micromol/L of 4-nitroaniline within 72h under aerobic conditions. There was an inverse linear relationship (R(2)=0.96) between the rate of degradation (V) and 4-nitraoaniline concentrations [S] over 100-1000micromol/L. The bacterial culture was also capable of decolorizing structurally different azo dyes (Acid Red-88, Reactive Black-5, Direct Red-81, and Disperse Orange-3) and also degraded nitrobenzene. Our findings show that enrichment cultures from activated sludge can be effective for the removal of dyes and their toxic intermediates, and that treatment may best be accomplished using an anaerobic-aerobic process. PMID:19114284

  1. Intracellular azo decolorization is coupled with aerobic respiration by a Klebsiella oxytoca strain.

    PubMed

    Yu, Lei; Zhang, Xiao-Yu; Xie, Tian; Hu, Jin-Mei; Wang, Shi; Li, Wen-Wei

    2015-03-01

    Reduction of azo dye methyl red coupled with aerobic respiration by growing cultures of Klebsiella oxytoca GS-4-08 was investigated. In liquid media containing dye and 0.6 % glucose in a mineral salts base, 100 mg l(-1) of the dye are completely removed in 3 h under shaking conditions. The dye cannot be aerobically decolorized by strain GS-4-08 without extra carbon sources, indicating a co-metabolism process. Higher initial dye concentration prolonged the lag phase of the cell growth, but final cell concentrations of each batches reached a same level with range from 6.3 to 7.6 mg l(-1) after the dye adaption period. This strain showed stronger dye tolerance and decolorization ability than many reported strains. Furthermore, a new intracellular oxygen-insensitive azoreductase was isolated from this strain, and the specific activity of enzyme was 0.846 and 0.633 U mg(-1) protein in the presence of NADH and NADPH, respectively. N,N dimethyl-p-phenylenediamine and anthranilic acid were stoichiometrically released from MR dye, indicating the breakage of azo bonds accounts for the intracellular decolorization. Combining the characteristics of azoreductase, the stoichiometry of EMP, and TCA cycle, the electron transfer chain theory of aerobic respiration, and the possible mechanism of aerobic respiration coupled with azo reduction by K. oxytoca GS-4-08 are proposed. This study is expected to provide a sound theoretical basis for the development of the K. oxytoca strain in aerobic process for azo dye containing wastewaters. PMID:25343980

  2. Adsorption of C.I. Reactive Red 228 and Congo Red dye from aqueous solution by amino-functionalized Fe3O4 particles: kinetics, equilibrium, and thermodynamics.

    PubMed

    Yan, Ting-guo; Wang, Li-Juan

    2014-01-01

    A magnetic adsorbent was synthesized by γ-aminopropyltriethoxysilane (APTES) modification of Fe(3)O(4) particles using a two-step process. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and vibration sample magnetometry were used to characterize the obtained magnetic adsorbent. EDS and XPS showed that APTES polymer was successfully introduced onto the as-prepared Fe(3)O(4)/APTES particle surfaces. The saturation magnetization of the magnetic adsorbent was around 65 emu g(-1), which indicated that the dye can be removed fast and efficiently from aqueous solution with an external magnetic field. The maximum adsorption capacities of Fe(3)O(4)/APTES for C.I. Reactive Red 228 (RR 228) and Congo Red (CR) were 51.4 and 118.8 mg g(-1), respectively. The adsorption of C.I. Reactive Red 228 (RR 228) and Congo Red (CR) on Fe(3)O(4)/APTES particles corresponded well to the Langmuir model and the Freundlich model, respectively. The adsorption processes for RR 228 and CR followed the pseudo-second-order model. The Boyd's film-diffusion model showed that film diffusion also played a major role in the studied adsorption processes for both dyes. Thermodynamic study indicated that both of the adsorption processes of the two dyes are spontaneous exothermic. PMID:24552735

  3. Biodegradation of Reactive blue 13 in a two-stage anaerobic/aerobic fluidized beds system with a Pseudomonas sp. isolate.

    PubMed

    Lin, Jun; Zhang, Xingwang; Li, Zhongjian; Lei, Lecheng

    2010-01-01

    Pseudomonas sp. strain L1 capable of degrading the azo textile dye Reactive blue 13, was isolated from activated sludge in a sequencing batch reactor. A continuous two-stage anaerobic/aerobic biological fluidized bed system was used to decolorize and mineralize Reactive blue 13. The key factors affecting decolorization were investigated and the efficiency of degradation was also optimized. An overall color removal of 83.2% and COD removal of 90.7% was achieved at pH 7, a residence time of 70 h and a glucose concentration of 2 g/L, HRT=70 h and C(glucose)=2000 mg/L. Oxygen was contributing to blocking the azo bond cleavage. Consequently, decolorization occurred in the anaerobic reactor while partial mineralization was achieved in the aerobic reactor. A possible degradation pathway based on the analysis of intermediates and involving azoreduction, desulfonation, deamination and further oxidation reactions is presented. PMID:19713103

  4. Azobenzene-caged sulforhodamine dyes: a novel class of ‘turn-on’ reactive probes for hypoxic tumor cell imaging

    NASA Astrophysics Data System (ADS)

    Chevalier, Arnaud; Piao, Wen; Hanaoka, Kenjiro; Nagano, Tetsuo; Renard, Pierre-Yves; Romieu, Anthony

    2015-12-01

    New sulforhodamine-based fluorescent ‘turn-on’ probes have been developed for the direct imaging of cellular hypoxia. Rapid access to this novel class of water-soluble ‘azobenzene-caged’ fluorophores was made possible through an easily-implementable azo-coupling reaction between a fluorescent primary arylamine derived from a sulforhodamine 101 scaffold (named SR101-NaphtNH 2 ) and a tertiary aniline whose N-substituents are neutral, cationic, or zwitterionic. The detection mechanism is based on the bioreductive cleavage of the azo bond that restores strong far-red fluorescence (emission maximum at 625 nm) by regenerating the original sulforhodamine SR101-NaphtNH 2 . This valuable fluorogenic response was obtained for the three ‘smart’ probes studied in this work, as shown by an in vitro assay using rat liver microsomes placed under aerobic and then under hypoxic conditions. Most importantly, the probe namely SR101-NaphtNH 2 -Hyp-diMe was successfully applied for imaging the hypoxic status of tumor cells (A549 cells).

  5. Degradation products of the artificial azo dye, Allura red, inhibit esterase activity of carbonic anhydrase II: A basic in vitro study on the food safety of the colorant in terms of enzyme inhibition.

    PubMed

    Esmaeili, Sajjad; Ashrafi-Kooshk, Mohammad Reza; Khaledian, Koestan; Adibi, Hadi; Rouhani, Shohre; Khodarahmi, Reza

    2016-12-15

    Allura red is a widely used food colorant, but there is debate on its potential security risk. In the present study, we found that degradation products of the dye were more potent agents with higher carbonic anhydrase inhibitory action than the parent dye. The mechanism by which the compounds inhibit the enzyme activity has been determined as competitive mode. In addition, the enzyme binding properties of the compounds were investigated employing different spectroscopic techniques and molecular docking. The analyses of fluorescence quenching data revealed the existence of the same binding site for the compounds on the enzyme molecule. The thermodynamic parameters of ligand binding were not similar, which indicates that different interactions are responsible in binding of the parent dye and degradation products to the enzyme. It appears that enzyme inhibition should be considered, more seriously, as a new opened dimension in food safety. PMID:27451209

  6. Decolourisation of simulated reactive dyebath effluents by electrochemical oxidation assisted by UV light.

    PubMed

    López-Grimau, V; Gutiérrez, M C

    2006-01-01

    This study is focused on the optimisation of the electrochemical decolourisation of textile effluents containing reactive dyes with the aim of making feasible-technically and economically-this method at industrial scale. Coloured waters were treated in continuous at low current density, to reduce the electrical consumption. Ti/PtO(x) electrodes were used to oxidize simulated dyebaths prepared with an azo/dichlorotriazine reactive dye (C.I. Reactive Orange 4). The decolourisation yield was dependent on the dyeing electrolyte (NaCl or Na(2)SO(4)). Dyeing effluents which contained from 0.5 to 20 gl(-1) of NaCl reached a high decolourisation yield, depending on the current density, immediately after the electrochemical process. These results were improved when the effluents were stored for several hours under solar light. After the electrochemical treatment the effluents were stored in a tank and exposed under different lighting conditions: UV light, solar light and darkness. The evolution of the decolourisation versus the time of storage was reported and kinetic constants were calculated. The time of storage was significantly reduced by the application of UV light. A dye mineralization study was also carried out on a concentrated dyebath. A TOC removal of 81% was obtained when high current density was applied for a prolonged treatment with recirculation. This treatment required a high electrical consumption. PMID:15893798

  7. Activation of the skeletal muscle Ca2+ release channel by the triazine dyes cibacron blue F3A-G and reactive red 120

    SciTech Connect

    Xu, L.; Jones, R.V.; Meissner, G. )

    1989-11-01

    Vesicle-{sup 45}Ca2+ ion flux and planar lipid bilayer single-channel measurements have shown that the Ca2+ release channel of skeletal muscle sarcoplasmic reticulum (SR) is activated by micromolar concentrations of Cibacron Blue F3A-G (Reactive Blue 2) and Reactive Red 120. Cibacron Blue increased the {sup 45}Ca2+ efflux rate from heavy SR vesicles by apparently interacting with both the adenine nucleotide and caffeine activating sites of the channel. Dye-induced {sup 45}Ca2+ release was inhibited by Mg2+ and ruthenium red. In single channel recordings with the purified channel protein complex, Cibacron Blue increased the open time of the Ca2+ release channel without an apparent change in the conductance of the main and subconductance states of the channel.

  8. Application of H2O and UV/H2O2 processes for enhancing the biodegradability of reactive black 5 dye.

    PubMed

    Kalpana, S Divya; Kalyanaraman, Chitra; Gandhi, N Nagendra

    2011-07-01

    Leather processing is a traditional activity in India during which many organic and inorganic chemicals are added while part of it is absorbed by the leather, the remaining chemicals are discharged along with the effluent. The effluent contains both easily biodegradable and not easily biodegradable synthetic organics like dyes, syntans. Easily biodegradable organics are removed in the existing biological treatment units whereas synthetic organics present in the wastewater are mostly adsorbed over the microbes. As the tannery effluent contains complex chemicals, it is difficult to ascertain the degradation of specific pollutants. To determine the increase in the biodegradability, one of the complex and synthetic organic chemical like dye used in the tanning operation was selected for Advanced Oxidation Process (AOPs) treatment for cleaving complex organics and its subsequent treatment in aerobic process. In the present study, Reactive Black 5 Dye used in the tanning operation was selected for Hydrogen Peroxide (H2O2) and UV/H2O2 pre-treatment for different operating conditions like pH, contact time and different volume of H2O2. A comparison was made between the untreated, Hydrogen Peroxide (H2O2) and UV/H2O2 treated effluent in order to ascertain the influence of AOP on the improvement of biodegradability of effluent. An increase in the BOD5/COD ratio from 0.21 to 0.435 was achieved in the UV/H2O2 pre-treatment process. This pre-treated effluent was further subjected to aerobic process. Biochemical Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) removal efficiency of the UV/H2O2 pre-treated dye solution in the aerobic process was found to be 86.39% and 77.82% when compared to 52.43% of BOD5 and 51.55% of COD removal efficiency without any pre-treatment. Hence from these results, to increase the biodegradability of Reactive Black 5 dye pre-treatment methods like H2O2 and UV/H2O2 can be used prior to biological treatment process. PMID:23029927

  9. [Benzidine dyes and risk of bladder cancer].

    PubMed

    Miyakawa, M; Yoshida, O

    1989-12-01

    Until the early 1970's there was little concern about dyes which contain benzidine as an integral part of their chemical structure. Furthermore, use of the finished dyes was not considered dangerous. To ascertain whether azo dyes are associated with risk of development of bladder tumors in workers who handpaint Yuzen-type silk kimonos in Kyoto, we investigated the disintegration of dyes to benzidine. In these studies, we found that in rats and mice benzidine-based dyes are metabolized to benzidine and that the azo linkage of benzidine dyes is reduced by Escherichia coli and soil bacteria. These experimental findings were reported previously. In this report, we outline an approach to these studies. Many of the dyes used to color paper, textiles, lipstick, bait used by fishermen, as well as hair dyes, and dyes used in research, for pharmaceutical products, and by defence personnel for the detection of liquid chemical warfare agents, have been shown to be potentially mutagenic or carcinogenic. We review the literature on these dyes. PMID:2618904

  10. Enhanced photocatalytic-electrolytic degradation of Reactive Brilliant Red X-3B in the presence of water jet cavitation.

    PubMed

    Wang, Xiaoning; Jia, Jinping; Wang, Yalin

    2015-03-01

    Photocatalysis, electrolysis, water jet cavitation (WJC), alone and in combinations were applied to degrade an azo dye, Reactive Brilliant Red X-3B (X-3B). Experiments were conducted in a 4.0 L aqueous solution with different initial dye concentrations, TiO₂ dose, and solution pH. WJC substantially increased the photocatalytic, electrolytic and photocatalytic-electrolytic rates of the dye removal. The observed first-order rate of X-3B decolorization in the process of combined photocatalysis and electrolysis coupled with WJC was 1.6-2.9 times of that in the process of combined photocatalysis and electrolysis coupled with mechanical stirring. The rate enhancements may be attributed primarily to the reduced diffusion layer thickness on the electrodes and the deagglomeration of photocatalyst particles due to the chemical and physical effects of WJC. Under the conditions of 80 mg/L X-3B solution, 100 mg/L TiO₂ dose and solution pH 6.3, 97% and 71% of color and chemical oxygen demand (CODCr) were removed, respectively, within 90-min photocatalytic-electrolytic treatment coupled with WJC. During this process, azo groups and naphthalene, benzene and triazine structures of the dye can be destroyed. Industrial textile effluent was also investigated, and a positive synergistic effect between photocatalytic-electrolytic system and WJC was observed considering color removal. PMID:25453209

  11. Comparative Study on Synergetic Degradation of a Reactive Dye Using Different Types of Fly Ash in Combined Adsorption and Photocatalysis

    NASA Astrophysics Data System (ADS)

    Giri Babu, P. V. S.; Swaminathan, G.

    2016-07-01

    A comprehensive study was carried out on four different fly ashes used as a catalyst for the degradation of Acid Red 1 using ultraviolet rays. These fly ashes are collected from different thermal power stations located at various places in India and having different chemical compositions. Three fly ashes are from lignite-based thermal power plants, and one is from the coal-based power plant. One fly ash is classified as Class F, two fly ashes are classified as Class C and remaining one is not conforming to ASTM C618 classification. X-Ray Fluorescence analysis was used to identify the chemical composition of fly ashes and SiO2, Al2O3, CaO, Fe2O3 and TiO2 were found to be the major elements present in different proportions. Various analysis were carried out on all the fly ashes like Scanning Electron Microscopy to identify the microphysical properties, Energy Dispersive X-Ray spectroscopy to quantify the elements present in the catalyst and X-Ray Diffraction to identify the catalyst phase analysis. The radical generated during the reaction was identified by Electron paramagnetic resonance spectroscopy. The parameters such as initial pH of the dye solution, catalyst dosage and initial dye concentration which influence the dye degradation efficiency were studied and optimised. In 60 min duration, the dye degradation efficiency at optimum parametric values of pH 2.5, initial dye concentration of 10 mg/L and catalyst dosage of 1.0 g/L using various fly ashes, i.e., Salam Power Plant, Barmer Lignite Power Plant, Kutch Lignite Power Plant and Neyveli Lignite Thermal Power plant (NLTP) were found to be 40, 60, 67 and 95 % respectively. The contribution of adsorption alone was 18 % at the above mentioned optimum parametric values. Among the above four fly ash NLTP fly ashes proved to be most efficient.

  12. Algal decolorization and degradation of monoazo and diazo dyes.

    PubMed

    Omar, Hanan Hafez

    2008-05-15

    This study is to inspect how the variation of molecular structures and functional groups present in our models, monoazo dye (Tartrazine) and diazo dye (Ponceau), affects decolorization capabilities of green algae, cyanobacteria and diatoms. The results revealed that the removal of azo dyes was rapid at the initial period of study (3 days) and became slowly with the time (6 days). The maximum decolorization was observed at 5 ppm Tartrazine with S. bijugatus (68%) and N. muscourm after 6 days incubation. The reduction of color removal appears to be related to the molecular structure of the dyes and species of algae used. The culture of the diatom Nitzschia perminuta was completely died after 2 days of incubation. Azo reductase of algae, which is responsible for degradation of azo dyes into aromatic amine by breaking the azo linkage, was estimated. IR spectra represented a new peak at 3300 cm(-1) and a reduction in the azo band at 1642-1631 cm(-1). In order to investigate the sorption behavior of algae, Langmuir equilibrium model was tested. PMID:18817261

  13. Structural Insights into 2,2′-Azino-Bis(3-Ethylbenzothiazoline-6-Sulfonic Acid) (ABTS)-Mediated Degradation of Reactive Blue 21 by Engineered Cyathus bulleri Laccase and Characterization of Degradation Products

    PubMed Central

    Kenzom, T.; Srivastava, P.

    2014-01-01

    Advanced oxidation processes are currently used for the treatment of different reactive dyes which involve use of toxic catalysts. Peroxidases are reported to be effective on such dyes and require hydrogen peroxide and/or metal ions. Cyathus bulleri laccase, expressed in Pichia pastoris, catalyzes efficient degradation (78 to 85%) of reactive azo dyes (reactive black 5, reactive orange 16, and reactive red 198) in the presence of synthetic mediator ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)]. This laccase was engineered to degrade effectively reactive blue 21 (RB21), a phthalocyanine dye reported to be decolorized only by peroxidases. The 816-bp segment (toward the C terminus) of the lcc gene was subjected to random mutagenesis and enzyme variants (Lcc35, Lcc61, and Lcc62) were selected based on increased ABTS oxidizing ability. Around 78 to 95% decolorization of RB21 was observed with the ABTS-supplemented Lcc variants in 30 min. Analysis of the degradation products by mass spectrometry indicated the formation of several low-molecular-weight compounds. Mapping the mutations on the modeled structure implicated residues both near and far from the T1 Cu site that affected the catalytic efficiency of the mutant enzymes on ABTS and, in turn, the rate of oxidation of RB21. Several inactive clones were also mapped. The importance of geometry as well as electronic changes on the reactivity of laccases was indicated. PMID:25261507

  14. Degradation of Reactive Black 5 dye by CWPO using Fe/mining sand under photo-Fenton process

    NASA Astrophysics Data System (ADS)

    Amri, Nurulhuda; Nasuha, Norhaslinda; Halim, Siti Fatimah Abdul; Ngah, Khairuddin

    2015-05-01

    This present study was conducted to investigate the effectiveness of catalytic wet peroxide oxidation (CWPO) process using photo-Fenton method and the used of mining sand as support catalyst as well as to determine the optimum parameters and effect of catalyst wt%, pH, H2O2 concentration, initial dye concentration and catalyst dosage on RB 5 degradation. The Fe/mining sand was prepared by impregnation technique and a solar degradation of RB 5 carried out by mean photo-Fenton reaction promoted by solar energy. The dye degradation was monitored during the experimental runs through UV/Vis spectrophotometer. In this process, the reaction condition were optimized at 0.4 of catalyst wt%, pH 2, 4 mM of H2O2 concentration and 0.5 g of catalyst dosage which achieved degradation efficiency at 100% for the three experiments except catalyst dosage which achieved 97.54% respectively within 180 min. The degradation of RB 5 also decreased with the increasing of dye concentration with 10 mg/L achieved the optimum degradation of 99.93%. The results demonstrated that photo-Fenton method could effectively degrade RB 5 and reduce the operating cost by conducting the experiment at optimum conditions.

  15. Application of central composite design and artificial neural network in modeling of reactive blue 21 dye removal by photo-ozonation process.

    PubMed

    Mehrizad, Ali; Gharbani, Parvin

    2016-01-01

    The present study deals with use of central composite design (CCD) and artificial neural network (ANN) in modeling and optimization of reactive blue 21 (RB21) removal from aqueous media under photo-ozonation process. Four effective operational parameters (including: initial concentration of RB21, O(3) concentration, UV light intensity and reaction time) were chosen and the experiments were designed by CCD based on response surface methodology (RSM). The obtained results from the CCD model were used in modeling the process by ANN. Under optimum condition (O(3) concentration of 3.95 mg L(-1), UV intensity of 20.5 W m(-2), reaction time of 7.77 min and initial dye concentration of 40.21 mg L(-1)), RB21 removal efficiency reached to up 98.88%. A topology of ANN with a three-layer consisting of four input neurons, 14 hidden neurons and one output neuron was designed. The relative significance of each major factor was calculated based on the connection weights of the ANN model. Dye and ozone concentrations were the most important variables in the photo-ozonation of RB21, followed by reaction time and UV light intensity. The comparison of predicted values by CCD and ANN with experimental results showed that both methods were highly efficient in the modeling of the process. PMID:27386996

  16. Efficient and rapid adsorption characteristics of templating modified guar gum and silica nanocomposite toward removal of toxic reactive blue and Congo red dyes.

    PubMed

    Pal, Sagar; Patra, Abhay Shankar; Ghorai, Soumitra; Sarkar, Amit Kumar; Mahato, Vivekananda; Sarkar, Supriyo; Singh, R P

    2015-09-01

    The present study highlights the potentiality of sol-gel synthesized guar gum-graft-poly (acrylamide)/silica (g-GG/SiO2) hybrid nanocomposite toward the rapid removal of toxic reactive blue 4 (RB) and Congo red (CR) dyes from aqueous solution. Various physicochemical characterizations support the feasibility of the functionalized guar gum matrix as efficient template for the formation of homogeneous nanoscale silica particles. The composite demonstrates rapid and superior adsorption efficiency of RB (Qmax: 579.01 mg g(-1) within 40 min) and CR (Qmax: 233.24 mg g(-1) within 30 min) dyes from aqueous environment. Here, the pH driven adsorption process depends strongly on the ionic strength of the salt solution. The adsorption kinetics data predicts that pseudo second-order (surface adsorption) and intraparticle diffusion take place simultaneously. The adsorption equilibrium is in good agreement with the Langmuir isotherm, while the thermodynamics study confirms spontaneous nature of the adsorption process. Desorption study predicts the excellent regenerative efficacy of nanocomposite. PMID:26002148

  17. The role of intestinal microflora in the activation of benzidine and benzidine congener based dyes

    SciTech Connect

    Cerniglia, C.E.; Franklin, W.; Campbell, W.L. )

    1988-09-01

    Benzidine-based dyes are widely used in the dye manufacturing, textile dyeing, color paper printing and leather industries. Some benzidine based dyes have been shown to be carcinogenic due to their biotransformation in the liver or in the gastrointestinal tract to benzidine, a long recognized human urinary bladder carcinogen. Occupational exposure to workers can be through skin absorption, inhalation and ingestion of the benzidine based dyes. Previous studies of benzidine based dye metabolism have shown that enzymatic reduction of the azo group, yielding benzidine is an essential step in the activation of these compounds to genotoxic species. Azo reduction activity is present in both the liver and gastrointestinal tract and little is known whether the first step in the toxification process of benzidine based dyes occurs at either site. They are investigating the capacity of intestinal microflora to metabolize benzidine-based dyes and determine their overall importance in the activation of this class of industrially important chemicals.

  18. Near-IR squaraine dye-loaded gated periodic mesoporous organosilica for photo-oxidation of phenol in a continuous-flow device.

    PubMed

    Borah, Parijat; Sreejith, Sivaramapanicker; Anees, Palapuravan; Menon, Nishanth Venugopal; Kang, Yuejun; Ajayaghosh, Ayyappanpillai; Zhao, Yanli

    2015-09-01

    Periodic mesoporous organosilica (PMO) has been widely used for the fabrication of a variety of catalytically active materials. We report the preparation of novel photo-responsive PMO with azobenzene-gated pores. Upon activation, the azobenzene gate undergoes trans-cis isomerization, which allows an unsymmetrical near-infrared squaraine dye (Sq) to enter into the pores. The gate closure by cis-trans isomerization of the azobenzene unit leads to the safe loading of the monomeric dye inside the pores. The dye-loaded and azobenzene-gated PMO (Sq-azo@PMO) exhibits excellent generation of reactive oxygen species upon excitation at 664 nm, which can be effectively used for the oxidation of phenol into benzoquinone in aqueous solution. Furthermore, Sq-azo@PMO as the catalyst was placed inside a custom-built, continuous-flow device to carry out the photo-oxidation of phenol to benzoquinone in the presence of 664-nm light. By using the device, about 23% production of benzoquinone with 100% selectivity was achieved. The current research presents a prototype of transforming heterogeneous catalysts toward practical use. PMID:26601266

  19. Carcinogenicity of hair dye components.

    PubMed

    Van Duuren, B L

    1980-03-01

    The available animal carcinogenicity data on hair dye components was reviewed. From this review it became clear that certain hair dye components, some of which are still in hair dye formulations now on the market, are animal carcinogens. The compounds of concern that are still in use are: 3-amino-4-methoxyaniline, 2-nitro-4-aminoaniline and 3-nitro-4-hydroxyaniline. Certain azo dyes formerly used, and related compounds still in use, contain the benzidine moiety. Two of these compounds, Direct Blue 6 and Direct Black 38, have been shown to be metabolized in animals to the human carcinogen benzidine. Furthermore, skin absorption studies carried out with radiolabeled hair dye components applied to animal or human skin have conclusively shown that these compounds are systemically absorbed and excreted. Known cocarcinogens such as catechol and pyrogallol, which enhance benzo(a)pyrene carcinogenicity on mouse skin, are used as hair dye components. It is not known whether such compounds will enhance the carcinogenicity of substituted aniline hair dye chemicals. The available epidemiologic data are not sufficient to link hair dye use with an increased incidence in human cancer. PMID:6993608

  20. 40 CFR 721.5930 - Phenylenebis[imino (chlorotriazinyl)imino(substituted naphthyl)azo(substituted phenyl)azo, sodium...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...)imino(substituted naphthyl)azo(substituted phenyl)azo, sodium salt (generic name). 721.5930 Section 721... Phenylenebis[imino (chlorotriazinyl)imino(substituted naphthyl)azo(substituted phenyl)azo, sodium salt (generic... identified generically as phenylenebis[imino (chlorotriazinyl)imino(substituted naphthyl)azo...