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Sample records for citrazinic acid azo

  1. A pH dependent Raman and surface enhanced Raman spectroscopic studies of citrazinic acid aided by theoretical calculations.

    Science.gov (United States)

    Sarkar, Sougata; Chowdhury, Joydeep; Dutta, Soumen; Pal, Tarasankar

    2016-12-01

    A pH dependent normal Raman scattering (NRS) and surface enhanced Raman scattering (SERS) spectral patterns of citrazinic acid (CZA), a biologically important molecule, have been investigated. The acid, with different pKa values (~4 and ~11) for the two different functional groups (-COOH and -OH groups), shows interesting range of color changes (yellow at pH~14 and brown at pH~2) with the variation in solution pH. Thus, depending upon the pH of the medium, CZA molecule can exist in various protonated and/or deprotonated forms. Here we have prescribed the existence different possible forms of CZA at different pH (Forms "C", "H" and "Dprot" at pH~14 and Forms "A", "D", and "P" at pH~2 respectively). The NRS spectra of these solutions and their respective SERS spectra over gold nanoparticles were recorded. The spectra clearly differ in their spectral profiles. For example the SERS spectra recorded with the CZA solution at pH~2 shows blue shift for different bands compared to its NRS window e.g. 406 to 450cm(-1), 616 to 632cm(-1), 1332 to 1343cm(-1) etc. Again, the most enhanced peak at ~1548cm(-1) in NRS while in the SERS window this appears at ~1580cm(-1). Similar observation was also made for CZA at pH~14. For example, the 423cm(-1) band in the NRS profile experience a blue shift and appears at ~447cm(-1) in the SERS spectrum as well as other bands at ~850, ~1067 and ~1214cm(-1) in the SERS window are markedly enhanced. It is also worth noting that the SERS spectra at the different pH also differ from each other. These spectral differences indicate the existence of various adsorptive forms of the CZA molecule depending upon the pH of the solution. Therefore based on the experimental findings we propose different possible molecular forms of CZA at different pH (acidic and alkaline) conditions. For example forms 'A', 'D' and 'P' existing in acidic pH (pH~2) and three other deprotonated forms 'C', 'H' and 'Dprot' in alkaline pH (pH~14). The DFT calculations for these

  2. Synthesis of azo derivatives of 4-aminosalicylic acid

    Institute of Scientific and Technical Information of China (English)

    Zheng Bao Zhao; Hui Xia Zheng; Yuan Gui Wei; Jiang Liu

    2007-01-01

    For searching a better 4-aminosalicylic acid derivative with higher activity and less side effects against the inflammatory bowel disease, 4-aminosalicylic acid (4-ASA) was protected by benzyloxycarbonyl and acetyl, respectively.The resultant was hydrogenized to remove protective group of amino group, then the product was reacted with NaNO2 to give diazonium salt, which was conjugated with salicylic acid, hydroxybenzene, N-salicyloyl glycine acid to get azo derivatives of 4-ASA.The azo derivatives were hydrolyzed under the alkaline condition to get the target products.All compounds were characterized by FT-IR, 1H NMR, 13C NMR spectra in details.New derivatives of 4-ASA were characterized.The synthetic route was reasonable and feasible.

  3. The mechanism and kinetics of the electrochemical cleavage of azo bond of 2-hydroxy-5-sulfophenyl-azo-benzoic acids

    Energy Technology Data Exchange (ETDEWEB)

    Mandic, Zoran; Nigovic, Biljana; Simunic, Branimir

    2004-02-15

    The electrochemical reduction of 2-hydroxy-5-[(4-sulfophenyl)azo]benzoic acid, 2-hydroxy-5-[(3-sulfophenyl)azo]benzoic acid, 2-hydroxy-5-[(2-sulfophenyl)azo]benzoic acid and 2-hydroxy-5-azo-benzoic acid has been carried out in aqueous solutions at glassy carbon electrode using cyclic voltammetry and chronoamperometry. The position of sulfo substituent relative to azo bridge as well as pH of the solution have significant impact on the electrochemical behavior of these compounds. It has been proposed that these compounds are reduced predominantly as hydrazone tautomers resulting in corresponding hydrazo compounds. The overall electrochemical reduction follows DISP2 mechanism, ultimately leading to the 5-amino salicylic acid and sulfanilic acid. The rate determining step is the homogenous redox reaction between intermediate hydrazo compound and 5-amino salicylic acid quinoneimine. The mechanism is proposed in which activated complex of 5-amino salicylic acid quinoneimine and intermediate hydrazo compound is formed with the simultaneous loss of one proton.

  4. Aerobic biodegradation of azo dye Acid Black-24 by Bacillus halodurans.

    Science.gov (United States)

    Prasad, A S Arun; Rao, K V Bhaskara

    2014-05-01

    Bacillus halodurans MTCC 865 was employed for decolorization of textile azo dye, Acid Black-24 (AB-24). Thousand mgl⁻¹ of AB-24 was decolorized with 90% efficiency by the strain within 6 hrs at pH 9 and 37 °C with 5% NaCl under static conditions in screening medium. Decolorization was evaluated by measuring the periodic decrease in absorbance at 557 nm (λ(max)). Biodegradation of Acid Black-24 was determined by FTIR and HPLC. The FTIR spectrum of the AB-24 dye suggests the presence of azo bond (-N = N-) peak at 1618.28 cm⁻¹. Absence of the azo bond in the degraded sample spectrum indicates biodegradation of the dye. Formation of metabolites with different retention times in HPLC analysis further confirmed degradation of the azo dye, Acid Black-24 by Bacillus halodurans.

  5. Synthesis of Thermostable Azo-type Photoswitches towards Photoreaulatina Nucleic Acid Structures

    Institute of Scientific and Technical Information of China (English)

    WANG Qi; GAO Shuang; ZHOU Kai; CHEN Wenbin; NIU Congwei; XI Zhen

    2009-01-01

    In order to design efficient and thermostable azo-type regulators,a series of azo-type compounds were synthesized and characterized.While introducing an inductive electron-withdrawing group to an azobenzene para or meta-position,the obtained compound can be an excellent photoswitch.3,3'-Azo-di-benzyl alcohol was designed and synthesized as one of therrnostable and efficient photoswitches,which can efficiently reversibly photoregulate the nucleic acid structure with its cis-isomer being sufficiently stable at physiological temperature.

  6. Mineralization of sulfonated azo dyes and sulfanilic acid by Phanerochaete chrysosporium and Streptomyces chromofuscus.

    Science.gov (United States)

    Paszczynski, A; Pasti-Grigsby, M B; Goszczynski, S; Crawford, R L; Crawford, D L

    1992-11-01

    Five 14C-radiolabeled azo dyes and sulfanilic acid were synthesized and used to examine the relationship between dye substitution patterns and biodegradability (mineralization to CO2) by a white-rot fungus and an actinomycete. 4-Amino-[U-14C]benzenesulfonic acid and 4-(3-sulfo-4-aminophenylazo)-[U-14C]benzenesulfonic acid were used as representative compounds having sulfo groups or both sulfo and azo groups. Such compounds are not known to be present in the biosphere as natural products. The introduction of lignin-like fragments into the molecules of 4-amino-[U-14C]benzenesulfonic acid and 4-(3-sulfo-4-aminophenylazo)-[U-14C]benzenesulfonic acid by coupling reactions with guaiacol (2-methoxyphenol) resulted in the formation of the dyes 4-(3-methoxy-4-hydroxyphenylazo)-[U-14C]benzenesulfonic acid and 4-(2-sulfo-3'-methoxy-4'-hydroxy-azobenzene-4-azo)-[U-14C]benzenesulf oni c acid, respectively. The synthesis of acid azo dyes 4-(2-hydroxy-1-naphthylazo)-[U-14C]benzenesulfonic acid and 4-(4-hydroxy-1-naphthylazo)-[U-14C]benzenesulfonic acid also allowed the abilities of these microorganisms to mineralize these commercially important compounds to be evaluated. Phanerochaete chrysosporium mineralized all of the sulfonated azo dyes, and the substitution pattern did not significantly influence the susceptibility of the dyes to degradation. In contrast, Streptomyces chromofuscus was unable to mineralize aromatics with sulfo groups and both sulfo and azo groups. However, it mediated the mineralization of modified dyes containing lignin-like substitution patterns. This work showed that lignocellulolytic fungi and bacteria can be used for the biodegradation of anionic azo dyes, which thus far have been considered among the xenobiotic compounds most resistant to biodegradation.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Mineralization of sulfonated azo dyes and sulfanilic acid by Phanerochaete chrysosporium and Streptomyces chromofuscus.

    OpenAIRE

    Paszczynski, A; Pasti-Grigsby, M B; Goszczynski, S; Crawford, R L; Crawford, D. L.

    1992-01-01

    Five 14C-radiolabeled azo dyes and sulfanilic acid were synthesized and used to examine the relationship between dye substitution patterns and biodegradability (mineralization to CO2) by a white-rot fungus and an actinomycete. 4-Amino-[U-14C]benzenesulfonic acid and 4-(3-sulfo-4-aminophenylazo)-[U-14C]benzenesulfonic acid were used as representative compounds having sulfo groups or both sulfo and azo groups. Such compounds are not known to be present in the biosphere as natural products. The ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alessandra C. [Chemical Engineering Program, COPPE, Federal University of Rio de Janeiro, Av. Horacio Macedo, 2030, P.O. Box, 68502, CEP 21941-972, Rio de Janeiro, RJ (Brazil); Pic, Jean Stephane [Institut National des Sciences Appliquees, INSA-GPE-LIPE, Toulouse (France); Sant' Anna, Geraldo L., E-mail: lippel@peq.coppe.ufrj.br [Chemical Engineering Program, COPPE, Federal University of Rio de Janeiro, Av. Horacio Macedo, 2030, P.O. Box, 68502, CEP 21941-972, Rio de Janeiro, RJ (Brazil); Dezotti, Marcia [Chemical Engineering Program, COPPE, Federal University of Rio de Janeiro, Av. Horacio Macedo, 2030, P.O. Box, 68502, CEP 21941-972, Rio de Janeiro, RJ (Brazil)

    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{sup -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.

  9. Synthesis, characterization and dyeing assessment of novel acid azo dyes and mordent acid azo dyes based on 2-hydroxy-4-methoxybenzophenone on wool and silk fabrics

    Directory of Open Access Journals (Sweden)

    DHIRUBHAI J. DESAI

    2010-05-01

    Full Text Available Novel acid mono azo and mordent acid mono azo dyes were synthesised by the coupling of diazonium salt solution of different aromatic amines with 2-hydroxy-4-methoxybenzophenone. The resulting dyes were characterized by spectral techniques, i.e., elemental analysis, IR, 1H-NMR and UV–visible spectroscopy. The dyeing performance of all the dyes was evaluated on wool and silk fabrics. The dyeing of chrome pre-treated wool and silk fabrics showed better hues on mordented fabrics. Dyeing of wool and silk fabrics resulted in pinkish blue to red shades with very good depth and levelness. The dyed fabrics showed excellent to very good light, washing, perspiration, sublimation and rubbing fastness. The results of antibacterial studies of chrome pre-treated fabrics revealed that the toxicity of mordented dyes against Escherichia coli, Staphylococcus aureus, Salmonella typhi, Bacillus subtilis bacteria was fairly good.

  10. Sulfanilic acid: behavioral change related to azo food dyes in developing rats.

    Science.gov (United States)

    Goldenring, J R; Batter, D K; Shaywitz, B A

    1982-01-01

    The effects of sulfanilic acid, a major azo food dye metabolite, were studied in normal developing rat pups and pups treated with 6-hydroxydopamine (60HDA). Chronic daily intraperitoneal injection of sulfanilic acid during the first postnatal month elicited hyperactivity and impaired shock escape performance in vehicle pups. No differences were noted in 60HDA treated rat pups receiving sulfanilic acid. These findings, which are similar to the results of our study of chronic administration of a food dye mix, suggest that sulfanilic acid may be one of the causative agents in food dye-induced behavioral changes in developing rats. While our work suggests a significant effect of azo food dyes on the developing rat central nervous system, species differences in parameters such as absorption, metabolism, and blood-brain barrier properties do not permit any extrapolation of these observations to proposed effects in children.

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

    Science.gov (United States)

    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.

  12. Synthesis and evaluation of mutual azo prodrug of 5-aminosalicylic acid linked to 2-phenylbenzoxazole-2-yl-5-acetic acid in ulcerative colitis

    Directory of Open Access Journals (Sweden)

    Jilani JA

    2013-07-01

    Full Text Available Jamal A Jilani,1 Maha Shomaf,2 Karem H Alzoubi3 1Department of Medicinal Chemistry and Pharmacognosy, Jordan University of Science and Technology, Irbid, Jordan; 2Department of Pathology, Jordan University, Amman, Jordan; 3Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid, Jordan Abstract: In this study, the syntheses of 4-aminophenylbenzoxazol-2-yl-5-acetic acid, (an analogue of a known nonsteroidal anti-inflammatory drug [NSAID] and 5-[4-(benzoxazol-2-yl-5-acetic acidphenylazo]-2-hydroxybenzoic acid (a novel mutual azo prodrug of 5-aminosalicylic acid [5-ASA] are reported. The structures of the synthesized compounds were confirmed using infrared (IR, hydrogen-1 nuclear magnetic resonance (1H NMR, and mass spectrometry (MS spectroscopy. Incubation of the azo compound with rat cecal contents demonstrated the susceptibility of the prepared azo prodrug to bacterial azoreductase enzyme. The azo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were evaluated for inflammatory bowel diseases, in trinitrobenzenesulfonic acid (TNB-induced colitis in rats. The synthesized diazo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were found to be as effective as 5-aminosalicylic acid for ulcerative colitis. The results of this work suggest that the 4-aminophenylbenzoxazol-2-yl-5-acetic acid may represent a new lead for treatment of ulcerative colitis. Keywords: benzoxazole acetic acid, azo prodrug, colon drug delivery

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

    Science.gov (United States)

    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.

  14. Mutual azo prodrug of 5-aminosalicylic acid for colon targeted drug delivery: Synthesis, kinetic studies and pharmacological evaluation

    Directory of Open Access Journals (Sweden)

    Nagpal Deepika

    2006-01-01

    Full Text Available Mutual azo prodrug of 5-aminosalicylic acid with histidine, was synthesized by coupling L-histidine with salicylic acid, for targeted drug delivery to the inflamed gut tissue, in inflammatory bowel disease. In vitro kinetic studies in HCl buffer (pH 1.2 showed negligible release of 5-aminosalicylic acid, whereas in phosphate buffer (pH 7.4, only 14% release was observed over a period of 6h. In rat fecal matter, the release of 5-aminosalicylic acid was almost complete (85.6%, with a half life of 163 min, following zero order kinetics. The azo conjugate was evaluated for its ulcerogenic potential by Rainsford′s cold stress method. Therapeutic efficacy of the carrier system and the mitigating effect of the azo conjugate were evaluated in trinitrobenzenesulphonic acid- induced experimental colitis model. The synthesized prodrug was found to be equally effective in mitigating the colitis in rats, as that of sulfasalazine, without the ulcerogenicity of 5-aminosalicylic acid, and adverse effects of sulfasalazine.

  15. Citric Acid Fuctionalized Magnetic Ferrite Nanoparticles for Photocatalytic Degradation of Azo Dye.

    Science.gov (United States)

    Mahto, Triveni Kumar; Roy, Anurag; Sahoo, Banalata; Sahu, Sumanta Kumar

    2015-01-01

    In this study different magnetic ferrite nanoparticles (MFe2O4, where M = Fe, Mn, Zn) were synthesized through an aqueous coprecipitation method and then functionalized with citric acid for the degradation of azo dye present in industrial waste water. Here we evaluated the role of citric acid for photocatalytic application. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and the catalytic activity in degradation of methyl orange (MO) was evaluated. The rate of MO degradation in different magnetic systems was determined by UV-Vis spectroscopy. The effect of active parameters (pH, initial MO concentration and effect of sunlight) on degradation performance was investigated. For the first time, citric acid chemistry is successfully exploited to develop a photocatalyst that can successfully degrade the dyes. This citric acid functionalized magnetic ferrite nanoparticles are very much effective for photocalytic degradation of dye and also these can be recollected with the help of permanent magnet for successive uses.

  16. Shifting the Azo-hydrazone tautomeric equilibrium of methyl yellow in acidic medium by the formation of inclusion complexes with cyclodextrins

    Science.gov (United States)

    Ferreira, Ivania R.; Ando, Rômulo A.

    2012-01-01

    The protonation of methyl yellow (MY) leads to a tautomeric equilibrium involving the azo and hydrazone species, where the latter is predominant. Electronic and Raman spectroscopic data show that when MY in acidic medium is included in cyclodextrins, there is an inversion in the relative ratio of tautomers, in which the azo species become the major species. This indicates that the azo bond is included in cyclodextrin precluding its protonation. The understanding of the protonation, tautomeric and inclusion equilibria of these systems plays an important role in the designing of cyclodextrin based molecular machines controlled by light.

  17. Mechanism of azo dye degradation by ionizing radiation. Degradation of sulfanilic acid azochromotrop and its parent compounds in aqueous solution

    International Nuclear Information System (INIS)

    Complete text of publication follows. Mechanistic studies were made on ·OH radical and hydrated electron reaction with Sulfanilic Acid Azochromotrop (SPADNS) as model azo dye. SPADNS contains 4,5-dihydroxynaphtalene 2,7-disulfonic acid part and 4-sulfophenylazo group. To establish the details of the reaction mechanism the reactions of two simpler molecules without 4-sulfophenylazo part were also studied: one of them contained one (in position 4, II), the other two (in positions 4 and 5, III) -OH groups. ·OH radicals react with these molecules with radical addition to the naphthalene 2,7-disulfonic acid part. The adduct cyclohexadienyl type radical may decay in radical-radical reactions, or undergoes a (pH dependent) water elimination to naphthoxy radical, radical decay takes place on the ms timescale. ·OH radical addition on the azo bond in dyes has low importance. Degradation efficiencies are 0.6-0.8. The hydrated electron in the case of the two simpler molecules reacts with the rings, while in the case of dye with the azo bond. Electron scavenging is followed by protonation, this reaction in the case of II and III yields cyclohexadienyl, while with the dye hydrazo radical. The efficiency of degradation with II and III is 0.2-0.6, while for the dye it is close to 1.

  18. Kinetics and Equilibrium Studies on Adsorption of Acid Red 18 (Azo-Dye) Using Multiwall Carbon Nanotubes (MWCNTs) from Aqueous Solution

    OpenAIRE

    Shirmardi, Mohammad; Mesdaghinia, Alireza; MAHVI, Amir Hossein; Nasseri, Simin; Nabizadeh, Ramin

    2012-01-01

    Azo dyes are one of the synthetic dyes that are used in many textile industries. Adsorption is one of the most effective techniques for removal of dye-contaminated wastewater. In this work, efficiency of multiwalled carbon nanotubes (MWCNTs) as an adsorbent for removal of Acid Red 18 (azo-dye) from aqueous solution was determined. The parameters affecting the adsorption process such as contact time, pH, adsorbent dosage, and initial dye concentration were studied. Experimental results have sh...

  19. Effect of a sulfonated azo dye and sulfanilic acid on nitrogen transformation processes in soil.

    Science.gov (United States)

    Topaç, F Olcay; Dindar, Efsun; Uçaroğlu, Selnur; Başkaya, Hüseyin S

    2009-10-30

    Introduction of organic dyes into soil via wastewater and sludge applications has been of increasing concern especially in developing or under-developed countries where appropriate management strategies are scarce. Assessing the response of terrestrial ecosystems to organic dyes and estimating the inhibition concentrations will probably contribute to soil remediation studies in regions affected by the same problem. Hence, an incubation study was conducted in order to investigate the impact of a sulfonated azo dye, Reactive Black 5 (RB5) and sulfanilic acid (SA), a typical representative of aromatic sulfonated amines, on soil nitrogen transformation processes. The results apparently showed that nitrogen related processes in soil can be used as bioindicators of anthropogenic stress caused by organic dyes. It was found that urease activity, arginine ammonification rate, nitrification potential and ammonium oxidising bacteria numbers decreased by 10-20% and 7-28% in the presence of RB5 (> 20 mg/kg dry soil) and SA (> 8 mg/kg dry soil), respectively. Accordingly, it was concluded that organic dye pollution may restrict the nitrogen-use-efficiency of plants, thus further reducing the productivity of terrestrial ecosystems. Furthermore, the response of soil microbiota to SA suggested that inhibition effects of the organic dye may continue after the possible reduction of the parent dye to associated aromatic amines.

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

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Correlation of acid-base properties of substituted polystyrene-azo-pyrocatechol and characteristics of their chelates with zirconium

    International Nuclear Information System (INIS)

    Acid-base and complexing properties of new synthesized polymeric chelate-forming sorbents (PCS) - substituents of polystyrene-azo-pyrocatechol - are investigated and quantitative correlations between pKOH of functional analytical group (FAG) of sorbent and Hammet constants for para-substituent and ΔpKOH-ΔpK50 correlations of zirconium chelate-forming and pKOH-lgKstb (Kstb - constant of stability of PCS complexes with zirconium) of polychelates to study regularities of effect of peculiarities of structure and acid-base properties of FAG on parameters of zirconium chemical sorption. Established correlations make it possible to predict quantitative physicochemical parameters of sorbents and zirconium chemisorption process with the aim of directed synthesis and application of PCS in concentrating processes

  3. Adsorption behavior of Azo Dye C.I.Acid Red 14 in aqueous solution on surface soils

    Institute of Scientific and Technical Information of China (English)

    Qu Baocheng; ZHOU Jiti; XIANG Xuemin; ZHENG Chunli; ZHAO Hongxia; ZHOU Xiaobai

    2008-01-01

    Azo dyes have received considerable attention because of their association with various human health problems.The aim of the investigation is to determine the adsorption behavior of azo dyes in aqueous solution on DG06,GSE17200,and GSE17201 soils using C. I.Acid Red 14 (AR14) as example.The experimental results indicate that the Freundlich model expresses the adsorption isothelm better than the Langmuir model and the pseudo-second-order model achieves adsorption of AR14 Oil the three soils well.Based on the pseudosecond-order model.the adsorption thermodynamic of AR14 on DG06 soil have been studied and the thermodynamics parameter of △G0 is determined and △G0 value shows the adsorption process of AR14 on DG06 is mainly physical in nature.Furthermore, the effects of temperature,pH and salinity (NaCl) on adsorption have been investigated.The decrease in pH or the increase in salinity enhances the adsorption of ARl4 by DG06, GSE17200, and GSE17201.

  4. 40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection of Environment... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2140 Carbo-poly-cycli-col...

  5. Application of acidic treated pumice as an adsorbent for the removal of azo dye from aqueous solutions: kinetic, equilibrium and thermodynamic studies

    OpenAIRE

    Saied Bashiri; Gholam Hossein Safari; Abdeltif Amrane; Mohammad Noori Sepehr; Mansur Zarrabi; Mohammad Reza Samarghandi

    2012-01-01

    Abstract 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 e...

  6. High performance degradation of azo dye Acid Orange 7 and sulfanilic acid in a laboratory scale reactor after seeding with cultured bacterial strains.

    Science.gov (United States)

    Coughlin, Michael F; Kinkle, Brian K; Bishop, Paul L

    2003-06-01

    Bacterial strains 1CX and SAD4i--previously isolated from the mixed liquor of a municipal sewage treatment plant--are capable of degrading the azo dye Acid Orange 7 (AO7) and sulfanilic acid, respectively. A rotating drum bioreactor (RDBR), operating under continuous flow and nutrient conditions designed to simulate the effluent from a dye manufacturing plant, was seeded with strains 1CX and SAD4i, forming a biofilm capable of degrading AO7 and sulfanilic acid. In addition, an RDBR containing a pre-existing biofilm capable of degrading AO7, but not sulfanilic acid, was seeded with strain SAD4i alone. Strain SAD4i was incorporated into the existing biofilm and degraded the sulfanilic acid resulting from the degradation of AO7 by indigenous members of the biofilm. The ability to seed a bioreactor with bacterial strains capable of degrading azo dyes, and resulting by-products, in a mixed microbial community suggests that this process could have commercial applications.

  7. Inhibition of acidic corrosion of carbon steel by some mono and bis azo dyes based on 1,5 dihydroxynaphihalene.

    Science.gov (United States)

    Abdallah, Metwally; Moustafa, Moustafa E

    2004-01-01

    Inhibition of the corrosion of carbon steel in hydrochloric acid solution by some mono- and bis-azo dyes based on 1,5-dihydroxynaphthalene was studied in relation to the concentration of inhibitors using weight loss and potentiostatic polarization techniques. The percentage inhibition efficiency calculated from two methods is in a good agreement with each other. The inhibition mechanism of the additives was ascribed to the formation of complex compound adsorbed on the metal surface. The adsorption process follows Freundlich adsorption isotherm. The formation of the complex compound was studied by conductometric and potentiometric titrations. The stability constants of the Fe-complexes were determined using the latter technique and related to the inhibition efficiency.

  8. Toxicity of the azo dyes Acid Red 97 and Bismarck Brown Y to Western clawed frog (Silurana tropicalis).

    Science.gov (United States)

    Soriano, Jeriel J; Mathieu-Denoncourt, Justine; Norman, Grant; de Solla, Shane R; Langlois, Valérie S

    2014-03-01

    Azo compounds are used in a variety of industrial applications, such as textile colorant. Azo dyes have been found to contaminate aquatic environments and it has been shown that these compounds could potentially be toxic or induce endocrine disruption in aquatic organisms. However, there are few data available on the toxicity of these dyes, specifically Acid Red 97 (AR97) and Bismarck Brown Y (BBY). The aim of this study was to determine the toxicity and the endocrine-disrupting properties of AR97 and BBY in frogs. As fugacity modeling predicted that both compounds would sorb to sediment, sediment exposures were performed using a geometric range of concentrations (0, 1, 10, 100 and 1,000 ppm). Both AR97 and BBY dyes were not lethal to Silurana tropicalis embryos; however, BBY significantly induced malformations. Gene expression analysis of oxidative stress and mutagen-related genes was performed in BBY-treated larvae. There were significant two-fold increases of the tumor-suppressing protein p53 and heat shock protein 70 mRNA at 1,000 ppm suggesting that BBY induces cellular stress in early S. tropicalis development. Transcripts of the heat shock protein 90 did not change. Furthermore, reproductive-related genes were assessed and a 2.1-fold change was observed in the mRNA of the steroidogenic acute regulatory protein while steroid 5 alpha-reductase type 2 and androgen receptor transcript levels did not vary among treatments. In conclusion, high concentrations of BBY lead to increased developmental defects in frog embryogenesis and early larval development.

  9. Preparation and Absorption Spectral Property of a Multifunctional Water-Soluble Azo Compound with D-π-A Structure, 4-(4- Hydroxy-1-Naphthylazo)Benzoic Acid

    Science.gov (United States)

    Hu, L.; Lv, H.; Xie, C. G.; Chang, W. G.; Yan, Z. Q.

    2015-07-01

    A multifunctional water-soluble azo dye with the D-π-A conjugated structure, 4-(4-hydroxy-1-naphthylazo) benzoic acid ( HNBA), was designed and synthesized using 1-naphanol as the electron donator, benzoic acid as the electron acceptor, and -N=N- as the bridging group. After its structure was characterized by FTIR, 1H NMR, and element analysis, the UV-Vis absorption spectral performance of the target dye was studied in detail. The results showed that the dye, combining hydroxyl group, azo group, and carboxyl group, possessed excellent absorption spectral properties (ɛ = 1.2·104 l·mol-1·cm-1) changing with pH and solvents. In particular, in polar and protonic water, it had excellent optical response to some metal ions, i.e., Fe3+ and Pb2+, which might make it a latent colorimetric sensor for detecting heavy metal ions.

  10. Biodegradation of azo dyes acid red 183, direct blue 15 and direct red 75 by the isolate Penicillium oxalicum SAR-3.

    Science.gov (United States)

    Saroj, Samta; Kumar, Karunesh; Pareek, Nidhi; Prasad, R; Singh, R P

    2014-07-01

    Soils contaminated with dyes were collected and screened for obtaining potential fungal strains for the degradation of azo dyes. A strain that demonstrated broad spectrum ability for catabolizing different azo dyes viz. Acid Red 183 (AR 183), Direct Blue 15 (DB 15) and Direct Red 75 (DR 75) at 100 mg L(-1) concentration was subsequently identified as Penicillium oxalicum SAR-3 based on 18S and internal transcribed spacer (ITS) rDNA gene sequence analysis. The strain has shown remarkably higher levels of degradation (95-100%) for almost all the dyes within 120 h at 30°C at pH 7.0. Notable levels of manganese peroxidase (659.4 ± 20 UL(-1)) during dye decolorization indicated the involvement of this enzyme in the decolorization process. The dyes following decolorization were catabolized as evident by spectroscopic analyses.

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

    Science.gov (United States)

    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.

  12. Anaerobic azo dye reduction

    OpenAIRE

    Zee, van der, KG Kristoffer

    2002-01-01

    Azo dyes, aromatic moieties linked together by azo (-N=N-) chromophores, represent the largest class of dyes used in textile-processing and other industries. The release of these compounds into the environment is undesirable, not only because of their colour, but also because many azo dyes and their breakdown products are toxic and/or mutagenic to life. To remove azo dyes from wastewater, a biological treatment strategy based on anaerobic reduction of the azo dyes, followed by aerobic transfo...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  15. Monopolar Electro-Coagulation Process for Azo Dye C.I. Acid Red 18 Removal from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Ghasem Azarian

    2014-12-01

    Full Text Available The discharge of wastewaters containing an untreated dye results in aesthetic problems and an increase in gases solubility, which causes light transmission inhibition into water bodies. In spite of advantages of physicochemical and biological methods, these processes produce huge amounts of sludge, toxic by-products and require several oxidant chemicals. By contrast, electrochemical processes because of their high versatility, high efficiency and eco-friendly properties are more acceptable. In the present study, the removal of azo dye Acid Red 18 and chemical oxygen demand (COD from synthetic wastewater by monopolar (EC process was investigated and key parameters such as operating time, current density (CD, initial pH and energy, and electrode consumption were optimized. It was found that the process had a very good efficiency in the removal of both COD and color; for the iron electrode, the maximum amounts of color and COD removal were 99.5% and 59.0%, respectively. An operating time of 45 min, pH of 7 and CD of 1.2 mA/cm2 was selected as the optimized condition. The optimization of variables is extremely crucial as it results in a decrease in costs, energy and electrode consumption. Overall, the iron electrode used less energy than the aluminum electrode and was more acceptable for use in this process due to economical reasons. The findings of UV/vis spectra illustrated that the structures of this dye were removed by the process. In comparison with traditional methods such as aerobic and anaerobic systems, the EC process is a suitable alternative for the treatment of wastewaters containing dye pollutants.

  16. Optical and thermal properties of azo derivatives of salicylic acid thin films

    Science.gov (United States)

    Ghoneim, M. M.; El-Ghamaz, N. A.; El-Sonbati, A. Z.; Diab, M. A.; El-Bindary, A. A.; Serag, L. S.

    2015-02-01

    N-acryloyl-4-aminosalicylic acid (4-AMSA), monomer (HL) and 5-(4‧-alkyl phenylazo)-N-acryloyl-4-aminosalicylic acid (HLn) are synthesized and characterized with various physico-chemical techniques. Thin films of 5-(4‧-alkyl phenylazo)-N-acryloyl-4-aminosalicylic acid (HLn) are prepared by spin coating technique. The X-ray diffraction (XRD) patterns of 4-aminosalicylic acid (4-ASA) and its derivatives are investigated in powder and thin film forms. Thermal properties of the compounds are investigated by thermogravemetric analysis (TGA). The optical energy gap and the type of optical transition are investigated in the wavelength range (200-2500 nm) for 4-ASA, HL and HLn. The values of fundamental energy gap (Eg) are in the range 3.60-3.69 eV for all compounds and the type of optical transition is found to be indirect allowed. The onset energy gap Eg∗ appeared only for azodye compounds is found to be in the range 0.95-1.55 eV depending on the substituent function groups. The refractive index, n, shows a normal dispersion in the wavelength range 650-2500 nm, while shows anomalous dispersion in the wavelength rang 200-650 nm. The dispersion parameters ε∞, εL, Ed, Eo and N /m∗ are calculated. The photoluminescence phenomena (PL) appear for thin films of 4-ASA and its derivatives show three main emission transitions.

  17. Mechanism of azo dye degradation in Advanced Oxidation Processes: Degradation of Sulfanilic Acid Azochromotrop and its parent compounds in aqueous solution by ionizing radiation

    Science.gov (United States)

    Pálfi, Tamás; Wojnárovits, László; Takács, Erzsébet

    2011-03-01

    Mechanistic studies were made on hydroxyl radical and hydrated electron reaction with Sulfanilic Acid Azochromotrop (SPADNS) as model azo dye in dilute aqueous solution. SPADNS contains 4,5-dihydroxynaphthalene-2,7-disulfonic acid part and 4-sulfophenylazo group. To establish the details of the reaction mechanism the reactions of two simpler molecules without 4-sulfophenylazo part were also studied: one of them contained one (in position 4, II), the other two (in positions 4 and 5, III) -OH groups. Hydroxyl radicals react with these molecules with radical addition to the naphthalene-2,7-disulfonic acid part. The adduct hydroxycyclohexadienyl type radical decays in radical-radical reactions, or undergoes a (pH dependent) water elimination to yield naphthoxy radical. The radical decay takes place on the ms timescale. Degradation efficiencies are 0.6-0.8. Hydrated electron in the case of the two simpler molecules reacts with the rings, while in the case of dye with the azo bond. Electron scavenging is followed by protonation, this reaction in the case of II and III yields cyclohexadienyl, while with the dye hydrazo radical. The efficiency of degradation with II and III is 0.2-0.6, while for SPADNS it is close to 1.

  18. Mechanism of azo dye degradation in Advanced Oxidation Processes: Degradation of Sulfanilic Acid Azochromotrop and its parent compounds in aqueous solution by ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Palfi, Tamas; Wojnarovits, Laszlo [Institute of Isotopes, Hungarian Academy of Sciences, H-1525 Budapest, P.B. 77 (Hungary); Takacs, Erzsebet, E-mail: takacs@iki.kfki.h [Institute of Isotopes, Hungarian Academy of Sciences, H-1525 Budapest, P.B. 77 (Hungary)

    2011-03-15

    Mechanistic studies were made on hydroxyl radical and hydrated electron reaction with Sulfanilic Acid Azochromotrop (SPADNS) as model azo dye in dilute aqueous solution. SPADNS contains 4,5-dihydroxynaphthalene-2,7-disulfonic acid part and 4-sulfophenylazo group. To establish the details of the reaction mechanism the reactions of two simpler molecules without 4-sulfophenylazo part were also studied: one of them contained one (in position 4, II), the other two (in positions 4 and 5, III) -OH groups. Hydroxyl radicals react with these molecules with radical addition to the naphthalene-2,7-disulfonic acid part. The adduct hydroxycyclohexadienyl type radical decays in radical-radical reactions, or undergoes a (pH dependent) water elimination to yield naphthoxy radical. The radical decay takes place on the ms timescale. Degradation efficiencies are 0.6-0.8. Hydrated electron in the case of the two simpler molecules reacts with the rings, while in the case of dye with the azo bond. Electron scavenging is followed by protonation, this reaction in the case of II and III yields cyclohexadienyl, while with the dye hydrazo radical. The efficiency of degradation with II and III is 0.2-0.6, while for SPADNS it is close to 1.

  19. Anaerobic azo dye reduction

    NARCIS (Netherlands)

    Zee, van der F.P.

    2002-01-01

    Azo dyes, aromatic moieties linked together by azo (-N=N-) chromophores, represent the largest class of dyes used in textile-processing and other industries. The release of these compounds into the environment is undesirable, not only because of their colour, but also because many azo

  20. Evaluation of genotoxicity and pro-oxidant effect of the azo dyes: acids yellow 17, violet 7 and orange 52, and of their degradation products by Pseudomonas putida mt-2.

    Science.gov (United States)

    Ben Mansour, Hedi; Corroler, David; Barillier, Daniel; Ghedira, Kamel; Chekir, Leila; Mosrati, Ridha

    2007-09-01

    Acids yellow 17, violet 7 and orange 52, very important commercial azo dyes used in the textile, food, paper and cosmetic industries, were degraded by Pseudomonas putida mt-2 at concentrations up to 100mg/l. The culture media was completely decolorized under static incubation for 60 h, this faster than under continuous shaking incubation. SOS chromotest using Escherichia coli PQ37, with and without metabolic activation (S-9 preparations), was used to assess genotoxicity potential of these dyes before and after biodegradation. None of these dyes or their metabolites was found to be genotoxic in the absence of "Araclor-Induced rat liver microsome" preparations (S-9). However, in presence of the preparation S-9, the genotoxicity of the biodegradation products was highlighted. Metabolites resulting from static cultures were more genotoxic than those obtained in shaken conditions. In addition to genotoxic effects, metabolites have shown a significant ability to induce the formation of superoxide free radical anion (O(2)(*-)). The toxicities generated by the pure azo dyes and the pure azo-reduction products (sulfanilic acid, N,N'-dimethyl-p-phenylenediamine and 4'-aminoacetanilid) were compared. These results suggest that P. putida mt-2 degrades the studied azo dyes in two steps: an azo-reduction followed by an oxygen-dependent metabolization. Some of the derived metabolites would be responsible of genotoxicity and metabolic toxicity.

  1. Interaction between toxic azo dye C.I. Acid Red 88 and serum albumins

    Energy Technology Data Exchange (ETDEWEB)

    Naveenraj, Selvaraj [Nanomaterials and Solar Energy Conversion Lab, Department of Chemistry, National Institute of Technology, Tiruchirappalli 620015 (India); Solomon, Rajadurai Vijay; Venuvanalingam, Ponnambalam [School of Chemistry, Bharathidasan University, Tiruchirappalli 620024 (India); Asiri, Abdullah M. [The Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah 21413, P.O. Box 80203 (Saudi Arabia); Anandan, Sambandam, E-mail: sanand@nitt.edu [Nanomaterials and Solar Energy Conversion Lab, Department of Chemistry, National Institute of Technology, Tiruchirappalli 620015 (India)

    2013-11-15

    Serum albumin-toxic dye interaction studies will be of paramount importance in the field of toxicology due to its relation towards the distribution and transportation of dye in blood. In this regard, the binding between C.I. Acid Red 88 (AR88) and serum albumins (HSA and BSA) was investigated by using combination of spectroscopic and molecular modeling methods. The fluorescence results revealed that AR88 interact with serum albumins through the combination of static and dynamic quenching mechanism. The distance “r” between serum albumin and AR88 was obtained according to the Forster resonance energy transfer (FRET) theory. Synchronous fluorescence and CD spectral results showed alterations in the microenvironment and conformation of serum albumins. The molecular docking method is also employed to understand the interaction of AR88 with serum albumins. All these studies confirm that BSA has more affinity towards AR88 than that of HSA which suggests that AR88 is more easily transported in the body of bovid than human and so it is more hazardous to bovids. -- Highlights: • AR88 interacts with serum albumin through the combination of both static and dynamic quenching mechanism. • The binding site of AR88 in serum albumins is nearer to tryptophan moiety. • Circular Dichroism spectra showed that AR88 alters α-helicity of serum albumin. • This interaction study could be greatly imperative for further investigations in toxicology.

  2. Post-treatment of anaerobically degraded azo dye Acid Red 18 using aerobic moving bed biofilm process: Enhanced removal of aromatic amines

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini Koupaie, E., E-mail: ehssan.hosseini.k@gmail.com [Civil and Environmental Engineering Department, Amirkabir University of Technology (AUT), Hafez Ave., Tehran 15875-4413 (Iran, Islamic Republic of); Alavi Moghaddam, M.R., E-mail: alavim@yahoo.com [Civil and Environmental Engineering Department, Amirkabir University of Technology (AUT), Hafez Ave., Tehran 15875-4413 (Iran, Islamic Republic of); Hashemi, S.H., E-mail: h_hashemi@sbu.ac.ir [Environmental Science Research Institute, Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

    2011-11-15

    Highlights: {yields} Biofilm process was applied as post-treatment of anaerobically degraded an azo dye. {yields} More than 65% of the dye total metabolites was completely mineralized. {yields} Based on HPLC analysis, more than 80% of 1-naphthylamine-4-sulfonate was removed. {yields} Inhibition of biofilm growth was increased with increasing the initial dye concentration. {yields} Considerable porous morphology was observed in the SEM photographs of the biofilm. - Abstract: The application of aerobic moving bed biofilm process as post-treatment of anaerobically degraded azo dye Acid Red 18 was investigated in this study. The main objective of this work was to enhance removal of anaerobically formed the dye aromatic metabolites. Three separate sequential treatment systems were operated with different initial dye concentrations of 100, 500 and 1000 mg/L. Each treatment system consisted of an anaerobic sequencing batch reactor (An-SBR) followed by an aerobic moving bed sequencing batch biofilm reactor (MB-SBBR). Up to 98% of the dye decolorization and more than 80% of the COD removal occurred anaerobically. The obtained results suggested no significant difference in COD removal as well as the dye decolorization efficiency using three An-SBRs receiving different initial dye concentrations. Monitoring the dye metabolites through HPLC suggested that more than 80% of anaerobically formed 1-naphthylamine-4-sulfonate was completely removed in the aerobic biofilm reactors. Based on COD analysis results, at least 65-72% of the dye total metabolites were mineralized during the applied treatment systems. According to the measured biofilm mass and also based on respiration-inhibition test results, increasing the initial dye concentration inhibited the growth and final mass of the attached-growth biofilm in MB-SBBRs.

  3. Post-treatment of anaerobically degraded azo dye Acid Red 18 using aerobic moving bed biofilm process: Enhanced removal of aromatic amines

    International Nuclear Information System (INIS)

    Highlights: → Biofilm process was applied as post-treatment of anaerobically degraded an azo dye. → More than 65% of the dye total metabolites was completely mineralized. → Based on HPLC analysis, more than 80% of 1-naphthylamine-4-sulfonate was removed. → Inhibition of biofilm growth was increased with increasing the initial dye concentration. → Considerable porous morphology was observed in the SEM photographs of the biofilm. - Abstract: The application of aerobic moving bed biofilm process as post-treatment of anaerobically degraded azo dye Acid Red 18 was investigated in this study. The main objective of this work was to enhance removal of anaerobically formed the dye aromatic metabolites. Three separate sequential treatment systems were operated with different initial dye concentrations of 100, 500 and 1000 mg/L. Each treatment system consisted of an anaerobic sequencing batch reactor (An-SBR) followed by an aerobic moving bed sequencing batch biofilm reactor (MB-SBBR). Up to 98% of the dye decolorization and more than 80% of the COD removal occurred anaerobically. The obtained results suggested no significant difference in COD removal as well as the dye decolorization efficiency using three An-SBRs receiving different initial dye concentrations. Monitoring the dye metabolites through HPLC suggested that more than 80% of anaerobically formed 1-naphthylamine-4-sulfonate was completely removed in the aerobic biofilm reactors. Based on COD analysis results, at least 65-72% of the dye total metabolites were mineralized during the applied treatment systems. According to the measured biofilm mass and also based on respiration-inhibition test results, increasing the initial dye concentration inhibited the growth and final mass of the attached-growth biofilm in MB-SBBRs.

  4. Application of Acidic Treated Pumice as an Adsorbent for the Removal of Azo Dye from Aqueous Solutions:kinetic, Equilibrium and Thermodynamic Studies

    Directory of Open Access Journals (Sweden)

    Saied Bashiri

    2012-11-01

    Full Text Available 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 anefficient 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 ofAR14 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.

  5. Application of acidic treated pumice as an adsorbent for the removal of azo dye from aqueous solutions: kinetic, equilibrium and thermodynamic studies

    Directory of Open Access Journals (Sweden)

    Samarghandi Mohammad

    2012-11-01

    Full Text Available Abstract 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.

  6. [Predicting biodegradability from the electrochemical characteristic of azo dyes].

    Science.gov (United States)

    Guo, Jian-bo; Zhou, Ji-ti; Wang, Dong; Tian, Cun-ping; Ge, Jun; Wang, Ping; Yu, Hui

    2006-10-01

    Experiments were conducted to study some electrochemical factors affecting the bacterial reduction (cleavage) of four azo dyes. And a common mixed culture was used as test organism and the reduction of azo dyes Acid Yellow 4, 11, 17 and Acid Yellow Bis was studied. It was found that the azo dyes were reduced at different rates,which could be correlated with the reduction potential of the azo compounds in cyclic voltammetric experiments. Acid Yellow Bis (Er = -616.75 mV) was reduced at the highest rate of 0.01209 mol x (L x h)(-1), Acid Yellow 11 (Er = -593.25 mV) at 0.01040 mol x (L x h)(-1) and Acid Yellow 4 (Er = - 513 mV) at 0.007575 mol x (L x h)(-1). It is showed that the reduction potential is a preliminary tool to predict the decolorization capacity of oxidative and reductive biocatalysts.

  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.

    Science.gov (United States)

    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.

  8. The significance of azo-reduction in the mutagenesis and carcinogenesis of azo dyes.

    Science.gov (United States)

    Chung, K T

    1983-04-01

    Azo dyes are widely used in textile, printing, cosmetic, drug and food-processing industries. They are also used extensively in laboratories as either biological stains or pH indicators. The extent of such use is related to the degree of industrialization. Since intestinal cancer is more common in highly industrialized countries, a possible connection may exist between the increase in the number of cancer cases and the use of azo dyes. Azo dyes can be reduced to aromatic amines by the intestinal microflora. The mutagenicity of a number of azo dyes is reviewed in this paper. They include Trypan Blue, Ponceau 3R, Pinceau 2R, Methyl Red, Methyl Yellow, Methyl Orange, Lithol Red, Orange I, Orange II, 4-Phenylazo-Naphthylamine, Sudan I, Sudan IV, Acid Alizarin Violet N, Fast Garnet GBC, Allura Red, Ponceau SX, Sunset Yellow, Tartrazine, Citrus Red No. 2, Orange B, Yellow AB, Carmoisine, Mercury Orange, Ponceau S, Versatint Blue, Phenylazophenol, Evan's Blue and their degraded aromatic amines. The significance of azo reduction in the mutagenesis and carcinogenesis of azo dyes is discussed.

  9. Post-treatment of anaerobically degraded azo dye Acid Red 18 using aerobic moving bed biofilm process: enhanced removal of aromatic amines.

    Science.gov (United States)

    Koupaie, E Hosseini; Moghaddam, M R Alavi; Hashemi, S H

    2011-11-15

    The application of aerobic moving bed biofilm process as post-treatment of anaerobically degraded azo dye Acid Red 18 was investigated in this study. The main objective of this work was to enhance removal of anaerobically formed the dye aromatic metabolites. Three separate sequential treatment systems were operated with different initial dye concentrations of 100, 500 and 1000 mg/L. Each treatment system consisted of an anaerobic sequencing batch reactor (An-SBR) followed by an aerobic moving bed sequencing batch biofilm reactor (MB-SBBR). Up to 98% of the dye decolorization and more than 80% of the COD removal occurred anaerobically. The obtained results suggested no significant difference in COD removal as well as the dye decolorization efficiency using three An-SBRs receiving different initial dye concentrations. Monitoring the dye metabolites through HPLC suggested that more than 80% of anaerobically formed 1-naphthylamine-4-sulfonate was completely removed in the aerobic biofilm reactors. Based on COD analysis results, at least 65-72% of the dye total metabolites were mineralized during the applied treatment systems. According to the measured biofilm mass and also based on respiration-inhibition test results, increasing the initial dye concentration inhibited the growth and final mass of the attached-growth biofilm in MB-SBBRs.

  10. Nanocrystalline semiconductor doped rare earth oxide for the photocatalytic degradation studies on Acid Blue 113: A di-azo compound under UV slurry photoreactor.

    Science.gov (United States)

    Suganya Josephine, G A; Mary Nisha, U; Meenakshi, G; Sivasamy, A

    2015-11-01

    Preventive measures for the control of environmental pollution and its remediation has received much interest in recent years due to the world-wide increase in the contamination of water bodies. Contributions of these harmful effluents are caused by the leather processing, pharmaceutical, cosmetic, textile, agricultural and other chemical industries. Nowadays, advanced oxidation processes considered to be better option for the complete destruction of organic contaminants in water and wastewater. Acid Blue 113 is a most widely used di-azo compound in leather, textile, dying and food industry as a color rending compound. In the present study, we have reported the photo catalytic degradation of Acid Blue 113 using a nanocrystalline semiconductor doped rare earth oxide as a photo catalyst under UV light irradiation. The photocatalyst was prepared by a simple precipitation technique and were characterized by XRD, FT-IR, UV-DRS and FE-SEM analysis. The experimental results proved that the prepared photo catalyst was nanocrystalline and highly active in the UV region. The UV-DRS results showed the band gap energy was 3.15eV for the prepared photo catalyst. The photodegradation efficiency was analyzed by various experimental parameters such as pH, catalyst dosage, variation of substrate concentration and effect of electrolyte addition. The photo degradation process followed a pseudo first order kinetics and was continuously monitored by UV-visible spectrophotometer. The experimental results proved the efficacy of the nanocrystalline zinc oxide doped dysprosium oxide which are highly active under UV light irradiations. It is also suggested that the prepared material would find wider applications in environmental remediation technologies to remove the carcinogenic and toxic moieties present in the industrial effluents.

  11. Synthesis, structural characterization and antimicrobial activities of diorganotin(IV) complexes with azo-imino carboxylic acid ligand: Crystal structure and topological study of a doubly phenoxide-bridged dimeric dimethyltin(IV) complex appended with free carboxylic acid groups

    Science.gov (United States)

    Roy, Manojit; Roy, Subhadip; Devi, N. Manglembi; Singh, Ch. Brajakishor; Singh, Keisham Surjit

    2016-09-01

    Diorganotin(IV) complexes appended with free carboxylic acids were synthesized by reacting diorganotin(IV) dichlorides [R2SnCl2; R = Me (1), Bu (2) and Ph (3)] with an azo-imino carboxylic acid ligand i.e. 2-{4-hydroxy-3-[(2-hydroxyphenylimino)methyl]phenylazo}benzoic acid in presence of triethylamine. The complexes were characterized by elemental analysis, IR and multinuclear NMR (1H, 13C and 119Sn) spectroscopy. The structure of 1 in solid state has been determined by X-ray crystallography. Crystal structure of 1 reveals that the compound crystallizes in monoclinic space group P21/c and is a dimeric dimethyltin(IV) complex appended with free carboxylic acid groups. In the structure of 1, the Sn(IV) atoms are hexacoordinated and have a distorted octahedral coordination geometry in which two phenoxy oxygen atoms and the azomethine nitrogen atom of the ligand coordinate to each tin atom. One of the phenoxy oxygen atom bridges the two tin centers resulting in a planar Sn2O2 core. Topological analysis is used for the description of molecular packing in 1. Tin NMR spectroscopy study indicates that the complexes have five coordinate geometry around tin atom in solution state. Since the complexes have free carboxylic acids, these compounds could be further used as potential metallo-ligands for the synthesis of other complexes. The synthesized diorganotin(IV) complexes were also screened for their antimicrobial activities and compound 2 showed effective antimicrobial activities.

  12. Biodegradation of bioaccessible textile azo dyes by Phanerochaete chrysosporium

    OpenAIRE

    Martins, Maria Adosinda; Ferreira, Isabel C.F.R.; Santos, Isabel; Queiroz, Maria João R. P.; Lima, Nelson

    2000-01-01

    Azo dyes are important chemical pollutants of industrial origin. Textile azo dyes with bioaccessible groups for lignin degrading fungi, such as 2-methoxyphenol (guaiacol) and 2,6-dimethoxyphenol (syringol), were synthesised using different aminobenzoic and aminosulphonic acids as diazo components. The inocula of the best biodegradation assays were obtained from a pre-growth medium (PAM), containing one of the synthesised dyes. The results of the dye biodegradation assays were eval...

  13. The decolorization and mineralization of Acid Orange 6 azo dye in aqueous solution by advanced oxidation processes: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Hsing, H.-J. [Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Road, Taipei 106, Taiwan (China); Chiang, P.-C. [Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Road, Taipei 106, Taiwan (China)]. E-mail: pcchiang@ntu.edu.tw; Chang, E.-E. [Department of Biochemistry, Taipei Medical University, 25 Wu-Shin Street, Taipei 106, Taiwan (China); Chen, M.-Y. [Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Road, Taipei 106, Taiwan (China)

    2007-03-06

    The comparison of different advanced oxidation processes (AOPs), i.e. ultraviolet (UV)/TiO{sub 2}, O{sub 3}, O{sub 3}/UV, O{sub 3}/UV/TiO{sub 2}, Fenton and electrocoagulation (EC), is of interest to determine the best removal performance for the destruction of the target compound in an Acid Orange 6 (AO6) solution, exploring the most efficient experimental conditions as well; on the other hand, the results may provide baseline information of the combination of different AOPs in treating industrial wastewater. The following conclusions can be drawn: (1) in the effects of individual and combined ozonation and photocatalytic UV irradiation, both O{sub 3}/UV and O{sub 3}/UV/TiO{sub 2} processes exhibit remarkable TOC removal capability that can achieve a 65% removal efficiency at pH 7 and O{sub 3} dose = 45 mg/L; (2) the optimum pH and ratio of [H{sub 2}O{sub 2}]/[Fe{sup 2+}] found for the Fenton process, are pH 4 and [H{sub 2}O{sub 2}]/[Fe{sup 2+}] = 6.58. The optimum [H{sub 2}O{sub 2}] and [Fe{sup 2+}] under the same HF value are 58.82 and 8.93 mM, respectively; (3) the optimum applied voltage found in the EC experiment is 80 V, and the initial pH will affect the AO6 and TOC removal rates in that acidic conditions may be favorable for a higher removal rate; (4) the AO6 decolorization rate ranking was obtained in the order of O{sub 3} < O{sub 3}/UV = O{sub 3}/UV/TiO{sub 2} < EC < Fenton; (5) the ranking of TOC removal efficiency of selected AOPs was in the order of O{sub 3} = Fenton < EC < O{sub 3}/UV < O{sub 3}/UV/TiO{sub 2} for 30 min of reaction time.

  14. Facile Preparation of Phosphotungstic Acid-Impregnated Yeast Hybrid Microspheres and Their Photocatalytic Performance for Decolorization of Azo Dye

    Directory of Open Access Journals (Sweden)

    Lan Chen

    2013-01-01

    Full Text Available Phosphotungstic acid (HPW-impregnated yeast hybrid microspheres were prepared by impregnation-adsorption technique through tuning pH of the aqueous yeast suspensions. The obtained products were characterized by field emission scanning electron microscopy (FE-SEM, energy dispersive spectrometry (EDS, X-ray diffraction (XRD, thermogravimetry-differential scanning calorimetry (TG-DSC, and ultraviolet-visible spectrophotometry (UV-Vis, respectively. FE-SEM and EDS ascertain that the HPW has been effectively introduced onto the surface of yeast, and the resulting samples retain ellipsoid shape, with the uniform size (length 4.5 ± 0.2 μm, width 3.0 ± 0.3 μm and good monodispersion. XRD pattern indicates that the main crystal structure of as-synthesized HPW@yeast microsphere is Keggin structure. TG-DTA states that the HPW in composites has better thermal stability than pure HPW. Fourier transform infrared spectroscopy (FT-IR elucidates that the functional groups or chemical bonds inherited from the pristine yeast cell were critical to the assembling of the composites. UV-Vis shows that the obtained samples have a good responding to UV light. The settling ability indicates that the hybrid microspheres possess an excellent suspension performance. In the test of catalytic activity, the HPW@yeast microsphere exhibits a high photocatalytic activity for the decoloration of Methylene blue and Congo red dye aqueous solutions, and there are a few activity losses after four cycles of uses.

  15. Decolorization of azo dyes in bioelectrochemical systems.

    Science.gov (United States)

    Mu, Yang; Rabaey, Korneel; Rozendal, René A; Yuan, Zhiguo; Keller, Jürg

    2009-07-01

    Azo dyes are ubiquitously used in the textile industry. These dyes need to be removed from the effluent prior to discharge to sewage due to their intense color and toxicity. In this study we investigated the use of a bioelectrochemical system (BES) to abioticlly cathodic decolorization of a model azo dye, Acid Orange 7 (AO7), where the process was driven by microbial oxidation of acetate atthe anode. Effective decolorization of AO7 at rates up to 264 +/- 0.03 mol m(-3) NCC d(-1) (net cathodic compartment, NCC) was achieved at the cathode, with concomitant energy recovery. The AO7 decolorization rate was significantly enhanced when the BES was supplied with power, reaching 13.18 +/- 0.05 mol m(-3) NCC d(-1) at an energy consumption 0.012 +/- 0.001 kWh mol(-1) AO7 (at a controlled cathode potential of -400 mV vs SHE). Compared with conventional anaerobic biological methods, the required dosage of organic cosubstrate was significantly reduced in the BES. A possible cathodic reaction mechanism for the decolorization of AO7 is suggested based on the decolorization products identified: the azo bond of AO7 was cleaved at the cathode, resulting in the formation of the colorless sulfanilic acid and 1-amino-2-naphthol.

  16. 40 CFR 721.9538 - Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic).

    Science.gov (United States)

    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...

  17. Solubilidade de corantes azo

    OpenAIRE

    Leal, Cláudia Sofia Mendes

    2011-01-01

    Os corantes são substâncias, de origem natural ou sintética, que conferem cor aos materiais. A quantidade de corantes proveniente dos processos de tingimento que é lançada no ambiente ainda é muito grande, nomeadamente de corantes azo. São poucos os valores de solubilidade publicados, destes corantes, apesar de a solubilidade ser um parâmetro físico-químico importante, quer nos processos de tingimento quer na disponibilidade do corante no meio ambiente. Neste trabalho é efectuada uma revisão ...

  18. Voltammetric determination of dopamine in the presence of uric acid using a 2-hydroxy-1-(1-hydroxynaphthyl-2-azo-naphthalin-4-sulfonic acid modified glassy carbon electrode

    Directory of Open Access Journals (Sweden)

    ALI ASGHAR ENSAF

    2010-12-01

    Full Text Available A polymerized film of 2-hydroxy-1-(1-hydroxynaphthyl-2-azo-naphthalin-4-sulfonic acid (HHNANSA was prepared at the surface of a glassy carbon electrode by electropolymerization. The modified electrode was used for the simultaneous determination of dopamine (DA and uric acid (UA. The electrochemical behaviors of the compounds at the surface of the modified electrode were studied using cyclic voltammetry, chronoamperometry, and square wave voltammetry (SWV. The experimental results indicated that the modified electrode exhibited an efficient electrocatalytic activity towards the oxidation of DA and UA, with a peak separation of about 140 mV at pH 5.0. Using chronoamperometry, the catalytic reaction rate constant was measured and found to equal to 1.23×104 mol-1 L s-1. At pH 5.0, the catalytic peak currents linearly depended on the DA and/or UA concentrations in the range of 1.0–300 µmol L-1 DA (two linear segments with different slopes and 6.7–20 µmol L-1 UA, using SWV. The detection limits for DA and UA were 0.25 and 1.17 µmol L-1, respectively. The RSD % for 40.0 and 140.0 µmol L-1 DA were 1.9 and 2.2 %, respectively, whereas for 10.0 and 20.0 µmol L-1 UA, they were 1.8 and 1.2 %, respectively. The modified electrode showed good sensitivity, selectivity, and stability. It was successfully applied for the determination of DA and UA in real samples, such as drugs and urine.

  19. Azo-hydrazone tautomerism of aryl azo pyridone dyes

    Directory of Open Access Journals (Sweden)

    Mirković Jelena M.

    2013-01-01

    Full Text Available In the last three or four decades disperse dyes derived from pyridones (in particular azo pyridone dyes have gained in importance, and are widely used in various fields. These compounds have excellent coloration properties, and are suitable for the dyeing of polyester fabrics. Basic features of these dyes are simplicity of their synthesis by diazotation and azo coupling. They generally have high molar extinction coefficient with medium to high light and wet fastness. The absorption maxima of these dyes show their visible absorption wavelength ranging from yellow to orange, which can be attributed to poorly delocalized electrons in the pyridone ring. However, there are several dyes with deep colors such as red or violet. Pyridone dyes with alkyl and aryl groups in ortho position to azo group show 2-pyridone/2-hydroxypyridine tautomerism, while those containing OH and NHR groups conjugated with the azo group show azo-hydrazone tautomerism. Determining azo-hydrazone tautomerism could be therefore interesting, since the tautomers have different physico-chemical properties and most importantly different coloration. The literature on azo-hydrazone tautomerism, determination of equilibrium position, and investigation of substituent and solvent influence on tautomerism has been summarized in the presented review. The general conclusion is that the equilibrium between two tautomers is influenced by the structure of the compounds and by the solvents used. The tautomeric behavior patterns of the arylazo pyridone dyes in the reviewed literature has been studied using various instrumental techniques, including FT-IR, UV-vis, and NMR spectroscopy. The quantum chemical calculations related to the azo-hydrazon tautomerism have also been included. A large number of pyridone dyes exist in hydrazone form in solid state, while in solvents there is a mixture of tautomers. In addition, the X-ray single-crystal diffraction data analysis of some commercial pyridone

  20. Effects of reduction products of ortho-hydroxyl substituted azo dyes on biodecolorization of azo dyes

    Energy Technology Data Exchange (ETDEWEB)

    Liu Guangfei [Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental and Biological Science and Technology, Dalian University of Technology, Linggong Road No. 2, Dalian 116024 (China); Wang Jing, E-mail: wangjingbio@yahoo.cn [Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental and Biological Science and Technology, Dalian University of Technology, Linggong Road No. 2, Dalian 116024 (China); Lu Hong; Jin Ruofei; Zhou Jiti; Zhang Long [Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental and Biological Science and Technology, Dalian University of Technology, Linggong Road No. 2, Dalian 116024 (China)

    2009-11-15

    The mediated effects of reduction products of some ortho-hydroxyl substituted azo dyes on biodecolorization were investigated. The results indicated that the addition of reduction products could effectively accelerate dye decolorization by Shigella sp. QRZ-1. The best accelerating effect was obtained with the addition of reduction products of Acid Red 14 (AR14), resulting in an over 3-fold increase in decolorization efficiency of many azo dyes. In sequencing batch reactor experiments, the accelerating effect of reduction products of AR14 was more obvious (1.5-fold) during the startup of the system. When the dye concentration was increased to 500 mg L{sup -1}, the accelerated decolorization efficiency was still maintained around 95%. The presence of AR14 in the feed enhanced the decolorization performance of anaerobic sludge, indicating that the strategy may be beneficial for practical application. 1-Naphthol-2-amino-4-sulfonic acid, which is one of the reduction products of AR14, may function as redox mediator to speed up azo dye biodecolorization.

  1. Effects of reduction products of ortho-hydroxyl substituted azo dyes on biodecolorization of azo dyes

    International Nuclear Information System (INIS)

    The mediated effects of reduction products of some ortho-hydroxyl substituted azo dyes on biodecolorization were investigated. The results indicated that the addition of reduction products could effectively accelerate dye decolorization by Shigella sp. QRZ-1. The best accelerating effect was obtained with the addition of reduction products of Acid Red 14 (AR14), resulting in an over 3-fold increase in decolorization efficiency of many azo dyes. In sequencing batch reactor experiments, the accelerating effect of reduction products of AR14 was more obvious (1.5-fold) during the startup of the system. When the dye concentration was increased to 500 mg L-1, the accelerated decolorization efficiency was still maintained around 95%. The presence of AR14 in the feed enhanced the decolorization performance of anaerobic sludge, indicating that the strategy may be beneficial for practical application. 1-Naphthol-2-amino-4-sulfonic acid, which is one of the reduction products of AR14, may function as redox mediator to speed up azo dye biodecolorization.

  2. Microbial conversion of selected azo dyes and their breakdown products.

    Science.gov (United States)

    Yemashova, N; Kalyuzhnyi, S

    2006-01-01

    Four selected azo dyes (acid orange 6, acid orange 7, methyl orange and methyl red) were completely decolourised in the presence of anaerobic granular sludge, while only methyl red was degraded in aerobic conditions using a conventional activated sludge. Additional experiments with culture broth devoid of cells showed that anaerobic decolourisation of azo dyes was performed by extracellular reducing agents produced by anaerobic bacteria. This was further confirmed by abiotic experiments with sulphide and NADH. The presence of redox mediators such as riboflavin led to dramatic acceleration of the anaerobic biodecolourisation process. The azo dye reduction products were found to be sulphanilic acid and 4-aminoresorcinol for acid orange 6; sulphanilic acid and 1-amino-2-naphthol for acid orange 7; N,N-dimethyl-1,4-phenylenediamine and sulphanilic acid for methyl orange; and N,N-dimethyl-1,4-phenylenediamine and anthranilic acid for methyl red. Anaerobic toxicity assays showed that the azo dyes were more toxic than their breakdown products (aromatic amines), except 1-amino-2-naphthol. In the presence of activated sludge, only anthranilic acid was completely mineralised while sulphanilic acid was persistent. 4-aminoresorcinol, 1-amino-2-naphthol and N,N-dimethyl-1,4-phenylenediamine underwent autooxidation in aerobic conditions yielding coloured polymeric products. On the contrary, in the presence of granular methanogenic sludge, 4-aminoresorcinol, 1-amino-2-naphthol and anthranilic acid were quantitatively methanised, sulphanilic acid was partially (70%) mineralised while N,N-dimethyl-1,4-phenylenediamine was only demethylated producing 1,4-phenylenediamine as an end product.

  3. Biodegradation of azo dyes in cocultures of anaerobic granular sludge with aerobic aromatic amine degrading enrichment cultures

    NARCIS (Netherlands)

    Tan, N.C.G.; Prenefeta-Boldú, F.X.; Opsteeg, J.L.; Lettinga, G.; Field, J.A.

    1999-01-01

    A prerequisite for the mineralization (complete biodegradation) of many azo dyes is a combination of reductive and oxidative steps. In this study, the biodegradation of two azo dyes, 4-phenylazophenol (4-PAP) and Mordant Yellow 10 (4-sulfophenylazo-salicylic acid; MY10), was evaluated in batch exper

  4. .Investigation the  Zero-Valent Iron (ZVI Performance in the Presence of UV light and Hydrogen Peroxide on Removal of Azo Dyes Acid Orange 7 and Reactive Black 5 from Aquatic Solutions

    Directory of Open Access Journals (Sweden)

    Mansur Zarrabi

    2013-02-01

    Full Text Available Background and Objectives: Colored wastewaters are known as one of the most important sources of environmental pollutants. Having toxic chemicals and aesthetic problems has made treatment of these wastewaters very crucial. So far a number of methods such as electrochemical treatment, coagulation and flocculation, and adsorption have been used for treatment of textile industries wastewater. Hence,  the efficiency of zero-valent iron powder in the presence of UV light and hydrogen peroxide to remove Acid Orange 7 and Reactive Black 5 from the synthetic solutions was investigated.Materials and Methods: Conducting all experiments in a batch reactor, we examined different parameters including initial concentration of the color (25, 50, 75 mg/L, contact time (30,  60, 120 min, pH (3, 7, 11, the amount of iron powder (0.6, 1.3,  2  g/l, and hydrogen peroxide concentration (10, 15, 20  ml/l.Result: The results showed that dye removal efficiency was increased by increasing contact time, the amount of iron powder and hydrogen peroxide concentration. On the other hand, with the increasing pH and initial concentration of dye, removal efficiency decreased in both AO7and RB5 dyes.Conclusion: We found that the integrated ZVI/UV/H2O2 method has  high efficiency in removing azo dyes Acid Orange 7 and Reactive Black 5.

  5. One-pot in situ mixed film formation by azo coupling and diazonium salt electrografting.

    Science.gov (United States)

    Esnault, Charles; Delorme, Nicolas; Louarn, Guy; Pilard, Jean-François

    2013-06-24

    So simple: The in situ synthesis of an aryldiazonium salt and an azo-aryldiazonium salt by azo coupling from sulfanilic acid and aniline is reported. Formation of a mixed organic layer is monitored by cyclic voltammetry and atomic force microscopy. A compact mixed layer is obtained with a global roughness of 0.4 nm and 10-15 % vertical extension in the range 1.5-6 nm.

  6. Characterization and performance of carbonaceous materials obtained from exhausted sludges for the anaerobic biodecolorization of the azo dye Acid Orange II

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Carbonaceous materials were prepared from exhausted sludge materials. • High surface area and good physicochemical properties were achieved. • Utilization of waste sludge materials and mixed anaerobic cultures were used in a continuous anaerobic UPBR system (upflow packed bed biological reactor). • Effective treatment of dye contaminated wastewater in a cheapest and environmental friendly method was demonstrated. - Abstract: 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 202.0 m2/g of surface area. Biodecolorization levels of 76% were achieved for SBC600 and 86% for SBC800 at space time (τ) of 1.0 min, 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

  7. 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.

    Science.gov (United States)

    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.

  8. Binding properties of HABA-type azo derivatives to avidin and avidin-related protein 4.

    Science.gov (United States)

    Repo, Susanna; Paldanius, Tiina A; Hytönen, Vesa P; Nyholm, Thomas K M; Halling, Katrin K; Huuskonen, Juhani; Pentikäinen, Olli T; Rissanen, Kari; Slotte, J Peter; Airenne, Tomi T; Salminen, Tiina A; Kulomaa, Markku S; Johnson, Mark S

    2006-10-01

    The chicken genome encodes several biotin-binding proteins, including avidin and avidin-related protein 4 (AVR4). In addition to D-biotin, avidin binds an azo dye compound, 4-hydroxyazobenzene-2-carboxylic acid (HABA), but the HABA-binding properties of AVR4 are not yet known. Differential scanning calorimetry, UV/visible spectroscopy, and molecular modeling were used to analyze the binding of 15 azo molecules to avidin and AVR4. Significant differences are seen in azo compound preferences for the two proteins, emphasizing the importance of the loop between strands beta3 and beta4 for azo ligand recognition; information on these loops is provided by the high-resolution (1.5 A) X-ray structure for avidin reported here. These results may be valuable in designing improved tools for avidin-based life science and nanobiotechnology applications.

  9. [Leather azo dyes: mutagenic and carcinogenic risks].

    Science.gov (United States)

    Clonfero, E; Venier, P; Granella, M; Levis, A G

    1990-01-01

    The paper reviews the carcinogenicity and mutagenicity data on azo dyes used in the leather industry. Two water soluble benzidine-based dyes were classified as "probably carcinogenic to humans" by the International Agency for Research on Cancer (IARC). No other dyes have been evaluated by the IARC. Of the 48 azo dyes assayed in the Salmonella/microsome test, 20 gave positive results. Attention is drawn to the important role of the in vivo metabolism of azo compounds, which includes a preliminary reduction of the azo bonds and subsequent release of the aromatic amines of the dye. A useful assay (Prival test) for evaluating the mutagenic properties of azo dyes involves a reductive step that permits the release of any genotoxic agents present in the compounds. A list of leather azo dyes is furnished that are considered as potentially harmful due to the presence of a carcinogenic aromatic amine (benzidine, p-aminobenzene and derivatives) in their formulae.

  10. Decolorization and partial degradation of selected azo dyes by methanogenic sludge.

    Science.gov (United States)

    Yemashova, Natalia; Telegina, Anna; Kotova, Irina; Netrusov, Alexander; Kalyuzhnyi, Sergey

    2004-10-01

    The toxicity potential and decolorization of three acid azo dyes (Acid Orange 6, Acid Orange 7, and Acid Orange 52) by methanogenic granular sludge from an anaerobic expanded granular sludge bed reactor was assayed. Complete bioreduction was found for all three azo dyes. Sulfanilic acid and 4-aminoresorcinol were detected from the decolorization of Acid Orange 6, sulfanilic acid and 1-amino-2-naphtol were detected from the reduction of Acid Orange 7, and sulfanilic acid and N,N-dimethyl-1,4-phenylenediamine (DMP) were found to be intermediates of Acid Orange 52 degradation. Sulfanilic acid and 1-amino-2-naphtol were persistent in the anaerobic conditions, whereas 4-aminoresorcinol was completely mineralized by anaerobic sludge and DMP was transformed into 1,4-phenylenediamine. Enrichment cultures obtained via consecutive passages on basal medium with only azo dye as a carbon and an energy source seemed to be morphologically heterogeneous. Baculiform and coccus cells were found when viewed under a light microscope. Cocci were joined in chains. Because anaerobic sludge contains sulfate-reducing bacteria and therefore may generate sulfide, azo dyes were tested for chemical decolorization by sulfide to compare rates of chemical and biologic reduction.

  11. Synthesis and Characterization of Photoresponsive Azo Polyelectrolytes

    Institute of Scientific and Technical Information of China (English)

    WU Lifeng; PENG Huagen; WANG Xiaogong; LIU Deshan; ZHOU Qixiang

    2001-01-01

    Optical active azo polymers are very important functional materials because of their photoresponsive properties.This paper investigates three kinds of aromatic azo polyelectrolytes synthesized by chemical modification of poly(acryloyl chloride)which was prepared by free radical polymerization.Poly was esterified with three different kinds of aromatic azo compounds containing hydroxyl groups to give polymeric intermediates,which were used to prepare the azo polyelectrolytes by hydrolysis.The products were characterized by elementary analysis,IR,1H-NMR,and UV-Vis spectrography.

  12. STUDY ON PHOTODYNAMIC AND PHOTORESPONSIVE AZO POLYELECTROLYTES

    Institute of Scientific and Technical Information of China (English)

    Xiao-gong Wang; Li-feng Wu; Qi-xiang Zhou; Lian Li; Srinivasan Balasubraminian; Jayant Kumar; Sukant K. Tripathy

    2000-01-01

    Several kinds of novel azobenzene-containing polyelectrolytes with special molecular design have been developed from acryloyl chloride or epoxy based precursor polymers. The acryloyl chloride based precursor polymer, poly(acryloyl chloride), was prepared by free radical polymerization of acryloyl chloride. The azo polyelectrolytes were prepared by an esterification reaction between the precursor polymer and corresponding azo chromophores containing a reactive hydroxyl group, followed by hydrolysis of the unreacted acyl chloride groups. The epoxy based precursor polymer was prepared by the reaction between 1,4-cyclohexanedimethanol diglycidyl ether and aniline, and postfunctionalized by azo coupling reaction to form azo polymers containing chromophores with ionizable groups. The polyelectrolytes were characterized by elemental analysis, 1H-NMR, IR and UV-Vis spectroscopy. The photodynamic and photoresponsive properties, as well as self-assembly ofthese azo polyelectrolytes are reported in this paper[1].

  13. Synthesis of azo pyridone dyes

    Directory of Open Access Journals (Sweden)

    Mijin Dušan Ž.

    2011-01-01

    Full Text Available Over 50% of all colorants which are used nowdays are azo dyes and pigments, and among them arylazo pyridone dyes (and pigments have became of interest in last several decades due to the high molar extinction coefficient, and the medium to high light and wet fastness properties. They find application generally as disperse dyes. The importance of disperse dyes increased in the 1970s and 1980s due to the use of polyester and nylon as the main synthetic fibers. Also, disperse dyes were used rapidly since 1970 in inks for the heat-transfer printing of polyester. The main synthetic route for the preparation of azo dyes is coupling reaction between an aromatic diazo compound and a coupling component. Of all dyes manufactured, about 60% are produced by this reaction. Arylazo pyridone dyes can be prepared from pyridone moiety as a coupling component, where substituent can be on nitrogen, and diazonim salts which can be derived from different substituted anilines or other heterocyclic derivatives. In addition, arylazo dyes containing pyridone ring can be prepared from arylazo diketones or arylazo ketoesters (obtained by coupling β-diketones or β-ketoesters with diazonim salts by condensation with cyanoacetamide. Disazo dyes can be prepared by tetrazotizing a dianiline and coupling it with a pyridone or by diazotizing aniline and coupling it with a dipyridone. Trisazo dyes can be also prepared by diazotizing of aniline and coupling it with a tripyridone or by hexazotizing a trianiline and coupling it with a pyridone. The main goal of this paper is to give a brief review on the synthesis of arylazo pyridone dyes due to the lack of such reviews. In addition, some properties of arylazo pyridone dyes as light fastness and azo-hydrazon tautomerism are disccused.

  14. Decomposed characteristic of azo dyes by ozonization with ultrasonic enhancement

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Azo dyes have been used in many industries (textile mill, printing and dyeing mill, paper and pulp mill) and have caused great environmental pollution due to complicated constitution and high chemical stability. The construction of azo dyes can be destroyed by ozonization, but not thoroughly when the ozone dosage is controlled to a certain extent and the operating cost is higher. Ozonization decomposed ability with ultrasonic enhancement on azo dyes has been demonstrated in the study. The conclusion derived from this investigation may be summarized as follows: (1) The decoloration rate of arsenazoⅠsolutions during sonozone treatment is more rapid than the rate obtained with ozone alone because the complicated constitution has been destroyed by the O free radical from ozone decomposition. (2) The destructing pathway of arsenazoⅠby ozone with ultrasound is identical with that of by ozone alone: the breakdown of -N== N- bonds, the conversion of benzene ring to carboxylic acid, and -HSO3 bonds to H2SO4. So, pH value of the arsenazo Ⅰ solution continuously drops down to 3.2.

  15. Molecular dynamics study of biodegradation of azo dyes via their interactions with AzrC azoreductase.

    Science.gov (United States)

    Haghshenas, Hamed; Kay, Maryam; Dehghanian, Fariba; Tavakol, Hossein

    2016-01-01

    Azo dyes are one of the most important class of dyes, which have been widely used in industries. Because of the environmental pollution of azo dyes, many studies have been performed to study their biodegradation using bacterial systems. In present work, the AzrC of mesophilic gram-positive Bacillus sp. B29 has been considered to study its interaction with five common azo dyes (orange G, acid red 88, Sudan I, orange I, and methyl red). The molecular dynamics simulations have been employed to study the interaction between AzrC and azo dyes. The trajectory was confirmed using root mean square deviation and the root mean square fluctuation analyses. Then, the hydrogen bond and alanine scanning analyses were performed to reveal active site residues. Phe105 (A), Phe125 (B), Phe172 (B), and Pro132 (B) have been found as the most important hydrophobic residues whereas Asn104 (A), Tyr127 (B), and Asn187 (A) have key role in making hydrogen bond. The results of molecular mechanics Poisson-Boltzmann surface area and molecular mechanics generalized Born surface area calculations proved that the hydrophobic azo dyes like Acid red 88 binds more tightly to the AzrC protein. The calculated data suggested MR A 121 (B) I as a potential candidate for improving the AzrC-MR interactions.

  16. Reduction and partial degradation mechanisms of naphthylaminesulfonic azo dye amaranth by Shewanella decolorationis S12.

    Science.gov (United States)

    Hong, Yiguo; Guo, Jun; Xu, Zhicheng; Mo, Cuiyun; Xu, Meiying; Sun, Guoping

    2007-06-01

    Reduction and biodegradation mechanisms of naphthylaminesulfonic azo dye amaranth using a newly isolated Shewanella decolorationis strain S12 were investigated. Under anaerobic conditions, amaranth was reduced by strain S12, and a stoichiometric amount of two reduction products RP-1 and RP-2 were generated. UV/visible spectrophotometric and high performance liquid chromatography (HPLC) analysis indicated that RP-1 and RP-2 were 1-aminenaphthylene -4-sulfonic acid and 1-aminenaphthylene-2-hydroxy-3, 6-disulfonic acid. The result strongly supports a mechanism of azo dye reduction by the process via the reductive cleavage of the azo bond to form corresponding aromatic amines. The result of HPLC analyses revealed that these aromatic amines were not able to be mineralized by strain S12 under anaerobic conditions. But after re-aeration of the decolorized culture, RP-2 was mineralized completely by this microorganism, but the consumption of RP-1 was not observed. Ames test showed that amaranth had mutagenic but no cytotoxic potential. The mutagenic potential was relieved after the anaerobic treatment with strain S12 as the mutagenic effect of the two reduction products from amaranth was not detected by Ames test. Thus, the ability of strain S12 to reduce and partially mineralize the naphthylaminesulfonic azo dye efficiently was demonstrated, which can potentially be used to biodegrade and detoxify wastewater containing azo dyes using an alternating anaerobic/aerobic treatment procedure.

  17. AZO-Ag-AZO transparent electrode for amorphous silicon solar cells

    International Nuclear Information System (INIS)

    Metal-based transparent electrodes can be fabricated at low temperatures, which is crucial for various substrate materials and solar cells. In this work, an oxide-metal-oxide (OMO) transparent electrode based on aluminum zinc oxide (AZO) and silver is compared to AZO layers, fabricated at different temperatures and indium tin oxides. With the OMO structure, a sheet resistance of 7.1/square and a transparency above 80% for almost the entire visible spectrum were achieved. The possible application of such electrodes on a textured solar cell was demonstrated on the example of a rough ZnO substrate. An OMO structure is benchmarked in a n-i-p amorphous silicon solar cell against an AZO front contact fabricated at 200 °C. In the experiment, the OMO electrode shows a superior performance with an efficiency gain of 30%. - Highlights: • Multilayer transparent electrode based on aluminum zinc oxide (AZO) and Ag • Comparison of AZO-Ag-AZO transparent electrode to AZO and indium tin oxide • Performance of AZO-Ag-AZO transparent electrodes on textured surfaces • Comparison of amorphous silicon solar cells with different transparent electrodes

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

    Energy Technology Data Exchange (ETDEWEB)

    Seshadri, S.; Bishop, P.L. (Univ. of Cincinnati, OH (United States). Dept. of Civil and Environmental Engineering); Agha, A.M. (Univ. of Aleppo (Syrian Arab Republic). 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.

  19. Electrostatic Self-Assembled Multilayers from Side Chain Azo Polyelectrolytes

    Institute of Scientific and Technical Information of China (English)

    庹新林; 陈峥; 邓永红; 王晓工; 刘德山

    2002-01-01

    Photoresponsive behavior and self-assembly properties of three side chain azo polyelectrolytes, poly (2-(4-phenylazophenoxy) ethanol-co-acrylic acid) (PPAPE), poly (2-(4-(4′-nitrophenylazo) phenoxy) ethanol-co-acrylic acid) (PNAPE), and poly (2-(4-(4′-ethoxyphenylazo) phenoxy) ethanol-co-acrylic acid) (PEAPE), were studied. These polyelectrolytes with different degrees of functionalization of azo chromophores were fabricated into nano-composite multilayers using two types of dipping solutions through a layer-by-layer electrostatic self-assembling process. Results show that the ratio between tetrahydrofuran (THF) and H2O significantly influences the photoresponsive behavior of PNAPE in THF-H2O mixture. The THF-H2O dipping solution, used in this work for self-assembly of hydrophobic polyelectrolytes, is proved to be as applicable as aqueous dipping solution for normal self-assembly of hydrophobic polyelectrolytes. However, significant differences in the multilayer growth between the two systems were also observed, which resulted from the remarkable difference of the existing forms of the polyelectrolytes in these two dipping solutions.

  20. 生物炭催化过硫酸盐脱色偶氮染料金橙Ⅱ%Biochar Catalyzed Persulfate Decoloration of Azo Dye Acid Orange 7

    Institute of Scientific and Technical Information of China (English)

    刘娜; 王柳; 邱华; Alberto Bento Charru; 王航; 王锐

    2014-01-01

    As a kind of inexpensive material-biochar,the function of soil restoration and other aspects has caused wide public concern,but its catalytic role has been studied rarely.The feasibility of persulfate (PS)catalyzed by biochar(BC)to decolor an azo dye (acid orange (AO7))was studied.Some factors influencing the decolorizing efficiency of PS/BC system were evaluated, including pH, concentration of biochar and PS/AO7 mole ratio.What’s more,the recycle effect and characteristics of biochar were studied.Results showed that the decolorizing effect of the PS/BC system was obviously better than the only PS system.The decoloration of AO7 by both reaction systems followed first order reaction kinetics. The optimum pH of PS/BC system was near-neutral. The higher the biochar concentration,the better the decolorizing effect was.Similar trend was observed for the PS/AO7 mole ratio,whereas the catalytic effect did not increase accordingly.The reused biochar could still decolor %生物炭作为一种廉价易得的材料,在土壤修复等各方面的功能已引起广泛关注,但其催化作用却鲜有研究。首次对生物炭(biochar BC)催化过硫酸盐(Na2 S2 O8 PS)使偶氮染料金橙Ⅱ(AO7)脱色的可行性进行研究,对影响催化体系脱色效率的因素(包括 pH、生物炭质量浓度和 PS/AO7摩尔比)进行探讨,同时研究了生物炭的重复利用效果及前后性质变化。结果表明:PS/BC 体系明显比单独的 PS 体系脱色效果好;两个反应体系都遵循一级反应动力学;PS/BC 体系反应的最适 pH 接近中性;生物炭质量浓度越大,脱色效果越好;PS/AO7摩尔比越大,脱色效果越好,但是催化效果却没有相应的改善;生物炭重复利用后对 AO7仍然有脱色效果;BC 的孔大多位于层状结构表面,且为小孔,重复使用后,表面孔会堵塞;除了灰分和氧元素外,其他元素(C、N、H、S)含量都有一定程度的减小;BC 表面官能团种类很多,主要

  1. Integrated sequential anaerobic/aerobic biodegradation of azo dyes

    NARCIS (Netherlands)

    Tan, N.C.G.

    2001-01-01

    Azo dyes constitute a major class of environmental pollutants accounting for 60 to 70% of all dyes and pigments used. These compounds are characterized by aromatic moieties linked together with azo groups (-N=N-). The release of azo dyes into the environment is a concern due to coloration of natural

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

    Science.gov (United States)

    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 subject to reporting. (1) The chemical substance identified generically as an azo monochloro...

  3. Synthesis, Structural Evaluation and Applications of Vinylsulfone Based Azo Reactive Dyes

    International Nuclear Information System (INIS)

    In this work, three novel vinylsulfone based azo reactive dyes were successfully synthesized by successive condensations, diazotization and coupling reaction steps using reactive acids i.e. H-acid, J-acid and gamma-acid respectively. Synthesized dyes were applied with 3% dye (stock) solutions on the mill scoured; bleached and desized cotton fabric by exhaust method of dyeing. UV- visible absorption spectroscopic properties of the azo dyes were recorded among wavelength range (400-800 nm), prepared in double distilled water as lambda/sub max/. The prepared dyes were purified with physico- chemical method and characterized by means of different analytical techniques i.e. FT-IR and ESI-MS-MS to evaluate their chemical structures and molecular mass. (author)

  4. Rapid decolorization of water soluble azo-dyes by nanosized zero-valent iron immobilized on the exchange resin

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Nanosized zero-valent iron (NZVI) supported on the cation exchange resin was synthesized and applied to decompose some water soluble azo dyes. The decomposition efficiency for azo dyes was evaluated by using the aqueous suspensions and parked column of this material. Batch experiments indicated that this novel material exhibited excellent degradation ability for 0.05 g·L1 of Acid Orange 7, Acid Orange 8, Acid Orange 10, Sunset Yellow, and Methyl Orange, with decolorization ratio up to 95% in 4 min; pH value was the key factor for degradation and H+ was one of the reactants; adsorption of azo dyes onto the material existed at the beginning but reduced gradually until disappearing completely. For the packed column system, 58%~90% of azo dyes were decomposed in the 1st circle of solution passing through the column, and the adsorption onto the materials could accelerate the degradation azo dyes with the increasing reaction time. During the degradation process, Fe2+, the product of NZVI, was exchanged to the resin again and could be reduced to Fe0 by KBH4 for reusing. The 10th refreshed NZVI possessed reductive activity up to 90% of the newly systhesized NZVI. Decomposing pollutants in the aqueous solution with columns packed with NZVI immobilized on the cation exchange resin is a promising technology that can solve the reclaiming and refreshing problem of NZVI.

  5. Rapid decolorization of water soluble azo-dyes by nanosized zero-valent iron immobilized on the exchange resin

    Institute of Scientific and Technical Information of China (English)

    ZHAO ZongShan; LIU JingFu; TAI Chao; ZHOU QunFang; HU JingTian; JIANG GuiBin

    2008-01-01

    Nanosized zero-valent iron (NZVI) supported on the cation exchange resin was synthesized and applied to decompose some water soluble azo dyes.The decomposition efficiency for azo dyes was evaluated by using the aqueous suspensions and parked column of this material.Batch experiments indicated that this novel material exhibited excellent degradation ability for 0,05 g·L-1 of Acid Orange 7, Acid Orange 8, Acid Orange 10, Sunset Yellow, and Methyl Orange, with decolorization ratio up to 95% in 4 min; pH value was the key factor for degradation and H+ was one of the reactants; adsorption of azo dyes onto the material existed at the beginning but reduced gradually until disappearing completely.For the packed column system, 58%~90% of azo dyes were decomposed in the 1st circle of solution passing through the column, and the adsorption onto the materials could accelerate the degradation azo dyes with the increasing reaction time.During the degradation process, Fe2+, the product of NZVI, was exchanged to the resin again and could be reduced to Fe0 by KBH4 for reusing.The 10th refreshed NZVI possessed reductive activity up to 90% of the newly systhesized NZVI.Decomposing pollutants in the aqueous solution with columns packed with NZVI immobilized on the cation exchange resin is a promising technology that can solve the reclaiming and refreshing problem of NZVI.

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

    Directory of Open Access Journals (Sweden)

    Naeem Ali

    2010-12-01

    Full Text Available 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.

  7. Biological wastewater treatment of azo dyes

    Energy Technology Data Exchange (ETDEWEB)

    Shaul, G.M.; Dempsey, C.R.; Dostal, K.A. (Environmental Protection Agency, Cincinnati, OH (USA))

    1988-09-01

    EPA Water Engineering Research Laboratory, Office of Research and Development, undertook a study to determine the fate of specific water soluble azo dye compounds in the activated sludge process (ASP). The study was approached by dosing the feed to the pilot ASP systems with various water soluble azo dyes and by monitoring each dye compound through the system, analyzing both liquid and sludge samples. The fate of the parent dye compound was assessed via mass balance calculations. These data could determine if the compound was removed by adsorption, apparent biodegradation, or not removed at all. The paper presents results for 18 dye compounds tested from June 1985 through August 1987. The study was conducted at EPAs Test and Evaluation Facility in Cincinnati, Ohio. The objective of this study was to determine the partitioning of water soluble azo dyes in the ASP.

  8. Enzymatic reduction of azo and indigoid compounds

    OpenAIRE

    Pricelius, S.; Held, C; Murkovic, M.; Bozic, M.; Kokol, V.; Paulo, Artur Cavaco; Gübitz, Georg M.

    2007-01-01

    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...

  9. Biodegradation of textile azo dye by Shewanella decolorationis S12 under microaerophilic conditions.

    Science.gov (United States)

    Xu, Meiying; Guo, Jun; Sun, Guoping

    2007-09-01

    The complete biodegradation of azo dye, Fast Acid Red GR, was observed under microaerophilic conditions by Shewanella decolorationis S12. Although the highest decolorizing rate was measured under anaerobic condition and the highest biomass was obtained under aerobic condition, a further biodegradation of decolorizing products can only be achieved under microaerophilic conditions. Under microaerophilic conditions, S. decolorationis S12 could use a range of carbon sources for azo dye decolorization, including lactate, formate, glucose and sucrose, with lactate being the optimal carbon source. Sulfonated aromatic amines were not detected during the biotransformation of Fast Acid Red GR, while H(2)S formed. The decolorizing products, aniline, 1,4-diaminobenzene and 1-amino-2-naphthol, were followed by complete biodegradation through catechol and 4-aminobenzoic acid based on the analysis results of GC-MS and HPLC.

  10. Reduction of azo dyes by flavin reductase from Citrobacter freundii A1

    Directory of Open Access Journals (Sweden)

    Mohd Firdaus Abdul-Wahab

    2012-12-01

    Full Text Available Citrobacter freundii A1 isolated from a sewage treatment facility was demonstrated to be able to effectively decolorize azo dyes as pure and mixed culture. This study reports on the investigation on the enzymatic systems involved. An assay performed suggested the possible involvement of flavin reductase (Fre as an azo reductase. A heterologouslyexpressed recombinant Fre from C. freundii A1 was used to investigate its involvement in the azo reduction process. Three model dyes were used, namely Acid Red 27 (AR27, Direct Blue 15 (DB15 and Reactive Black 5 (RB5. AR27 was found to be reduced the fastest by Fre, followed by RB5, and lastly DB15. Redox mediators nicotinamide adenine dinucleotide (NADH and riboflavin enhance the reduction, suggesting the redox activity of the enzyme. The rate and extent of reduction of the model dyes correlate well with the reduction potentials (Ep. The data presented here strongly suggest that Fre is one of the enzymes responsible for azo reduction in C. freundii A1, acting via an oxidation-reduction reaction.

  11. RAPID DEGRADATION OF AZO DYES USING NANO-SCALE ZERO VALENT IRON

    Directory of Open Access Journals (Sweden)

    Nabila Rahman

    2014-01-01

    Full Text Available In the present study, nano-scale Zero Valent Iron (NZVI was synthesized in ethanol medium by the method of ferric iron reduction using sodium borohydride as a reducing agent under atmospheric conditions. The obtained iron nanoparticles are mainly in zero valent oxidation state and remain without significant oxidation for hours. A systematic characterization of NZVI was performed using XRD, SEM and TEM studies. The obtained iron nanoparticles consist of a zero valent core surrounding a rest oxide shell. The diameter of iron nanoparticles was predominantly within the range 20-110 nm. Refractory azo-dye compounds used in the textile industry are commonly detected in many industrial waste water. In this study the removal efficiency of three azo dyes, namely, methyl orange, sunset yellow and acid blue a, with laboratory synthesized NZVI particles in relation to the NZVI dosage, dye concentration and pH was determined. Increasing the dose of NZVI particles enhanced the decolonization of the dyes. The degradation decreased with increasing solution pH and concentration of dyes. These findings demonstrated the fast removal of azo dye compounds with NZVI and the advantage of the synthesized NZVI particles to treat azo dye contaminated wastewater.

  12. Simultaneous chromate reduction and azo dye decolourization by Brevibacterium casei: Azo dye as electron donor for chromate reduction

    International Nuclear Information System (INIS)

    Chromate [Cr(VI)] and azo dyes are common pollutants which may co-exist in some industrial effluents. Hence studies of biological treatment of industrial wastewater should include investigation of the co-removal of these two pollutants. Brevibacterium casei, which can reduce Cr(VI) in the presence of the azo dye Acid Orange 7 (AO7) under nutrient-limiting condition, was isolated from a sewage sludge sample of a dyeing factory. Response surface methodology, which is commonly used to optimize growth conditions for food microorganisms to maximize product(s) yield, was used to determine the optimal conditions for chromate reduction and dye decolourization by B. casei. The optimal conditions were 0.24 g/L glucose, 3.0 g/L (NH4)2SO4 and 0.2 g/L peptone at pH 7 and 35 deg. C. The predicted maximum chromate reduction efficiencies and dye decolourization were 83.4 ± 0.6 and 40.7 ± 1.7%, respectively. A new mechanism was proposed for chromate reduction coupling with AO7 decolourization by B. casei. Under nutrient-limiting condition, AO7 was used as an e- donor by the reduction enzyme(s) of B. casei for the reduction of Cr(VI). The resulted Cr(III) then complexed with the oxidized AO7 to form a purple coloured intermediate.

  13. Simultaneous chromate reduction and azo dye decolourization by Brevibacterium casei: Azo dye as electron donor for chromate reduction

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Tsz Wai; Cai Qinhong [Department of Biology, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Wong, Chong-Kim [Department of Biology, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Environmental Science Programme, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Chow, Alex T. [Department of Biosystems Engineering, Clemson University, SC 29634 (United States); Department of Forestry and Natural Resources, Clemson University, SC 29634 (United States); Wong, Po-Keung, E-mail: pkwong@cuhk.edu.hk [Department of Biology, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Environmental Science Programme, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong)

    2010-10-15

    Chromate [Cr(VI)] and azo dyes are common pollutants which may co-exist in some industrial effluents. Hence studies of biological treatment of industrial wastewater should include investigation of the co-removal of these two pollutants. Brevibacterium casei, which can reduce Cr(VI) in the presence of the azo dye Acid Orange 7 (AO7) under nutrient-limiting condition, was isolated from a sewage sludge sample of a dyeing factory. Response surface methodology, which is commonly used to optimize growth conditions for food microorganisms to maximize product(s) yield, was used to determine the optimal conditions for chromate reduction and dye decolourization by B. casei. The optimal conditions were 0.24 g/L glucose, 3.0 g/L (NH{sub 4}){sub 2}SO{sub 4} and 0.2 g/L peptone at pH 7 and 35 deg. C. The predicted maximum chromate reduction efficiencies and dye decolourization were 83.4 {+-} 0.6 and 40.7 {+-} 1.7%, respectively. A new mechanism was proposed for chromate reduction coupling with AO7 decolourization by B. casei. Under nutrient-limiting condition, AO7 was used as an e{sup -} donor by the reduction enzyme(s) of B. casei for the reduction of Cr(VI). The resulted Cr(III) then complexed with the oxidized AO7 to form a purple coloured intermediate.

  14. A novel recombinant AzrC protein proposed by molecular docking and in silico analyses to improve azo dye's binding affinity.

    Science.gov (United States)

    Dehghanian, Fariba; Kay, Maryam; Kahrizi, Danial

    2015-09-15

    Azo dyes are broadly used in different industries through their chemical stability and ease of synthesis. These dyes are usually identified as critical environmental pollutants and many attentions were performed to degradation of azo dyes using biological systems. In this study, the interactions of an azoreductase from mesophilic gram-positive Bacillus sp. B29, AzrC, with four common azo dyes (orange I, orange II, orange G and acid red 88) were investigated. Fifteen points, double, triple and quadruple mutant forms of AzrC were made using Molegro Virtual Docker 6.0 in order to improve the binding affinity of azo dyes to AzrC. The impact of 15 different mutations on azo dye affinity potency of AzrC was computationally analyzed using AzrC-azo dye molecular docking, and each interaction was scored based on AutoDock 4.2 free binding energy. Our results have indicated that Asn 104 (A), Asn 187 (B), and Tyr 151 (A) make stable hydrogen bond between AzrC and azo dyes. The hydrophobic amino acids like Phe105 (A), Phe 125 (B), and Phe 172 (B) in wild type form make hydrophobic interactions. In addition, the presence of more hydrophobic residues F60 (B), I119 (B), I121 (B) and F132 (B) in mutant forms made more powerful hydrophobic pocket in the active site. In conclusion, recombinant AzrC with quadruple mutations was suggested in order to increase the biodegradation capacity of AzrC through improving its affinity to four studied azo dyes. This study would be promising for future experimental analyses in order to produce recombinant form of AzrC.

  15. A novel recombinant AzrC protein proposed by molecular docking and in silico analyses to improve azo dye's binding affinity.

    Science.gov (United States)

    Dehghanian, Fariba; Kay, Maryam; Kahrizi, Danial

    2015-09-15

    Azo dyes are broadly used in different industries through their chemical stability and ease of synthesis. These dyes are usually identified as critical environmental pollutants and many attentions were performed to degradation of azo dyes using biological systems. In this study, the interactions of an azoreductase from mesophilic gram-positive Bacillus sp. B29, AzrC, with four common azo dyes (orange I, orange II, orange G and acid red 88) were investigated. Fifteen points, double, triple and quadruple mutant forms of AzrC were made using Molegro Virtual Docker 6.0 in order to improve the binding affinity of azo dyes to AzrC. The impact of 15 different mutations on azo dye affinity potency of AzrC was computationally analyzed using AzrC-azo dye molecular docking, and each interaction was scored based on AutoDock 4.2 free binding energy. Our results have indicated that Asn 104 (A), Asn 187 (B), and Tyr 151 (A) make stable hydrogen bond between AzrC and azo dyes. The hydrophobic amino acids like Phe105 (A), Phe 125 (B), and Phe 172 (B) in wild type form make hydrophobic interactions. In addition, the presence of more hydrophobic residues F60 (B), I119 (B), I121 (B) and F132 (B) in mutant forms made more powerful hydrophobic pocket in the active site. In conclusion, recombinant AzrC with quadruple mutations was suggested in order to increase the biodegradation capacity of AzrC through improving its affinity to four studied azo dyes. This study would be promising for future experimental analyses in order to produce recombinant form of AzrC. PMID:26026905

  16. Phytoremediation of industrial effluent containing azo dye by model up-flow constructed wetland

    Institute of Scientific and Technical Information of China (English)

    S.A.Ong; K.Uchiyama; D.Inadama; Y.Ishida; K.Yamagiwa

    2009-01-01

    This study assessed the treatment of azo dye Acid Orange 7(AO7)containing wastewater by laboratory-scale up-flow constructed wetland(UFCW)with and without supplementary aeration.The supplementary aeration could effectively control the ratio of anaerobic and aerobic zones in the UFCW reactor.The results dearly show the supplementary aeration boosted the biodegradation of organic pollutants and mineralization of intermediate aromatic amines formed by AO7 degradation.

  17. Comparative azo reductase activity of red azo dyes through caecal and hepatic microsomal fraction in rats.

    Science.gov (United States)

    Singh, S; Das, M; Khanna, S K

    1997-09-01

    In order to study the rate of formation of toxic aromatic amines, anaerobic reduction of four red azo dyes viz. amaranth, carmoisine, fast Red E and ponceau 4R was investigated by incubating caecal content and hepatic microsomal fraction of rats with 37.5 microM concentration of dyes in sodium phosphate buffer pH 7.4 using NADPH generating system, glucose oxidase system and nitrogen as the gaseous phase. Caecal suspension exhibited higher azo reductase activity than that of hepatic microsomal fraction using any of the 4 azo dyes. Caecal microbes showed maximal azo reductase activity when ponceau 4R was used as a substrate followed by fast Red E and carmoisine, while with amaranth the activity was minimum. Similarly ponceau 4 R exhibited maximum hepatic microsomal azo reductase activity followed by fast Red E and carmoisine whereas, amaranth had minimum activity. Caecal flora possessed almost 17 fold higher degradative capability of ponceau 4 R and fast Red E colourants than the hepatic microsomal fraction. The higher reductive ability through caecal flora for ponceau 4R and fast Red E signifies the formation of more aromatic amines which may be re-absorbed through the intestine to be either eliminated through urine as conjugates or retained in the target tissues to elicit toxic effects.

  18. Effects of Controlling the AZO Thin Film's Optical Band Gap on AZO/MEH-PPV Devices with Buffer Layer

    Directory of Open Access Journals (Sweden)

    Jaehyoung Park

    2012-01-01

    Full Text Available Organic/inorganic hybrid solar cells were fabricated incorporating aluminum-doped zinc oxide (AZO thin films of varying optical band gap in AZO/poly(2-methoxy-5-(2′-ethyl-hexyloxy-p-phenylene vinylene structures. The band gaps were controlled by varying the flow rates of Ar and O2 used to deposit the AZO. Devices with CdS buffer layer were also fabricated for improved efficiency. The effects of AZO optical band gap were assessed by testing the I–V characteristics of devices with structures of glass/ITO/AZO/MEH-PPV/Ag under AM1.5 illumination (100 mW/cm2. Efficiency was improved about 30 times by decreasing the AZO optical band gap, except in devices deposited without oxygen. A power conversion efficiency of 0.102% was obtained with the incorporation of a CdS buffer layer.

  19. Degradation of azo dyes by environmental microorganisms and helminths

    Energy Technology Data Exchange (ETDEWEB)

    Kingthom Chung; Stevens, S.E. Jr. (Memphis State Univ., TN (United States). 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.

  20. Study of Novel Oligomeric Azo Dyes

    Directory of Open Access Journals (Sweden)

    Patel J. R.

    2012-08-01

    Full Text Available Diazotization of p-anisidine and coupling with 3-amino-phenol-Formaldehyde (APF resin give oligomaric azo dye TAPF, based on 3-amino-phenol-Formaldehyde (APF polymer. The TAPF was then treated with 5-chloro methyl-8-quinolinol hydrochloride in the presence of a THF in alkaline medium (pH 9-10 at room temperature for 7 hrs. The resultant oligomaric ligand designated as azo polyphenol-formaldehyde-5-chloromethyl-8-quinolinol (AAPFQ was characterized by elemental analysis, IR spectral studies, and thermogravimetry. The polymeric metal chelates of AAPFQ with Cu2+, Zn2+, Mn2+, Ni2+, Fe3+ and Co2+ metal ions were prepared and characterised by metal:ligand ratio, IR and reflectance studies, magnetic properties and thermogravimetry. The AAPFQ sample was also screened for its chelating and ion-exchanging properties. Batch equilibration method has been adopted for evolution of ion-exchange properties.

  1. Synthesis and Evaluation of Changes Induced by Solvent and Substituent in Electronic Absorption Spectra of New Azo Disperse Dyes Containig Barbiturate Ring

    Directory of Open Access Journals (Sweden)

    Hooshang Hamidian

    2013-01-01

    Full Text Available Six azo disperse dyes were prepared by diazotizing 4-amino hippuric acid and coupled with barbituric acid and 2-thiobarbituric acid. Then, the products were reacted with aromatic aldehyde, sodium acetate, and acetic anhydride, and oxazolone derivatives were formed. Characterization of the dyes was carried out by using UV-Vis, FT-IR, 1H NMR and 13C NMR, and mass spectroscopic techniques. The solvatochromic behavior of azo disperse dyes was evaluated in various solvents. The effects of substituents of aromatic aldehyde, barbiturate, and thiobarbiturate ring on the color of dyes were investigated.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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…

  4. 4-Dimethylaminoazobenzenes: carcinogenicities and reductive cleavage by microsomal azo reductase.

    Science.gov (United States)

    Lambooy, J P; Koffman, B M

    1985-01-01

    Twenty-four 4-dimethylaminoazobenzenes (DABs) in which systematic structural modifications have been made in the prime ring have been studied for substrate specificity for microsomal azo reductase. The DABs were also evaluated for carcinogenicity and it was found that there was no correlation between carcinogenicity and extent of azo bond cleavage by azo reductase. While any substituent in the prime ring reduces the rate of cleavage of the azo bond relative to the unsubstituted dye, there is a correlation between substituent size and susceptibility to the enzyme. Substituent size was also found to be a significant factor in the induction of hepatomas by the dyes. Preliminary studies have shown that there appears to be a positive correlation between microsomal riboflavin content and the activity of the azo reductase.

  5. The microbial degradation of azo dyes: minireview.

    Science.gov (United States)

    Chengalroyen, M D; Dabbs, E R

    2013-03-01

    The removal of dyes in wastewater treatment plants still involves physical or chemical processes. Yet numerous studies currently exist on degradation based on the use of microbes-which is a well-studied field. However progress in the use of biological methods to deal with this environmentally noxious waste is currently lacking. This review focuses on the largest dye class, that is azo dyes and their biodegradation. We summarize the bacteria identified thus far which have been implicated in dye decolorization and discuss the enzymes involved and mechanisms by which these colorants are broken down.

  6. The effect of substituent groups on the reductive degradation of azo dyes by zerovalent iron

    Energy Technology Data Exchange (ETDEWEB)

    Hou Meifang [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, 510650 Guangzhou (China); Li Fangbai [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, 510650 Guangzhou (China)]. E-mail: cefbli@soil.gd.cn; Liu Xinming [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, 510650 Guangzhou (China); Wang Xugang [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, 510650 Guangzhou (China); Wan Hongfu [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, 510650 Guangzhou (China)

    2007-06-25

    To investigate the effects of substituent groups on the reductive degradation of azo dyes by zerovalent iron, Orange I, Orange II and Methyl Orange were selected as the model azo dyes with different substituent groups. The results showed that Orange I, Orange II and Methyl Orange could be effectively reduced by Fe{sup 0}, and the degradation of Orange I and Orange II could be described by the first-order kinetic model, while the degradation of Methyl Orange could be described by the zeroth-order kinetic model. The initial degradation rate followed the order as Orange I > Orange II > Methyl Orange under the same experimental conditions owing to the substituent effects. The degradation kinetic constants of Orange I and Orange II increased with the increase in the Fe{sup 0} dosage, and with the decrease in the initial pH value and their initial concentration, while that of Methyl Orange increased with the decrease in the initial pH value, and with the increase in the Fe{sup 0} dosage and their initial concentration. The results of high-performance liquid chromatography (HPLC)-mass spectra (MS) showed that sulfanilic acid was the same intermediate, while the second intermediate was 1-amino-4-naphthol for Orange I, 1-amino-2-naphthol for Orange II, and p-dimethylaminoaniline for Methyl Orange. It was suggested that the larger conjugated {pi} system of naphthalene rings of Orange I and Orange II for the delocalization of the nonbonding electron pairs of substituents and nitrogen in the azo bond might be favorable for the degradation of Orange I and Orange II, compared with the structure of Methyl Orange. The higher degradation rate of Orange I might be ascribed to its effective electron delocalization and favorable position effects, compared with Orange II. It should be concluded that the reductive degradation of azo dyes by zerovalent iron strongly depends on the effect of substituent groups.

  7. Recent advances in azo dye degrading enzyme research.

    Science.gov (United States)

    Chen, Huizhong

    2006-04-01

    Azo dyes, which are characterized by one or more azo bonds, are a predominant class of colorants used in tattooing, cosmetics, foods, and consumer products. These dyes are mainly metabolized by bacteria to colorless aromatic amines, some of which are carcinogenic, by azoreductases that catalyze a NAD(P)H-dependent reduction. The resulting amines are further degraded aerobically by bacteria. Some bacteria have the ability to degrade azo dyes both aerobically and anaerobically. Plant-degrading white rot fungi can break down azo dyes by utilizing a number of oxidases and peroxidases as well. In yeast, a ferric reductase system participates in the extracellular reduction of azo dyes. Recently, two types of azoreductases have been discovered in bacteria. The first class of azoreductases is monomeric flavin-free enzymes containing a putative NAD(P)H binding motif at their N-termini; the second class is polymeric flavin dependent enzymes which are studied more extensively. Azoreductases from bacteria represent novel families of enzymes with little similarity to other reductases. Dissociation and reconstitution of the flavin dependent azoreductases demonstrate that the non-covalent bound flavin prosthetic group is required for the enzymatic functions. In this review, structures and carcinogenicity of azo colorants, protein structure, enzymatic function, and substrate specificity, as well as application of the azo dyes and azoreductases will be discussed.

  8. Adsorption of azo dyes on polymer materials

    Directory of Open Access Journals (Sweden)

    Panić Vesna V.

    2013-01-01

    Full Text Available The use of polymeric adsorbents for the removal of azo dyes from solution has been reviewed. Adsorption techniques are widely used to remove certain classes of pollutants from waters, especially those which are not easily biodegradable. The removal of azo dyes as pollutants from wastewaters of textile, paper, printing, leather, pharmaceutical and other industries has been addressed by the researchers. The wider use of already available adsorbents is restricted due to their high costs which lead to investigation and development of new materials that can be cheaper, eficient and easy regenerated. The aim of this article is to present to the readers the widespread investigations in recent years of synthetic and natural polymers as adsorbents and potential replacement of conventional adsorbents. This review presents only the data obtained using raw, hydrogel, grafted and crosslinked forms of synthetic and nature based polymers, and the discussion is limited to these polymer-based materials and their adsorption properties. [Projekat Ministarstva nauke Republike Srbije, br. 43009 i br. 172062.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

    2012-11-30

    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.

  12. An Improved Method for Removal of Azo Dye Orange II from Textile Effluent Using Albumin as Sorbent

    Directory of Open Access Journals (Sweden)

    Tadashi Ohashi

    2012-11-01

    Full Text Available 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.

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

    Science.gov (United States)

    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

  14. Synthesis of (p-Formylphenyl)azo Calix[4]arenes

    Institute of Scientific and Technical Information of China (English)

    BAI,Zhu(柏祝); YU,Lei(俞磊); LU,Guo-Yuan(陆国元); GUO,Xun(郭勋)

    2004-01-01

    Five novel azo calix[4]arenes were reported.The p-aminobenzaldehyde was diazotized with sodium nitrite in aqueous hydrochloride solution.Mono-,bis-,tris- and tetrakis(p-formylphenyl)azo calix[4]arenes (including proximal and distal isomers) were obtained respectively by diazo-coupling in different molar ratio to calix[4]arene (1) under pH=7.5-8.5 at 0-5℃.All (p-formylphenyl)azo calix[4]arenes were characterized by 1H NMR,13C NMR,IR,MS (ESIMS) spectroscopies and elemental analysis.

  15. Biodegradation of azo dyes by genetically engineered azoreductase

    Institute of Scientific and Technical Information of China (English)

    WANG Jing; YAN Bin; ZHOU Ji-ti; BAO Yong-ming; LU Hong; YUAN Xiao-dong

    2005-01-01

    A azoreductase gene with 537 bp was obtained by PGR amplification from Rhodobacter sphaeroides AS1.1737. The enzyme,with a molecular weight of 18.7 kD, was efficiently expressed in Escherichia coli and its biodegradation characteristics for azo dyes were investigated. Furthermore, the reaction kinetics and mechanism of azo dyes catalyzed by the genetically engineered azoreductase were studied in detail. The presence of a hydrazo-intermediate was identified, which provided a convincing evidence for the assumption that azo dyes were degraded via an incomplete reduction stage.

  16. Preparation and Photo-thermal Isomerization of Azo [2.2.1]-and Azo[2.2.3]metacyclophane Tweezers

    OpenAIRE

    Sawada, Tsuyoshi; Thiemann, Thies; Mataka, Shuntaro

    1999-01-01

    Azo[2.2.1]metacyclophane (MCP) tweezer 11 and azo[2.2.3]MCP tweezer 12 were prepared from [2.2.1]MCP 1a and [2.2.3]MCP 8, respectively, by ipso-nitration followed by reductive coupling using LiAlH_4. The photochemical and thermal isomerization of azo[2.2.n]MCP tweezers were studied by UV spectroscopy. The activation parameter (E_a) of the thermal cis-trans isomerization of 11 and 12 was determined as 81.7 kJmol^ and 90.9 kJmol^, respectively.

  17. Microstructures and thermochromic characteristics of VO2/AZO composite films

    Science.gov (United States)

    Xiao, Han; Li, Yi; Yuan, Wenrui; Fang, Baoying; Wang, Xiaohua; Hao, Rulong; Wu, Zhengyi; Xu, Tingting; Jiang, Wei; Chen, Peizu

    2016-05-01

    A vanadium dioxide (VO2) thin film was fabricated on a ZnO doped with Al (AZO) conductive glass by magnetron sputtering at room temperature followed by annealing under air atmosphere. The microstructures and optical properties of the thin film were studied. The results showed that the VO2/AZO composite film was poly-crystalline and the AZO layer did not change the preferred growth orientation of VO2. Compared to the VO2 film fabricated on soda-lime glass substrate through the same process and condition, the phase transition temperature of the VO2/AZO composite film was decreased by about 25 °C, thermal hysteresis width narrowed to 6 °C, the visible light transmittance was over 50%, the infrared transmittances before and after phase transition were 21% and 55%, respectively at 1500 nm.

  18. REMOVAL OF AZO DYES BY THE ACTIVATED SLUDGE PROCESS

    Science.gov (United States)

    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 ...

  19. All-Optical Switching Based on Azo Polymer Material

    Institute of Scientific and Technical Information of China (English)

    DENG Yan; LUO Yan-Hua; WANG Pei; LU Yong-Hua; MING Hai; ZhANG Qi-Jing

    2007-01-01

    Conventional all-optical switches based on azo polymer films and the all-optical switches based on the attenuated total reflection (ATR) geometry are investigated. A conventional switch system, including a pump beam of 532nm and a probe beam of 650nm, is based on the photoinduced birefringence effect of azo polymer. An ATR switch in a prism-multilayer configuration is achieved by changing the reflectance of the probe beam with an external pump beam. The ATR method provides the substantial improvement of the speed and the efficiency of the modulation over the conventional method. Although the azo polymer response still remains relatively slow,an enhanced nonlinear refractive index of the azo polymer film can effectively increase the modulation.

  20. Re-evaluation of azo dyes as food additives

    DEFF Research Database (Denmark)

    Pratt, Iona; Larsen, John Christian; Mortensen, Alicja;

    2013-01-01

    additives to be assessed by the Scientific Committee on Food, many years ago, (ii) because of concern regarding possible health effects of artificial colours arising since the original evaluations.Concerns includedbehavioural effects in children, allergic reactions, genotoxicity and possible carcinogenicity......Aryl azo compounds are widely used as colorants (azo dyes) in a wide range of products including textiles, leather, paper, cosmetics, pharmaceuticals and food.As part of its systematic re-evaluation of food additives, the European Food Safety Authority (EFSA) has carried out new risk assessments...... of allazo dyes permitted in food. EFSA has also evaluated a number of azo dyes found illegally in food in recent years, including Sudan dyes, Para Red and Orange II. The re-evaluation of all food colours, including the azo dyes,was considered high priority (i) because colorants were among the first...

  1. AZO dye-doped photorefractive polymers

    Energy Technology Data Exchange (ETDEWEB)

    Volodin, B.; Meerholz, K.; Sandalphon; Peyghambarian, N. [Univ. of Arizona, Tucson, AZ (United States). Optical Sciences Center; Kippelen, B. [Groupe d`Optique Nonlineaire et d`Optoelectronique, Strasbourg (France)

    1994-12-31

    The authors report the studies of the photorefractive properties of the two polymer composites based on poly(N-vinylcarbazole) (PVK). The polymers were obtained by doping PVK with 2,4,7 trinitro-9-fluorenone as a sensitizer agent and two different azo dyes as nonlinear chromophores. Best results were obtained for the polymer doped with 2,5-dimethyl-4-p-nitrophenylazoanisole, which showed a maximum diffraction efficiency of 34% at 40 V/{micro}m external electric field strength in 105 {micro}m thick samples. The influence of different geometries of the hologram writing-retrieval on the diffraction efficiency is described. Net amplification of one of the writing beams in two-beam coupling within the material has been observed. Recording of the holograms of 2-dimensional objects in real time has been demonstrated with good resolution and image brightness. All the results were obtained with a low power visible laser diode emitting at 675 nm.

  2. Decolorization of textile azo dye and Congo red by an isolated strain of the dissimilatory manganese-reducing bacterium Shewanella xiamenensis BC01.

    Science.gov (United States)

    Ng, I-Son; Chen, Tingting; Lin, Rong; Zhang, Xia; Ni, Chao; Sun, Dongzhe

    2014-03-01

    Shewanella xiamenensis BC01 (SXM) was isolated from sediment collected off Xiamen, China and was identified based on the phylogenetic tree of 16S rRNA sequences and the gyrB gene. This strain showed high activity in the decolorization of textile azo dyes, especially methyl orange, reactive red 198, and recalcitrant dye Congo red, decolorizing at rates of 96.2, 93.0, and 87.5%, respectively. SXM had the best performance for the specific decolorization rate (SDR) of azo dyes compared to Proteus hauseri ZMd44 and Aeromonas hydrophila NIU01 strains and had an SDR similar to Shewanella oneidensis MR-1 in Congo red decolorization. Luria-Bertani medium was the optimal culture medium for SXM, as it reached a density of 4.69 g-DCW L(-1) at 16 h. A mediator (manganese) significantly enhanced the biodegradation and flocculation of Congo red. Further analysis with UV-VIS, Fourier Transform Infrared spectroscopy, and Gas chromatography-mass spectrometry demonstrated that Congo red was cleaved at the azo bond, producing 4,4'-diamino-1,1'-biphenyl and 1,2'-diamino naphthalene 4-sulfonic acid. Finally, SEM results revealed that nanowires exist between the bacteria, indicating that SXM degradation of the azo dyes was coupled with electron transfer through the nanowires. The purpose of this work is to explore the utilization of a novel, dissimilatory manganese-reducing bacterium in the treatment of wastewater containing azo dyes.

  3. Azo dye decolorization assisted by chemical and biogenic sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Prato-Garcia, Dorian [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico); Cervantes, Francisco J. [División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa de San José 2055, San Luis Potosí 78216 (Mexico); Buitrón, Germán, E-mail: gbuitronm@ii.unam.mx [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico)

    2013-04-15

    Highlights: ► Azo dyes were reduced efficiently by chemical and biogenic sulfide. ► Biogenic sulfide was more efficient than chemical sulfide. ► There was no competition between dyes and sulfate for reducing equivalents. ► Aromatic amines barely affected the sulfate-reducing process. -- Abstract: The effectiveness of chemical and biogenic sulfide in decolorizing three sulfonated azo dyes and the robustness of a sulfate-reducing process for simultaneous decolorization and sulfate removal were evaluated. The results demonstrated that decolorization of azo dyes assisted by chemical sulfide and anthraquinone-2,6-disulfonate (AQDS) was effective. In the absence of AQDS, biogenic sulfide was more efficient than chemical sulfide for decolorizing the azo dyes. The performance of sulfate-reducing bacteria in attached-growth sequencing batch reactors suggested the absence of competition between the studied azo dyes and the sulfate-reducing process for the reducing equivalents. Additionally, the presence of chemical reduction by-products had an almost negligible effect on the sulfate removal rate, which was nearly constant (94%) after azo dye injection.

  4. Azo dye decolorization assisted by chemical and biogenic sulfide

    International Nuclear Information System (INIS)

    Highlights: ► Azo dyes were reduced efficiently by chemical and biogenic sulfide. ► Biogenic sulfide was more efficient than chemical sulfide. ► There was no competition between dyes and sulfate for reducing equivalents. ► Aromatic amines barely affected the sulfate-reducing process. -- Abstract: The effectiveness of chemical and biogenic sulfide in decolorizing three sulfonated azo dyes and the robustness of a sulfate-reducing process for simultaneous decolorization and sulfate removal were evaluated. The results demonstrated that decolorization of azo dyes assisted by chemical sulfide and anthraquinone-2,6-disulfonate (AQDS) was effective. In the absence of AQDS, biogenic sulfide was more efficient than chemical sulfide for decolorizing the azo dyes. The performance of sulfate-reducing bacteria in attached-growth sequencing batch reactors suggested the absence of competition between the studied azo dyes and the sulfate-reducing process for the reducing equivalents. Additionally, the presence of chemical reduction by-products had an almost negligible effect on the sulfate removal rate, which was nearly constant (94%) after azo dye injection

  5. Key factors regarding decolorization of synthetic anthraquinone and azo dyes.

    Science.gov (United States)

    Boonyakamol, A; Imai, T; Chairattanamanokorn, P; Higuchi, T; Sekine, M

    2009-07-01

    The factors affecting decolorization of anthraquinone dye represented by Reactive Blue 4 (RB4) and azo dye represented by Methyl Orange (MO) were studied in batch experiments under mesophilic (35 degrees C) and thermophilic (55 degrees C) anaerobic conditions. The results indicated differences in decolorization properties of the dyes with different chromophore structures. In abiotic conditions, MO could be decolorized by a physicochemical reaction when it was sterilized at 121 degrees C together with sludge cells or glucose. RB4 only showed absorption onto the cell mass. The presence of a redox mediator accelerated the decolorizing reaction when supplied together with glucose in the presence of sterilized sludge cells. In biotic conditions, the results indicated that the biological activity of microorganisms was an important factor in decolorization. The main factor involved in decolorization was the conversion of cosubstrate as electron donor, which reacted with dye as an electron acceptor in electron transfer. Redox mediators, anthraquinone-2-sulfonic acid, and anthraquinone could accelerate decolorization even if a small amount (0.2 mM) was applied. On the other hand, a high concentration of redox mediator (1.0 mM) had an inhibitory effect on decolorization especially under thermophilic conditions. In addition, the decolorization of dye was accelerated by increasing treatment temperature, as shown in biotic treatments. Based on these results, increasing the treatment temperature could be used to improve the decolorizing process of textile dye wastewater treatment, especially for recalcitrant dyes such as anthraquinone.

  6. BF3.SiO2: an efficient catalyst for the synthesis of azo dyes at room temperature

    Directory of Open Access Journals (Sweden)

    Bi Bi Fatemeh Mirjalili

    2012-07-01

    Full Text Available A rapid one-pot method has been developed for the synthesis of azo dyes via ‎sequential diazotization–diazo coupling of aromatic amines with coupling agents at room ‎temperature in the presence of BF3.SiO2 as acidic catalyst. The obtained aryl diazonium salts bearing silica supported boron tri-flouride counter ion‎ was sufficiently stable to be kept at room ‎temperature in the dry state.‎

  7. Characterization of AZO and Ag based films prepared by RF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Dagang [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China); Jiang, Shouxiang, E-mail: kinor.j@polyu.edu.hk [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China); Zhao, Hongmei [Department of Prosthodontics, The Affiliated Hospital of Qingdao University, Qingdao (China); Shang, Songmin; Chen, Zhuoming [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China)

    2014-12-15

    Highlights: • Highly infrared reflective AZO and Ag based films were prepared. • Ag showed better crystallization on AZO film than on glass substrate. • Infrared reflection rate was inversely proportional to the film sheet resistance. • Film with infrared reflection of 97% in FIR region was acquired. - Abstract: Ag, AZO/Ag, Ag/AZO and AZO/Ag/AZO films were prepared on glass substrates by radio frequency (RF) magnetron sputtering technology. The prepared films were systematically investigated by X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), UV–visible spectrophotometer, a four-point probe system and Fourier Transform Infrared Spectroscopy. The results indicated that Ag inner layer starts forming a continuous film at the thickness of 10 nm and Ag layer presents superior crystallization on AZO substrate than that on glass substrate. The continuous Ag inner layer film provided the highest average visible transmittance of 85.4% (AZO/Ag/AZO). The lowest sheet resistance of 3.21 Ω/sq and the highest infrared reflection rate of 97% in FIR region can be obtained on AZO/Ag (15 nm)/AZO film. The high infrared reflection property of the AZO/Ag/AZO coating makes it a promising candidate for solar control films.

  8. Synthesis, characterization and photoluminescence properties of graphene oxide functionalized with azo molecules

    Indian Academy of Sciences (India)

    R Devi; G Prabhavathi; R Yamuna; S Ramakrishnan; Nikhil K Kothurkar

    2014-01-01

    Two different azo molecules functionalized graphene oxide (GO) through an ester linkage have been synthesized for the first time. Chemical structure of the azo-GO hybrids was confirmed by Fourier transform infrared spectroscopy and UV-visible spectroscopy. The GO functionalized with 5-((4-methoxyphenyl)azo)-salicylaldehyde was further characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The SEM studies demonstrated that the morphology of the azo-GO hybrid was found to be similar to the GO sheets but slightly more wrinkled. Further, TEM image of azo-GO indicates some dark spots on the GO sheets due to azo functionalization. AFM results also reveal that the azo functionalization increases the thickness of GO sheet to 4-5 nm from 1.2-1.8 nm. Both the azo-hybrids show absorption band around 379 nm due to the -* transition of the trans azo units. Photoluminescence spectra of azo-GO hybrids show a strong quenching compared with azo molecules due to the photoinduced electron or energy transfer from the azo chromophore to the GO sheets. It also reveals strong electronic interaction between azo and GO sheets.

  9. The hydrogen sulfate recognition properties of azo-salicylaldehyde schiff base receptors

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Azo-salicylaldehyde Schiff base-typed receptors containing an acidic H-bond donor moiety were syn-thesized and characterized. The UV-Vis data indicate that these receptors could act as selective col-orimetric sensors for basic anions and acidic species hydrogen sulfate by different color changes in a water-containing medium. The experiment of Brφnsted acid-base reaction by adding the sodium hy-droxide or perchloric acid revealed that the mechanism of recognition of anions might be deprotona-tion/protonation of the OH fragments by interacting with different anions and that the deprotona-tion/protonation process is fully reversible. The deprotonation/protonation of the receptors is respon-sible for the dramatic color change.

  10. The hydrogen sulfate recognition properties of azo-salicylaldehyde schiff base receptors

    Institute of Scientific and Technical Information of China (English)

    WEI TaiBao; WANG Jun; ZHANG YouMing

    2008-01-01

    Azo-salicylaldehyde Schiff base-typed receptors containing an acidic H-bond donor moiety were syn-thesized and characterized. The UV-Vis data indicate that these receptors could act as selective col-orimetric sensors for basic anions and acidic species hydrogen sulfate by different color changes in a water-containing medium, The experiment of Brφnsted acid-base reaction by adding the sodium hy-droxide or perchloric acid revealed that the mechanism of recognition of anions might be deprotona-tion/protonation of the OH fragments by interacting with different anions and that the deprotona-tion/protonation process is fully reversible. The deprotonation/protonation of the receptors is respon-sible for the dramatic color change.

  11. Synthesis, Characterization and Photoinduction of Optical Anisotropy in Liquid Crystalline Diblock Azo-Copolymers

    DEFF Research Database (Denmark)

    Forcén, P; Oriol, L; Sánchez, C;

    2007-01-01

    behavior similar to that of the azo homopolymers. Thin films of these copolymers were characterized by transmission elevtron microscopy (TEM). A lamellar nanostructure was observed for azo content down to 20 wt %, while no structure is observed for the copolymer with a 7% azo content. The optical...

  12. Biological waste-water treatment of azo dyes

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Microbial fuel cell with an azo-dye-feeding cathode

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Liang [Chinese Academy of Sciences, Guangzhou (China). Guangzhou Inst. of Geochemistry; Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou (China). Guangdon Key Lab. of Agricultural Environment Pollution Integrated Control; Graduate Univ. of Chinese Academy of Sciences, Beijing (China); Li, Fang-bai [Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou (China). Guangdon Key Lab. of Agricultural Environment Pollution Integrated Control; Feng, Chun-hua [South China Univ. of Technology, Guangzhou (China). School of Chemistry and Chemical Engineering; Li, Xiang-zhong [Hong Kong Polytechnic Univ., Hong Kong (China). Dept. of Civil and Structural Engineering

    2009-11-15

    Microbial fuel cells (MFCs) were constructed using azo dyes as the cathode oxidants to accept the electrons produced from the respiration of Klebsiella pneumoniae strain L17 in the anode. Experimental results showed that a methyl orange (MO)-feeding MFC produced a comparable performance against that of an air-based one at pH 3.0 and that azo dyes including MO, Orange I, and Orange II could be successfully degraded in such cathodes. The reaction rate constant ({kappa}) of azo dye reduction was positively correlated with the power output which was highly dependent on the catholyte pH and the dye molecular structure. When pH was varied from 3.0 to 9.0, the k value in relation to MO degradation decreased from 0.298 to 0.016 {mu}mol min{sup -1}, and the maximum power density decreased from 34.77 to 1.51 mW m{sup -2}. The performances of the MFC fed with different azo dyes can be ranked from good to poor as MO > Orange I > Orange II. Furthermore, the cyclic voltammograms of azo dyes disclosed that the pH and the dye structure determined their redox potentials. A higher redox potential corresponded to a higher reaction rate. (orig.)

  14. AZO/Ag/AZO anode for resonant cavity red, blue, and yellow organic light emitting diodes

    Science.gov (United States)

    Gentle, A. R.; Yambem, S. D.; Burn, P. L.; Meredith, P.; Smith, G. B.

    2016-06-01

    Indium tin oxide (ITO) is the transparent electrode of choice for organic light-emitting diodes (OLEDs). Replacing ITO for cost and performance reasons is a major drive across optoelectronics. In this work, we show that changing the transparent electrode on red, blue, and yellow OLEDs from ITO to a multilayer buffered aluminium zinc oxide/silver/aluminium zinc oxide (AZO/Ag/AZO) substantially enhances total output intensity, with better control of colour, its constancy, and intensity over the full exit hemisphere. The thin Ag containing layer induces a resonant cavity optical response of the complete device. This is tuned to the emission spectra of the emissive material while minimizing internally trapped light. A complete set of spectral intensity data is presented across the full exit hemisphere for each electrode type and each OLED colour. Emission zone modelling of output spectra at a wide range of exit angles to the normal was in excellent agreement with the experimental data and hence could, in principle, be used to check and adjust production settings. These multilayer transparent electrodes show significant potential for both eliminating indium from OLEDs and spectrally shaping the emission.

  15. Conducting polypyrrole films as a potential tool for electrochemical treatment of azo dyes in textile wastewaters.

    Science.gov (United States)

    Haque, Md Mominul; Smith, Warren T; Wong, Danny K Y

    2015-01-01

    In this paper, we demonstrate conducting polypyrrole films as a potential green technology for electrochemical treatment of azo dyes in wastewaters using Acid Red 1 as a model analyte. These films were synthesised by anodically polymerising pyrrole in the presence of Acid Red 1 as a supporting electrolyte. In this way, the anionic Acid Red 1 is electrostatically attracted to the cationic polypyrrole backbone formed to maintain electroneutrality, and is thus entrapped in the film. These Acid Red 1-entrapped polypyrrole films were characterised by electrochemical, microscopic and spectroscopic techniques. Based on a two-level factorial design, the solution pH, Acid Red 1 concentration and polymerisation duration were identified as significant parameters affecting the entrapment efficiency. The entrapment process will potentially aid in decolourising Acid Red 1-containing wastewaters. Similarly, in a cathodic process, electrons are supplied to neutralise the polypyrrole backbone, liberating Acid Red 1 into a solution. In this work, following an entrapment duration of 480 min in 2000 mg L(-1) Acid Red 1, we estimated 21% of the dye was liberated after a reduction period of 240 min. This allows the recovery of Acid Red 1 for recycling purposes. A distinctive advantage of this electrochemical Acid Red 1 treatment, compared to many other techniques, is that no known toxic by-products are generated in the treatment. Therefore, conducting polypyrrole films can potentially be applied as an environmentally friendly treatment method for textile effluents.

  16. STUDI DEGRADASI ZAT PEWARNA AZO, METIL ORANYE MENGGUNAKAN FERRAT (FeO42-)

    OpenAIRE

    Dian Windy Dwiasi; Mardiyah Kurniasih

    2008-01-01

    Synthesis of ferrate and its application to azo dyes degradation have been investigated. The synthesis was carried out by reacting Fe(NO3)3 solution with NaOCl in alkaline condition. Oxidation reaction of azo dyes was carried out by adjusting the molar ratio of ferrate to azo dyes. When ferrate reacted with azo dyes, its absorbance was monitored using UV-Vis spectrophotometer at pH condition that had been optimized. Kinetics study for azo dyes degradation was carried out at the absorbance max...

  17. STUDI DEGRADASI ZAT PEWARNA AZO, METIL ORANYE MENGGUNAKAN FERRAT (FeO42-

    Directory of Open Access Journals (Sweden)

    Dian Windy Dwiasi

    2008-05-01

    Full Text Available Synthesis of ferrate and its application to azo dyes degradation have been investigated. The synthesis was carried out by reacting Fe(NO33 solution with NaOCl in alkaline condition. Oxidation reaction of azo dyes was carried out by adjusting the molar ratio of ferrate to azo dyes. When ferrate reacted with azo dyes, its absorbance was monitored using UV-Vis spectrophotometer at pH condition that had been optimized. Kinetics study for azo dyes degradation was carried out at the absorbance maximum of azo dyes, as a function of time. Ferrate can oxidize azo dyes, methyl oranye effectively in optimum pH of 9.6. With the molar ratio of ferrate/azo dyes 5/1, it showed that the percentages of methyl oranye degradation reached 100%. The azo dyes degradation followed first order of kinetics. Analysis using UV-Vis spectrofotometry suggests that the products of azo dyes degradation are nitrate, ammonia, and benzene. This results showed that ferrate is an alternative and green oxidizing agent which can be used for azo dyes degradation.

  18. Simultaneous removal of color, organic compounds and nutrients in azo dye-containing wastewater using up-flow constructed wetland

    International Nuclear Information System (INIS)

    Combination of aerobic and anaerobic processes in constructed wetlands can enhance the treatment performance in textile wastewater. This study assessed the treatment of azo dye Acid Orange 7 (AO7) and nutrients using five laboratory-scale up-flow constructed wetlands (UFCW) with and without supplementary aeration, and with different emergent plants. Supplementary aeration controlled the size of aerobic and anaerobic zones in the UFCW reactors as evidenced by the oxidation-reduction potential (ORP) and dissolved oxygen (DO) profile of the UFCW. The AO7 removal efficiency was above 95% in all UFCW reactors and most of the color was extensively removed in the anaerobic region of the UFCW beds. The intermediates produced through the breakage of azo bond were significantly reduced in the UFCW reactors with supplementary aeration. The results indicated the applicability of the UFCW reactors to the treatment of azo dye-containing wastewater. The removals of T-N and T-P were in the range of 60-67% and 26-37%, respectively, among the UFCW reactors. The COD and NH4-N removals in the aerated reactors were about 86 and 96%, respectively. On the other hand, the COD and NH4-N removals were in the range of 78-82% and 41-48%, respectively, in the non-aerated reactors. The supplementary aeration enhanced the removal efficiencies in organic matter, NH4-N and aromatic amines in the UFCW reactors.

  19. Temperature-dependent photoinduced third-harmonic-generation variation in azo-homopolymer and azo-doped polymer thin films

    International Nuclear Information System (INIS)

    The temperature effect on the variation of photoinduced third-harmonic generation (THG) of an azo-polyurethane homopolymer and an azo guest-host polymer is studied at several different temperatures. At higher temperatures, both angular hole burning and molecule angular redistribution motions weaken, due to the decreases of cis-to-trans thermal relaxation time and the cis population and the increase of orientational diffusion coefficient. Smaller photoinduced THG variation is observed in both samples at higher temperatures. Results from the THG recovery experiment show that polyurethane homopolymer thin films pumped at a high temperature have the best photoinduced THG variation stability after turning off the pump beam

  20. Degradation of commercial azo dye reactive Black B in photo/ferrioxalate system

    International Nuclear Information System (INIS)

    The photolysis and photo-catalysis of ferrioxalate in the presence of hydrogen peroxide with UV irradiation (UV/ferrioxalate/H2O2 process) for treating the commercial azo dye, reactive Black B (RBB), is examined. An effort is made to decolorize textile effluents at near neutral pH for suitable discharge of waste water. pH value, light source, type of initial catalyst (Fe3+ or Fe2+) and concentration of oxalic acid (Ox) strongly affected the RBB removal efficiency. The degradation rate of RBB increased as pH or the wavelength of light declined. The optimal molar ratio of oxalic acid to Fe(III) is three, and complete color removal is achieved at pH 5 in 2 h of the reaction. Applying oxalate in such a photo process increases both the RBB removal efficiency and the COD removal from 68% and 21% to 99.8% and 71%, respectively

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

    Science.gov (United States)

    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.

  2. A built-in zero valent iron anaerobic reactor to enhance treatment of azo dye wastewater.

    Science.gov (United States)

    Zhang, Yaobin; Jing, Yanwen; Quan, Xie; Liu, Yiwen; Onu, Pascal

    2011-01-01

    Waste scrap iron was packed into an upflow anaerobic sludge blanket (UASB) reactor to form a zero valent iron (ZVI) - UASB reactor system for treatment of azo dye wastewater. The ZVI acted as a reductant to decrease ORP in the reactor by more than 40 mv and functioned as an acid buffer to increase the pH in the reactor from 5.44 to 6.29, both of which improved the performance of the anaerobic reactor. As a result, the removal of color and COD in this reactor was 91.7% and 53%, respectively, which was significantly higher than that of a reference UASB reactor without ZVI. The UV-visible spectrum demonstrated that absorption bands of the azo dye from the ZVI-UASB reactor were substantially reduced. The ZVI promoted methanogenesis, which was confirmed by an increase in CH(4) content in the biogas from 47.9% to 64.8%. The ZVI bed was protected well from rusting, which allowed it to function stably. The effluent could be further purified only by pH adjustment because the Fe(2+) released from ZVI served as a flocculent.

  3. Metabolism of the benzidine-based azo dye Direct Black 38 by human intestinal microbiota

    Energy Technology Data Exchange (ETDEWEB)

    Manning, B.W.; Cerniglia, C.E.; Federle, T.W.

    1985-07-01

    Benzidine-based azo dyes are proven mutagens and have been linked to bladder cancer. Previous studies have indicated that their initial reduction is the result of the azo reductase activity of the intestinal microbiota. Metabolism of the benzidine-based dye Direct Black 38 was examined by using a semicontinuous culture system that simulates the lumen of the human large intestine. The system was inoculated with freshly voided feces, and an active flora was maintained as evidenced by volatile fatty acid and gas production. Within 7 days after exposure to the dye, the following metabolites were isolated and identified by gas chromatography - mass spectrometry: benzidine, 4-aminobiphenyl, monoacetylbenzidine, and acetylaminobiphenyl. Benzidine reached its peak level after 24 h, accounting for 39.1% of the added dye. Its level began to decline, and by day 7 the predominant metabolite was acetylaminobiphenyl, which accounted for 51.1% of the parent compound. Formation of the deaminated and N-acetylated analogs of benzidine, which have enhanced mutagenicity and lipophilicity, previously has not been attributed to the intestinal microbiota.

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

    Science.gov (United States)

    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).

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

    Science.gov (United States)

    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

  6. A rapid and ultrasensitive SERRS assay for histidine and tyrosine based on azo coupling.

    Science.gov (United States)

    Sui, Huimin; Wang, Yue; Yu, Zhi; Cong, Qian; Han, Xiao Xia; Zhao, Bing

    2016-10-01

    A simple and highly sensitive surface-enhanced resonance Raman scattering (SERRS)-based approach coupled with azo coupling reaction has been put forward for quantitative analysis of histidine and tyrosine. The SERRS-based assay is simple and rapid by mixing the azo reaction products with silver nanoparticles (AgNPs) for measurements within 2min. The limits of detection (LODs) of the method are as low as 4.33×10(-11) and 8.80×10(-11)M for histidine and tyrosine, respectively. Moreover, the SERRS fingerprint information specific to corresponding amino acids guarantees the selective detection for the target histidine and tyrosine. The results from serum indicated the potential application of the proposed approach into biological samples. Compared with the methods ever reported, the main advantages of this methodology are simpleness, rapidity without time-consuming separation or pretreatment steps, high sensitivity, selectivity and the potential for determination of other molecules containing imidazole or phenol groups. PMID:27474300

  7. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl amino substituted triazine amino... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato...

  8. Azo-polysiloxanes as new supports for cell cultures

    Energy Technology Data Exchange (ETDEWEB)

    Hurduc, Nicolae, E-mail: nhurduc@ch.tuiasi.ro [“Gheorghe Asachi” Technical University of Iasi, Department of Natural and Synthetic Polymers, Prof. Dimitrie, Mangeron Street, 73, 700050-Iasi (Romania); Macovei, Alina [Institute of Biochemistry of the Romanian Academy, Department of Viral Glycoproteins, Splaiul Independentei 296, Sector 6, 060041-Bucuresti (Romania); Paius, Cristina; Raicu, Alina [“Gheorghe Asachi” Technical University of Iasi, Department of Natural and Synthetic Polymers, Prof. Dimitrie, Mangeron Street, 73, 700050-Iasi (Romania); Moleavin, Ioana [CEA, LIST Saclay, Laboratoire Capteurs et Architectures Électroniques, F-91191 Gif-sur-Yvette, Cedex (France); Branza-Nichita, Norica, E-mail: nichita@biochim.ro [Institute of Biochemistry of the Romanian Academy, Department of Viral Glycoproteins, Splaiul Independentei 296, Sector 6, 060041-Bucuresti (Romania); Hamel, Matthieu [CEA, LIST Saclay, Laboratoire Capteurs et Architectures Électroniques, F-91191 Gif-sur-Yvette, Cedex (France); Rocha, Licinio, E-mail: Licinio.ROCHA@cea.fr [CEA, LIST Saclay, Laboratoire Capteurs et Architectures Électroniques, F-91191 Gif-sur-Yvette, Cedex (France)

    2013-05-01

    The paper introduces a new class of materials with azo-polysiloxanic structure bearing the property to generate nano-structured surfaces by laser irradiation. The ability to modulate the optical response of the film, through a modification of the polymer chemical structure, has been investigated. The azo-materials were tested for their ability to support cell adhesion and growth, with very promising results. A future use of these materials as growth support in cell cultures is of great interest, due to an easy, one step-method to generate the surface relief grating and to the possibility to introduce a large range of chemical modifications due to the presence of the chlorobenzyl groups in the polymeric side-chain. - Graphical abstract: Cell development on a nano-structured surface obtained from an azo-polysiloxanic film. Highlights: ► New azo-polysiloxanic films for biological applications were reported. ► Nanostructured surfaces with controllable geometry are obtained by laser irradiation. ► Cells are very sensitive to the chemical and physical properties of the polymeric substrate.

  9. Azo-polysiloxanes as new supports for cell cultures

    International Nuclear Information System (INIS)

    The paper introduces a new class of materials with azo-polysiloxanic structure bearing the property to generate nano-structured surfaces by laser irradiation. The ability to modulate the optical response of the film, through a modification of the polymer chemical structure, has been investigated. The azo-materials were tested for their ability to support cell adhesion and growth, with very promising results. A future use of these materials as growth support in cell cultures is of great interest, due to an easy, one step-method to generate the surface relief grating and to the possibility to introduce a large range of chemical modifications due to the presence of the chlorobenzyl groups in the polymeric side-chain. - Graphical abstract: Cell development on a nano-structured surface obtained from an azo-polysiloxanic film. Highlights: ► New azo-polysiloxanic films for biological applications were reported. ► Nanostructured surfaces with controllable geometry are obtained by laser irradiation. ► Cells are very sensitive to the chemical and physical properties of the polymeric substrate

  10. Detoxification of azo dyes by bacterial oxidoreductase enzymes.

    Science.gov (United States)

    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.

  11. Toxicity assessment and microbial degradation of azo dyes.

    Science.gov (United States)

    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.

  12. Synthesis of dis-azo black dyes for electrowetting displays

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Yifen, E-mail: carol.chiang@jintex.com.tw [Institute of Organic and Polymer Materials, National Taipei University of Technology, 1, Sec. 3, Chung-hsiao E. Rd., Taipei 10608, Taiwan, ROC (China); Chao, Yuchou, E-mail: ycchao@ntut.edu.tw [Institute of Organic and Polymer Materials, National Taipei University of Technology, 1, Sec. 3, Chung-hsiao E. Rd., Taipei 10608, Taiwan, ROC (China)

    2012-11-01

    Highlights: Black-Right-Pointing-Pointer The electrowetting technology with high reflectivity, high contrast, and fast response speed. Black-Right-Pointing-Pointer Color electrowetting display is manufactured by using black oil ink as an absorbing switch. Black-Right-Pointing-Pointer Conventional dis-azo black dyes possess poor solubility in linear alkanes. Black-Right-Pointing-Pointer Previous researches have focused on designing of electrowetting devices. Black-Right-Pointing-Pointer These dis-azo black dyes were resulted in having high solubility and neutral hue. - Abstract: This study was to design and synthesize a series of dis-azo dyes derived from p-n-alkyl aniline by introducing different alkyl group resulted in having high solubility in linear alkanes solvents, even absorption intensity of visible wavelengths. Results indicated that elementary properties of black oil ink were (1) non-polar; (2) low viscosity (<3.0 cps); (3) specified surface tension (<30 mN/m); (4) intensity of visible absorption uniformly covering 400-800 nm; (5) FoM equal to 100-1000; (6) hue close to standard black (L = 0, a = 0, b = 0). We can conclude that dis-azo black dyes fulfills elementary conditions of colored oil ink for electrowetting display.

  13. Optimization of AZO films prepared on flexible substrates

    Indian Academy of Sciences (India)

    C C Hu; T W Lu; C Y Chou; J T Wang; H H Huang; C Y Hsu

    2014-10-01

    Transparent conductive Al2O3-doped zinc oxide (in AZO, Al2O3 content is ∼ 2 wt%) thin films are deposited on flexible polyethylene terephthalate (PET) substrates, using radio frequency (rf) magnetron sputtering. The Taguchi method with an 9 (34) orthogonal array, a signal-to-noise ratio and analysis of variance (ANOVA) was used to determine the performance characteristics of the coating operations. Using grey relational analysis, the optimization of these deposition process parameters for AZO thin films with multiple characteristics was performed. The electrical resistivity of AZO/PET films is reduced from 2.6 × 10-2 to 5.5 × 10-3 -cm and the visible range transmittance is > 83%, using the grey relational analysis. ANOVA results for the grey relational grade indicate that rf power and working pressure are the two most influential factors. The effect of the rf power (in the range from 30 to 70 W) and the argon working pressure (in the range from 0.90 to 1.1 Pa) on the morphology and optoelectronic performance of AZO films are also investigated. An analysis of the influence of the dominant parameters in the optimal design region is helpful for adjustment of the coating parameters.

  14. Carcinogenicity of azo colorants: influence of solubility and bioavailability.

    Science.gov (United States)

    Golka, Klaus; Kopps, Silke; Myslak, Zdislaw W

    2004-06-15

    In the past, azo colorants based on benzidine, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine (o-tolidine), and 3,3'-dimethoxybenzidine (o-dianisidine) have been synthesized in large amounts and numbers. Studies in exposed workers have demonstrated that the azoreduction of benzidine-based dyes occurs in man. The metabolic conversion of benzidine-, 3,3'-dimethylbenzidine- and 3,3'-dimethoxybenzidine-based dyes to their (carcinogenic) amine precursors in vivo is a general phenomenon that must be considered for each member of this class of chemicals. Several epidemiological studies have demonstrated that the use of the benzidine-based dyes has caused bladder cancer in humans. However, in contrast to water-soluble dyes, the question of biological azoreduction of (practically insoluble) pigments has been a matter of discussion. As a majority of azo pigments are based on 3,3'-dichlorobenzidine, much of the available experimental data are focused on this group. Long-term animal carcinogenicity studies performed with pigments based on 3,3'-dichlorobenzidine did not show a carcinogenic effect. The absence of a genotoxic effect has been supported by mutagenicity studies with the 3,3'-dichlorobenzidine-based Pigment Yellow 12. Studies in which azo pigments based on 3,3'-dichlorobenzidine had been orally administered to rats, hamsters, rabbits and monkeys could generally not detect significant amounts of 3,3'-dichlorobenzidine in the urine. It, therefore, appears well established that the aromatic amine components from azo pigments based on 3,3'-dichlorobenzidine are practically not bioavailable. Hence, it is very unlikely that occupational exposure to insoluble azo pigments would be associated with a substantial risk of (bladder) cancer in man. According to current EU regulations, azo dyes based on benzidine, 3,3'-dimethoxybenzidine and 3,3'-dimethylbenzidine have been classified as carcinogens of category 2 as "substances which should be regarded as if they are carcinogenic

  15. A comparison of transmittance properties between ZnO∶Al films for transparent conductors for solar cells deposited by sputtering of AZO and cosputtering of AZO/ZnO

    Institute of Scientific and Technical Information of China (English)

    LEE Chongmu; YIM Keunbin; CHO Youngjoon; Lee J.G.

    2006-01-01

    Aluminum-doped zinc oxide (AZO) thin films were deposited on sapphire (002) andglass substrates by two different sputtering techniques radio frequency magnetron cosputtering of AZO and ZnO targets and sputtering of an AZO target. The dependence of the photoluminescence (PL) and transmittance properties of the AZO films deposited by cosputtering and sputtering on the AZO/ZnO target power ratio, R and the O2/Ar flow ratio, r were investigated, respectively. Only a deep level emission peak appears in the PL spectra of cosputtered AZO films whereas both UV emission and deep level emission peaks are observed in the PL spectra of sputtered AZO films. The absorption edges in the transmittance spectra of the AZO films shift to the lower wavelength region as R and r increase. Effects ofcrystallinity, surface roughness, PL on the transmittance of the AZO films werealso explained using the X-ray diffraction (XRD), atomic force microscopy (AFM), and PL analysis results.

  16. Conducting polypyrrole films as a potential tool for electrochemical treatment of azo dyes in textile wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Md. Mominul [Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109 (Australia); Smith, Warren T. [Samadha Pacifica Pty Ltd, Woonona, NSW 2517 (Australia); Wong, Danny K.Y., E-mail: Danny.Wong@mq.edu.au [Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109 (Australia)

    2015-02-11

    Highlights: • Anion exchange property of polypyrrole films exploited in developing a treatment method for Acid Red 1. • An environmentally friendly treatment method for Acid Red 1 without generating any toxic by-products. • Acid Red 1 is anodically entrapped and cathodically liberated at polypyrrole films. • Analytical characteristics of Acid Red 1-entrapped polypyrrole films. - Abstract: In this paper, we demonstrate conducting polypyrrole films as a potential green technology for electrochemical treatment of azo dyes in wastewaters using Acid Red 1 as a model analyte. These films were synthesised by anodically polymerising pyrrole in the presence of Acid Red 1 as a supporting electrolyte. In this way, the anionic Acid Red 1 is electrostatically attracted to the cationic polypyrrole backbone formed to maintain electroneutrality, and is thus entrapped in the film. These Acid Red 1-entrapped polypyrrole films were characterised by electrochemical, microscopic and spectroscopic techniques. Based on a two-level factorial design, the solution pH, Acid Red 1 concentration and polymerisation duration were identified as significant parameters affecting the entrapment efficiency. The entrapment process will potentially aid in decolourising Acid Red 1-containing wastewaters. Similarly, in a cathodic process, electrons are supplied to neutralise the polypyrrole backbone, liberating Acid Red 1 into a solution. In this work, following an entrapment duration of 480 min in 2000 mg L{sup −1} Acid Red 1, we estimated 21% of the dye was liberated after a reduction period of 240 min. This allows the recovery of Acid Red 1 for recycling purposes. A distinctive advantage of this electrochemical Acid Red 1 treatment, compared to many other techniques, is that no known toxic by-products are generated in the treatment. Therefore, conducting polypyrrole films can potentially be applied as an environmentally friendly treatment method for textile effluents.

  17. An Improved Method for Removal of Azo Dye Orange II from Textile Effluent Using Albumin as Sorbent

    OpenAIRE

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

    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 propor...

  18. Structural basis of the mutagenicity of 1-amino-2-naphthol-based azo dyes.

    Science.gov (United States)

    Rosenkranz, H S; Klopman, G

    1990-03-01

    A structure-activity study of 1-amino-2-naphthol derived azo dyes using CASE, the Computer Automated Structure Evaluation system, revealed that for optimal mutagenicity, reduction of the azo bond was required, thus suggesting that activity could be related to the liberated aromatic amines. Although it has long been known that sulfonation of azo dyes resulted in decreased carcinogenicity and mutagenicity, the present study elucidates the sites of sulfonation which will decrease mutagenicity maximally. Comparison of CASE predictions with available mutagenicity data indicates a concordance. Unexpectedly, CASE indicates that one of the aromatic amines obtained upon azo reduction of FD and C Red no. 40 is predicted to be mutagenic.

  19. Biosorption of Azo dyes by spent Rhizopus arrhizus biomass

    Science.gov (United States)

    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.

  20. Equilibrium and thermodynamics of azo dyes biosorption onto Spirulina platensis

    OpenAIRE

    G. L. Dotto; M. L. G. Vieira; V. M. Esquerdo; L. A. A. PINTO

    2013-01-01

    The equilibrium and thermodynamics of azo dye (tartrazine and allura red) biosorption onto Spirulina platensis biomass were investigated. The equilibrium curves were obtained at 298, 308, 318 and 328 K, and four isotherm models were fitted the experimental data. Biosorption thermodynamic parameters (ΔG, ΔH and ΔS) were estimated. The results showed that the biosorption was favored by a temperature decrease. For both dyes, the Sips model was the best to represent the equilibrium...

  1. Removal of azo dye from aqueous solutions using chitosan

    OpenAIRE

    Zuhair Jabbar; G. Hadi Ferdoos Sami; A , Angham

    2014-01-01

    Adsorption of Congo Red (CR) from aqueous solution onto chitosan was investigated in a batch system. The effects of solution pH, initial dye concentration, and temperature were studied. Results indicated that chitosan could be used as a biosorbent to remove the azo dyes from contaminated water. Synthesize of chitosan involved three main stages as preconditioning, demineralization, deproteinization and deacetylation. Chitosan was characterized using Fourier Transform Infrared Spectroscopy (FTI...

  2. Novel photochromic 2,2´-bithiophene azo dyes

    OpenAIRE

    Paulo J. Coelho; Carvalho, Luís H. Melo de; Moura, João C. V. P.; Raposo, M. Manuela M.

    2009-01-01

    The photochromic behaviour of two series of 2,2’-bithiophene azo dyes in THF solutions was studied. The photochromic properties and colour constancy were strongly dependent on the substitution pattern of the dyes. Under visible irradiation (> 420 nm) while some dyes exhibited a significant change in the colour intensity others exhibited an almost stable absorption. The photokinetic parameters of these systems are described. Fundação para a Ciência e a Tecnologia (FCT)

  3. Azo-bridged triazoles:Green energetic materials

    Institute of Scientific and Technical Information of China (English)

    Lemi TüRKER

    2016-01-01

    In this short review, excerpts from the literature of azo-bridged triazoles (mainly 1,2,4-triazoles), some of their derivatives (chloromethyl, dinitro and trinitro pyrazole substituted ones, etc.) and some of their salts, have been presented focusing on the most recent investigations. These classes of compounds, known as high nitrogen compounds, are generally high energy density materials. Therefore, if available some of their ballistic properties were included.

  4. The Hydractinia echinata Test-System. III: Structure-Toxicity Relationship Study of Some Azo-, Azo-Anilide, and Diazonium Salt Derivatives

    Directory of Open Access Journals (Sweden)

    Sergiu Adrian Chicu

    2014-07-01

    Full Text Available 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.

  5. Degradation of disperse azo dyes from waters by solar photoelectro-Fenton

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, Ricardo [Departamento de Ciencias del Ambiente, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACh, Casilla 40, Correo 33, Santiago (Chile); Garcia-Segura, Sergi [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Ureta-Zanartu, M.S. [Departamento de Ciencias del Ambiente, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACh, Casilla 40, Correo 33, Santiago (Chile); Brillas, Enric, E-mail: brillas@ub.edu [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain)

    2011-07-15

    Highlights: > Reactive azo dyes are almost totally mineralized by solar photoelectro-Fenton. > The process yields high current efficiencies and low energy consumptions. > It is more efficient and inexpensive by decreasing current and increasing dye content. > Nitrate ions are the main inorganic ions released during the mineralization process. > The process is also effective for the remediation of textile dyeing solutions. - Abstract: Solutions of the azo dyes Disperse Red 1 (DR1) and Disperse Yellow 3 (DY3), commonly used in the Chilean textile industry, in 0.1 mol dm{sup -3} Na{sub 2}SO{sub 4} and 0.5 mmol dm{sup -3} Fe{sup 2+} of pH 3.0 were comparatively degraded by electro-Fenton (EF) and solar photoelectro-Fenton (SPEF) using a 2.5 dm{sup 3} recirculation flow plant containing a BDD/air-diffusion cell coupled with a solar photoreactor. Organics were oxidized in EF with hydroxyl radicals formed at the anode surface from water oxidation and in the bulk from Fenton's reaction between electrogenerated H{sub 2}O{sub 2} and added Fe{sup 2+}. The oxidizing power of SPEF was enhanced by the additional production of hydroxyl radicals from the photolysis of Fe(III) hydrated species and the photodecomposition of Fe(III) complexes with intermediates by UV light of solar irradiation. Total decolorization, complete dye removal and almost overall mineralization for both dye solutions were only achieved using the most potent SPEF process, yielding higher current efficiencies and lower energy consumptions than EF. Final carboxylic acids like pyruvic, acetic, oxalic and oxamic were detected during the SPEF treatments. NO{sub 3}{sup -} ion was released as inorganic ion. The use of a solution pH of 2.0-3.0 at 50 mA cm{sup -2} was found preferable for SPEF. Synthetic textile dyeing solutions containing the dyes were treated under these conditions yielding lower decolorization rate, slower dye removal and smaller mineralization degree than only using 0.1 mol dm{sup -3} Na

  6. 40 CFR 721.984 - Amino-hydroxy sulfonaphthylazo-disubstituted phenyl azo benzene carboxylate salt (generic).

    Science.gov (United States)

    2010-07-01

    ...-disubstituted phenyl azo benzene carboxylate salt (generic). 721.984 Section 721.984 Protection of Environment...-disubstituted phenyl azo benzene carboxylate salt (generic). (a) Chemical substance and significant new uses...-disubstituted phenyl azo benzene carboxylate salt (PMN P-00-0351) is subject to reporting under this section...

  7. Enhanced optical and electrical properties of Ni inserted ITO/Ni/AZO tri-layer structure for photoelectric applications

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M. Melvin David; Kim, Hyunki [Department of Electrical Engineering, Incheon National University, Incheon 406772 (Korea, Republic of); Park, Yun Chang [Measurement and Analysis Division, National Nanofab Center (NNFC), Daejeon 305-806 (Korea, Republic of); Kim, Joondong, E-mail: joonkim@incheon.ac.kr [Department of Electrical Engineering, Incheon National University, Incheon 406772 (Korea, Republic of)

    2015-05-15

    Highlights: • Ni-embedding transparent conductor effectively reduces the resistivity. • Ni insertion improves the carrier mobility and collection efficiencies. • ITO/Ni/AZO is effective to improve photo-responses compared to ITO/AZO. - Abstract: A thin Ni layer of 5 nm thickness was deposited in between indium-tin-oxide (ITO) and aluminum-doped-zinc oxide (AZO) layers of 50 nm thickness each. The Ni inserting tri-layer structure (ITO/Ni/AZO) showed lower resistivity of 5.51 × 10{sup −4} Ωcm which is nearly 20 times lesser than 97.9 × 10{sup −4} Ωcm of bilayer structure (ITO/AZO). A thin Ni layer in between ITO and AZO enhanced the carrier concentration, mobility and photoresponse behaviors so that figure of merit (FOM) value of ITO/Ni/AZO device was greater than that of ITO/AZO device. ITO/Ni/AZO structure showed improved quantum efficiencies over a broad range of wavelengths (∼350–950 nm) compared to that of ITO/AZO bilayer structure, resulting in enhanced photoresponses. These results show that the optical, electrical and photoresponse properties of ITO/AZO structure could be enhanced by inserting Ni layer of 5 nm thickness in between ITO and AZO layers.

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

    Science.gov (United States)

    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.

  9. Cyclodextrin-induced host–guest effects of classically prepared poly(NIPAM bearing azo-dye end groups

    Directory of Open Access Journals (Sweden)

    Gero Maatz

    2012-11-01

    Full Text Available A thermo-, pH- and cyclodextrin- (CD responsive poly(N-isopropylacrylamide (PNIPAM, with a N,N-dimethylaminoazobenzene end group was synthesized. Using 3-mercaptopropionic acid as a chain transfer agent, PNIPAM with a well-defined COOH end group was obtained. The acid end group was transferred to the corresponding acid chloride and then functionalized with N,N-dimethyl[4-(4’-aminophenylazophenyl]amine. This dye-end-group-labeled polymer showed acidochromic effects, depending on the pH and the presence of randomly methylated β-cyclodextrin (RAMEB-CD. Also higher cloud-point values for the lower critical solution temperature (LCST in the presence of RAMEB-CD were observed. Additionally, this azo-dye-end-group-labeled polymer was complexed with hyperbranched polyglycerol (HPG decorated with β-CD to generate hedgehog-like superstructures.

  10. The contribution of biotic and abiotic processes during azo dye reduction in anaerobic sludge

    NARCIS (Netherlands)

    Zee, van der F.P.; Bisschops, I.A.E.; Blanchard, V.G.; Bouwman, R.H.M.; Lettinga, G.; Field, J.A.

    2003-01-01

    Azo dye reduction results from a combination of biotic and abiotic processes during the anaerobic treatment of dye containing effluents. Biotic processes are due to enzymatic reactions whereas the chemical reaction is due to sulfide. In this research, the relative impact of the different azo dye red

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

    NARCIS (Netherlands)

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

    2001-01-01

    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 cataly

  12. Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 202 Haihe Road, Harbin 150090 (China); Lee, Hyung-Sool [Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West Waterloo, Ontario, Canada N2L 3G1 (Canada); Wang, Ai-Jie, E-mail: waj0578@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 202 Haihe Road, Harbin 150090 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer A membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor was developed. Black-Right-Pointing-Pointer Alizarin Yellow R as the mode of azo dyes was efficiently converted to p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA). Black-Right-Pointing-Pointer PPD and 5-ASA were further oxidized in a bio-contact oxidation reactor. Black-Right-Pointing-Pointer The mechanism of UBER for azo dye removal was discussed. - Abstract: 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 g m{sup -3} d{sup -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 g m{sup -3} d{sup -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.

  13. Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor

    International Nuclear Information System (INIS)

    Highlights: ► A membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor was developed. ► Alizarin Yellow R as the mode of azo dyes was efficiently converted to p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA). ► PPD and 5-ASA were further oxidized in a bio-contact oxidation reactor. ► The mechanism of UBER for azo dye removal was discussed. - Abstract: 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 g m−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 g m−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.

  14. Comparative metabolism and mutagenicity of azo and hydrazone dyes in the Ames test.

    Science.gov (United States)

    De France, B F; Carter, M H; Josephy, P D

    1986-02-01

    Enteric bacterial and hepatic azoreductase enzymes are capable of reducing azo dyes to yield the constituent aromatic amines. Azo dyes based on benzidine and benzidine congeners have received particular attention because of their widespread use and the known carcinogenicity of benzidine to humans. Azo dyes based on beta-diketone coupling components exist preferentially as the tautomeric hydrazones. A series of hydrazone dyes based on benzidine and benzidine congeners was prepared and characterized by NMR and UV-visible spectroscopy. These dyes were tested for mutagenicity using a modified Ames assay and, unlike the true azo dyes, showed no significant mutagenic activity. The hydrazone dyes were resistant to enzymatic reduction by FMN-supplemented hamster-liver post-mitochondrial supernatant (S-9); under identical conditions, azo dyes such as trypan blue were rapidly reduced.

  15. 6AZO-CONTAINING SELF-ASSEMBLY ULTRA-THIN FILMS AND THEIR PHOTOVOLTAIC PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    Mao-feng Zhang; Qiao-hong Yao; Chun-hui Huang; Wei-xiao Cao

    2005-01-01

    A kind of azo-containing resin (Azo-R) was synthesized by a simple way through the coupling reaction of 2-nitroN-methyldiphenylamine-4-diazoresin (NDR) with phenol, and a new covalentely attached multilayer film from Azo-R as H-donor and photosensitive diazoresin, diphenylamine-4-diazoresin (DR) as H-acceptor via H-bonding attraction by selfassembly technique has been fabricated. Following the decomposition of diazonium group of DR under exposure to UV light, the H-bonds between the layers of the film convert to covalent bonds and the film becomes very stable toward polar solvents or electrolyte aqueous solutions. Thus the UV-irradiated azo-containing films can be used to measure photocurrent in a conventional three-electrode photoelectrochemical cell using KCl as supporting electrolyte. It was confirmed that the azo-containing multilayer film is responsible for the photocurrent generation.

  16. Novel hierarchical architectures of Sb2WO6: template-free hydrothermal synthesis and photocatalytic reduction property for azo compound

    International Nuclear Information System (INIS)

    Novel hierarchical architectures of Sb2WO6 are synthesized successfully by a simple hydrothermal process without any organic solvent or surfactant. The physicochemical properties of the as-prepared products are characterized in detail. Interestingly, the morphologies of Sb2WO6 could be selectively controlled by adjusting pH values of the reactive solutions. The tuft-like, cockscomb-like, and flower-like hierarchical architectures are obtained at pH = 1, 3, and 5, respectively. Based on the time-dependent experimental results, a possible growth mechanism is proposed, which reasonably follows a synergy interaction of reaction–crystallization and dissolution–recrystallization processes. The photocatalytic activities of the novel hierarchical Sb2WO6 are evaluated by the decomposition of azo compounds for the first time. Results show that the as-prepared samples exhibit the excellent photocatalytic activity and universality for the reduction of azo compounds. The conversion of methyl orange reaches 98 % after 140 min of light irradiation. HPLC–MS indicates that the selectivity of 4-aminobenzene sulfonic acid is over 99 %.

  17. Effect of inducers on the decolorization and biodegradation of textile azo dye Navy blue 2GL by Bacillus sp. VUS.

    Science.gov (United States)

    Dawkar, Vishal V; Jadhav, Umesh U; Ghodake, Gajanan S; Govindwar, Sanjay P

    2009-11-01

    Bacillus sp. VUS decolorized azo dye Navy blue 2GL in 48 h at static anoxic condition in yeast extract medium, whereas it took only 18 h for the decolorization in presence of CaCl(2). Different inducers played role in the decolorization of Navy blue 2GL. CaCl(2) found to be the most effective inducer among all inducers tested. The activity of enzymes like lignin peroxidase, laccase and reductases viz. NADH-DCIP, azo and riboflavin induced during decolorization represents their role in the biodegradation. Extracellular LiP and intracellular laccase activity induced with CaCl(2). Yeast extract was best medium for faster decolorization than other media. UV-vis spectrophotometer analysis and visual examinations showed decolorization of dye. High performance liquid chromatography, Fourier transforms infrared spectroscopy showed degradation of dye. Gas Chromatography-Mass Spectroscopy revealed formation of 4-Amino-3-(2-bromo-4, 6-dinitro-phenylazo)-phenol and acetic acid 2-(-acetoxy-ethylamino)-ethyl ester as final products. Bacillus sp. VUS also decolorized synthetic effluent. Phytotoxicity study showed detoxification of Navy blue 2GL.

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

    Science.gov (United States)

    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

  19. Preparation of azo polyelectrolyte self-assembled multilayers by using N,N-dimethylformamide/H2O mixtures as solvents

    Institute of Scientific and Technical Information of China (English)

    Tuo Xinlin; Chen Di; Wang Xiaogong

    2006-01-01

    N,N-Dimethylformamide (DMF)/H2O mixtures were used as solvents to fabricate azo polyelectrolyte (PEAPH)/poly(diallyldimethyl ammonium chloride)(PDAC)self-assembled multilayers with the layer-by-layer electrostatic adsorption technique.PEAPH is a copolymer of acrylic acid and azobenzene-containing acrylate.The effect of the ratio of DMF to water on the .multilayer growth,structure and surface morphology was studied in some details.Results show that DMF/H2O mixtures are proper media for PEAPH/PDAC multilayer fabrication.The ratio of DMF to water in the mixture has significant influence on the multilayer structure and surface morphology.With the increase of DMF content,the multilayer thickness has a better linear growth relationship with the bilayer number,and the multilayer surface becomes smoother.Moreover,azo chromophores show less H-aggregation when the multilayers are fabricated from DMF/H2O mixtures with higher DMF contents.These studies demonstrate that using organic solvent and water mixtures is an effective way to control the multilayer construction by adjusting the media properties.This method can be applied to multilayer fabrication of other water-insoluble polyelectrolytes.

  20. Differential catalytic action of Brevibacillus laterosporus on two dissimilar azo dyes Remazol red and Rubine GFL.

    Science.gov (United States)

    Kurade, Mayur B; Waghmode, Tatoba R; Tamboli, Dhawal P; Govindwar, Sanjay P

    2013-02-01

    This comparative study disclosed the diverse catalytic activities of Brevibacillus laterosporus on two different azo dyes. It decolorized 100% of Remazol red and 95% of Rubine GFL within 30 and 48 h respectively, under static condition at 50 mg l⁻¹ dye concentration. Significant increase was observed in azo reductase, NADH-DCIP reductase, veratryl alcohol oxidase and tyrosinase in cells obtained after decolorization of Remazol red; whereas these values were much different with complete inhibition of azo reductase during decolorization of Rubine GFL. The plausible pathway of dye degradation obtained from Gas chromatography-Mass spectroscopy (GC-MS) data confirmed the different metabolic fate of these structurally unidentical dyes. FTIR and HPTLC analysis of extracted metabolites confirmed the biodegradation, while phytotoxicity study assured the detoxification of both the dyes studied. The results obtained in this study suggests, i) sulpho and hydroxyl group present at ortho position to azo group stimulated reduction of azo bond by azo reductase in Remazol red, ii) the same reduction was totally hampered due to presence of ethyl-amino propanenitrile group at para position to azo group in Rubine GFL.

  1. Fullerene-catalyzed reduction of azo derivatives in water under UV irradiation

    KAUST Repository

    Guo, Yong

    2012-09-27

    Metal-free fullerene (C60) was found to be an effective catalyst for the reduction of azo groups in basic aqueous solution under UV irradiation in the presence of NaBH4. Use of NaBH4 by itself is not sufficient to reduce the azo dyes without the assistance of a metal catalyst such as Pd and Ag. Experimental and theoretical results suggest that C 60 catalyzes this reaction by using its vacant orbital to accept the electron in the bonding orbital of azo dyes, which leads to the activation of the N=N bond. UV irradiation increases the ability of C60 to interact with electron-donor moieties in azo dyes. Filling a vacancy: Experimental and theoretical methods have been combined to show that C60-catalyzed reductions of azo compounds form aromatic amines under UV irradiation (see scheme). The obtained results show that C60 acts as an electron acceptor to catalyze the reduction of azo compounds, and the role of UV irradiation is to increase the ability of C60 to interact with electron-donor moieties in azo compounds. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Analytical procedures for the determination of disperse azo dyes

    Energy Technology Data Exchange (ETDEWEB)

    Betowski, L.D.; Jones, T.L. (Environmental Protection Agency, Las Vegas, NV (USA)); Munslow, W.; Nunn, N.J. (Lockheed Engineering and Management Services Co., Las Vegas, NV (USA))

    1988-09-01

    Disperse Blue 79 is the most widely-used azo dye in the US. Its economic importance for the dye industry and textile industry is very great. Because of its use and potential for degradation to aromatic amines, this compound has been chosen for testing by the Interagency Testing Committee. The authors laboratory has been developing methods for the analytical determination of Disperse Blue 79 and any possible degradation products in wastewater. This work has been taking place in conjunction with the study of the fate of azo dyes in the wastewater treatment processes by the Water Engineering Research Laboratory of the US EPA in Cincinnati. There were various phases for this analytical development. The first step involved purifying the commercial material or presscake to obtain a standard for quantitative determination. A combination of HPLC, TLC and mass spectrometric methods was used to determine purity after extraction and column cleanup. Phase two involved the extraction of the dye from the matrices involved. The third phase was the actual testing of Disperse Blue 79 in the waste activated sludge system and anaerobic digester. Recovery of the dye and any degradation products at each sampling point (e.g., secondary effluent, waste activated sludge) was the goal of this phase.

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

    Directory of Open Access Journals (Sweden)

    Ghorban Asgari

    2013-01-01

    Full Text Available 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.

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

    Directory of Open Access Journals (Sweden)

    Yuling Han

    Full Text Available 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.

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

    Science.gov (United States)

    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

  6. EPOXY-BASED AZO POLYMERS WITH HIGH CHROMOPHORE DENSITY:SYNTHESIS, CHARACTERIZATION AND PHOTOINDUCED BIREFRINGENCE

    Institute of Scientific and Technical Information of China (English)

    Xiao-lin Wang; Xiao-gong Wang

    2012-01-01

    Three epoxy-based azo polymers (PEP-AZ-C1,PEP-AZ-CN and PEP-AZ-NT) with high chromophore density were synthesized by using post-polymerization azo-coupling reactions between epoxy-bascd precursor polymer (PEP-AN)and diazonium salts of 4-chloroaniline,4-aminobenzonitrile and 4-nitroaniline,respectively.The structures and properties of the azo polymers were characterized by using 1H-NMR,FT-IR,UV-Vis and thermal analyses.The photoinduced birefringence of the azo polymers was studied by irradiating spin-coated films of the polymers with laser beam at three different wavelengths (488,532,and 589 nm).The results indicate that the photoinduced birefringence of the azo polymers is related with the electron-withdrawing group on azo chromophores and the excitation wavelength.The excitation wavelength that can cause the efficient responses is determined by the absorption band positions of the azo chromophores,which are mainly affected by the electron-withdrawing group on the chromophores.Therefore,the azo polymers containing chromophores with different electron-withdrawing groups show different responsive behavior to the irradiation light at different wavelengths.When irradiated with 488 nm light,PEP-AZ-Cl shows the shortest time to reach the saturated birefringence but with the lowest saturation birefringence level compared with the other two azo polymers.When irradiated with 532 nm light,PEP-AZ-CN shows the shortest time to reach the saturated birefringence.When irradiated with 532 and 589 nm light,PEP-AZ-NT shows the highest saturation birefringence level.

  7. The pH-sensitive properties of azo dyes in aqueous environment

    OpenAIRE

    Meyer, Thierry; Hemelsoet, Karen; Van der Schueren, Lien; PAUWELS, EWALD; De Clerck, Karen; Van Speybroeck, Veronique

    2012-01-01

    Azo dyes consist of a double nitrogen-nitrogen bond connected to two aromatic moieties, creating a large conjugated pi-system. A relatively simple synthesis and large variety of colours have made azo dyes the most abundant class of colourants. The dye studied in this research, ethyl orange (EO), is a prototypical example of a halochromic (pH-sensitive) azo dye. Halochromic dyes have already proven useful for application in textile sensors since the colour change of such sensors is easy to per...

  8. Effect of dye structure and redox mediators on anaerobic azo and anthraquinone dye reduction

    Directory of Open Access Journals (Sweden)

    Mayara Carantino Costa

    2012-01-01

    Full Text Available We investigated the biological decolourisation of dyes with different molecular structures. The kinetic constant values (k1 achieved with azo dye Reactive Red 120 were 7.6 and 10.1 times higher in the presence of RM (redox mediators AQDS and riboflavin, respectively, than the assays lacking RM. The kinetic constant achieved with the azo dye Congo Red was 42 times higher than that obtained with the anthraquinone dye Reactive Blue 4. The effect of RM on dye reduction was more evident for azo dyes resistant to reductive processes, and ineffective for anthraquinone dyes because of the structural stability of the latter.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  11. The Study of Microwave and Electric Hybrid Sintering Process of AZO Target

    Directory of Open Access Journals (Sweden)

    Ling-yun Han

    2016-01-01

    Full Text Available We simulated the microwave sintering of ZnO by 3D modelling. A large-size Al-doped ZnO (AZO green ceramic compact was prepared by slurry casting. Through studying the microwave and electric hybrid sintering of the green compact, a relative density of up to 98.1% could be obtained by starting microwave heating at 1200°C and increasing the power 20 min later to 4 kW for an AZO ceramic target measuring 120 × 240 × 12 mm. The resistivity of AZO targets sintered with microwave assistance was investigated. The energy consumption of sintering could be greatly reduced by this heating method. Until now, few studies have been reported on the microwave and electric hybrid sintering of large-size AZO ceramic targets. This research can aid in developing sintering technology for large-size high-quality oxide ceramic targets.

  12. Synthesis and Characterization of Azo Dye Para Red and New Derivatives

    OpenAIRE

    Al-Rubaie, L. Abd-Alredha R.; R. Jameel Mhessn

    2012-01-01

    Azo dyes para red was synthesized. The products were characterized by FTIR and UV-Visible spectrophotometers. The antibacterial activities of the compounds were studied using gram positive and gram negative microorganism.

  13. Light sensitive polymer obtained by dispersion of azo-functionalized POSS nanoparticles

    Science.gov (United States)

    Miniewicz, A.; Tomkowicz, M.; Karpinski, P.; Sznitko, L.; Mossety-Leszczak, B.; Dutkiewicz, M.

    2015-07-01

    Hybrid inorganic-organic nanoparticles based on cubic siloxane cage (RSiO3/2)8, known as polyhedral oligosilsesquioxane (POSS), have been functionalized by eight groups of azo-benzene mesogens and dispersed in poly(methyl methacrylate) PMMA matrix. Presence of azo-benzene units adds an important light-driven functionality to the system due to their photoisomerization resulting in refractive index and/or absorption changes of the whole system. The polymer films containing various concentrations of azo-POSS nanoparticles show remarkable changes of surface morphology being either transparent (at low POSS concentration) or highly scattering (at high POSS concentration) for visible light. Surface structures were examined by optical microscopy as well as by atomic force microscopy (AFM). Results of photoinduced alignment are discussed in the framework of light-induced modification of the aliphatic chains containing azo-benzene photoisomerizing moieties and self-organization process.

  14. Synthesis, structural elucidation, solvatochromism and spectroscopic properties of some azo dyes derived from 6-chloro-4-hydroxyquinoline-2(1H)-one

    Science.gov (United States)

    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.

  15. Enzymatic reduction and oxidation of fibre-bound azo-dyes

    OpenAIRE

    Pricelius, S.; Held, C; Sollner, S.; Deller, S.; Murkovic, M.; Ullrich, R; Hofrichter, M.; Paulo, Artur Cavaco; Macheroux, P.; Guebitz, G. M.

    2007-01-01

    A new customer and environmental friendly method of hair bound dye decolouration was developed. Biotransformation of the azo-dyes Flame Orange and Ruby Red was studied using different oxidoreductases. The pathways of azo dye conversion by these enzymes were investigated and the intermediates and metabolites were identified and characterised using UV–vis spectroscopy, high-performance liquid chromatography (HPLC) and mass spectrometry (MS). Laccase from Pycnoporus cinnabarinus, manganese perox...

  16. Texture-modified activated carbons as catalysts in biodecolourisation of azo dyes

    OpenAIRE

    Mezohegyi, Gergo; Gonçalves, Filomena; Órfao, José J.M.; Bengoa, Christophe José; Stüber, Frank Erich; Font Capafons, Josep; Fortuny Sanromá, Agustín; Fabregat Llangotera, Azael

    2009-01-01

    Considerable attention has been focused on the reduction of azo dyes discharged from dyeing, textile and other industries since some of them or their metabolites may cause toxicity. The efficient treatment of these effluents at industrual scale presents many difficulties, particularly at high dye concentrations and at low energy consumptions. Anaerobic biodecolourisation seems to be the most economic and environmentally friendly method for azo dye wastewater treatment. In a rec...

  17. Isolation and screening of azo dye decolorizing bacterial isolates from dye-contaminated textile wastewater

    OpenAIRE

    Shahid Mahmood; Muhammad Arshad; Azeem Khalid; Zilli Huma Nazli; Tariq Mahmood

    2011-01-01

    Azo dyes are released into wastewater streams without any pretreatment and pollute water and soilenvironments. To prevent contamination of our vulnerable resources, removal of these dye pollutants is of greatimportance. For this purpose, wastewater samples were collected from dye-contaminated sites of Faisalabad. About200 bacterial isolates were isolated through enrichment and then tested for their potential to remove RemazolBlack-B azo dye in liquid medium. Five bacterial isolates capable of...

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

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rishi, E-mail: kkraina@gmail.com; Sood, Srishti, E-mail: kkraina@gmail.com; Raina, K. K., E-mail: kkraina@gmail.com [School of Physics and Materials Science, Thapar University, Patiala-147004 (India)

    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.

  19. Fabrication of integrated waveguide grating in azo polymers.

    Science.gov (United States)

    Jalilpiran, Saber; Karimi-Alavijeh, Hamidreza; Katebi-Jahromi, Alireza; Gharavi, Alireza

    2011-11-01

    In this Letter, we have introduced a technique, new to our knowledge, to fabricate gratings on a waveguide of azo-functionalized polymeric films using a slit mask and a fast, direct-writing method. To prevent the destruction of the waveguide by the grating formation on the waveguide, we placed a slit mask on the waveguide. By properly adjusting the resonance, this grating can be used as an integrated wavelength filter. We have produced an attenuation of 13.4 dB at 1562 nm with a FWHM of 3.45 nm. The grating has been fabricated as narrow as the width of the waveguide to couple filtered light into the waveguide by using a slit mask. Any light shifted from the resonance will pass through the waveguide undisturbed.

  20. The complexation of lanthanides by azo-. beta. -diketones stability constants

    Energy Technology Data Exchange (ETDEWEB)

    Zabra, A.M.; Ramadian, A.A.I.; El-Shetary, B.A.; Abdel-Moez, M.S.

    1982-03-01

    In the present investigation the overall stability constants of an interest tridentate organic ligands and tervalent lanthanide ions have been measured potentiometrically. The stability constants of the complexes between the trivalent lanthanide series of cations and series of azo-..beta..-diketone ligands are reported. The measurements were conducted at 30/sup 0/ at an ionic strength of zero, in 100% methanol. The relation between the overall stability constant (log ..beta../sub 2/) and atomic number of the lanthanide elements, shows a buffer zone at the gadolinium area. The relation between (log ..beta../sub 2/) and the basicity of the studied ligands (..sigma..pK's) are also, discussed. The overall stability values obtained reflected a great affinity of the organic ligands for chelation with lanthanide ions.

  1. Photoresponse and photocapacitor properties of Au/AZO/p-Si/Al diode with AZO film prepared by pulsed laser deposition (PLD) method

    Science.gov (United States)

    Alyamani, A.; Tataroğlu, A.; El Mir, L.; Al-Ghamdi, Ahmed A.; Dahman, H.; Farooq, W. A.; Yakuphanoğlu, F.

    2016-04-01

    The electrical and photoresponse properties of Au/nanostructure AZO/p-Si/Al diode were investigated. Al-doped ZnO (AZO) thin films were deposited via pulsed laser deposition method on silicon substrate. Structural properties of the films were performed by using transmission electron microscopy and X-ray powder diffraction (XRD). The XRD patterns showed that the AZO films are polycrystalline with hexagonal wurtzite structure preferentially oriented in (002) direction. Electrical and photoresponse properties of the diode were analyzed under in a wide range of frequencies and illumination intensities. It is observed that the reverse current of the diode increases with increasing illumination intensity. This result confirms that the diode exhibits both photoconducting and photovoltaic behavior. Also, the transient photocurrent, photocapacitance and photoconductance measured as a function of time highly depend on transient illumination. In addition, the frequency dependence of capacitance and conductance is attributed to the presence of interface states.

  2. Influence of various thickness metallic interlayers on opto-electric and mechanical properties of AZO thin films on PET substrates

    Energy Technology Data Exchange (ETDEWEB)

    Chang, R.C., E-mail: rcc@mail.sju.edu.tw [Department of Mechanical and Computer-Aided Engineering, St. John' s University, Tamsui, Taipei 25135, Taiwan (China); Li, T.C.; Lin, C.W. [Department of Mechanical and Computer-Aided Engineering, St. John' s University, Tamsui, Taipei 25135, Taiwan (China)

    2012-02-01

    Various thickness metallic interlayers to improve the opto-electric and mechanical properties of aluminum-doped zinc oxide (AZO) thin films deposited on flexible polyethylene terephtalate (PET) substrates are studied. The effects of the interlayers on the resistance and transmittance of the AZO thin films are discussed. The result shows that the metallic interlayers effectively improve the electric resistance but reduce the optical transmittance of the AZO thin films. These phenomena become more obvious as the interlayer thickness increases. However, the AZO with an aluminum interlayer still behaves an acceptable transmittance. Moreover, mechanical tests indicate that the aluminum interlayer increases the hardness and modulus, and reduce the residual stress of the AZO thin films. In contrast, the silver and copper interlayers decrease the AZO's mechanical properties. Comparing to those without any interlayer, the results show that the best interlayer is the 6 nm thick aluminum film.

  3. Influence of various thickness metallic interlayers on opto-electric and mechanical properties of AZO thin films on PET substrates

    Science.gov (United States)

    Chang, R. C.; Li, T. C.; Lin, C. W.

    2012-02-01

    Various thickness metallic interlayers to improve the opto-electric and mechanical properties of aluminum-doped zinc oxide (AZO) thin films deposited on flexible polyethylene terephtalate (PET) substrates are studied. The effects of the interlayers on the resistance and transmittance of the AZO thin films are discussed. The result shows that the metallic interlayers effectively improve the electric resistance but reduce the optical transmittance of the AZO thin films. These phenomena become more obvious as the interlayer thickness increases. However, the AZO with an aluminum interlayer still behaves an acceptable transmittance. Moreover, mechanical tests indicate that the aluminum interlayer increases the hardness and modulus, and reduce the residual stress of the AZO thin films. In contrast, the silver and copper interlayers decrease the AZO's mechanical properties. Comparing to those without any interlayer, the results show that the best interlayer is the 6 nm thick aluminum film.

  4. Light sensitive polymer obtained by dispersion of azo-functionalized POSS nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Miniewicz, A., E-mail: andrzej.miniewicz@pwr.edu.pl [Advanced Materials Engineering and Modelling, Faculty of Chemistry, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Tomkowicz, M.; Karpinski, P.; Sznitko, L. [Advanced Materials Engineering and Modelling, Faculty of Chemistry, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Mossety-Leszczak, B. [Faculty of Chemistry, Rzeszow University of Technology, Al. Powstancow Warszawy 12, 35-959 Rzeszow (Poland); Dutkiewicz, M. [Faculty of Chemistry, Adam Mickiewicz University of Poznan, Umultowska 89 B, 61-614 Poznan (Poland)

    2015-07-29

    Highlights: • Nanocomposite material PMMA containing azo-functionalized POSS has been prepared. • Surface topographies of prepared films are porous and dependent on azo-POSS content. • Photo-induced optical anisotropies both static and dynamic have been characterized. - Abstract: Hybrid inorganic–organic nanoparticles based on cubic siloxane cage (RSiO{sub 3/2}){sub 8}, known as polyhedral oligosilsesquioxane (POSS), have been functionalized by eight groups of azo-benzene mesogens and dispersed in poly(methyl methacrylate) PMMA matrix. Presence of azo-benzene units adds an important light-driven functionality to the system due to their photoisomerization resulting in refractive index and/or absorption changes of the whole system. The polymer films containing various concentrations of azo-POSS nanoparticles show remarkable changes of surface morphology being either transparent (at low POSS concentration) or highly scattering (at high POSS concentration) for visible light. Surface structures were examined by optical microscopy as well as by atomic force microscopy (AFM). Results of photoinduced alignment are discussed in the framework of light-induced modification of the aliphatic chains containing azo-benzene photoisomerizing moieties and self-organization process.

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

    Science.gov (United States)

    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.

  6. Preparation of Polyaniline/TiO2 Composite Nanotubes for Photodegradation of AZO Dyes

    Institute of Scientific and Technical Information of China (English)

    CHENG Yang; AN Liang; ZHAO Zongshan; WANG Guanghui

    2014-01-01

    Polyaniline (PANI) composite nanotubes (90-130 nm in diameter) containing titanium dioxide (TiO2) nanoparticles (about 10 nm in diameter) were synthesized through a self-assembly process in the presence of â-naphthalenesulfonic acid (â-NSA) as the dopant. It was found that PANI-TiO2 composites and PANI nanotubes both behaved with significant photocatalytic activities towards AZO dyes, during 2 h photocatalytic processes under natural light, the degradation ratio was 94.2%and 97.2%respectively (methyl orange and orange II). The morphology of such products was characterized by SEM. The specific surface area of such composite nanotubes was 14.7 m2/g compared to normal polyaniline which was 0.27 m2/g. IR and X-ray diffraction characterizations showed that the chemical chain of the composite nanotubes was identical to that of the doped PANI. It may provide a new way for photodegradation of organic contaminants by using conjugated polymer with dimensional structure.

  7. Study on Cyclometalated Palladium-azo Complexes as Colorimetric Probes for Hazardous Gas in Water

    Institute of Scientific and Technical Information of China (English)

    YU,Chun-Wei; LI,Shun-Hua; ZHENG,Hong; XU,Jin-Gou

    2007-01-01

    A synthesized cyclometalated palladium-azo complex was explored as a multifunctional probe for visual detection of SO2, H2S and NH3 in water. In acidic aqueous environment, the sensing solution underwent a sharp color change from poor violet to deep blue when titrated with Na2SO3 standard solution. But the color changed from poor violet to bright yellow when titrated with Na2S standard solution. In basic environment, the sensing solution rapidly changed to magenta when titrated by NH4Cl-NH3 standard buffer solution at high concentration. However, the color of sensing solution changed to blue when titrated by NH4Cl-NH3 standard buffer solution at low concentration although the pH was kept constant during the titration. Different species of these hazardous gases at environmentally relevant concentration levels were differentiated by independent optical signal outputs, and the interference from other inorganic ions commonly existing in water was very small.

  8. Decolorization of the AO24 azo dye and reduction of toxicity and genotoxicity in trickling biofilters.

    Science.gov (United States)

    Garzóón-Zúñga, Marco A; Sandoval-Villasana, Ana M; Moeller-Chávez, Gabriela E

    2011-02-01

    Acid Orange 24 (AO24) dye was degraded in a trickling biofilter packed with peat and wood chips and inoculated with biomass from a petrochemical industry wastewater system. Different operating strategies were tested; in the first stage, two biofilters were operated independently--one non-aerated biofilter (passive) and the other with aeration-subsequently, the systems were operated serially, and effluent from the non-aerated biofilter was fed to the biofilter with aeration. This treatment train was used to test three different filtration velocities--0.141, 0.282, and 0.423 m/d. The results show that, when operating the systems with a dye charge of 0.035 kg AO24 m2/d and treating the effluent in a single step, good removal efficiencies of AO24 (95 and 89%), COD (63 and 53%), and acute toxicity (63 and 78%) were obtained in both biofilters (with and without air), although mutagenic and potentially carcinogenic intermediary compounds were not removed, because genotoxicity exhibits values higher than 2.0 units for the mutation rate. When using the non-aerated biofilter/aerated biofilter treatment train, it is possible to treat a dye charge 3 times greater (0.106 kg AO24 m2/d) and efficiently remove 98% AO24, 76% COD, 100% acute toxicity, and 100% genotoxicity, which indicates that, with this biological system, an advanced degree of biotransformation and mineralization of the azo dye AO24 is achieved.

  9. Synergistic Decolouration of Azo Dye by Pulsed Streamer Discharge Immobilized TiO2 Photocatalysis

    Institute of Scientific and Technical Information of China (English)

    LI Jie; WANG Huijuan; LI Guofeng; WU Yan; QUAN Xie; LIU Zhigang

    2007-01-01

    Photocatalyst was prepared by immobilizing TiO2 on glass beads using the traditional sol-gel method.Ultraviolet light(UV)produced by pulsed streamer discharge Was then used to induce photocatalytic activity of TiO2 photocatalyst.Decolouration efficiency of the representative azo dye(acid orange 7,AO7)was investigated using the synergistic system of pulsed streamer discharge plasma and TiO2 photocatalysis.The obtained results showed that the decolouration rate of AO7 could be increased by 16.7% under the condition of adding supported TiO2 in the pulsed streamer discharge system,compared to that in the sole pulsed streamer discharge plasma system,due to the synergistic effect of pulsed streamer discharge and TiO2 photocatalysis induced by pulsed streamer discharge.The synergistic system of pulsed streamer discharge and TiO2 photocatalyst Was found to have more reactive radicals for degradation of organic compounds in Water.

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

    Science.gov (United States)

    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

  11. Preconcentration of uranium in seawater with heterocyclic azo dyes supported on silica gel

    International Nuclear Information System (INIS)

    The chelating adsorbents, heterocyclic azo dyes supported on silica gel, were prepared and their adsorption behaviors of metal ions were investigated. The 1-(2-pyridylazo)-2-naphthol(PAN)-SG and 2-(2-thiazolylazo)-p-cresol(TAC)-SG show greater affinity for UO2(II) and ZrO(II), compared with the other metal ions like Cu, Cd, Fe and alkaline earths. Trace uranyl can be quantitatively retained on the column of the gels at neutral pH region and flowrate 3-4 ml/min. The uranyl retained is easily eluted from the column bed with a mixture of acetone and nitric acid (9:1 v/v) and determined by spectrophotometry using Arsenazo-III. Matrix components in seawater do not interfere and the spiked recovery of uranyl in artificial seawater was found to be average 98.6%, with the relative standard deviation of 1.08%. Both gels were applied to the determination of uranium in seawater with satisfactory results. 16 references, 3 figures, 3 tables

  12. Isolation and characterization of a Klebsiella oxytoca strain for simultaneous azo-dye anaerobic reduction and bio-hydrogen production.

    Science.gov (United States)

    Yu, Lei; Li, Wen-Wei; Lam, Michael Hon-Wah; Yu, Han-Qing; Wu, Chao

    2012-07-01

    A facultative anaerobic bacteria strain GS-4-08, isolated from an anaerobic sequence batch reactor for synthetic dye wastewater treatment, was investigated for azo-dye decolorization. This bacterium was identified as a member of Klebsiella oxytoca based on Gram staining, morphology characterization and 16S rRNA gene analysis. It exhibited a good capacity of simultaneous decolorization and hydrogen production in the presence of electron donor. The hydrogen production was less affected even at a high Methyl Orange (MO) concentration of 0.5 mM, indicating a superior tolerability of this strain to MO. This efficient bio-hydrogen production from electron donor can not only avoid bacterial inhibition due to accumulation of volatile fatty acids during MO decolorization, but also can recover considerable energy from dye wastewater.

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

    Science.gov (United States)

    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.

  14. Formation of a carcinogenic aromatic amine from an azo dye by human skin bacteria in vitro.

    Science.gov (United States)

    Platzek, T; Lang, C; Grohmann, G; Gi, U S; Baltes, W

    1999-09-01

    Azo dyes represent the major class of dyestuffs. They are metabolised to the corresponding amines by liver enzymes and the intestinal microflora following incorporation by both experimental animals and humans. For safety evaluation of the dermal exposure of consumers to azo dyes from wearing coloured textiles, a possible cleavage of azo dyes by the skin microflora should be considered since, in contrast to many dyes, aromatic amines are easily absorbed by the skin. A method for measuring the ability of human skin flora to reduce azo dyes was established. In a standard experiment, 3x10(11) cells of a culture of Staphylococcus aureus were incubated in synthetic sweat (pH 6.8, final volume 20 mL) at 28 degrees C for 24 h with Direct Blue 14 (C.I. 23850, DB 14). The reaction products were extracted and analysed using HPLC. The reduction product o-tolidine (3,3'-dimethylbenzidine, OT) could indeed be detected showing that the strain used was able to metabolise DB 14 to the corresponding aromatic amine. In addition to OT, two further metabolites of DB 14 were detected. Using mass spectrometry they were identified as 3,3'-dimethyl-4-amino-4'-hydroxybiphenyl and 3, 3'-dimethyl-4-aminobiphenyl. The ability to cleave azo dyes seems to be widely distributed among human skin bacteria, as, under these in vitro conditions, bacteria isolated from healthy human skin and human skin bacteria from strain collections also exhibited azo reductase activity. Further studies are in progress in order to include additional azo dyes and coloured textiles. At the moment, the meaning of the results with regard to consumer health cannot be finally assessed.

  15. Tratamiento del Colorante Azo Rojo Directo 23 mediante Reactores Discontinuos Secuenciados Anaerobios/Aerobios Treatment of Direct Red 23 Azo Dye by Anaerobic/Aerobic Sequencing Batch Reactors

    Directory of Open Access Journals (Sweden)

    Fernanda Morales-Guzmán

    2009-01-01

    Full Text Available Se evaluó el tratamiento del colorante azo Rojo Directo 23 mediante un proceso anaerobio/aerobio integrado en un sólo reactor. Se utilizaron dos reactores: uno de lecho expandido con carbón activado granular como mediador redox y otro conteniendo la biomasa suspendida, ambos operados en discontinuo. Se evaluó la eficiencia del proceso mediante la reducción y transformación del colorante a aminas aromáticas totales en la fase anaerobia y la degradación de éstas en la fase aerobia. La eliminación del colorante fue por microorganismos y no por adsorción en el carbón activado granular. Las concentraciones de colorante utilizadas fueron de 25 a 100 mg L-1. En el reactor de lecho expandido la eficiencia de degradación global del colorante fue del 90 % y la eliminación de las aminas formadas fue del 100 %.The treatment of the azo dye Direct Red 23 was evaluated by an anaerobic/aerobic process done in a single reactor. Two reactors were used: one was an expanded-bed with granular activated carbon as redox mediator and the other containing the suspended biomass, both operated in batch mode. The efficiency of the process was evaluated by the reduction and transformation of the azo dye to total aromatic amines in the anaerobic phase and the degradation of these in the aerobic phase. The elimination of azo dye direct red was by microorganisms and not by adsorption in the granular activated carbon. The concentration of azo dye used was of 25 to 100 mg L-¹. In the expanded-bed reactor the removal efficiency of the dye was 90 % and the elimination of the amines formed was of 100 %.

  16. Synthesis and Intramolecular Azo Coupling of 4-Diazopyrrole-2-carboxylates: Selective Approach to Benzo and Hetero [c]-Fused 6H-Pyrrolo[3,4-c]pyridazine-5-carboxylates.

    Science.gov (United States)

    Galenko, Ekaterina E; Galenko, Alexey V; Khlebnikov, Alexander F; Novikov, Mikhail S; Shakirova, Julia R

    2016-09-16

    A high yield synthesis of fluorescent benzo, thieno, and furo [c]-fused methyl 7-aryl-6H-pyrrolo[3,4-c]pyridazine-5-carboxylates, including unprecedented heterocyclic skeletons, was performed by the transformation of methyl 4-aminopyrrole-2-carboxylate into the corresponding diazo compound, followed by intramolecular azo coupling under acid conditions onto a nucleophilic aryl or hetaryl group in the 3-position. Azo coupling is completely regioselective and, according to DFT calculations, a kinetically controlled reaction. N-Methylation of 1,3-disubstituted 2H-pyrrolo[3,4-c]cinnolines occurs selectively at N5 under kinetic control, leading exclusively to 5-methyl-5H-pyrrolo[3,4-c]cinnoline derivatives. PMID:27548333

  17. 负载型纳米Fe-Pd降解水溶性偶氮染料%Degradation of azo dye by resin-supported nano-iron/palladium

    Institute of Scientific and Technical Information of China (English)

    武俐; 邰超; 王晴晴; 赵同谦

    2012-01-01

    采用阳离子交换树脂表面为载体,合成了负载型纳米Fe-Pd二元复合金属材料,采用扫描电子显微镜(SEM)和能谱分析对该材料进行表征,研究了其对一些水溶性偶氮染料的降解效果.实验表明,该材料对0.05 g.L^-1甲基橙、日落黄、酸性橙8、金橙G和活性红2等偶氮染料有较好的降解效果,纳米双金属中Pd含量的增加有利于染料的降解;反应体系初始pH值对染料的降解率影响较大,本研究中,pH 4酸性条件下降解效果最佳;制备的材料在第10次活化后,仍有较好的降解效果;为环境中偶氮染料的降解提供了一种有效的方法.%In the paper,the resin-supported nano-iron/ palladium was synthesized by liquid-phase chemical reduction method.The obtained nano particles were characterized by scanning electron microscope(SEM),and the degradation of typical water-soluble azo dyes by the resin-supported nano-iron/palladium was studied.The experimental results indicated 0.05 g · L^-1 of typical azo dyes,including Methyl Orange,Sunset Yellow,Acid Orange 8,Orange G and Reactive Red 2,were efficiently degraded by the nano-iron/palladium.With increasing palladium content,better degradation effect of azo dyes was obtained.Initial pH was proven to have significant effect on the degradation of azo dyes,with the best degradation effect obtained in the acidic condition.The supported nano-iron/palladium still had good degradation effect even after ten cycles of degradation and activation.

  18. Use of titanium dioxide photocatalysis on the remediation of model textile wastewaters containing azo dyes.

    Science.gov (United States)

    Saggioro, Enrico Mendes; Oliveira, Anabela Sousa; Pavesi, Thelma; Maia, Cátia Gil; Ferreira, Luis Filipe Vieira; Moreira, Josino Costa

    2011-12-14

    The photocatalytic degradation of two commercial textile azo dyes, namely C.I Reactive Black 5 and C.I Reactive Red 239, has been studied. TiO(2) P25 Degussa was used as catalyst and photodegradation was carried out in aqueous solution under artificial irradiation with a 125 W mercury vapor lamp. The effects of the amount of TiO(2) used, UV-light irradiation time, pH of the solution under treatment, initial concentration of the azo dye and addition of different concentrations of hydrogen peroxide were investigated. The effect of the simultaneous photodegradation of the two azo dyes was also investigated and we observed that the degradation rates achieved in mono and bi-component systems were identical. The repeatability of photocatalytic activity of the photocatalyst was also tested. After five cycles of TiO(2) reuse the rate of colour lost was still 77% of the initial rate. The degradation was followed monitoring the change of azo dye concentration by UV-Vis spectroscopy. Results show that the use of an efficient photocatalyst and the adequate selection of optimal operational parameters may easily lead to a complete decolorization of the aqueous solutions of both azo dyes.

  19. Use of Titanium Dioxide Photocatalysis on the Remediation of Model Textile Wastewaters Containing Azo Dyes

    Directory of Open Access Journals (Sweden)

    Josino Costa Moreira

    2011-12-01

    Full Text Available The photocatalytic degradation of two commercial textile azo dyes, namely C.I Reactive Black 5 and C.I Reactive Red 239, has been studied. TiO2 P25 Degussa was used as catalyst and photodegradation was carried out in aqueous solution under artificial irradiation with a 125 W mercury vapor lamp. The effects of the amount of TiO2 used, UV-light irradiation time, pH of the solution under treatment, initial concentration of the azo dye and addition of different concentrations of hydrogen peroxide were investigated. The effect of the simultaneous photodegradation of the two azo dyes was also investigated and we observed that the degradation rates achieved in mono and bi-component systems were identical. The repeatability of photocatalytic activity of the photocatalyst was also tested. After five cycles of TiO2 reuse the rate of colour lost was still 77% of the initial rate. The degradation was followed monitoring the change of azo dye concentration by UV-Vis spectroscopy. Results show that the use of an efficient photocatalyst and the adequate selection of optimal operational parameters may easily lead to a complete decolorization of the aqueous solutions of both azo dyes.

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

    Science.gov (United States)

    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 (100-300mg/L). The bacterial consortium, when subjected to an application of 200mg/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.

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

    Directory of Open Access Journals (Sweden)

    Sylvine Lalnunhlimi

    2016-03-01

    Full Text Available Abstract 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.

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

    Science.gov (United States)

    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.

  3. A REVIEW ON EFFICACIOUS METHODS TO DECOLORIZE REACTIVE AZO DYE

    Directory of Open Access Journals (Sweden)

    Jagadeesan Vijayaraghavan

    2013-01-01

    Full Text Available This paper deals with the intensive review of reactive azo dye, Reactive Black 5. Various physicochemical methods namely photo catalysis, electrochemical, adsorption, hydrolysis and biological methods like microbial degradation, biosorption and bioaccumulation have been analyzed thoroughly along with the merits and demerits of each method. Among these various methods, biological treatment methods are found to be the best for decolorization of Reactive Black 5. With respect to dye biosorption, microbial biomass (bacteria, fungi, microalgae, etc, and outperformed macroscopic materials (seaweeds, crab shell, etc. are used for decolorization process. The use of living organisms may not be an option for the continuous treatment of highly toxic organic/inorganic contaminants. Once the toxicant concentration becomes too high or the process operated for a long time, the amount of toxicant accumulated will reach saturation. Beyond this point, an organism's metabolism may be interrupted, resulting in death of the organism. This scenario is not existed in the case of dead biomass, which is flexible to environmental conditions and toxicant concentrations. Thus, owing to its favorable characteristics, biosorption has received much attention in recent years.

  4. Structural evolution, electrical and optical properties of AZO films deposited by sputtering ultra-high density target

    Indian Academy of Sciences (India)

    Jiwen Xu; Zupei Yang; Hua Wang; Xiaowen Zhang

    2014-06-01

    Aluminum-doped zinc oxide (AZO) target was fabricated using AZO nanopowders synthesized by co-precipitation method and then the AZO films with different thicknesses were deposited on glass by d.c. magnetron sputtering at room temperature. AZO target is nodules free and shows homogeneous microstructure, ultra-high density and low resistivity. ZnAl2O4 phase appears in AZO target and disappears in AZO films. All AZO films show c-axis preferred orientation and hexagonal structure. With increasing film thickness from 153 to 1404 nm, the crystallinity was improved and the angle of (002) peak was close to 34.45°. The increase in grain size and surface roughness is due to the increase in film thickness. The decrease of resistivity is ascribed to the increases of carrier concentration and Hall mobility. The lowest resistivity is 9.6 × 10-4 .cm. The average transmittance of AZO films exceeds 80%, and a sharp fundamental absorption edge with red-shifting is observed in the visible range. The bandgap decreases from 3.26 to 3.02 eV.

  5. [Azo dyes, their environmental effects, and defining a strategy for their biodegradation and detoxification].

    Science.gov (United States)

    Gudelj, Ivana; Hrenović, Jasna; Dragičević, Tibela Landeka; Delaš, Frane; Soljan, Vice; Gudelj, Hrvoje

    2011-03-01

    Intense industrial development has been accompanied by the production of wastewaters of very complex content, which pose a serious hazard to the environment, put at risk sustainable development, and call for new treatment technologies that would more effectively address the issue. One particular challenge in terms of science and technology is how to biodegrade xenobiotics such as azo dyes, which practically do not degrade under natural environmental conditions. These compounds tend to bioaccumulate in the environment, and have allergenic, carcinogenic, mutagenic, and teratogenic properties for humans. Removal of azo dyes from effluents is mostly based on physical-chemical methods. These methods are often very costly and limited, as they accumulate concentrated sludge, which also poses a significant secondary disposal problem, or produce toxic end-products. Biotechnological approach may offer alternative, lowcost biological treatment systems that can completely biodegrade and detoxify even the hard-to-biodegrade azo dyes.

  6. Screening of azo dyes for mutagenicity with Ames/Salmonella assay.

    Science.gov (United States)

    Kaur, A; Sandhu, R S; Grover, I S

    1993-01-01

    Azo dyes, the largest portion of manufactured dyestuffs, are primarily used as colouring substances in food, textiles, and the plastic industry. It has been estimated that 128 tonnes per annum of dyes are released into the environment worldwide [Anliker, 1977]. Certain azo compounds are known to be mutagenic in bacterial tests [Yahagi et al., 1975; Venitt and Bushell, 1976; Brown et al., 1978]. Watersoluble dyes are biotransformed by intestinal micro-organisms in the gastro intestinal tract, and the toxicity, mutagenicity, and carcinogenicity of these dyes in the gut or liver may be attributed to their metabolites. Since it is desirable to have a genotoxic evaluation of a chemical being released into the environment in order to check their indiscriminate use, a project has been initiated to determine the mutagenicity of the azo dyes being used commercially. The present report deals with the results of 13 dyes tested in Salmonella typhimurium with and without metabolic activation.

  7. The physical properties of AZO films deposited by RF magnetron sputtering in hydrogen-diluted argon

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jwayeon; Han, Jungsu; Jin, Hyunjoon [Hoseo University, Asan (Korea, Republic of); Kim, Youhyuk [Dankook University, Cheonan (Korea, Republic of); Park, Kyeongsoon [Sejong University, Seoul (Korea, Republic of)

    2014-08-15

    The properties of AZO (98-wt% ZnO, 2-wt% Al{sub 2}O{sub 3}) films produced in pure Ar and Ar (98%) + H{sub 2} (2%) (H{sub 2}-diluted Ar) by radio-frequency (RF) magnetron sputtering were investigated as functions of the substrate temperatures. H{sub 2}-diluted Ar improved the electrical properties of the AZO films fabricated at low substrate temperatures, but this benefit gradually diminished with increasing substrate temperature. This phenomenon was explained by O-H stretching in the Zn-O bond at low temperatures and by the formation of oxygen vacancies at high temperatures. The average optical transmission was over ∼85%, and the orientation of the AZO films deposited both in pure Ar and in H{sub 2}-diluted Ar was in the [002] direction.

  8. Optical and Thermal Properties of Nickel-Azo Dyes for Digital Versatile Disc-Recordable

    Institute of Scientific and Technical Information of China (English)

    魏斌; 吴谊群; 顾冬红; 干福熹

    2003-01-01

    We investigate the absorption spectra, optical constants and thermal decomposition as well as red-light (650 nm)static recording properties of three novel nickel-azo dye filrns based on 4-methylthiazole, benzothiazole and 6-methylbenzothiazole. Particularly, we obtain the nickel-azo complex film based on 4-methylthiazole, peaking at 562nm and 613nm, with higher refractive index (n = 2.46) and lower extinction coefficient (k = 0.18) at the wavelength 650nm and a sharp threshold of thermal decomposition at 330℃. The results of the static optical recording test of this dye film indicate that high reflectivity contrast of 51% can be observed at a laser writing power of 5.9mW and pulse width of 350ns. These results imply that the nickel-azo complex based on 4-methylthiazole is a promising candidate for a recording medium of digital versatile disc-recordable.

  9. Photoresponse and trap characteristics of transparent AZO-gated AlGaN/GaN HEMT

    Science.gov (United States)

    Wang, Chong; Zhao, Meng-Di; He, Yun-Long; Zheng, Xue-Feng; Zhang, Kun; Wei, Xiao-Xiao; Mao, Wei; Ma, Xiao-Hua; Zhang, Jin-Cheng; Hao, Yue

    2016-10-01

    AZO-gated and Ni/Au-gated AlGaN/GaN HEMTs are fabricated successfully, and an excellent transparency of AZO-gated electrode is achieved. After a negative gate bias stress acts on two kinds of the devices, their photoresponse characteristics are investigated by using laser sources with different wavelengths. The effect of photoresponse on AZO-gated electrode device is more obvious than on Ni/Au-gated electrodes device. The electrons are trapped in the AlGaN barrier of AZO-gated HEMT after it has experienced negative gate bias stress, and then the electrons can be excited effectively after it has been illuminated by the light with certain wavelengths. Furthermore, the trap state density D T and the time constant τ T of the AZO-gated Schottky contact are extracted by fitting the measured parallel conductance in a frequency range from 10 kHz to 10 MHz. The constants of the trap range from about 0.35 μs to 20.35 μs, and the trap state density increased from 1.93 × 1013 eV-1·cm-2 at an energy of 0.33 eV to 3.07 × 1011 eV-1·cm-2 at an energy of 0.40 eV. Moreover, the capacitance and conductance measurements are used to characterize the trapping effects under different illumination conditions in AZO-gated HEMTs. Reduced deep trap states' density is confirmed under the illumination of short wavelength light. Project supported by the National Natural Science Foundation of China (Grant Nos. 61574110, 61574112, and 61106106).

  10. Chlorine disinfection of dye wastewater: Implications for a commercial azo dye mixture

    Energy Technology Data Exchange (ETDEWEB)

    Vacchi, Francine Inforcato; Albuquerque, Anjaina Fernandes; Vendemiatti, Josiane Aparecida; Morales, Daniel Alexandre [Faculdade de Tecnologia, Universidade Estadual de Campinas, Limeira, SP, 13484-332 (Brazil); Ormond, Alexandra B.; Freeman, Harold S. [Department of Textile Engineering, Chemistry, and Science, North Carolina State University, Raleigh, NC 27695-8301 (United States); Zocolo, Guilherme Juliao; Zanoni, Maria Valnice Boldrin [Departamento de Quimica Analitica, Universidade Estadual Paulista Julio de Mesquita Filho, Instituto de Quimica de Araraquara, Araraquara, SP 14801-970 (Brazil); Umbuzeiro, Gisela, E-mail: giselau@ft.unicamp.br [Faculdade de Tecnologia, Universidade Estadual de Campinas, Limeira, SP, 13484-332 (Brazil)

    2013-01-01

    Azo dyes, the most widely used family of synthetic dyes, are often employed as colorants in areas such as textiles, plastics, foods/drugs/cosmetics, and electronics. Following their use in industrial applications, azo dyes have been found in effluents and various receiving waters. Chemical treatment of effluents containing azo dyes includes disinfection using chlorine, which can generate compounds of varying eco/genotoxicity. Among the widely known commercial azo dyes for synthetic fibers is C.I. Disperse Red 1. While this dye is known to exist as a complex mixture, reports of eco/genotoxicity involve the purified form. Bearing in mind the potential for adverse synergistic effects arising from exposures to chemical mixtures, the aim of the present study was to characterize the components of commercial Disperse Red 1 and its chlorine-mediated decoloration products and to evaluate their ecotoxicity and mutagenicity. In conducting the present study, Disperse Red 1 was treated with chlorine gas, and the solution obtained was analyzed with the aid of LC-ESI-MS/MS to identify the components present, and then evaluated for ecotoxicity and mutagenicity, using Daphnia similis and Salmonella/microsome assays, respectively. The results of this study indicated that chlorination of Disperse Red 1 produced four chlorinated aromatic compounds as the main products and that the degradation products were more ecotoxic than the parent dye. These results suggest that a disinfection process using chlorine should be avoided for effluents containing hydrophobic azo dyes such commercial Disperse Red 1. -- Highlights: Black-Right-Pointing-Pointer Aqueous solutions of Disperse Red 1 were treated with chlorine. Black-Right-Pointing-Pointer The chlorination products of Disperse Red 1 were identified using LC-ESI-MS/MS. Black-Right-Pointing-Pointer Daphnia and Salmonella/microsome were employed for eco/genotoxicity testing. Black-Right-Pointing-Pointer The chlorinated dye was more mutagenic

  11. Degradação redutiva de azo-corantes utilizando-se ferro metálico Reductive degradation of azo-dyes by metallic iron

    Directory of Open Access Journals (Sweden)

    Cláudio Lima de Souza

    2006-03-01

    Full Text Available Corantes azo são extensivamente utilizados em processos de tingimento de fibras têxteis, sendo caracterizados por elevada resistência frente a processos aeróbios de biodegradação e, por conseqüência, persistência nos processos convencionais de tratamento de resíduos. Neste trabalho reporta-se a degradação redutiva de corantes azo, utilizando-se ferro metálico. Em condições experimentais otimizadas (pH 7 e 10 g de lã de aço comercial a completa descoloração do corante modelo (preto reativo 5 foi conseguida em um sistema contínuo, operando com tempos de retenção de 6 min. Nestas condições, o ferro solubilizado alcança concentrações compatíveis com os limites impostos pela atual legislação brasileira (12 mg L-1. Trata-se de um resultado bastante promissor, principalmente levando-se em consideração o caráter recalcitrante dos azo corantes e a simplicidade do sistema proposto.Azo dyes are extensively used in textile dying processes and are characterized by extreme resistance to biodegradation and consequently persistence during conventional wastewater treatment processes. In this work the reductive degradation of azo dyes was studied using zero-valent iron. At optimized experimental conditions (pH 7 and 10 g of commercial iron wool complete decolorization of the model dye (reactive black 5 was afforded in a continuous system operating with hydraulic retention time of 6 min. At these conditions the released total soluble iron reaches a concentration compatible with the limits imposed by the current Brazilian legislation (12 mg L-1. That is a very promising result, mainly taking into account the high recalcitrant character of azo dyes and the simplicity of the proposed system.

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

    Science.gov (United States)

    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

  13. Fluorescent Sensing of Chlorophenols in Water Using an Azo Dye Modified β-Cyclodextrin Polymer

    OpenAIRE

    Bhekie B. Mamba; Phendukani Ncube; Krause, Rui W

    2011-01-01

    A water soluble azo dye modified β-cyclodextrin polymer 4 was synthesized and used as a chemosensor for the detection of chlorinated phenols, model chlorinated by-products (CBPs) of water treatment for drinking purposes. The characterization of the intermediates and the azo dye modified β-CD polymer was done by UV/Vis Spectrophotometry, FT-IR and 1H-NMR spectroscopies. The chlorophenols were capable of quenching the fluorescence of the polymer. The polymer showed greater sensitivity towards 2...

  14. Effect of Azo Dyes on the Thermal Degradation of Post-consumer Polyester Fabrics

    Directory of Open Access Journals (Sweden)

    Qin Dan

    2016-01-01

    Full Text Available Thermogravimetric analysis(TGA and pyrolysis gas chromatography mass spectrometry (Py-GC-MS investigations were carried out on the thermal degradation of white and red post-consumer polyester fabrics. The results show that red PET fabrics which was dyed with C.I. Disperse red 167 for its typical azo structure exhibits larger activation energy compared with white PET. The addition of azo dyes displays an inhibiting effect on the deep pyrolysis and the formation of biphenyl and bis(2-hydroxybutyl terephthalate produced by the free radical mechanism.

  15. SYNTHESIS AND CHARACTERIZATION OF COMB-LIKE POLYMERS BEARING HETEROCYCLIC AZO GROUP AND MESOGENIC GROUP

    Institute of Scientific and Technical Information of China (English)

    Hui-qi Zhang; Wen-qiang Huang; Chen-xi Li; Bing-lin He

    1999-01-01

    The synthesis and characterization of a series of novel comb-like polymethacrylates bearing heterocyclic azo group and mesogenic group are described. The thermal properties of the polymers such as thermal stability and phase transition behavior were investigated by thermogravimetric analysis, differential thermal analysis and polarizing optical microscopy techniques. The experimental results show that all the synthesized polymers do not exhibit liquid crystallinity except the homopolymer of the mesogenic monomer MAPB2 and the glass transition temperatures of the polymers increase with increasing content of azo moiety in polymers linearly.

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

    Science.gov (United States)

    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.

  17. Comparative theoretical studies of energetic azo s-triazines.

    Science.gov (United States)

    Wang, Fang; Du, Hong-chen; Zhang, Jian-ying; Gong, Xue-dong

    2011-10-27

    In this work, the properties of the synthesized high-nitrogen compounds 4,4',6,6'-tetra(azido)azo-1,3,5-triazine (TAAT) and 4,4',6,6'-tetra(azido)hydrazo-1,3,5-triazine (TAHT), and a set of designed bridged triazines with similar bridges were studied theoretically to facilitate further developments for the molecules of interests. The gas-phase heats of formation were predicted based on the isodesmic reactions by using the DFT-B3LYP/AUG-cc-PVDZ method. The estimates of the condensed-phase heats of formation and heats of sublimation were estimated in the framework of the Politzer approach. Calculation results show that the method gives a good estimation for enthalpies, in comparison with available experimental data for TAAT and TAHT. The crystal density has been computed using molecular packing calculations. The calculated detonation velocities and detonation pressures indicate that -NF(2), -NO(2), -N═N-, and -N═N(O)- groups are effective structural units for improving the detonation performance of the bridged triazines. The synthesized TAAT and TAHT are not preferred energetic materials due to their inferior detonation performance. The p→π conjugation effect between the triazine rings and bridges makes the molecule stable as a whole. The electrostatic behavior of the bridged triazines is characterized by an anomalous surface potential imbalance when incorporating the strongly electron-withdrawing -NF(2) and -NO(2) groups into the molecule. An analysis of the bond dissociation energies shows that all these derivatives have good thermal stability over RDX and HMX, and the -NH-NH- bridge is more helpful for improving the stability than -N═N(O)- and -N═N- bridges. Considering the detonation performance and thermal stability, three bridged triazines may be considered as the potential candidates of high-energy density materials (HEDMs). PMID:21910431

  18. Heterogenous Photocatalysis Treatement of Azo Dye Methyl Orange by Nano Composite Tio2/Diatomite

    Directory of Open Access Journals (Sweden)

    Rachida Cherrak

    2015-09-01

    Full Text Available The objective of this work is to study the removal of an azo dye methyl orange (MeO by dioxide titanium supported on the surface of diatomite, as a new nano-composite by an advanced oxidation method as heterogeneous Photocatalysis. The titanium oxide (Degussa-25 was immobilized on the powder of diatomaceous earth with a very simple method and low expensive. Diatomite used in this study has porosity more 72%; was thermal activated at temperatures of 800 ° c and 900 ° c and 1000 ° C for 2 h and chemically by sulfuric acid at reflux. Photocatalytic degradation of methyl orange use, was studied in the presence of the materials prepared in solution aqueous with different compositions, M1 (1 g diatomite + 0.5 g TiO2 and M2 (5 g diatomite + 0.5 g TiO2. The photocatalytic activity of the prepared catalysts was tested in a single reactor followed by pH analyzes conductivity and the absorbance. The prepared materials exhibit a very porous morphology, which has been confirmed by several methods DRX, SEM and IR. The results of the photocatalytic treatment of water synthetically polluted with MeO at initial concentration 10 ppm showed a good performance for four nano composite prepared: M1TA is composed by material M1 with diatomite treated by sulfuric acid, and M1TT is composed by material M1 with diatomite calcined at 1000 ° C, and M2TA is M2 material with diatomite treated by sulfuric acid, and M2TT is M2 material with diatomite calcined at 1000 ° c. Maximum efficiency of removing MeO that reaches 84% and 72% for M2TA, M1TT According to the kinetic study reveals that the phenomenon is mixed resulting in a rapid response that is established after 30 minutes, the reaction kinetics of the methyl orange photodegradation following the model of the first order.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  1. The enhanced conductivity of AZO thin films on soda lime glass with an ultrathin Al2O3 buffer layer

    International Nuclear Information System (INIS)

    Aluminum doped zinc oxide (AZO) films were deposited by radio frequency (RF) magnetron sputtering on the Al2O3-coated and bare soda lime glass substrates, respectively. The properties of AZO films were analyzed using X-ray diffraction (XRD), atomic force microscope (AFM), Hall effect measurement and ultraviolet-visible (UV-vis) spectrophotometer. The results of XRD measurement showed that all the AZO thin films had a preferentially oriented (0 0 2) peak and the intensity of (0 0 2) peak decreased with increase in the thickness of the Al2O3 buffer layer. The Hall measurement results showed that the conductivity of the AZO film with a 3 nm Al2O3 buffer layer had a remarkable 41.3% increase when compared with that of the single AZO film. The figures of merit from optical transmittance and electrical conductivity for AZO films on the 3 nm Al2O3-coated and bare glass substrates were 5466 and 3772 S cm-1, respectively. All the results suggested that the use of an ultrathin Al2O3 buffer layer effectively improved the quality of AZO film on the glass substrate.

  2. Enhanced azo dye removal in a continuously operated up-flow anaerobic filter packed with henna plant biomass.

    Science.gov (United States)

    Huang, Jingang; Wu, Mengke; Chen, Jianjun; Liu, Xiuyan; Chen, Tingting; Wen, Yue; Tang, Junhong; Xie, Zhengmiao

    2015-12-15

    Effects of henna plant biomass (stem) packed in an up-flow anaerobic bio-filter (UAF) on an azo dye (AO7) removal were investigated. AO7 removal, sulfanilic acid (SA) formation, and pseudo first-order kinetic constants for these reactions (kAO7 and kSA) were higher in the henna-added UAF (R2) than in the control UAF without henna (R1). The maximum kAO7 in R1 and R2 were 0.0345 and 0.2024 cm(-1), respectively, on day 18; the corresponding molar ratios of SA formation to AO7 removal were 0.582 and 0.990. Adsorption and endogenous bio-reduction were the main AO7 removal pathways in R1, while in R2 bio-reduction was the dominant. Organics in henna could be released and fermented to volatile fatty acids, acting as effective electron donors for AO7 reduction, which was accelerated by soluble and/or fixed lawsone. Afterwards, the removal process weakened over time, indicating the demand of electron donation and lawsone-releasing during the long-term operation of UAF.

  3. PHYSICO CHEMICAL ANALYSIS OF TEXTILE EFFLUENT AND DECOLORIZATION OF TEXTILE AZO DYE BY BACILLUS ENDOPHYTICUS STRAIN VITABR13

    Directory of Open Access Journals (Sweden)

    Arun Prasad and Kokati Venkata Bhaskara Rao

    2011-01-01

    Full Text Available The physicochemical characterization of the textile industry effluent collected from Coimbatore in Tamil Nadu,India was been carried out and the results showed high rates of temperature ( 40°C , pH (7.51 and Electrical Conductivity (9565 μmhos/cm, Biological Oxygen Demand (275 mgl-1, Chemical Oxygen Demand (789 mgl-1, Total Suspended Solids (1750 mgl-1, Total Dissolved Solids (5875mg l-1 , heavy metal ions, Total hardness ( Ca2+, Mg2+, Cl- & SO42- and colour over the prescribed fresh water limits. A potential bacterial strain(VITABR13 was isolated and selected from the textile effluent on the basis of rapid azo dye Acid Red 128(100mgl-1decolorization and later identified as belonging to genus Bacillus based on Phenotypic characterization and phylogenetic analysis of the 16s rRNA gene sequence. Effects of physicochemical parameters (pH, Temperature, Carbon and Nitrogen sources on the Acid Red 128 decolorization by the selected bacterium were studied. Decolorization was effective at pH 8, 35°C with starch and peptone as carbon and nitrogen sources and in static conditions. This decolorization potential increased the applicability of this microorganism for the dye removal.

  4. Azo polymers with electronical push and pull structures prepared via RAFT polymerization and its photoinduced birefringence behavior

    Directory of Open Access Journals (Sweden)

    2008-08-01

    Full Text Available Two methacrylate monomers containing azo and electronical push and pull structure, e.g. 2-Methyl-acrylic-acid-2-{[4-(4-cyano-phenylazo-3-methyl-phenyl]-ethyl-amino-ethyl ester (MACP with cyano substituted and 2-Methylacrylic-acid-2-{ethyl-[4-(4-methoxy-phenylazo-3-methyl-phenyl]-amino}-ethyl ester (MAMP with methoxy substituted, were synthesized and polymerized using 2-cyanoprop-2-yl dithiobenzoate (CPDB as chain transfer agent and 2,2'-azobisisobutyronitrile (AIBN as initiator. The results showed that the polymerization displayed characteristics of ‘living’/controlled free radical polymerization. Thus, the obtained polymers, polyMACP (pMACP and polyMAMP (pMAMP, had controlled molecular weights and narrow molecular weights distribution. The chain extension experiments of pMACP and pMAMP using styrene as the second monomer were successfully carried out. The photo-induced trans-cis-trans isomerization kinetic of pMACP and pMAMP in chloroform solution were described. Marked differences in rate for the trans-cis and cis-trans isomerization of pMACP and pMAMP were observed in chloroform solution due to the different electronic effects in these two polymers. Photoinduced birefringence and surface relief grating (SRG of the pMACP and pMAMP were investigated in thin film state.

  5. The effect of cyclic anaerobic-aerobic conditions on biodegradation of azo dyes.

    Science.gov (United States)

    Yaşar, Semra; Cirik, Kevser; Cinar, Ozer

    2012-03-01

    The effect of cyclic anaerobic-aerobic conditions on the biodegradative capability of the mixed microbial culture for the azo dye Remazol Brilliant Violet 5R (RBV-5R) was investigated in the sequencing batch reactor (SBR) fed with a synthetic textile wastewater. The SBR had a 12-h cycle time with anaerobic-aerobic periods of 3/9, 6/6 and 9/3 h. General SBR performance was assessed by measurement of catabolic enzymes (catechol 2,3-dioxygenase, azo reductase), chemical oxygen demand (COD), color and amount of aromatic amines. In this study, under steady-state conditions, the anaerobic period of the cyclic SBR was found to allow the reductive decolorization of azo dye. Longer anaerobic periods resulted in higher color removal efficiencies, approximately 71% for the 3-h, 87% for 6-h and 92% for the 9-h duration. Total COD removal efficiencies were over 84% under each of the cyclic conditions and increased as the length of the anaerobic period was increased; however, the highest color removal rate was attained for the cycle with the shortest anaerobic period of 3 h. During the decolorization of RBV-5R, two sulfonated aromatic amines (benzene based and naphthalene based) were formed. Additionally, anaerobic azo reductase enzyme was found to be positively affected with the increasing duration of the anaerobic period; however; it was vice versa for the aerobic catechol 2,3-dioxygenase (C23DO) enzyme.

  6. PREPARASI Fe3+/TiO2- MONTMORILLONIT SEBAGAI KATALIS PADA DEGRADASI ZAT WARNA AZO

    Directory of Open Access Journals (Sweden)

    Is Fatimah

    2014-12-01

    Full Text Available Dalam penelitian ini dilakukan preparasi material Fe3+/TiO2-Montmorillonit dan uji aktivitasnya sebagai katalis pada degradasi senyawa azo. Keberhasilan preparasi material dipelajari melalui karakterisasi menggunakan X-ray Diffraction, BET surface area analyzer dan Diffuse Reflectance UV-Visible. Peranan katalitik material hasil preparasi pada degradasi senyawa azo: metil jingga(MO dan metilena biru(MB dipelajari melalui studi kinetika reaksi dengan mekanisme mirip foto-Fenton (Photo-Fenton like mechanism. Hasil penelitian menunjukkan keberhasilan preparasi material Fe3+/TiO2-Montmorillonit serta tercapainya tujuan penggunaannya sebagai katalis untuk degradasi zat warna azo melalui mekanisme Photo-Fenton like. Simulasi terhadap data kinetika menunjukkan bahwa degradasi kedua zat warna azo dengan katalis hasil preparasi mengikuti  model kinetika Langmuir-Hinshelwood dengan nilai k dan K untuk MO berturut-turut adalah sebesar 8,83x10-7 M/detik dan 328,29 dan untuk MB sebesar 4,56x10-5 M dan 555,60. Nilai konstanta laju reaksi dan konstanta adsorpsi-desorpsi reaksi degradasi kedua zat warna menjelaskan peranan mekanisme interaksi permukaan dalam proses katalisis.

  7. Comparison of decolorization of reactive azo dyes by microorganisms isolated from various sources

    Institute of Scientific and Technical Information of China (English)

    S.Padamavathy; S.Sandhya; K.Swaminathan; Y.V.Subrahmanyam; S.N.Kaul

    2003-01-01

    Azo dyes are among the oldest man-made chemicals and they are still widely used in the textile, printing and the food industries. About 10%-15% of the total dyes used in the industry is released into the environment during the manufacturing and usage. Some dyes and some of their N-substituted aromatic bio-transformation products are toxic and/or carcinogenic and therefore these dyes are considered to be environmental pollutants and health hazards. These azo dyes are degraded by physico-chemical and biological methods. Of these, biological methods are considered to be the most economical and efficient. In this work, attempts were made to degrade these dyes aerobically. The organisms which were efficient in degrading the following azo dyes-Red RB, Remazol Red, Remazol Blue, Remazol Violet, Remazol Yellow, Golden Yellow, Remazol Orange, Remazol Black- were isolated from three different sources viz., wastewater treatment plant, paper mill effluent treatment plant and tannery wastewater treatment plant. The efficiency of azo dye degradation by mixed cultures from each source was analyzed. It was found that mixed cultures from tannery treatment plant worked efficiently in decolorizing Remazol Red, Remazol Orange, Remazol Blue and Remazol Violet, while mixed cultures from the paper mill effluent worked efficiently in decolorizing Red RB, Golden Yellow and Remazol Yellow. The mixed cultures from wastewater treatment plant efficiently decolorized Remazol Black.

  8. Decolorization of azo dyes by marine Shewanella strains under saline conditions.

    Science.gov (United States)

    Liu, Guangfei; Zhou, Jiti; Meng, Xianming; Fu, Shiang Q; Wang, Jing; Jin, Ruofei; Lv, Hong

    2013-05-01

    Azo dye decolorization was studied with Shewanella strains under saline conditions. Growing cells of Shewanella algae and Shewanella marisflavi isolated from marine environments demonstrated better azo dye decolorization capacities than the other three strains from non-saline sources. Cell suspensions of S. algae and S. marisflavi could decolorize single or mixed azo dyes with different structures. Decolorization kinetics were described with Michaelis-Menton equation, which indicated better decolorization performance of S. algae over S. marisflavi. Lactate and formate were identified as efficient electron donors for amaranth decolorization by the two strains. S. algae and S. marisflavi could decolorize amaranth at up to 100 g L(-1) NaCl or Na2SO4. However, extremely low concentration of NaNO3 exerted strong inhibition on decolorization. Both strains could remove the color and COD of textile effluent during sequential anaerobic-aerobic incubation. Lower concentrations of NaCl (20-30 g L(-1)) stimulated the activities of azoreductase, laccase, and NADH-DCIP reductase. The decolorization intermediates were identified by high-performance liquid chromatography and Fourier transform infrared spectroscopy. Decolorization metabolites of amaranth were less toxic than original dye. These findings improved our knowledge of azo-dye-decolorizing Shewanella species and provided efficient candidates for the treatment of dye-polluted saline wastewaters.

  9. Decolorization of textile azo dyes by newly isolated halophilic and halotolerant bacteria.

    Science.gov (United States)

    Asad, S; Amoozegar, M A; Pourbabaee, A A; Sarbolouki, M N; Dastgheib, S M M

    2007-08-01

    Studies were carried out on the decolorization of textile azo dyes by newly isolated halophilic and halotolerant bacteria. Among the 27 strains of halophilic and halotolerant bacteria isolated from effluents of textile industries, three showed remarkable ability in decolorizing the widely utilized azo dyes. Phenotypic characterization and phylogenetic analysis based on 16S rDNA sequence comparisons indicate that these strains belonged to the genus Halomonas. The three strains were able to decolorize azo dyes in a wide range of NaCl concentration (up to 20%w/v), temperature (25-40 degrees C), and pH (5-11) after 4 days of incubation in static culture. They could decolorize the mixture of dyes as well as pure dyes. These strains also readily grew in and decolorized the high concentrations of dye (5000 ppm) and could tolerate up to 10,000 ppm of the dye. UV-Vis analyses before and after decolorization and the colorless bacterial biomass after decolorization suggested that decolorization was due to biodegradation, rather than inactive surface adsorption. Analytical studies based on HPLC showed that the principal decolorization was reduction of the azo bond, followed by cleavage of the reduced bond.

  10. Comparative studies of fungal degradation of single or mixed bioaccessible reactive azo dyes

    OpenAIRE

    Martins, M. Adosinda M.; Lima, Nelson; Silvestre, Armando J. D.; Queiroz, Maria João R. P.

    2003-01-01

    A screening using several fungi (Phanerochaete chrysosporium, Pleurotus ostreatus, Trametes versicolor and Aureobasidium pullulans) was performed on the degradation of syringol derivatives of azo dyes possessing either carboxylic or sulphonic groups, under optimized conditions previously established by us. T. versicolor showed the best biodegradation performance and its potential was confirmed by the degradation of differently substituted fungal bioaccessible dyes. Enzymatic assay...

  11. Cancer risk assessment of azo dyes and aromatic amines from garment and footwear

    NARCIS (Netherlands)

    Zeilmaker MJ; Kroese ED; Haperen P van; Veen MP van; Bremmer HJ; Kranen HJ van; Wouters MFA; Janus J; LBM

    1999-01-01

    A quantitative assessment was performed to estimate the cancer risk to individuals wearing garment and footwear coloured with azo dyes. Basically, the risk assessment consists of both a comparison of the (estimated) level of aromatic amines which, during the wearing of garment and footwear, enters

  12. Cancer risk assessment of azo dyes and aromatic amines from garment and footwear

    NARCIS (Netherlands)

    Zeilmaker MJ; Kroese ED; van Haperen P; van Veen MP; Bremmer HJ; van Kranen HJ; Wouters MFA; Janus J; LBM

    1999-01-01

    Dit rapport beschrijft een schatting voor het risico op kanker dat verbonden is aan het dragen van kleding en schoeisel waarin kankerverwekkende azo kleurstoffen aangetroffen zijn. In de risicoschatting wordt de (geschatte) hoeveelheid aromatische aminen die tijdens het dragen van kleding en schoei

  13. Development of a novel high-entropy alloy with eminent efficiency of degrading azo dye solutions

    Science.gov (United States)

    Lv, Z. Y.; Liu, X. J.; Jia, B.; Wang, H.; Wu, Y.; Lu, Z. P.

    2016-09-01

    In addition to its scientific importance, the degradation of azo dyes is of practical significance from the perspective of environmental protection. Although encouraging progress has been made on developing degradation approaches and materials, it is still challenging to fully resolve this long-standing problem. Herein, we report that high entropy alloys, which have been emerging as a new class of metallic materials in the last decade, have excellent performance in degradation of azo dyes. In particular, the newly developed AlCoCrTiZn high-entropy alloy synthesized by mechanical alloying exhibits a prominent efficiency in degradation of the azo dye (Direct Blue 6: DB6), as high as that of the best metallic glass reported so far. The newly developed AlCoCrTiZn HEA powder has low activation energy barrier, i.e., 30 kJ/mol, for the degrading reaction and thus make the occurrence of reaction easier as compared with other materials such as the glassy Fe-based powders. The excellent capability of our high-entropy alloys in degrading azo dye is attributed to their unique atomic structure with severe lattice distortion, chemical composition effect, residual stress and high specific surface area. Our findings have important implications in developing novel high-entropy alloys for functional applications as catalyst materials.

  14. Reductive decolourisation of azo dyes by mesophilic and thermophilic methanogenic consortia

    NARCIS (Netherlands)

    Cervantes, F.J.; Santos, dos A.B.; Madrid, de M.P.; Stams, A.J.M.; Lier, van J.B.

    2005-01-01

    The contribution of acidogenic bacteria and methanogenic archaea on the reductive decolourisation of azo dyes was assessed in anaerobic granular sludge. Acidogenic bacteria appeared to play an important role in the decolourising processes when glucose was provided as an electron donor; whereas metha

  15. Molecular determinants of azo reduction activity in the strain Pseudomonas putida MET94.

    Science.gov (United States)

    Mendes, Sónia; Pereira, Luciana; Batista, Carlos; Martins, Lígia O

    2011-10-01

    Azo dyes are the major group of synthetic colourants used in industry and are serious environmental pollutants. In this study, Pseudomonas putida MET94 was selected from 48 bacterial strains on the basis of its superior ability to degrade a wide range of structurally diverse azo dyes. P. putida is a versatile microorganism with a well-recognised potential for biodegradation or bioremediation applications. P. putida MET94 removes, in 24 h and under anaerobic growing conditions, more than 80% of the majority of the structurally diverse azo dyes tested. Whole cell assays performed under anaerobic conditions revealed up to 90% decolourisation in dye wastewater bath models. The involvement of a FMN dependent NADPH: dye oxidoreductase in the decolourisation process was suggested by enzymatic measurements in cell crude extracts. The gene encoding a putative azoreductase was cloned from P. putida MET94 and expressed in Escherichia coli. The purified P. putida azoreductase is a 40 kDa homodimer with broad substrate specificity for azo dye reduction. The presence of dioxygen leads to the inhibition of the decolourisation activity in agreement with the results of cell cultures. The kinetic mechanism follows a ping-pong bi-bi reaction scheme and aromatic amine products were detected in stoichiometric amounts by high-performance liquid chromatography. Overall, the results indicate that P. putida MET94 is a promising candidate for bioengineering studies aimed at generating more effective dye-reducing strains.

  16. Transparent conducting AZO and ITO films produced by pulsed laser ablation at 355 nm

    DEFF Research Database (Denmark)

    Thestrup, B.; Schou, Jørgen

    1999-01-01

    Thin films of aluminium-doped zinc oxide (AZO) and indium tin oxide (ITO) were deposited on glass substrates by laser ablation in an oxygen environment. The electrical and optical properties of films grown at various oxygen pressures were compared. With no substrate heating, highly transparent...

  17. Preparation and characterization of grafted polyethylene based azo-polymer films

    International Nuclear Information System (INIS)

    A series of grafted azo-polymers was prepared from commercial low density polyethylene thin plates (PE). Polyethylene was reacted in the presence of acryloyl chloride using gamma irradiation to give precursor grafted polymers. These materials were esterified in the presence of six different commercial azo-dyes: (E)-2-(ethyl(4-((4-nitrophenyl)diazenyl)phenyl)amino)ethanol (Disperse Red-1, DR-1), (E)-2-((4-((2-chloro-4-nitrophenyl)diazenyl)phenyl)(ethyl)amino)ethanol (Disperse Red-13, DR-13), (E)-2,2'-(4-((4-nitrophenyl)diazenyl)phenylazanediyl)diethanol (Disperse Red-19, DR-19), (E)-4-((4-nitrophenyl)diazenyl)aniline (Disperse Orange-3, DO-3), 4-((E)-(4-((E)-phenyldiazenyl)naphthalen-1-yl)diazenyl)phenol (Disperse Orange-13, DO-13) and 2-methyl-4-((E)-(4-((E)-phenyldiazenyl)phenyl)diazenyl)phenol (Disperse Yellow-7, DY-7) to give the expected grafted azo-polymer films. The obtained polymers were fully characterized; their thermal, optical properties and morphology were studied. In particular, the influence of the irradiation conditions and the incorporated azo-dye on the polymer properties is discussed.

  18. Preparation and characterization of grafted polyethylene based azo-polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Pilar Carreon-Castro, Maria del, E-mail: pilar@nucleares.unam.m [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior Ciudad Universitaria C.P. 04510, Mexico D.F. (Mexico); Rivera, Ernesto [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior Ciudad Universitaria C.P. 04510, Mexico D.F. (Mexico); Jesus Cruz, Jose de; Zavaleta, Gerardo [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior Ciudad Universitaria C.P. 04510, Mexico D.F. (Mexico); Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior Ciudad Universitaria C.P. 04510, Mexico D.F. (Mexico); Gutierrez-Nava, Manuel [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior Ciudad Universitaria C.P. 04510, Mexico D.F. (Mexico)

    2010-05-31

    A series of grafted azo-polymers was prepared from commercial low density polyethylene thin plates (PE). Polyethylene was reacted in the presence of acryloyl chloride using gamma irradiation to give precursor grafted polymers. These materials were esterified in the presence of six different commercial azo-dyes: (E)-2-(ethyl(4-((4-nitrophenyl)diazenyl)phenyl)amino)ethanol (Disperse Red-1, DR-1), (E)-2-((4-((2-chloro-4-nitrophenyl)diazenyl)phenyl)(ethyl)amino)ethanol (Disperse Red-13, DR-13), (E)-2,2'-(4-((4-nitrophenyl)diazenyl)phenylazanediyl)diethanol (Disperse Red-19, DR-19), (E)-4-((4-nitrophenyl)diazenyl)aniline (Disperse Orange-3, DO-3), 4-((E)-(4-((E)-phenyldiazenyl)naphthalen-1-yl)diazenyl)phenol (Disperse Orange-13, DO-13) and 2-methyl-4-((E)-(4-((E)-phenyldiazenyl)phenyl)diazenyl)phenol (Disperse Yellow-7, DY-7) to give the expected grafted azo-polymer films. The obtained polymers were fully characterized; their thermal, optical properties and morphology were studied. In particular, the influence of the irradiation conditions and the incorporated azo-dye on the polymer properties is discussed.

  19. Studies on Synthesis and Dyeing Preformance of Acid Dyes Based on 4,7-Dihydroxy-1,10-Phenanthroline-2,9-Dione

    OpenAIRE

    Patel, B. V.; Dasondi, P. H.

    2008-01-01

    Some new azo acid dyes were prepared by coupling various diazotized acid components such as anthranilic acid, sulphanilic acid, laurent acid, peri acid, tobias acid, H-acid, J-acid, gamma acid, sulphotobias acid, 4-aminotoluiene-3-sulphonic acid, 5-sulpho- anthranilic acid, 2-naphthylamine-3,6,8-trisulphonic acid, bronner acid, metanilic acid and cleve acid with 4,7-dihydroxy-1,10-phenanthroline-2,9-dione. The dyes were characterized by elemental, IR and TLC analyses. Their dyeing performance...

  20. Synthesis, self-assembly and photoinduced surface-relief gratings of a polyacrylate-based Azo polyelectrolyte

    Science.gov (United States)

    He, Yaning; Wang, Haopeng; Tuo, Xinlin; Deng, Wei; Wang, Xiaogong

    2004-06-01

    A polyacrylate-based azo polyelectrolyte was synthesized and characterized by the spectroscopic methods and thermal analysis. Layer-by-layer self-assembly of the azo polyelectrolyte through electrostatic adsorption was explored. By using a dipping solution of the anionic azo polyelectrolyte in anhydrous DMF, together with an aqueous solution of cationic poly(diallyldimethylammonium chloride) (PDAC), high quality multilayer films were obtained through the sequential deposition of the oppositely charged polyelectrolytes. With interfering illumination of Ar + laser beams (488 nm), significant surface-relief gratings formed on the self-assembled multiplayer films were observed.

  1. Comparative study on reaction selectivity of azo dye decolorization by Pseudomonas luteola.

    Science.gov (United States)

    Hsueh, Chung-Chuan; Chen, Bor-Yann

    2007-03-22

    This study is to inspect how the variation of molecular structures and functional groups present in our model azo dyes (i.e., Congo red, Eriochrome black T (EBT), methyl orange, and methyl red) affects biodecolorization capability of Pseudomonas luteola. The most viable decolorization was found at pH 7-9 and the optimal cellular age for the most effective decolorization was 7 days after static incubation in dye-free cultures. In decolorization, the maximal absorption wavelength in UV-vis spectra for the different dye-containing cultures shifted from visible light range towards the ultraviolet visible range. Methyl red was not decolorized in contrast to methyl orange, Congo red, and Eriochrome black T. The sulfonic group para to azo bond (-N=N-) in methyl orange was a strong electron-withdrawing group through resonance to cause an enhancement of color removal to be easily biodecolorized. As a charged carboxyl group on methyl red is at ortho position (i.e., in the proximity) to azo bond, this led to a complete inhibition to decolorization. However, decolorization of Congo red and EBT in the absence of charged group (e.g., hydroxy or amino group) near azo bond was not completely repressed like methyl red. Thus, the presence of electron-withdrawing groups as the substituents on azo dyes enhanced decolorization capability for biodegradability. In addition, Monod kinetic model provided better predictions to all dye decolorization at initial short periods of time due to negligible intermediate formed at initial short time duration, but significant intermediate accumulation took place at longer period of time. In contrast, the decolorization performances of methyl orange at 400ppm and EBT at 230ppm were significantly less than those predicted from the Monod kinetic model likely due to accumulated intermediates exceeding the threshold levels for feedback inhibition.

  2. SYNTHESIS OF SOME NEW 1-SUBSTITUTED 3-TRIFLUROMETHYL-5-PHENYL-4- (SUBSTITUTED PHENYL AZO PYRAZOLES AS ANTIFUNGAL AGENTS Synthese einiger NEW 1-substituierten 3-Trifluormethyl-5-phenyl-4- (Substituiertes Phenyl AZO PYRAZOLE als Antipilzmittel

    Directory of Open Access Journals (Sweden)

    Vineeta Sareen, Vineeta Khatri and Prakash Jain

    2011-08-01

    Full Text Available Some new fluorine containing azo pyrazoles have been synthesized by the condensation of hydrazono derivatives (obtained by the reaction of 1, 3-diketone with diazonium salts in the presence of sodium acetate, with substituted hydrazines to give 1-substituted-3-trifluoromethyl- 5-phenyl-4-(substituted phenyl azo pyrazoles. The structure of these compounds are confirmed on the basis of elemental analysis and spectral studies.

  3. TiO2/beads as a photocatalyst for the degradation of X3B azo dye

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The feasibility of photocatalytic degradation of X3B azo dye by TiO2/beads photocatalyst was studied. The effects of parameters such as the amount of TiO2/beads, airflow, as well as the concentrations of H2O2, Fe3+, Mg2+ and Na+ on the photocatalytic degradation of X3B azo dye were also studied. The results showed that 25 mg/dm3 X3B azo dye can be photocatalytically degraded completely by 30 min illumination with a 375W medium pressure mercury lamp. Adding a small amount of H2O2 or Fe3+, the efficiencies of photocatalytic degradation of X3B azo dye were increased rapidly. The mechanisms of the reaction and the role of the additives were also investigated. After 120 hours TiO2/beads showed no significant loss of the photocatalytic activity.

  4. Decolorization and biodegradation of reactive sulfonated azo dyes by a newly isolated Brevibacterium sp. strain VN-15

    OpenAIRE

    Franciscon, Elisangela; Grossman, Matthew James; Paschoal, Jonas Augusto Rizzato; Felix Guillermo Reyes REYES; Durrant, Lucia Regina

    2012-01-01

    Azo dyes constitute the largest and most versatile class of synthetic dyes used in the textile, pharmaceutical, food and cosmetics industries and represent major components in wastewater from these industrial dying processes. Biological decolorization of azo dyes occurs efficiently under low oxygen to anaerobic conditions. However, this process results in the formation of toxic and carcinogenic amines that are resistant to further detoxification under low oxygen conditions. Moreover, the abil...

  5. Bithiophene azo dyes bearing thiazole, benzothiazole and thiadiazole heterocycles : synthesis and comparative study of their photochromic properties

    OpenAIRE

    Castro, M. Cidália R.; Paulo J. Coelho; Fernandes, Sara S. M.; Fonseca, A. Maurício C.; Raposo, M. Manuela M.

    2012-01-01

    Although a large variety of diarylazo compounds are used in the design of optical materials, only a few reports concerning the photoisomerization of heterocyclic azo dyes can be found in the literature. In the last years our group reported for the first time the synthesis and characterization of heterocyclic azo dyes bearing thiophene and pyrrole moieties as thermally stable conducting materials, solvatochromic probes and nonlinear optical systems. The E/Z isomerizable N=N double bond within ...

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

    Science.gov (United States)

    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.

  7. Nanometer-thick amorphous-SnO2 layer as an oxygen barrier coated on a transparent AZO electrode

    Science.gov (United States)

    Lee, Hee Sang; Woo, Seong Ihl

    2016-07-01

    It is necessary for transparent conducting electrodes used in dye-sensitized or perovskite solar cells to have high thermal stability which is required when TiO2 is coated on the electrode. AZO films with their low-cost and good TCO properties are unfortunately unstable above 300 °C in air because of adsorbed oxygen. In this paper, the thermal stability of AZO films is enhanced by depositing an oxygen barrier on AZO films to block the oxygen. As the barrier material, SnO2 is used due to its high heat stability, electrical conductivity, and transmittance. Moreover, when the SnO2 is grown as amorphous phase, the protective effect become greater than the crystalline phase. The thermal stability of the amorphous-SnO2/AZO films varies depending on the thickness of the amorphous SnO2 layer. Because of the outstanding oxygen blocking properties of amorphous SnO2, its optimal thickness is very thin and it results in only a slight decrease in transmittance. The sheet resistance of the amorphous-SnO2/AZO film is 5.4 Ω sq-1 after heat treatment at 500 °C for 30 min in air and the average transmittance in the visible region is 83.4%. The results show that the amorphous-SnO2/AZO films have thermal stability with excellent electrical and optical properties. [Figure not available: see fulltext.

  8. Decolorization of acid and basic dyes: understanding the metabolic degradation and cell-induced adsorption/precipitation by Escherichia coli.

    Science.gov (United States)

    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.

  9. Steady performance of a zero valent iron packed anaerobic reactor for azo dye wastewater treatment under variable influent quality

    Institute of Scientific and Technical Information of China (English)

    Yaobin Zhang; Yiwen Liu; Yanwen Jing; Zhiqiang Zhao; Xie Quan

    2012-01-01

    Zero valent iron (ZVI) is expected to help create an enhanced anaerobic environment that might improve the performance of anaerobic treatment.Based on this idea,a novel ZVI packed upflow anaerobic sludge blanket (ZVI-UASB) reactor was developed to treat azo dye wastewater with variable influent quality.The results showed that the reactor was less influenced by increases of Reactive Brilliant Red X-3B concentration from 50 to 1000 mg/L and chemical oxygen demand (COD) from 1000 to 7000 mg/L in the feed than a reference UASB reactor without the ZVI.The ZVI decreased oxidation-reduction potential in the reactor by about 80 mV.Iron ion dissolution from the ZVI could buffer acidity in the reactor,the amount of which was related to the COD concentration.Fluorescence in situ hybridization test showed the abundance of methanogens in the sludge of the ZVI-UASB reactor was significantly greater than that of the reference one.Denaturing gradient gel electrophoresis showed that the ZVI increased the diversity of microbial strains responsible for high efficiency.

  10. Evaluation of energy transfer and utilization efficiency of azo dye removal by different pulsed electrical discharge modes

    Institute of Scientific and Technical Information of China (English)

    SHEN YongJun; LEI LeCheng; ZHANG XingWang

    2008-01-01

    The degradation of an azo dye, acid orange 7 (AO7), caused by different high voltage pulsed electrical discharge modes (spark, streamer and corona discharge) induced by the various initial conductivities was investigated. A new type of pulsed high voltage source with thyratron switch and Blumlein pulse forming net (BPFN) was used. The typical discharge waveforms of voltage, current, power, pulse en-ergy and the pictures of spark, streamer and corona discharge modes were presented. The results in-dicated that pulsed electrical discharges led to complete decolorization and substantial decrease of the chemical oxygen demand (COD) of the dye solution. The main intermediate products were monitored by GC-MS. The discharge modes changed from spark to streamer and to corona discharge, and the streamer length decreased with the liquid conductivity increasing. At a constant input power, the peak voltage, peak current, peak power and energy per pulse of the three discharge modes ranked in the following order: spark > streamer > corona. The effective energy transfer efficiency of AO7 removal was higher for spark discharge (57.2%) than for streamer discharge (40.4%) and corona discharge (27.6%). Moreover, the energy utilization efficiency of AO7 removal for spark discharge was 1.035×109 mol/J, and for streamer and corona discharge they were 0.646×10-8 and 0.589×10-9mol/J. Both the energy transfer efficiency and the energy utilization efficiency of spark discharge were the highest.

  11. Enhancement of the optical response in a biodegradable polymer/azo-dye film by the addition of carbon nanotubes

    Science.gov (United States)

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

    2014-04-01

    A new biodegradable photoresponsive material was developed using poly(lactic acid) (PLA) as the matrix material and Disperse Orange 3 (DO3) as photoisomerizable azo-dye. It was observed that the addition of multi-walled carbon nanotubes (MWCNTs) leads to a new phenomenon consisting of an enhancement of the optical anisotropy in a wide range of temperatures. In particular, the optical anisotropy increases 100% at room temperature. Moreover, the material containing MWCNTs shows a faster optical response that is evidenced as an increase in the growth rate of optical anisotropy. Spectroscopic data is provided to study the interaction among DO3, MWCNTs and PLA. The enhancement of optical anisotropy obtained with the addition of MWCNTs was related to the glass transition temperature (Tg) of each material. Maximum optical anisotropy was obtained 15 °C below the Tg for both materials. Results are interpreted in terms of the interactions among DO3, MWCNTs and PLA and the packing density of the dye into the polymer chains. In memory of Professor Iñaki Mondragon.

  12. Novel 2-phenyl-3-{4’-[N-(4”-aminophenylcarbamoyl]-phenyl}-quinazoline-4(3Hone-6-sulphonic acidbased mono azo reactive dyes

    Directory of Open Access Journals (Sweden)

    DIVYESH R. PATEL

    2011-02-01

    Full Text Available A series of new heterocyclic mono azo reactive dyes 7a–m were prepared by diazotization of 2-phenyl-3-{4’-[N-(4”-aminophenylcarbamoyl]-phenyl}-quinazoline-4(3H-one-6-sulphonic acid (3 and coupling with various cyanurated coupling components 6a–m and their dyeing performance on silk, wool and cotton fibres was assessed. These dyes were found to give a variety of colour shades with very good depth and levelness on the fibres. All the compounds were identified by conventional method (IR and 1H-NMR and elemental analyses. The percentage dye bath exhaustion on different fibres was reasonably good and acceptable. The dyed fibre showed moderate to very good fastness to light, washing and rubbing.

  13. Evaluation of three reagent dosing strategies in a photo-Fenton process for the decolorization of azo dye mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Prato-Garcia, D. [Laboratory for Research on Advanced Processes for Water Treatment, Instituto de Ingenieria, Unidad Academica Juriquilla, Universidad Nacional Autonoma de Mexico, Blvd. Juriquilla 3001, Queretaro 76230 (Mexico); Buitron, German, E-mail: gbuitronm@iingen.unam.mx [Laboratory for Research on Advanced Processes for Water Treatment, Instituto de Ingenieria, Unidad Academica Juriquilla, Universidad Nacional Autonoma de Mexico, Blvd. Juriquilla 3001, Queretaro 76230 (Mexico)

    2012-05-30

    Highlights: Black-Right-Pointing-Pointer Dosing strategies for a photo-Fenton process were evaluated. Black-Right-Pointing-Pointer The dosing strategy had no effect of on the decolorization. Black-Right-Pointing-Pointer The type of strategy influenced SUVA index, toxicity reduction and biodegradability. Black-Right-Pointing-Pointer A continuous reagents supply was found to be the most adequate strategy. Black-Right-Pointing-Pointer Decolorization as well as a less toxic and biodegradable effluent was produced. - Abstract: Three reagent dosing strategies used in the solar photo-assisted decolorization of a mixture of sulfonated dyes consisting of acid blue 113, acid orange 7 and acid red 151 were evaluated. Results demonstrated that the dosing strategy influenced both reagent consumption and the biodegradability and toxicity of the effluent. In one strategy (E{sub 1}), the Fenton's reactants were dosed in a punctual mode, while in the other two strategies (E{sub 2} an E{sub 3}), the reactants were dosed continuously. In the E{sub 2} strategy the reactants were dosed by varying the duration of the injection time. In the E{sub 3} strategy, the reactants were dosed during 60 min at a constant rate, but with different concentrations. All cases showed that feeding the reactor between 40% and 60% of the maximal dose was sufficient to decolorize more than 90% of the mixture of azo dyes. The E{sub 1} strategy was less effective for aromatic content reduction. Conversely, the continuous addition of the reagents (E{sub 2} and E{sub 3} strategies) improved the aromatic content removal. E{sub 3} strategy was substantially more appropriate than E{sub 1} strategy due to improved the effluent quality in two key areas: toxicity and biodegradability.

  14. A compilation of genotoxicity and carcinogenicity data on aromatic aminosulphonic acids.

    Science.gov (United States)

    Jung, R; Steinle, D; Anliker, R

    1992-07-01

    A review is presented to evaluate existing information on genotoxicity and carcinogenicity testing of various aromatic aminosulphonic acids (AASAs). A great variety of water-soluble azo dyes can form aromatic phenyl- or naphthyl-aminosulphonic acids by chemical and enzymatic reduction. AASAs are also used as intermediates in the synthesis of azo dyes and azo pigments and can arise as contaminants in the final products. Comparisons have been made with the data available on the corresponding unsulphonated analogues, some of which are known to be genotoxic and/or carcinogenic. The vast majority of the AASAs were conclusively non-mutagenic in the Ames test. In most cases the absence of genotoxicity was also demonstrated with a variety of other test systems in vitro and in vivo. It is concluded that AASAs, in contrast with some of their unsulphonated analogues, generally have no or very low genotoxic and tumorigenic potential.

  15. Optimization and kinetics evaluation of biodegradation of synthetic azo reactive dye by fungal consortium.

    Science.gov (United States)

    Chitradevi, V; Sivakumar, V

    2011-10-01

    Wastewater containing direct dyes discharged from various industries, in particular, textile industry, often cause many environmental problems. Among the various effluent treatment methods, biological methods found to be cost effective and do not end up in secondary pollutants. In this study, an attempt has been made to study the decolorization of cibacron yellow S-3R, an azo reactive dye by using fungal cultures such as Coriolus versicolor, Phanerochaete chrysosporium, Pleurotus ostreatus, and Myrothecium verrucaria. The fungi were able to decolorize individually the azo reactive dye cibacron yellow S-3R to an extent of nearly in the range 75 - 85%, whereas the mixed fungal consortium was able to decolorize to an extent of nearly 95%.The study is extended with the kinetics of decolorization of Cibacron yellow S-3R using mixed fungal consortium containing equal proportions of the cultures. The experimental results show that decolorization kinetics follow second order rate equation.

  16. Self-assembled cardanol azo derivatives as antifungal agent with chitin-binding ability.

    Science.gov (United States)

    Mahata, Denial; Mandal, Santi M; Bharti, Rashmi; Gupta, Vinay Krishna; Mandal, Mahitosh; Nag, Ahindra; Nando, Golok B

    2014-08-01

    Cardanol is a non-isoprenoic phenolic lipid-mixture of distilled cashew nut shell liquid obtained from Anacardium occidentale. Herein, cardanol is purified from cashew nut shell liquid (CNSL) and synthesized to new compounds with different azo amphiphiles. These synthesized compounds are allowed to self-assembled in hydrophobic environment and checked antifungal activity against Candida albicans. Self-assembled structure of CABA showed higher antifungal activity (16μg/mL) and chitin-binding ability in comparison to CAP and CANB. Furthermore, the self-assembled azo amphiphiles are immobilized with silver ions to prepare hydrogel which showed eight folds enhanced antifungal activity. Toxicity is reduced by several folds of self-assembled or hydrogel structure in comparison to pure compounds. Thus, the self-assembled structure of amphiphiles and their hydrogels have been found to be new macromolecules of interest with potential use as antifungal drugs. PMID:24836571

  17. Fluorescent Sensing of Chlorophenols in Water Using an Azo Dye Modified β-Cyclodextrin Polymer

    Directory of Open Access Journals (Sweden)

    Bhekie B. Mamba

    2011-04-01

    Full Text Available A water soluble azo dye modified β-cyclodextrin polymer 4 was synthesized and used as a chemosensor for the detection of chlorinated phenols, model chlorinated by-products (CBPs of water treatment for drinking purposes. The characterization of the intermediates and the azo dye modified β-CD polymer was done by UV/Vis Spectrophotometry, FT-IR and 1H-NMR spectroscopies. The chlorophenols were capable of quenching the fluorescence of the polymer. The polymer showed greater sensitivity towards 2,4-dichlorophenol, with a sensitivity factor of 0.35 compared to 0.05 and 0.12 for phenol and 4-chlorophenol, respectively. The stability constants (Ks of the pollutants were also determined by the Benesi-Hildebrand method to be 2.104 × 103 M−1 for 2,4-dichlorophenol and 1.120 × 102 M−1 for 4-chlorophenol.

  18. Synthesis and Properties of Novel Aromatic Azo Compounds from Hydroxyazobenzene and Cyanuric Chloride

    Institute of Scientific and Technical Information of China (English)

    李巍巍; 徐冬梅; 张志兰; 徐颖

    2012-01-01

    A new series of aromatic azo compounds with one, two, three and five azobenzene units were facilely constructed by dehydrochlorination reaction between p-hydroxyazobenzene, 4,4'-dihydroxyazobenzene and cyanuric chloride under very mild conditions. Their solubility, crystallinity, thermostability, UV-vis absorption properties and photoisomerization behaviors were carefully examined. When the number of azobenzene unit grew, the solubility of the synthesized compounds basically decreased, the crystallinity of the synthesized compounds firstly rose then dropped, while the thermostability and UV-vis absorption ability of the synthesized compounds greatly im- proved. All the aromatic azo compounds exhibited typical reversible photoisomerization behaviors and were expected to be applied in photosensitive material areas.

  19. Choline-based ionic liquids-enhanced biodegradation of azo dyes.

    Science.gov (United States)

    Sekar, Sudharshan; Surianarayanan, Mahadevan; Ranganathan, Vijayaraghavan; MacFarlane, Douglas R; Mandal, Asit Baran

    2012-05-01

    Industrial wastewaters such as tannery and textile processing effluents are often characterized by a high content of dissolved organic dyes, resulting in large values of chemical and biological oxygen demand (COD and BOD) in the aquatic systems into which they are discharged. Such wastewater streams are of rapidly growing concern as a major environmental issue in developing countries. Hence there is a need to mitigate this challenge by effective approaches to degrade dye-contaminated wastewater. In this study, several choline-based salts originally developed for use as biocompatible hydrated ionic liquids (i.e., choline sacchrinate (CS), choline dihydrogen phosphate (CDP), choline lactate (CL), and choline tartarate (CT)) have been successfully employed as the cosubstrate with S. lentus in the biodegradation of an azo dye in aqueous solution. We also demonstrate that the azo dye has been degraded to less toxic components coupled with low biomass formation.

  20. Optical Parameters and Absorption of Azo Dye and Its Metal-Substituted Compound Thin Films

    Institute of Scientific and Technical Information of China (English)

    魏斌; 吴谊群; 顾冬红; 干福熹

    2003-01-01

    We determine the complex refractive indices N ( N = n - ik), dielectric constants ε(ε = ε1 - iε2), and absorption coefficients α of a new azo dye [2-(6-methyl-2-benzothiazolyazo)-5-diethylaminophenol(MBADP)]-doped polymer and its nickel- and zinc-substituted compounds(Ni-MBADP and Zn-MBADP) spin-coated thin films from a scanning ellipsometer in the wavelength 400-700 nm region. Metal chelation strongly (about one times) enhances the optical and dielectric parameters at the peaks and results in a large bathochromic shift (50-60nm) of absorption band. Bathochromic shift of Ni-MBADP is about 10nm larger than that of Zn-MBADP due to different spatial configurations formed in the metal-azo complexes.

  1. Synthesis and Application of Some Azo and Azomethine Dyes Containing Pyrazolone Moiety

    Institute of Scientific and Technical Information of China (English)

    RIZK, Hala, F; El-BORAl, Mohamed, A; El-HEFNAWY, Gad, B; El-SAYED, Hatem, F

    2009-01-01

    3-Amino-1-phenyl-4,5-dihydro-1H-pyrazol-5-one (1) was used as starting material for the synthesis of a num- ber of azo compounds 3a-3c and azomethine derivative 4. The deblocking of 3a-3c and 4 gave rise to 5a-5c and 6 in which a free amino was revealed. The diazonium salts of 5a-5c and 6 were coupled with several phenols to produce a number of bis azo compounds 7a-7c and 8a-8c with azomethine in position 4 and azoic group in position 3. The prepared dyes were structurally confirmed by elemental analysis, spectral methods and applied to different fibers (wool, polyester and blend of wool/polyester) as disperse dyes and their fastness properties were measured.

  2. Evaluation of impact of exposure of Sudan azo dyes and their metabolites on human intestinal bacteria.

    Science.gov (United States)

    Pan, Hongmiao; Feng, Jinhui; He, Gui-Xin; Cerniglia, Carl E; Chen, Huizhong

    2012-08-01

    Sudan azo dyes are banned for food usage in most countries, but they are illegally used to maintain or enhance the color of food products due to low cost, bright staining, and wide availability of the dyes. In this report, we examined the toxic effects of these azo dyes and their potential reduction metabolites on 11 prevalent human intestinal bacterial strains. Among the tested bacteria, cell growth of 2, 3, 5, 5, and 1 strains was inhibited by Sudan I, II, III, IV, and Para Red, respectively. At the tested concentration of 100 μM, Sudan I and II inhibited growth of Clostridium perfringens and Lactobacillus rhamnosus with decrease of growth rates from 14 to 47%. Sudan II also affected growth of Enterococcus faecalis. Growth of Bifidobacterium catenulatum, C. perfringens, E. faecalis, Escherichia coli, and Peptostreptococcus magnus was affected by Sudan III and IV with decrease in growth rates from 11 to 67%. C. perfringens was the only strain in which growth was affected by Para Red with 47 and 26% growth decreases at 6 and 10 h, respectively. 1-Amino-2-naphthol, a common metabolite of the dyes, was capable of inhibiting growth of most of the tested bacteria with inhibition rates from 8 to 46%. However, the other metabolites of the dyes had no effect on growth of the bacterial strains. The dyes and their metabolites had less effect on cell viability than on cell growth of the tested bacterial strains. Clostridium indolis and Clostridium ramosum were the only two strains with about a 10 % decrease in cell viability in the presence of Sudan azo dyes. The present results suggested that Sudan azo dyes and their metabolites potentially affect the human intestinal bacterial ecology by selectively inhibiting some bacterial species, which may have an adverse effect on human health.

  3. The comet assay in eight mouse organs: results with 24 azo compounds.

    Science.gov (United States)

    Tsuda, S; Matsusaka, N; Madarame, H; Ueno, S; Susa, N; Ishida, K; Kawamura, N; Sekihashi, K; Sasaki, Y F

    2000-02-16

    The genotoxicity of 24 azo compounds selected from IARC (International Agency for Research on Cancer) groups 2A, 2B, and 3 were determined by the comet (alkaline single cell gel electrophoresis, SCG) assay in eight mouse organs. We treated groups of four mice once orally at the maximum tolerated dose (MTD) and sampled stomach, colon, liver, kidney, bladder, lung, brain, and bone marrow 3, 8, and 24 h after treatment. For the 17 azo compounds, the assay was positive in at least one organ; (1) 14 and 12 azo compounds induced DNA damage in the colon and liver, respectively, (2) the genotoxic effect of most of them was greatest in the colon, and (3) there were high positive responses in the gastrointestinal organs, but those organs are not targets for carcinogenesis. One possible explanation for this discrepancy is that the assay detects DNA damage induced shortly after administration of a relatively high dose, while carcinogenicity is detected after long treatment with relatively low doses. The metabolic enzymes may become saturated following high doses and the rates and pathways of metabolic activation and detoxification may differ following high single doses vs. low long-term doses. Furthermore, considering that spontaneous colon tumors are very rare in rats and mice, the ability to detect tumorigenic effects in the colon of those animals might be lower than the ability to detect genotoxic events in the comet assay. The in vivo comet assay, which has advantage of reflecting test chemical absorption, distribution, and excretion as well as metabolism, should be effective for estimating the risk posed by azo dyes to humans in spite of the difference in dosage regimen.

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

    OpenAIRE

    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 be...

  5. Biological Treatment of a Synthetic Dye Water and an Industrial Textile Wastewater Containing Azo Dye Compounds

    OpenAIRE

    Wallace, Trevor Haig

    2001-01-01

    In this research, the ability of anaerobic and aerobic biological sludges to reduce and stabilize azo dye compounds was studied. Synthetic dye solutions and an industrial textile wastewater were both treated using anaerobic and aerobic biomass, separately and in sequential step-treatment processes. The primary objective was to reduce the wastewater color to an intensity that complies with the Virginia Pollutant Discharge Elimination System (VPDES) permit level. This level is set at 300 Ame...

  6. Solvation and equilibrium studies of some compounds containing azo and nitroso chromophores

    Science.gov (United States)

    Masoud, Mamdouh S.; Kamel, Hesham M.; Ali, Alaa E.

    2015-02-01

    The stability studies of biologically active phenylazo-dinitroso resorsinol and o-hydroxy phenyl azo-dinitroso resorsinol compounds were studied. The dissociation constants and the thermodynamic parameters of dissociation were evaluated and determined potentiometrically. Regression analysis is applied for correlating the different parameters by using the SPSS program. The results help to assign the solute-solvent interactions and the solvatochromic potential of the investigated compounds.

  7. Decolorization of two azo dyes using marine Lysobacter sp. T312D9

    Directory of Open Access Journals (Sweden)

    Khouloud M. I. B.

    2013-01-01

    Full Text Available Aims: Novel azo dye-degrading bacterium T312D9 strain has been isolated from Abou Quir Gulf, Alexandria, Egypt. Methodology and Results: The identification of the isolate by 16S rRNA gene sequencing revealed to be Lysobacter sp. This marine ecofriendly isolate was exploited for its ability to degrade two synthetic azo dyes considered as detrimental pollutants from industrial effluents: congo red and methyl red. Using different dye concentrations showed the highest metabolic activity for complete degradation obtained from 100 to 500 mg/L within 30 h under static condition, also, sustaining higher dye loading of 1 g/L was carried out. The significant induction of enzymes NADH - 2,6-dichloroindophenol (NADH-DCIP reductase and tyrosinaseindicated their prominent role in dye degradation. The biodegradation of two azo dyes were analyzed by gas chromatographicmass spectrum analysis (GC-MS and Fourier transform infrared spectroscopy (FTIR before and after treatment. Toxicity study revealed the much less toxic nature of the metabolites produced after complete decolorization. Conclusion, significance and impact of study: Lysobacter sp T312D9 represent an inexpensive and promising marine bacteria for removal of both methyl and congo red. High sustainable metabolic activity for biodegradation under static condition. NADHDCIPreductase and tyrosinase were significantly induced during biodegradation of dyes. The obtained metabolites revealed to beless toxic in nature which offers a practical biological treatment.

  8. Application of RF magnetron sputtering for growth of AZO on glass substrate

    Science.gov (United States)

    Ghorannevis, Z.; Akbarnejad, E.; Salar Elahi, A.; Ghoranneviss, M.

    2016-08-01

    Aluminum zinc oxide (AZO), as one of the most promising transparent conducting oxide (TCO) materials, has now been widely used in thin film solar cells. In this study the optimization process of the RF magnetron sputtered AZO films was performed at room temperature by studying its physical properties such as structural, optical, electrical and morphological at different deposition times (10, 20, 40 and 60 min) for its use as a front contact for the Cadmium Telluride (CdTe) based thin film solar cell applications. Influence of the deposition time was investigated on the physical properties of the AZO thin film by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), spectrophotometer and four point probes. XRD analysis suggests that the preferred orientation of grains for all the samples prepared at different growth times are along (002) plane having the hexagonal structure. From optical measurements the films show an average transmission over 60%. Moreover it was found that by increasing the growth time, which implies increasing the film thicknesses as well as improving the crystallinity the resistivity of the grown films decrease from the 10-2 Ωcm to the order of 10-3 Ωcm.

  9. Isolation and screening of azo dye decolorizing bacterial isolates from dye-contaminated textile wastewater

    Directory of Open Access Journals (Sweden)

    Shahid Mahmood

    2011-04-01

    Full Text Available Azo dyes are released into wastewater streams without any pretreatment and pollute water and soilenvironments. To prevent contamination of our vulnerable resources, removal of these dye pollutants is of greatimportance. For this purpose, wastewater samples were collected from dye-contaminated sites of Faisalabad. About200 bacterial isolates were isolated through enrichment and then tested for their potential to remove RemazolBlack-B azo dye in liquid medium. Five bacterial isolates capable of degrading Remazol Black-B azo dye efficientlywere screened through experimentation on modified mineral salt medium. Isolate SS1 (collected from wastewater ofSupreme Textile Industry was able to completely remove the Remazol Black-B dye from the liquid medium in 18 h.Further, the isolate showed the best performance at the dye concentration of 100 mg L-1 medium (pH 7 and attemperature 35oC. Similarly, yeast extract proved to be the best carbon source for decolorization purpose. Theresults imply that the isolate SS1 could be used for the removal of the reactive dyes from textile effluents.

  10. Accelerated decolorization of reactive azo dyes under saline conditions by bacteria isolated from Arabian seawater sediment.

    Science.gov (United States)

    Khalid, Azeem; Kausar, Farzana; Arshad, Muhammad; Mahmood, Tariq; Ahmed, Iftikhar

    2012-12-01

    Presence of huge amount of salts in the wastewater of textile dyeing industry is one of the major limiting factors in the development of an effective biotreatment system for the removal of azo dyes from textile effluents. Bacterial spp. capable of thriving under high salt conditions could be employed for the treatment of saline dyecontaminated textile wastewaters. The present study was aimed at isolating the most efficient bacterial strains capable of decolorizing azo dyes under high saline conditions. Fiftyeight bacterial strains were isolated from seawater, seawater sediment, and saline soil, using mineral salt medium enriched with 100 mg l−1 Reactive Black-5 azo dye and 50 g NaCl l−1 salt concentration. Bacterial strains KS23 (Psychrobacter alimentarius) and KS26 (Staphylococcus equorum) isolated from seawater sediment were able to decolorize three reactive dyes including Reactive Black 5, Reactive Golden Ovifix, and Reactive Blue BRS very efficiently in liquid medium over a wide range of salt concentration (0-100 g NaCl l)⁻¹. Time required for complete decolorization of 100 mg dye l ⁻¹ varied with the type of dye and salt concentration. In general, there was an inverse linear relationship between the velocity of the decolorization reaction (V) and salt concentration. This study suggested that bacteria isolated from saline conditions such as seawater sediment could be used in designing a bioreactor for the treatment of textile effluent containing high concentration of salts.

  11. Design, synthesis and physical properties of poly(styrene–butadiene–styrene)/poly(thiourea-azo-sulfone) blends

    Indian Academy of Sciences (India)

    Ayesha Kausar

    2014-06-01

    A new aromatic azo-polymer, poly(thiourea-azo-sulfone), has been synthesized using 1-(4-thiocarbamoylaminophenylsulfonylphenyl)thiourea and diazonium salt solution. Conducting and thermally stable rubbery blends of poly(styrene-block-butadiene-block-styrene) (SBS) triblock copolymer and poly(thiourea-azo-sulfone) (PTAS) were produced by solution blending technique. PTAS possessed fine solubility in polar solvents and high molar mass 63 × 103 g moL-1. Microscopic analysis on SBS/PTAS blends revealed good adhesion between the two polymers without macro phase separation. Electrical conductivity measurement recommended that blending of SBS with 60% PTAS was sufficiently conducting 1.43 S cm-1. A relationship between PTAS loading and thermal stability of blends was observed. With the increasing PTAS content, 10% gravimetric loss was increased from 481 to 497 °C, while glass transition improved from 123 to 136 °C (better than neat SBS but lower than PTAS). The blends also established higher tensile strength (52.40–59.96 MPa) relative to SBS. Fine balance of properties renders new SBS/PTAS, potential engineering plastics for a number of aerospace relevance.

  12. An atomic force microscopy statistical analysis of laser-induced azo-polyimide periodic tridimensional nanogrooves.

    Science.gov (United States)

    Stoica, Iuliana; Epure, Luiza; Sava, Ion; Damian, Victor; Hurduc, Nicolae

    2013-09-01

    The surface morphology of azo-polyimide films was investigated after 355 nm Nd: YAG laser irradiation with two different incident fluencies. Atomic force microscopy (AFM) was employed to correlate the laser-induced tridimensional nanogrooved surface relief with the incident fluence and the number of irradiation pulses. The height images revealed that the grooves depth increased even tens of times by increasing the incident fluence, using the same numbers of irradiation pulses. For low incident fluence, the films were uniformly patterned till 100 pulses of irradiation. Instead, when using higher fluence, after 15 pulses of irradiation the accuracy of the surface relief definition was reduced. This behavior could be explained by means of two different mechanisms, one that suppose the film photo-fluidization due to the cis-trans isomerization processes of the azo-groups and the second one responsible for the directional mass displacement. The dominant surface direction and parameters like isotropy, periodicity, and period were evaluated from the polar representation for texture analysis, revealing the appearance of ordered and directionated nanostructures for most of the experimental conditions. Also, the graphical studies of the functional volume parameters have evidenced the improvement of the relief structuration during surface nanostructuration. The correlation of these statistical texture parameters with the irradiation characteristics is important in controlling the alignment of either the liquid crystals or the cells/tissues on patterned azo-polyimide surfaces for optoelectronic devices and implantable biomaterials, respectively. PMID:23801415

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

    Science.gov (United States)

    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.

  14. Studies on Synthesis and Dyeing Preformance of Acid Dyes Based on 4,7-Dihydroxy-3,8-di-α-naphthylazo-1,10-phenanthroline-2,9-Dione

    OpenAIRE

    Patel, B. V.; Dasondi, P. H.

    2007-01-01

    Some new azo acid dyes were prepared by coupling various diazotized acid components such as anthranilic acid, sulphanilic acid, laurentacid, peri acid, tobias acid, H-acid, J-acid, gamma acid, sulphotobias acid,4-aminotoluiene-3-sulphonic acid, 5-sulpho- anthranilic acid, 2-naphthylamine-3,6,8-trisulphonic acid, bronner acid, metanilic acid and cleve acid with 4,7-dihydroxy-3,8-di-α-naphthylazo-1,10-phenanthroline-2,9-dione. The dyes were characterized by elemental, IR and TLC analyses. Their...

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

    Science.gov (United States)

    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

  16. Si/ZnO nanorods/Ag/AZO structures as promising photovoltaic plasmonic cells

    Energy Technology Data Exchange (ETDEWEB)

    Placzek-Popko, E., E-mail: ewa.popko@pwr.edu.pl; Gwozdz, K.; Gumienny, Z.; Zielony, E.; Jacak, W. [Faculty of Fundamental Problems of Technology, Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Pietruszka, R.; Witkowski, B. S.; Wachnicki, Ł.; Gieraltowska, S. [Institute of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, 02-668 Warsaw (Poland); Godlewski, M. [Institute of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, 02-668 Warsaw (Poland); Department of Mathematics and Natural Sciences College of Science, Cardinal Stefan Wyszynski University, Dewajtis 5, 01-815 Warsaw (Poland); Chang, Liann-Be [Department of Electronic Engineering and Green Technology Research Center, Chang-Gung University, Taoyuan, Taiwan (China)

    2015-05-21

    The test structures for photovoltaic (PV) applications based on zinc oxide nanorods (NRs) that were grown using a low-temperature hydrothermal method on p-type silicon substrates (100) covered with Ag nanoparticles (NPs) were studied. The NPs of three different diameters, i.e., 5–10 nm, 20-30 nm, and 50–60 nm, were deposited using a sputtering method. The morphology and crystallinity of the structures were confirmed by scanning electron microscopy and Raman spectroscopy. It was found that the nanorods have a hexagonal wurtzite structure. An analysis of the Raman and photoluminescence spectra permitted the identification of the surface modes at 476 cm{sup −1} and 561 cm{sup −1}. The presence of these modes is evidence of nanorods oriented along the wurtzite c-axis. The NRs with Ag NPs were covered with a ZnO:Al (AZO) layer that was grown using the low-temperature atomic layer deposition technique. The AZO layer served as a transparent ohmic contact to the ZnO nanorods. The applicability of the AZO layer for this purpose and the influence of the Ag nanoparticles on the effectiveness of light acquisition by such prepared PV cells were checked by reflectance and transmittance measurements of the AZO/glass and AZO/NPs/glass reference structures. Based on these studies, the high-energy transmittance edge was assigned to the ZnO energy gap, although it is blueshifted with respect to the bulk ZnO energy gap because of Al doping. It was also shown that the most optimal PV performance is obtained from a structure containing Ag nanoparticles with a diameter of 20–30 nm. This result is confirmed by the current-voltage measurements performed with 1-sun illumination. The structures show a plasmonic effect within the short wavelength range: the PV response for the structure with Ag nanoparticles is twice that of the structure without the nanoparticles. However, the influence of the Ag nanoparticle diameters on the plasmonic effect is ambiguous.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. Studies of morphological optical and electrical properties of the MEH-PPV/azo-calix[4]arene composite layers

    International Nuclear Information System (INIS)

    Thin films of poly[2-methoxy-5-(20-ethylhexyloxy)-1,4 phenylenevinylene] (MEH-PPV), 5,17-bis(4-nitrophenylazo)-26,28-dihydroxy-25,27-di(ethoxycarbonylmethoxy) -calix[4]arene (azo-calix[4]arene) and MEH-PPV doped azo-calix[4]arene, with 30 wt% and 70 wt% doping ratios, were prepared from chloroform solution by spin coating technique on quartz and ITO substrates. Morphological and optical properties of the samples were investigated by scanning electron microscopy (SEM) and UV–visible spectrophotometry techniques, respectively. Further, the charge carrier transport properties and conduction mechanism of the composite MEH-PPV:azo-calix[4]arene thin films based junction were studied by using current–voltage (I–V) characteristics and dielectric spectroscopy technique. I–V characteristic of ITO/MEH-PPV:azo-calix[4]arene/Al devices showed that the space charge limited conduction (SCLC) dominates in the high voltage region. Moreover, frequency dependence of ac conductivity obeys Jonscher's universal power law. Finally, dielectric constant (ε′), dielectric loss (ε″) and loss tangent (tan δ) were investigated as function of amount of azo-calix[4]arene in the MEH-PPV polymer matrix

  1. Studies of morphological optical and electrical properties of the MEH-PPV/azo-calix[4]arene composite layers

    Science.gov (United States)

    Rouis, A.; Davenas, J.; Bonnamour, I.; Ben Ouada, H.

    2015-10-01

    Thin films of poly[2-methoxy-5-(20-ethylhexyloxy)-1,4 phenylenevinylene] (MEH-PPV), 5,17-bis(4-nitrophenylazo)-26,28-dihydroxy-25,27-di(ethoxycarbonylmethoxy)-calix[4]arene (azo-calix[4]arene) and MEH-PPV doped azo-calix[4]arene, with 30 wt% and 70 wt% doping ratios, were prepared from chloroform solution by spin coating technique on quartz and ITO substrates. Morphological and optical properties of the samples were investigated by scanning electron microscopy (SEM) and UV-visible spectrophotometry techniques, respectively. Further, the charge carrier transport properties and conduction mechanism of the composite MEH-PPV:azo-calix[4]arene thin films based junction were studied by using current-voltage (I-V) characteristics and dielectric spectroscopy technique. I-V characteristic of ITO/MEH-PPV:azo-calix[4]arene/Al devices showed that the space charge limited conduction (SCLC) dominates in the high voltage region. Moreover, frequency dependence of ac conductivity obeys Jonscher's universal power law. Finally, dielectric constant (ε‧), dielectric loss (ε″) and loss tangent (tan δ) were investigated as function of amount of azo-calix[4]arene in the MEH-PPV polymer matrix.

  2. Studies of morphological optical and electrical properties of the MEH-PPV/azo-calix[4]arene composite layers

    Energy Technology Data Exchange (ETDEWEB)

    Rouis, A., E-mail: rouisahlem2@yahoo.fr [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Faculté des Sciences de Monastir, Avenue de l’environnement, 5000 Monastir (Tunisia); Davenas, J. [Polymer Materials Engineering Laboratory IMP, UMR CNRS 5223, Université Claude Bernard Lyon 1, 15 boulevard Latarjet, 69622 Villeurbanne (France); Bonnamour, I. [Institut de Chimie & Biochimie Moléculaires & Supramoléculaires (ICBMS), UMR CNRS 5246, 43 Boulevard du 11 Novembre 1918, Université Claude Bernard Lyon 1, 69100 Villeurbanne (France); Ben Ouada, H. [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Faculté des Sciences de Monastir, Avenue de l’environnement, 5000 Monastir (Tunisia)

    2015-10-01

    Thin films of poly[2-methoxy-5-(20-ethylhexyloxy)-1,4 phenylenevinylene] (MEH-PPV), 5,17-bis(4-nitrophenylazo)-26,28-dihydroxy-25,27-di(ethoxycarbonylmethoxy) -calix[4]arene (azo-calix[4]arene) and MEH-PPV doped azo-calix[4]arene, with 30 wt% and 70 wt% doping ratios, were prepared from chloroform solution by spin coating technique on quartz and ITO substrates. Morphological and optical properties of the samples were investigated by scanning electron microscopy (SEM) and UV–visible spectrophotometry techniques, respectively. Further, the charge carrier transport properties and conduction mechanism of the composite MEH-PPV:azo-calix[4]arene thin films based junction were studied by using current–voltage (I–V) characteristics and dielectric spectroscopy technique. I–V characteristic of ITO/MEH-PPV:azo-calix[4]arene/Al devices showed that the space charge limited conduction (SCLC) dominates in the high voltage region. Moreover, frequency dependence of ac conductivity obeys Jonscher's universal power law. Finally, dielectric constant (ε′), dielectric loss (ε″) and loss tangent (tan δ) were investigated as function of amount of azo-calix[4]arene in the MEH-PPV polymer matrix.

  3. Enhanced electrical and optical properties of room temperature deposited Aluminium doped Zinc Oxide (AZO) thin films by excimer laser annealing

    Science.gov (United States)

    El hamali, S. O.; Cranton, W. M.; Kalfagiannis, N.; Hou, X.; Ranson, R.; Koutsogeorgis, D. C.

    2016-05-01

    High quality transparent conductive oxides (TCOs) often require a high thermal budget fabrication process. In this study, Excimer Laser Annealing (ELA) at a wavelength of 248 nm has been explored as a processing mechanism to facilitate low thermal budget fabrication of high quality aluminium doped zinc oxide (AZO) thin films. 180 nm thick AZO films were prepared by radio frequency magnetron sputtering at room temperature on fused silica substrates. The effects of the applied RF power and the sputtering pressure on the outcome of ELA at different laser energy densities and number of pulses have been investigated. AZO films deposited with no intentional heating at 180 W, and at 2 mTorr of 0.2% oxygen in argon were selected as the optimum as-deposited films in this work, with a resistivity of 1×10-3 Ω.cm, and an average visible transmission of 85%. ELA was found to result in noticeably reduced resistivity of 5×10-4 Ω.cm, and enhancing the average visible transmission to 90% when AZO is processed with 5 pulses at 125 mJ/cm2. Therefore, the combination of RF magnetron sputtering and ELA, both low thermal budget and scalable techniques, can provide a viable fabrication route of high quality AZO films for use as transparent electrodes.

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

    Science.gov (United States)

    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.

  5. Magnetron sputtered AZO thin films on commercial ITO glass for application of a very low resistance transparent electrode

    International Nuclear Information System (INIS)

    In this paper, we report a coating method of reducing the sheet resistance of commercial Sn-doped In2O3 (ITO) glass by DC magnetron sputtering, without reducing its optical transmittance in the visible range of spectra. Aluminium oxide doped zinc oxide (AZO) films deposited on ITO glass showed highly (002)-oriented textured structure. An experimental procedure was designed to minimize the sheet resistance of AZO/ITO films in the deposition parameter space (mainly deposition temperature). Resistivity measurements showed that the ITO films with AZO coated under optimized deposition conditions showed a significant 81.4% decrease of sheet resistance when compared with those formed without AZO. Room temperature Hall effect measurements showed that the Hall mobility of the combined layers was greatly increased compared with that for single layer ITO. A high quality transparent electrode, having a resistance as low as 4.13 Ω/square and a high optical transmittance of 80% in the visible spectral range (with substrate), was obtained. The bilayer AZO/ITO film glass may be a good alternative substrate to ITO glass for advanced electro-optic applications

  6. Effect of redox mediator, AQDS, on the decolourisation of a reactive azo dye containing triazine group in a thermophilic anaerobic EGSB reactor

    NARCIS (Netherlands)

    Bezerra Dos Santos, A.; Cervantes-Carillo, F.J.; Yaya Beas, R.E.; Lier, van J.B.

    2003-01-01

    The feasibility of thermophilic (55 degreesC) anaerobic treatment applied to colour removal of a triazine contained reactive azo dye was investigated in two 0.531 expanded granular sludge blanket (EGSB) reactors in parallel at a hydraulic retention time (HRT) of 10 h. Generally, this group of azo dy

  7. Radiolysis of Reactive Azo Dyes in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Agustin N.M. Bagyo

    2004-07-01

    Full Text Available The effects of radiation on aerated reactive dye solutions i.e Cibacron Violet, Cibacron Orange and Cibacron Yellow solutions have been studied. Parameters analysis were the change of pH after radiation, the change of absorption, degradation products and effects of pH on the radiolysis. The uv-vis absorption of solutions were observed before and after irradiation. pH variation was done from pHs 3, 5, 7, 9 and 12. Irradiation was done at doses of 0, 2, 4, 6, 8 and 10 kGy with dose rate of 5 kGy/h and was determined by a Fricke dosimeter. HPLC with UV detector was used to analyze the degradation products. Oxalic acid was the main degradation product and small amount of succinic acid was also detected.

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

    Directory of Open Access Journals (Sweden)

    Abdollah Hajivandi

    2016-06-01

    Full Text Available 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.

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

    Science.gov (United States)

    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

  10. Optical control of cardiac cell excitability based on two-photon infrared absorption of AzoTAB

    CERN Document Server

    Shcherbakov, D; Erofeev, I; Astafiev, A

    2014-01-01

    Recent studies of AzoTAB activity in excitable cell cultures have shown that this substance is able to control excitability depending on isomer, cis or trans, predominating in the cellular membrane. Control of isomerization can be performed noninvasively by UV-visual radiation. At the same time it is well-known that azobenezenes can be effectively transformed from one isomer into another by two-photon absorption. Current work is devoted to the study of trans-AzoTAB two-photon transformation in aqueous solution and inside primal neonatal contractive rat cardiomyocytes. In accordance with results obtained Azo-TAB can be used as a probe for two-photon optical control of cardiac excitability.

  11. Angular Multiplexing Storage in Azo-polymer Liquid Crystal Films Using Shearing Interferometer of Double-frequency Grating

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jiangying; MING Hai; WANG Pei; WU Yunxia; XIE Jianping; ZHANG Qijin; LIU Jian

    2002-01-01

    In this paper, the shearing interferometer of a double-frequency grating (DFG) and a small compact Nd∶YVO4 double frequency laser at 532 nm are used to study the multiple storage in azo-polymer liquid crystal (PLC) films. In a principle experiment, the angle-encoded multiple gratings are recorded and the experimental results give triplex gratings at the same region in azo-PLC films, the angle between two adjacent grating vectors being 45°. Compared to the two-beam interferometer and four-wave mixing method, this method has simple configuration, high fringe contrast and quake-proof. A compatible angular multiplexing storage system in azo-PLC films is proposed.

  12. Metabolic activation of aromatic amines and azo dyes.

    Science.gov (United States)

    Bartsch, H

    1981-01-01

    Aromatic amines, amides and nitro compounds are a class of chemicals that produce tumors in a wide variety of tissues in experimental animals, including liver, urinary bladder, forestomach, small intestine, Zymbal's gland, subcutaneous tissue or skin. In man, exposure to some aromatic amines is associated with tumours of the urinary bladder and carcinoma of the renal pelvis. Their biological activity as carcinogens or genotoxic agents is, in all the cases that have been studied in detail, dependent on metabolic activation in vivo, occurring by multiple pathways. Differences in these metabolic pathways may largely account for the differences in tissues and species susceptibilities to cancer induction. Carcinogenicity of aromatic amines or amides is dependent on their oxidation to N-hydroxy derivatives, whilst the carcinogenicity of aromatic nitro compounds is linked to their reduction to hydroxylamines. Further conversion of the N-hydroxylamine or N-hydroxyamide to reactive intermediates can occur in several ways, which include (i) esterification of the N-hydroxy group, (ii) non-enzymic protonation of the nitrogen of the hydroxylamine and (iii) oxidation to a free radical of arylhydroxamic acids. Following generation of such reactive electrophilic intermediates in tissues or cells, macromolecular binding has been observed to nucleic acids and proteins. In many cases, arylamidated and arylaminated products are formed with nucleic acid bases; in the case of the well-studied 2-acetylaminofluorene, nucleophilic atoms of guanine are the predominant site of reaction. Relatively little is known of the structure and biological consequences of DNA adducts formed from other aromatic amines, amides or nitro compounds; more research in these directions is warranted.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Mohammad Danish Khan

    Full Text Available 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.

  15. Large Scale Laser Crystallization of Solution-based Alumina-doped Zinc Oxide (AZO) Nanoinks for Highly Transparent Conductive Electrode

    Science.gov (United States)

    Nian, Qiong; Callahan, Michael; Saei, Mojib; Look, David; Efstathiadis, Harry; Bailey, John; Cheng, Gary J.

    2015-10-01

    A new method combining aqueous solution printing with UV Laser crystallization (UVLC) and post annealing is developed to deposit highly transparent and conductive Aluminum doped Zinc Oxide (AZO) films. This technique is able to rapidly produce large area AZO films with better structural and optoelectronic properties than most high vacuum deposition, suggesting a potential large-scale manufacturing technique. The optoelectronic performance improvement attributes to UVLC and forming gas annealing (FMG) induced grain boundary density decrease and electron traps passivation at grain boundaries. The physical model and computational simulation developed in this work could be applied to thermal treatment of many other metal oxide films.

  16. High-energy, stable and recycled molecular solar thermal storage materials using AZO/graphene hybrids by optimizing hydrogen bonds

    Science.gov (United States)

    Luo, Wen; Feng, Yiyu; Qin, Chengqun; Li, Man; Li, Shipei; Cao, Chen; Long, Peng; Liu, Enzuo; Hu, Wenping; Yoshino, Katsumi; Feng, Wei

    2015-10-01

    An important method for establishing a high-energy, stable and recycled molecular solar heat system is by designing and preparing novel photo-isomerizable molecules with a high enthalpy and a long thermal life by controlling molecular interactions. A meta- and ortho-bis-substituted azobenzene chromophore (AZO) is covalently grafted onto reduced graphene oxide (RGO) for solar thermal storage materials. High grafting degree and close-packed molecules enable intermolecular hydrogen bonds (H-bonds) for both trans-(E) and cis-(Z) isomers of AZO on the surface of nanosheets, resulting in a dramatic increase in enthalpy and lifetime. The metastable Z-form of AZO on RGO is thermally stabilized with a half-life of 52 days by steric hindrance and intermolecular H-bonds calculated using density functional theory (DFT). The AZO-RGO fuel shows a high storage capacity of 138 Wh kg-1 by optimizing intermolecular H-bonds with a good cycling stability for 50 cycles induced by visible light at 520 nm. Our work opens up a new method for making advanced molecular solar thermal storage materials by tuning molecular interactions on a nano-template.An important method for establishing a high-energy, stable and recycled molecular solar heat system is by designing and preparing novel photo-isomerizable molecules with a high enthalpy and a long thermal life by controlling molecular interactions. A meta- and ortho-bis-substituted azobenzene chromophore (AZO) is covalently grafted onto reduced graphene oxide (RGO) for solar thermal storage materials. High grafting degree and close-packed molecules enable intermolecular hydrogen bonds (H-bonds) for both trans-(E) and cis-(Z) isomers of AZO on the surface of nanosheets, resulting in a dramatic increase in enthalpy and lifetime. The metastable Z-form of AZO on RGO is thermally stabilized with a half-life of 52 days by steric hindrance and intermolecular H-bonds calculated using density functional theory (DFT). The AZO-RGO fuel shows a high

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

    Science.gov (United States)

    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.

  18. Nano-Sized Zero Valent Iron and Covalent Organic Polymer Composites for Azo Dye Remediation

    DEFF Research Database (Denmark)

    Mines, Paul D.; Byun, Jeehye; Hwang, Yuhoon;

    2014-01-01

    . In this study, the effect of various covalent organic polymers (COPs) as effective supporting materials for nZVI for optimal pollutant degradation was assessed. These COPs demonstrate promising results for the ability to adsorb and remove carbon dioxide, yielding the notion that they are capable of groundwater...... contaminant removal. Composites of nZVI impregnated within COPs of high surface areas exhibit effective ability to degrade azo dyes, up to 95%, over a 30-minute reaction period. Dye decolorization results were designated a precursor for effectiveness of pollutant decontamination; pollutants ranging...

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

    Science.gov (United States)

    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.

  20. Synergetic enhancement of photoconductivity in oxotitanium phthalocyanine nanocrystalline/fluoronone-based azo/BAH composite photoreceptors

    Institute of Scientific and Technical Information of China (English)

    HUANG Ji; SUN Jingzhi; LEI Ying; CHEN Hongzheng; WANG Mang

    2004-01-01

    A simple method of liquid phase direct precipitation (LPDP) is employed to prepare oxotitanium phthalocyanine (TiOPc) nanoparticles. By encapsulation within casein coating, the TiOPc nanoparticles exhibit uniform and well-controlled particle sizes. The results of photoinduced discharge experiment demonstrates that the photoconductivity of the photoreceptors fabricated with TiOPc nanoparticles and fluoronone-based azo pigments as composite carrier generation materials was substantially enhanced. The photosensitivity has been improved three times as the TiOPc particle size decreased from 100 nm to 40 nm.

  1. Reduction of azo dyes and nitroaromatic compounds by bacterial enzymes from the human intestinal tract

    Energy Technology Data Exchange (ETDEWEB)

    Rafii, F.; Cerniglia, C.E. [Food and Drug Administration, Jefferson, AR (United States)

    1995-06-01

    Several anaerobic bacteria from the human intestinal tract are capable of reducing azo dyes and nitropolycyclic aromatic hydrocarbons to the corresponding aromatic amines with enzymes that have azoreductase and nitroreductase activities. The majority of bacteria with these activities belong to the genera Clostridium and Eubacterium. The azoreductases and nitroreductases from three Clostridium strains and one Eubacterium strain were studied. Both enzymes were produced constitutively in each of the bacteria; the enzymes from various bacteria had different electrophoretic mobilities. The azoreductases from all of the bacteria had immunological homology, as was evident from the cross-reactivity of an antibody raised against the azoreductase of C perfringens with azoreductases from other bacteria. Comparison of azoreductases and nitroreductases showed that they both had identical electrophoretic mobilities on polyacrylamide gels and reacted with the antibody against the azoreductase from C. perfringens. Furthermore, the nitroaromatic compounds competitively inhibited the azoreductase activity. The data indicate that the reduction of both nitroaromatic compounds and azo dyes may be carried out by the same enzyme, which is possibly a flavin adenine dinucleotide dehydrogenase that is synthesized throughout the cell and not associated with any organized subcellular structure. 15 refs., 1 fig., 2 tabs.

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

    Science.gov (United States)

    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.

  3. Removal of anionic azo dyes from aqueous solution by functional ionic liquid cross-linked polymer

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Hejun [Key Laboratory of Colloid and Interface Chemistry, Shandong University, Ministry of Education, Jinan 250100 (China); Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong 637000 (China); Kan, Taotao [CNOOC Energy Technology and Services-oilfield Technology Services Co., Tanggu, Tianjin 300452 (China); Zhao, Siyuan; Qian, Yixia; Cheng, Xiyuan; Wu, Wenli [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Wang, Xiaodong [Shandong Provincial Analysis and Test Center, Jinan 250100 (China); Zheng, Liqiang, E-mail: lqzheng@sdu.edu.cn [Key Laboratory of Colloid and Interface Chemistry, Shandong University, Ministry of Education, Jinan 250100 (China)

    2013-10-15

    Highlights: • Equilibrium, kinetic and thermodynamic of adsorption of dyes onto PDVB-IL was investigated. • PDVB-IL has a high adsorption capacity to treat dyes solution. • Higher adsorption capacity is due to the functional groups of PDVB-IL. • Molecular structure of dyes influences the adsorption capacity. -- Abstract: A novel functional ionic liquid based cross-linked polymer (PDVB-IL) was synthesized from 1-aminoethyl-3-vinylimidazolium chloride and divinylbenzene for use as an adsorbent. The physicochemical properties of PDVB-IL were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The adsorptive capacity was investigated using anionic azo dyes of orange II, sunset yellow FCF, and amaranth as adsorbates. The maximum adsorption capacity could reach 925.09, 734.62, and 547.17 mg/g for orange II, sunset yellow FCF and amaranth at 25 °C, respectively, which are much better than most of the other adsorbents reported earlier. The effect of pH value was investigated in the range of 1–8. The result shows that a low pH value is found to favor the adsorption of those anionic azo dyes. The adsorption kinetics and isotherms are well fitted by a pseudo second-order model and Langmuir model, respectively. The adsorption process is found to be dominated by physisorption. The introduction of functional ionic liquid moieties into cross-linked poly(divinylbenzene) polymer constitutes a new and efficient kind of adsorbent.

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

    Directory of Open Access Journals (Sweden)

    S.Q. Silva

    2014-12-01

    Full Text Available 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.

  5. Removal of anionic azo dyes from aqueous solution by functional ionic liquid cross-linked polymer

    International Nuclear Information System (INIS)

    Highlights: • Equilibrium, kinetic and thermodynamic of adsorption of dyes onto PDVB-IL was investigated. • PDVB-IL has a high adsorption capacity to treat dyes solution. • Higher adsorption capacity is due to the functional groups of PDVB-IL. • Molecular structure of dyes influences the adsorption capacity. -- Abstract: A novel functional ionic liquid based cross-linked polymer (PDVB-IL) was synthesized from 1-aminoethyl-3-vinylimidazolium chloride and divinylbenzene for use as an adsorbent. The physicochemical properties of PDVB-IL were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The adsorptive capacity was investigated using anionic azo dyes of orange II, sunset yellow FCF, and amaranth as adsorbates. The maximum adsorption capacity could reach 925.09, 734.62, and 547.17 mg/g for orange II, sunset yellow FCF and amaranth at 25 °C, respectively, which are much better than most of the other adsorbents reported earlier. The effect of pH value was investigated in the range of 1–8. The result shows that a low pH value is found to favor the adsorption of those anionic azo dyes. The adsorption kinetics and isotherms are well fitted by a pseudo second-order model and Langmuir model, respectively. The adsorption process is found to be dominated by physisorption. The introduction of functional ionic liquid moieties into cross-linked poly(divinylbenzene) polymer constitutes a new and efficient kind of adsorbent

  6. Decolorization of Remazol Black-B azo dye in soil by fungi

    Directory of Open Access Journals (Sweden)

    Azeem Khalid*, Sadia Batool, Muhammad Tariq Siddique, Zilli Huma Nazli, Riffat Bibi, Shahid Mahmood and Muhammad Arshad

    2011-04-01

    Full Text Available Textile industry is known to release huge amount of dyes in the water and soil environments during the dyeingprocess. The present study was planned with the aim to remove azo dye toxicants from the soil using fungal strains.The fungi were isolated by using Remazol Black-B azo dye as the sole source of C and N. Ten isolates were initiallyselected for testing their decolorization potential in the liquid medium. Three most effective strains were used tostudy the decolorization of Remazol Black-B in soil. The strain S4 was found to be very effective in removing thedye Remazol Black-B from liquid medium as well as in soil suspension. More than 95% decolorization by the strainS4 was observed in soil under optimal incubation conditions. Overall, the dye decolorization was maximum at 100mg dye kg-1 soil at pH 7-8 under static conditions. Glucose, moisture and aeration also affected the decolorizationefficacy of the fungal strain in soil. This study implies that fungi could be used for bioremediation of dyecontaminatedsites.

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

    Science.gov (United States)

    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

  8. Adsorption of the reactive azo dyes onto NH4Cl-induced activated carbon

    Directory of Open Access Journals (Sweden)

    Sakine Shekoohiyan

    2016-03-01

    Full Text Available Background: The efficacy of NH4Cl-induced activated carbon (NAC was examined in order to adsorb RR198, an azo reactive model dye, from an aqueous solution. Methods: The effects of pH (3 to 10, adsorbent dose (0.1 to 1.2 g/L, dye concentration and contact time on the adsorption efficiency were investigated. Results: The results showed that the removal of dye was highest at a solution pH of 7 and a powder dose of 1.1 g/L. The 85.9%, 72.6% and 65.4% removal of RR198 was obtained for a concentration of 25, 50 and 100 mg/L, respectively, at a relatively short contact time of 30 minutes, and at optimum pH and NAC concentrations of 1 g/L. The experimental data for kinetic analysis illustrated a best fit to the pseudo-second-order model. The study data on equilibrium were modeled using Langmuir, Freundlich and Dubinin–Radushkevich models; the Langmuir equation provided the best fit for the data. Conclusion: Therefore, the NAC appears to be an efficient and appropriate adsorbent for the removal of reactive azo dyes from waste streams.

  9. Biodegradation of azo dyes in a sequential anaerobic-aerobic system.

    Science.gov (United States)

    Rajaguru, P; Kalaiselvi, K; Palanivel, M; Subburam, V

    2000-08-01

    A sequential anaerobic aerobic treatment process based on mixed culture of bacteria isolated from textile dye effluent-contaminated soil was used to degrade sulfonated azo dyes Orange G (OG), Amido black 10B (AB), Direct red 4BS (DR) and Congo red (CR). Under anaerobic conditions in a fixed-bed column using glucose as co-substrate, the azo dyes were reduced and amines were released by the bacterial biomass. The amines were completely mineralized in a subsequent aerobic treatment using the same isolates. The maximum degradation rate observed in the treatment system for OG was 60.9 mg/l per day (16.99 mg/g glucose utilized), for AB 571.3 mg/l per day (14.46 mg/g glucose utilized), for DR 112.5 mg/l per day (32.02 mg/g glucose utilized) and for CR 134.9 mg/l per day (38.9 mg/g glucose utilized).

  10. Decolorization and biodegradability of photocatalytic treated azo dyes and wool textile wastewater.

    Science.gov (United States)

    Hu, C; Wang, Y

    1999-11-01

    The photodegradation and biodegradability have been investigated for four non-biodegradable commercial azo dyes, Reactive YellowKD-3G, Reactive Red 15, Reactive Red 24, Cationic Blue X-GRL, an indicator. Methyl Orange, and one industrial wool textile wastewater, using TiO2 suspensions irradiated with a medium pressure mercury lamp. The color removal of dyes solution and dyeing wastewater reached to above 90% within 20-30 min. of photocatalytic treatment. Biochemical oxygen demand (BOD) was found to increase, while chemical oxygen demand (COD), total organic carbon (TOC) decreased, so that the ratio of BOD5/COD of the wastewater increased from original zero up to 0.75. The result implies that photocatalytic oxidation enhanced the biodegradability of the dye-containing wastewater and therefore relationship between decolorization and biodegradability exists. When the color disappeared completely, the wastewater biodegraded normally and could be discharged for further treatment. The experimental results demonstrate that it is possible to combine photocatalysis with conventional biological treatment for the remedy of wastewater containing generally non-biodegradable azo dyes.

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

    Science.gov (United States)

    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. Direct laser interference patterning of polystyrene films doped with azo dyes, using 355 nm laser light

    Science.gov (United States)

    Broglia, M. F.; Suarez, S.; Soldera, F.; Mücklich, F.; Barbero, C. A.; Bellingeri, R.; Alustiza, F.; Acevedo, D.

    2014-05-01

    The generation of line-like periodic patterns by direct laser interference patterning (DLIP) of polystyrene films (PS) at a wavelength of 355 nm has been investigated. No structuration is achieved in plain PS due to the weak absorption of the polymer at 355 nm. On the other hand, patterning is achieved on films doped (PSd) with an azo dye (2-anisidine → 2-anisidine) which is incorporated in the polymer solution used for film preparation. Periodic micro-structures are generated. DLIP on PSd results in the swelling of the surface at low fluences, while at high laser intensities it causes the ablation of the regions at the interference maxima positions. The results contrast with the usual process of DLIP on PS (at shorter wavelengths, like 266 nm) where only ablation is detected. The results suggest that decomposition of the azo dye is the driving force of the patterning which therefore differ from the patterning obtained when plain PS is irradiated with laser light able to be absorbed by the aromatic ring in PS (e.g. 266 nm). The biocompatibility of these materials and adhesion of cells was tested, the data from in vitro assays shows that fibroblast cells are attached and proliferate extensively on the PSd films.

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

    Science.gov (United States)

    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.

  14. Using chemical wet-etching methods of textured AZO films on a-Si:H solar cells for efficient light trapping

    International Nuclear Information System (INIS)

    In this paper, Al-doped ZnO (AZO) films are deposited on glasses substrate by RF magnetron sputtering. The optical, electrical and morphological properties of AZO films textured by wet-etching with different etchants, H3PO4, HCl, and HNO3 are studied. It is found that the textured structure could enhance the light scattering and light trapping ability of amorphous silicon solar cells. The textured AZO film etched with HNO3 exhibits optimized optical properties (T% ≧ 80% over entire wavelength, haze ratio > 40% at 550 nm wavelength) and excellent electrical properties (ρ = 5.86 × 10−4 Ωcm). Scanning electron microscopy and Atomic force microscopy are used to observe surface morphology and average roughness of each textured AZO films. Finally, the textured AZO films etched by H3PO4, HCl and HNO3 were applied to front electrode layer for p–i–n amorphous silicon solar cells. The highest conversion efficiency of amorphous silicon solar cell fabricated on HNO3-etched AZO film was 7.08% with open-circuit voltage, short-circuit current density and fill factor of 895 mV, 14.92 mA/cm2 and 0.56, respectively. It shows a significantly enhancement in the short-circuit current density and conversion efficiency by 16.2% and 20.2%, respectively, compared with the solar cell fabricated on as-grown AZO film. - Highlights: • The textured surface enhances light scattering and light trapping ability. • The HNO3-etched AZO film exhibits excellent optical and electrical properties. • The efficiency of a-Si:H solar cell fabricated on HNO3-etched AZO film was 7.08%. • The short-circuit current density enhances to 16.2%. • The conversion efficiency enhances to 20.2%

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

    Science.gov (United States)

    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.

  16. High-energy, stable and recycled molecular solar thermal storage materials using AZO/graphene hybrids by optimizing hydrogen bonds.

    Science.gov (United States)

    Luo, Wen; Feng, Yiyu; Qin, Chengqun; Li, Man; Li, Shipei; Cao, Chen; Long, Peng; Liu, Enzuo; Hu, Wenping; Yoshino, Katsumi; Feng, Wei

    2015-10-21

    An important method for establishing a high-energy, stable and recycled molecular solar heat system is by designing and preparing novel photo-isomerizable molecules with a high enthalpy and a long thermal life by controlling molecular interactions. A meta- and ortho-bis-substituted azobenzene chromophore (AZO) is covalently grafted onto reduced graphene oxide (RGO) for solar thermal storage materials. High grafting degree and close-packed molecules enable intermolecular hydrogen bonds (H-bonds) for both trans-(E) and cis-(Z) isomers of AZO on the surface of nanosheets, resulting in a dramatic increase in enthalpy and lifetime. The metastable Z-form of AZO on RGO is thermally stabilized with a half-life of 52 days by steric hindrance and intermolecular H-bonds calculated using density functional theory (DFT). The AZO-RGO fuel shows a high storage capacity of 138 Wh kg(-1) by optimizing intermolecular H-bonds with a good cycling stability for 50 cycles induced by visible light at 520 nm. Our work opens up a new method for making advanced molecular solar thermal storage materials by tuning molecular interactions on a nano-template.

  17. Enhanced bio-decolorization of azo dyes by co-immobilized quinone-reducing consortium and anthraquinone

    DEFF Research Database (Denmark)

    Su, YY; Zhang, Yifeng; Wang, J;

    2009-01-01

    exhibited good catalytic activity and increased the decolorization rate for many kinds of azo dyes. The reusability of the co-immobilized beads was evaluated with repeated-batch decolorization experiments. After ten repeated experiments, the decolorization rate of co-immobilized beads retained over 92.8% of...

  18. Preparation of symmetric and asymmetric aromatic azo compounds from aromatic amines or nitro compounds using supported gold catalysts.

    Science.gov (United States)

    Grirrane, Abdessamad; Corma, Avelino; Garcia, Hermenegildo

    2010-03-01

    This protocol describes the aerobic oxidation of aromatic anilines to aromatic azo compounds using gold (Au) nanoparticles supported on TiO(2) as a catalyst. Yields above 98% are achieved under a few bars of oxygen pressure. It should be noted that the use of stoichiometric amounts of environmentally unfriendly reagents, e.g., transition metals and nitrites, commonly used in current syntheses of azo compounds, is avoided using this approach. The protocol is illustrated with the synthesis of parent azobenzene from aniline, and this reaction takes 22 h. Au on TiO(2) can also be used as a hydrogenation catalyst, making it possible to prepare azo compounds directly from nitroaromatics through a two-step (hydrogenation followed by aerobic oxidation), one-pot, one-catalyst reaction. In addition, the catalytic process is efficient for the synthesis of symmetric and a range of asymmetric aromatic azo compounds from the mixtures of two anilines substituted with electron-donor and electron-acceptor substituents.

  19. Heterogeneous fenton degradation of azo dyes catalyzed by modified polyacrylonitrile fiber fe complexes: QSPR (quantitative structure peorperty relationship) study.

    Science.gov (United States)

    Li, Bing; Dong, Yongchun; Ding, Zhizhong

    2013-07-01

    The amidoximated polyacrylonitrile (PAN) fiber Fe complexes were prepared and used as the heterogeneous Fenton catalysts for the degradation of 28 anionic water soluble azo dyes in water under visible irradiation. The multiple linear regression (MLR) method was employed to develop the quantitative structure property relationship (QSPR) model equations for the decoloration and mineralization of azo dyes. Moreover, the predictive ability of the QSPR model equations was assessed using Leave-one-out (LOO) and cross-validation (CV) methods. Additionally, the effect of Fe content of catalyst and the sodium chloride in water on QSPR model equations were also investigated. The results indicated that the heterogeneous photo-Fenton degradation of the azo dyes with different structures was conducted in the presence of the amidoximated PAN fiber Fe complex. The QSPR model equations for the dye decoloration and mineralization were successfully developed using MLR technique. MW/S (molecular weight divided by the number of sulphonate groups) and NN=N (the number of azo linkage) are considered as the most important determining factor for the dye degradation and mineralization, and there is a significant negative correlation between MW/S or NN=N and degradation percentage or total organic carbon (TOC) removal. Moreover, LOO and CV analysis suggested that the obtained QSPR model equations have the better prediction ability. The variation in Fe content of catalyst and the addition of sodium chloride did not alter the nature of the QSPR model equations. PMID:24218861

  20. The contribution of fermentative bacteria and methanogenic archaea to azo dye reduction by a thermophilic anaerobic consortium

    NARCIS (Netherlands)

    Santos, dos A.B.; Cervantes, F.J.; Madrid, de M.P.; Bok, de F.A.M.; Stams, A.J.M.; Lier, van J.B.

    2006-01-01

    The contribution of fermentative bacteria and methanogenic archaea to azo dye reduction by a thermophilic anaerobic consortium was studied. Additionally, the effects of different electron-donating substrates and the redox mediator riboflavin on dye reduction were assessed by using either a methanoge

  1. Colorimetric Sugar Sensing Using Boronic Acid-Substituted Azobenzenes

    Directory of Open Access Journals (Sweden)

    Yuya Egawa

    2014-02-01

    Full Text Available In association with increasing diabetes prevalence, it is desirable to develop new glucose sensing systems with low cost, ease of use, high stability and good portability. Boronic acid is one of the potential candidates for a future alternative to enzyme-based glucose sensors. Boronic acid derivatives have been widely used for the sugar recognition motif, because boronic acids bind adjacent diols to form cyclic boronate esters. In order to develop colorimetric sugar sensors, boronic acid-conjugated azobenzenes have been synthesized. There are several types of boronic acid azobenzenes, and their characteristics tend to rely on the substitute position of the boronic acid moiety. For example, o-substitution of boronic acid to the azo group gives the advantage of a significant color change upon sugar addition. Nitrogen-15 Nuclear Magnetic Resonance (NMR studies clearly show a signaling mechanism based on the formation and cleavage of the B–N dative bond between boronic acid and azo moieties in the dye. Some boronic acid-substituted azobenzenes were attached to a polymer or utilized for supramolecular chemistry to produce glucose-selective binding, in which two boronic acid moieties cooperatively bind one glucose molecule. In addition, boronic acid-substituted azobenzenes have been applied not only for glucose monitoring, but also for the sensing of glycated hemoglobin and dopamine.

  2. Screening, identification and optimization of a yeast strain, Candida palmioleophila JKS4, capable of azo dye decolorization.

    Directory of Open Access Journals (Sweden)

    Narjes Jafari

    2013-12-01

    Full Text Available Synthetic dyes are recalcitrant to degradation and toxic to different organisms. Decolorization of textile wastewaters is one of the major concerns since last decades. Physical-chemical treatments are very expensive and frequently producing large amounts of toxic wastes. Biological treatments can be more convenient. In the present study, an attempt has been made for decolorization of azo dyes using microbial process.Screening of microorganisms capable of azo dye decolorization was performed from activated sludge. The decolorization of various dyes (Reactive Black 5, Reactive Orange 16, Reactive Red 198, Direct Blue 71, Direct Yellow 12 and Direct Black 22 was determined by measuring the absorbance of culture supernatant at their λmax. Culture supernatants were also analyzed for UV-Vis absorption between 200-800 nm. The effect of aeration, temperature, different concentrations of glucose and NaCl was studied with an aim to determine the optimal conditions required for maximum decolorization.The yeast (strain JKS4 which had high ability to decolorize different azo dyes was isolated. Under aerobic condition, the yeast strain showed 85.7% of decolorization at 200 mg/l Reactive Black 5 (as a model azo dye, 1% (w/v glucose concentration and 35°C after 24 h. All the examined dyes were extensively decolorized (53.35-97.9% after 24 h. With elongated incubation period, complete decolorization was observed in presence of all dyes. From the physiological properties and phylogenetic analysis based on the 26S rDNA sequences, strain JKS4 was classified into Candida palmioleophila.Because of high decolorizing activity against various azo dyes commonly used in the textile industries, it is proposed that the isolated yeast may have a practical application in the biotransformation of various dye effluents.

  3. Cancer risk assessment of azo dyes and aromatic amines from tattoo bands, folders of paper, toys, bed clothes, watch straps and ink

    NARCIS (Netherlands)

    Zeilmaker MJ; van Kranen HJ; van Veen MP; Janus J; LBM

    2000-01-01

    Dit rapport beschrijft een schatting voor het risico op kanker dat verbonden is aan het gebruik van tatoe bandjes, kinderspeelpapier, speelgoed, beddengoed, lederen horlogebandjes en inkt waarin kankerverwekkende azo kleurstoffen aangetroffen zijn. In genoemde producten zijn benzidine en de benzidi

  4. A Green and Facile Solid-state Synthesis Method for the Preparation of Diazenecarboxamide Azo Compounds with Potassium Ferricyanide and Sodium Hydroxide System

    Institute of Scientific and Technical Information of China (English)

    Wan Xin XUE; Jian Ping LI; Yu Lu WANG

    2004-01-01

    Eleven new-typed azo compounds were synthesized in good yields by dehydrogenating the corresponding aryl substituted semicarbazides using potassium ferricyanide and sodium hydroxide system under solid-state conditions.

  5. Investigation of third-order nonlinear optical properties of two azo-nickel chelate compounds

    Institute of Scientific and Technical Information of China (English)

    Xiang Hong; Tian Zhi-Yuan; Wang Shu-Feng; Wang Zhen-Wei; Li Zhi; Yang Hong; Yao Jian-Nian; Gong Qi-Huang

    2008-01-01

    This paper investigates the third-order nonlinear optical properties of two azo-nickel chelate compounds by the optical Kerr gate method at 830nm wavelength with pulse duration of 120fs. Both of the two compounds exhibited large third-order optical nonlinearity. The second-order hyperpolarizability, γ, of Compound 1 is of 1.0×10-31 esu. Due to the charge transfer, the γ of Compound 2 with electron donor and acceptor group is 4.9×10-31 esu, which is a four-time enhancement in comparison with Compound 1. The absorption spectra show that the electron push-pull effect, which induces intramolecular charge transfer, leads to the increased optical nonlinearity.

  6. Characterization of an azo-calix[4]arene-based optical sensor for Europium (III) ions

    International Nuclear Information System (INIS)

    Selective and sensitive optical sensor membranes (optodes) were elaborated to detect cations in aqueous solutions. The sensing films are based on chromogenic calix[4]arene derivatives. The optode membranes were studied using UV/Vis absorption spectroscopy measurements. The sensitivity of the optode has been tested for Pb2+, Cd2+, Mg2+ and Eu3+ ions at pH 6.8. The results showed a good selectivity response towards Eu3+. Low selectivity coefficients were observed for Cd2+ and Mg2+ where Pb2+ can be considered as interfering ions. The characteristics of this optode such as response time, regeneration, reproducibility and lifetime are discussed. - Highlights: ► We report optical sensing studies of chromogenic calixarene derivatives. ► We investigate optical interaction between azo-calix[4]arene and Eu3+. ► We study sensitivity and selectivity of optode films. ► We describe characteristics of optode films for determination of europium traces.

  7. SYNTHESIS AND CHARACTERIZATION OF POLYMETHACRYLATES BEARING HETEROCYCLIC AZO GROUP AND MESOGENIC GROUP FOR NONLINEAR OPTICS

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The methacrylate monomers bearing mesogenic group and heterocyclic azo dye have been synthesized. The monomeric dye was copolymerized with the mesogenic monomer using a free radical initiator to produce polymers useful for nonlinear optics. The monomers and polymers were characterized by IR, 1H-NMR, and UV-Vis spectra. The average molecular weight (-Mw and -Mn) of the polymers were determined by gel permeation chromatography. The thermal properties of the polymers such as thermal stability and phase transition behavior were studied by thermogravimetric analysis, differential thermal analysis, polarizing optical microscope and X-ray diffractometer. The results demonstrate that the synthesized polymers are crystalline polymers at room temperature and no liquid crystalline phases were observed for all of them.

  8. Photoassisted Electrochemical Treatment of Azo and Phtalocyanine Reactive Dyes in the Presence of Surfactants

    Directory of Open Access Journals (Sweden)

    Mireia Sala

    2016-03-01

    Full Text Available An electrochemical treatment (EC was applied at different intensities to degrade the chromophoric groups of dyes C.I. Reactive Black 5 (RB5 and C.I. Reactive Blue 7 (Rb7 until uncolored species were obtained. Decolorization rate constants of the azo dye RB5 were higher than the phtalocyanine Rb7 ones. In addition, the EC treatment was more efficient at higher intensities, but these conditions significantly increased the generation of undesirable by-products such as chloroform. The combination of EC with UV irradiation (UVEC drastically minimized the generation of chloroform. The photo-assisted electrochemical treatment was also able to achieve decolorization values of 99%. Finally, mixtures of dyes and surfactants were treated by EC and UVEC. In the presence of surfactants, the decolorization kinetic of dyes was slowed due to the competitive reactions of surfactants degradation. Both methods achieved total decolorization and in both cases, the generation of haloforms was negligible.

  9. Synthesis and application of new mordent and disperse azo dyes based on 2,4-dihydroxybenzophenone

    Directory of Open Access Journals (Sweden)

    BHARAT C. DIXIT

    2007-02-01

    Full Text Available Novel mordent and disperse azo dyes were prepared by the coupling of various diazo solutions of aromatic amines with 2,4-ihydroxybenzophenone. The resultant dyes were characterized by elemental analyses as well as IR and NMR spectral studies. The UV-visible spectral data have also been iscussed in terms of structural property relationship. The dyeing assessment of all the dyeswas evaluated on wool and polyester textile fibers. The dyeing of chrome treated (i.e., chrome mordented wool and polyesters was also monitored. The results show that a better hue was obtained on mordented fibers. The results of the anti-bacterial properties of the chrome dyes revealed that the toxicity of these dyes against bacteria is fairly good.

  10. New Quantitative Structure-Activity Relationship Models Improve Predictability of Ames Mutagenicity for Aromatic Azo Compounds.

    Science.gov (United States)

    Manganelli, Serena; Benfenati, Emilio; Manganaro, Alberto; Kulkarni, Sunil; Barton-Maclaren, Tara S; Honma, Masamitsu

    2016-10-01

    Existing Quantitative Structure-Activity Relationship (QSAR) models have limited predictive capabilities for aromatic azo compounds. In this study, 2 new models were built to predict Ames mutagenicity of this class of compounds. The first one made use of descriptors based on simplified molecular input-line entry system (SMILES), calculated with the CORAL software. The second model was based on the k-nearest neighbors algorithm. The statistical quality of the predictions from single models was satisfactory. The performance further improved when the predictions from these models were combined. The prediction results from other QSAR models for mutagenicity were also evaluated. Most of the existing models were found to be good at finding toxic compounds but resulted in many false positive predictions. The 2 new models specific for this class of compounds avoid this problem thanks to a larger set of related compounds as training set and improved algorithms.

  11. SYNTHESIS AND CHARACTERIZATION OF POLYMERS BEARING AZOBENZENE AND CARBAZOLE GROUPS VIA POST-AZO-COUPLING REACTION

    Institute of Scientific and Technical Information of China (English)

    Jun Shi; Zhi-wei Jiang; Li Zhang; Shao-kui Cao

    2005-01-01

    A series of polymers bearing azobenzene and carbazole groups for photorefractive purpose were prepared via post-azo-coupling reaction. The successful reaction was identified by spectroscopic analysis and gel permeation chromatography. This approach is more facile compared with the direct polymerization of corresponding functional monomer. The polymers prepared have weight average molecular weight of higher than 1.5 × 104 and are easily soluble in common organic solvents like chloroform and tetrahydrofuran, polymer films with high optical quality could be easily fabricated through solution casting. Glass transition temperature (Tg) of the polymers ranges from 60℃ to 182℃, depending on the alkylene spacer length between the functional side group and the polymer backbone, and the polymers are relatively stable under 300℃.

  12. Hollow Palladium Nanoparticles Facilitated Biodegradation of an Azo Dye by Electrically Active Biofilms

    Directory of Open Access Journals (Sweden)

    Shafeer Kalathil

    2016-08-01

    Full Text Available Dye wastewater severely threatens the environment due to its hazardous and toxic effects. Although many methods are available to degrade dyes, most of them are far from satisfactory. The proposed research provides a green and sustainable approach to degrade an azo dye, methyl orange, by electrically active biofilms (EABs in the presence of solid and hollow palladium (Pd nanoparticles. The EABs acted as the electron generator while nanoparticles functioned as the electron carrier agents to enhance degradation rate of the dye by breaking the kinetic barrier. The hollow Pd nanoparticles showed better performance than the solid Pd nanoparticles on the dye degradation, possibly due to high specific surface area and cage effect. The hollow cavities provided by the nanoparticles acted as the reaction centers for the dye degradation.

  13. Synthesis and antitumor evaluation of thiophene based azo dyes incorporating pyrazolone moiety

    Directory of Open Access Journals (Sweden)

    Moustafa A. Gouda

    2016-03-01

    Full Text Available A series of thiophene incorporating pyrazolone moieties 5a–f and 6a–c were synthesized via diazo coupling of diazonium salt of 3-substituted-2-amino-4,5,6,7-tetrahydrobenzo[b]thiophenes 1a–c with 3-methyl-1H-pyrazol-5(4H-one, 3-methyl-1-phenyl-1H-pyrazol-5(4H-one or 3-amino-1H-pyrazol-5(4H-one, respectively. Newly synthesized dyes were applied to polyester fabric as disperse dyes in which their color measurements and fastness properties were evaluated. These dyes showed generally red to blue shifted color with high extinction coefficient in comparison with aniline-based azo dyes. The antitumor activity of the synthesized dyes was evaluated. The results showed clearly that most of them exhibited good activity and compounds 5c and 5d exhibited moderate activity.

  14. Degradation of acid orange 7 in an aerobic biofilm.

    Science.gov (United States)

    Coughlin, Michael F; Kinkle, Brian K; Bishop, Paul L

    2002-01-01

    A stable microbial biofilm community capable of completely mineralizing the azo dye acid orange 7 (AO7) was established in a laboratory scale rotating drum bioreactor (RDBR) using waste liquor from a sewage treatment plant. A broad range of environmental conditions including pH (5.8-8.2), nitrification (0.0-4.0 mM nitrite), and aeration (0.2-6.2 mg O2 l(-1)) were evaluated for their effects on the biodegradation of AO7. Furthermore the biofilm maintained its biodegradative ability for over a year while the effects of these environmental conditions were evaluated. Reduction of the azo bond followed by degradation of the resulting aromatic amine appears to be the mechanism by which this dye is biodegraded. Complete loss of color, sulfanilic acid, and chemical oxygen demand (COD) indicate that AO7 is mineralized. To our knowledge this is the first reported occurrence of a sulfonated phenylazonaphthol dye being completely mineralized under aerobic conditions. Two bacterial strains (ICX and SAD4i) originally isolated from the RDBR were able to mineralize, in co-culture, up to 90% of added AO7. During mineralization of AO7, strain ICX reduces the azo bond under aerobic conditions and consumes the resulting cleavage product 1-amino-2-naphthol. Strain SAD4i consumes the other cleavage product, sulfanilic acid. The ability of the RDBR biofilm to aerobically mineralize an azo dye without exogenous carbon and nitrogen sources suggests that this approach could be used to remediate industrial wastewater contaminated with spent dye.

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

    Science.gov (United States)

    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.

  16. Genotoxic hazards of azo pigments and other colorants related to 1-phenylazo-2-hydroxynaphthalene.

    Science.gov (United States)

    Møller, P; Wallin, H

    2000-01-01

    Azo pigments are used extensively as coloring agents in inks, paints and cosmetics. We have surveyed the literature for genotoxic and cancer data on nine colorants, which are structurally related to 1-phenylazo-2-hydroxynaphthalene (C.I. Solvent yellow 14). C.I. Solvent yellow 14 is metabolized by oxidative and peroxidative enzymes. Metabolically activated C.I. Solvent yellow 14 forms both RNA and DNA adducts. It induces liver nodules in rats upon oral administration. Although there is a mixture of negative and positive findings in short-term tests and in animal cancer studies, C.I. Solvent yellow 14 should be considered genotoxic. C.I. Pigment red 3 should be considered carcinogenic but is only weakly genotoxic. C.I. Solvent yellow 7, C.I. Pigment orange 5, C.I. Pigment red 4, and C.I. Pigment red 23 should be considered genotoxic. C.I. Pigment red 53:1 is not genotoxic, and observations of spleen tumors in male rats but not in female rats or mice seem to be related to toxic effects of high doses of C.I. Pigment red 53:1 in this organ. The data in the literature indicate that Pigment red 57:1 is not genotoxic or carcinogenic. We did not find sufficient data for a relevant evaluation of C.I. Pigment red 2 and C.I. Pigment red 64:1. Some of the colorants have in common the 2-amino-1-naphthol structure. This compound is not genotoxic. On the other hand, reductive cleavage of the azo bonds or hydrolysis of anilido bonds would produce aromatic amines, most of which have been under suspicion for genotoxicity or carcinogenicity. For C.I. Pigment red 53:1 and 57:1, sulphonated aromatic amines would be formed that are not genotoxic.

  17. Direct laser interference patterning of polystyrene films doped with azo dyes, using 355 nm laser light

    Energy Technology Data Exchange (ETDEWEB)

    Broglia, M.F. [Universidad Nacional de Río Cuarto, Departamento de Química, Ruta 36 km 601, Río Cuarto, Córdoba 5800 (Argentina); Saarland University, Department of Materials Science, Campus, D-66123 Saarbrücken (Germany); Suarez, S.; Soldera, F.; Mücklich, F. [Saarland University, Department of Materials Science, Campus, D-66123 Saarbrücken (Germany); Barbero, C.A.; Bellingeri, R.; Alustiza, F. [Universidad Nacional de Río Cuarto, Departamento de Química, Ruta 36 km 601, Río Cuarto, Córdoba 5800 (Argentina); Acevedo, D., E-mail: dacevedo@exa.unrc.edu.ar [Universidad Nacional de Río Cuarto, Departamento de Química, Ruta 36 km 601, Río Cuarto, Córdoba 5800 (Argentina)

    2014-05-01

    Highlights: • We describe the first use of Direct Laser Interference Patterning on PS at 355 nm. . • The structured areas of regular lines are produced in several square millimeters. • The method, Direct Laser Interference Patterning (DLIP) uses a single laser pulse. • DLIP is applied at room temperature and atmospheric pressure. • DLIP is easier to use than other lithographic techniques. • The topography contrasts with the usual Polystyrene ablation at lower wavelengths. - Abstract: The generation of line-like periodic patterns by direct laser interference patterning (DLIP) of polystyrene films (PS) at a wavelength of 355 nm has been investigated. No structuration is achieved in plain PS due to the weak absorption of the polymer at 355 nm. On the other hand, patterning is achieved on films doped (PSd) with an azo dye (2-anisidine → 2-anisidine) which is incorporated in the polymer solution used for film preparation. Periodic micro-structures are generated. DLIP on PSd results in the swelling of the surface at low fluences, while at high laser intensities it causes the ablation of the regions at the interference maxima positions. The results contrast with the usual process of DLIP on PS (at shorter wavelengths, like 266 nm) where only ablation is detected. The results suggest that decomposition of the azo dye is the driving force of the patterning which therefore differ from the patterning obtained when plain PS is irradiated with laser light able to be absorbed by the aromatic ring in PS (e.g. 266 nm). The biocompatibility of these materials and adhesion of cells was tested, the data from in vitro assays shows that fibroblast cells are attached and proliferate extensively on the PSd films.

  18. Synthesis and application of p-tert-butylcalix[8]arene immobilized material for the removal of azo dyes

    International Nuclear Information System (INIS)

    Graphical abstract: The sorption of selected azo dyes is highly pH dependent and newly immobilized material 4 is potentially more effective sorbent as compared to pure silica (1) as well as p-tert-butylcalix[8]arene (3). Research highlights: → Sorption behavior investigation of p-tert-butyl-calix[8]arene immobilized material4. → Azo dyes (i.e. RB-5 and RR-45) were used as sorbate. → Optimization of different parameters to evaluate sorption performance of material 4. → Sorption efficiency of resin 4 for RB-5 and RR-45 azo dyes is highly pH dependent. → The sorption data was evaluated by sorption isotherms. - Abstract: The present study describes synthesis of a new resin through immobilization of p-tert-butylcalix[8]arene onto silica and its application for the removal of azo dyes from aqueous media as well as from textile effluents. The newly synthesized material 4 is characterized by FT-IR spectroscopy, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). Reactive Black-5 (RB-5) and Reactive Red-45 (RR-45) azo dyes were used as sorbate. Batch wise sorption experiments were conducted to optimize various experimental parameters such as the effect of sorbent dosage, electrolyte, pH, dye concentration, and contact time. The optimized pH for the effective removal of RB-5 and RR-45 dyes was 9 and 3, respectively. The increase in material 4 dosage increased the percent sorption. Both Langmuir and Freundlich isotherm models were applied to experimental data and Langmuir isotherm model found to be best fit. The results revealed that material 4 was potentially more effective sorbent for the sorption of selected azo dyes as compared to pure silica and p-tert-butylcalix[8]arene. The field studies also supported the effectiveness of material 4, which could be useful for the removal of both the dyes and also for the normalization of pH, TDS, conductivity and salinity near to the drinking water.

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

    Science.gov (United States)

    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

  20. Effect of dipping solution pH values on electrostatic layer-by-layer self-assembly of side-chain azo polyelectrolyte

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The effect of pH value on the electrostatic layer-by-layer self-assembly and the photo-responsive behavior of Poly{2-[4-(4-ethoxyphenylazo)phenoxy]ethyl acrylate-co-acrylic acid} (PEAPE) was studied.Results show that in the studied pH value range,the lower the pH value is,the higher is the UV-vis absorbance and the larger is the thickness of the multilayer films.FTIR studies indicate that the azo polyelectrolyte exhibits a different ionization degree in solutions with different pH values.The higher absorbance and the larger thickness of the layer-by-layer films can be attributed to the low ionization degree and the shrinkage conformation of PEAPE in the solution with low pH values.FTIR analysis also confirms that the driving force for layer-by-layer self-assembly of PEAPE and PDAC is the electrostatic interaction.

  1. An integrated (electro- and bio-oxidation) approach for remediation of industrial wastewater containing azo-dyes: Understanding the degradation mechanism and toxicity assessment.

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  3. A New Method of Synthesis of Azo Schiff Base Ligands with Azo and Azomethine Donors: Synthesis of N-4-Methoxybenzylidene-2-(3-hydroxyphenylazo)-5-hydroxyaniline and Its Nickel(Ⅱ) Complex

    Institute of Scientific and Technical Information of China (English)

    OFORKA, N. C; MKPENIE, V. N.

    2007-01-01

    A new method for the synthesis of azo Schiff an base ligand in which the azo and azomethine groups are coordination sites was developed through a Schiff base precursor. The precursor, A'-4-methoxybenzylidene-3-hydroxy-phenylamine (SB) derived from 3-aminophenol was regioselectively coupled with a diazonium ion para to the hydroxyl group of the amine component of the Schiff base. The para selectivity was controlled by the directing effect of the hydroxyl group. The ligand and its nickel(Ⅱ) complex were characterized by elemental analyses, IR and UV-Vis spectroscopy. The analytical and spectral data supported the mononuclear formulation of the complex with metal to ligand ratio (M : L= 1 : 2) and suggested a square planar geometry for the complex.

  4. Photocatalytic degradation of three azo dyes using immobilized TiO{sub 2} nanoparticles on glass plates activated by UV light irradiation: Influence of dye molecular structure

    Energy Technology Data Exchange (ETDEWEB)

    Khataee, A.R., E-mail: a_khataee@tabrizu.ac.ir [Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of); Laboratoire des Sciences du Genie Chimique, CNRS, Nancy Universite, ENSIC, 1, rue Grandville, BP 20451, F-54001 Nancy Cedex (France); Pons, M.N., E-mail: Marie-Noelle.Pons@ensic.inpl-nancy.fr [Laboratoire des Sciences du Genie Chimique, CNRS, Nancy Universite, ENSIC, 1, rue Grandville, BP 20451, F-54001 Nancy Cedex (France); Zahraa, O., E-mail: Orfan.Zahraa@ensic.inpl-nancy.fr [Departement de Chimie-Physique des Reactions, INPL, Nancy Universite, ENSIC, 1, rue Grandville, BP 451, F-54001 Nancy Cedex (France)

    2009-08-30

    In order to discuss the effect of chemical structure on photocatalysis efficiency, the photocatalytic degradation of three commercial textile dyes (C.I. Acid Orange 10 (AO10), C.I. Acid Orange 12 (AO12) and C.I. Acid Orange 8 (AO8)) with different structure and different substitute groups has been investigated using supported TiO{sub 2} photocatalyst under UV light irradiation. All the experiments were performed in a circulation photochemical reactor equipped with a 15-W UV lamp emitted around 365 nm. The investigated photocatalyst was industrial Millennium PC-500 (crystallites mean size 5-10 nm) immobilized on glass plates by a heat attachment method. SEM images of the immobilized TiO{sub 2} nanoparticles showed the good coating on the plates, after repeating the deposition procedure three times. Our results indicated that the photocatalytic decolorization kinetics of the dyes were in the order of AO10 > AO12 > AO8. Photocatalytic mineralization of the dyes was monitored by total organic carbon (TOC) decrease, changes in UV-vis spectra and ammonium ion formation. The dye solutions could be completely decolorized and effectively mineralized, with an average overall TOC removal larger than 94% for a photocatalytic reaction time of 6 h. The nitrogen-to-nitrogen double bond of the azo dyes was transformed predominantly into NH{sub 4}{sup +} ion. The kinetic of photocatalytic decolorization of the dyes was found to follow a first-order rate law. The photocatalysis efficiency was evaluated by figure-of-merit electrical energy per order (E{sub EO}).

  5. Controlled Release of 5-Aminosalicylic Acid (5-ASA from New Biodegradable Polyurethanes

    Directory of Open Access Journals (Sweden)

    El-Refaie Kenawy

    2010-03-01

    Full Text Available Segmented polyurethanes containing azo aromatic groups in the main chain were synthesized by reaction of 3,3'-azobis(6-hydroxybenzoic acid (ABHB, 5-[4-(hydroxyphenylazo] salicylic acid (HPAS, and 5-[1-hydroxynaphthylazo] salicylic acid (HNAS with hexamethylenediisocyanate (HDI. All synthesized monomers and polymers were characterized by elemental analysis, FTIR, 1H-NMR spectra, TGA and DSC analysis. All the synthesized azo polymers showed good thermal stability and the onset decomposition temperature of all these polymers was found to be above 195 ºC under nitrogen atmosphere.The release of 5-ASA under physiological conditions (pH = 7.8 and pH = 1.5 was investigated at body temperature (37 ºC. The release rate of 5-ASA increased with increasing pH (i.e., 7.8 > 1.5.

  6. Crystallization and preliminary X-ray diffraction analysis of the azoreductase PpAzoR from Pseudomonas putida MET94

    International Nuclear Information System (INIS)

    PpAzoR, an FMN-dependent NADPH azoreductase from Pseudomonas putida MET94, has been crystallized using the sitting-drop vapour-diffusion technique. PpAzoR, an FMN-dependent NADPH azoreductase from Pseudomonas putida MET94, has been crystallized using the sitting-drop vapour-diffusion technique. The crystals diffracted to 1.6 Å resolution using synchrotron radiation and belonged to the orthorhombic space group F222, with unit-cell parameters a = 72.1, b = 95.5, c = 146.1 Å. Data sets were collected from the native protein to 2.2 Å resolution using in-house equipment and to 1.6 Å resolution using synchrotron radiation and the three-dimensional structure was determined by the molecular-replacement method

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

    Science.gov (United States)

    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 P(H), 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

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

    Science.gov (United States)

    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

  9. Decolorization of Textile Dyes and Degradation of Mono-Azo Dye Amaranth by Acinetobacter calcoaceticus NCIM 2890

    OpenAIRE

    Ghodake, Gajanan; Jadhav, Umesh; Tamboli, Dhawal; Kagalkar, Anuradha; Govindwar, Sanjay

    2011-01-01

    Acinetobacter calcoaceticus NCIM 2890 (A. caloaceticus) was found to decolorize 20 different textile dyes of various classes. Decolorization of an azo dye amaranth was observed effectively (91%) at static anoxic condition, whereas agitated culture grew well but showed less decolorization (68%) within 48 h of incubation. Induction of intracellular and extracellular lignin peroxidase, intracellular laccase, dichlorophenol indophenol (DCIP) reductase and riboflavin reductase represented their in...

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

    International Nuclear Information System (INIS)

    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

  11. Azo dye degradation by Phanerochaete chrysosporium in the medium enriched with nitrogen in the presence of primary co-substrate

    OpenAIRE

    Marcus Vinicius Freire Andrade; Karla Mayara Lima da Silva; João Paulo da Silva Siqueira; Carlos Ronald Pessoa Wanderley; Rinaldo dos Santos Araújo; Gloria Marinho; Kelly Rodrigues

    2013-01-01

    This work sought to evaluate the ability of fungi Phanerochaete chryosporium to degrade congo red azo dye in batch reactor, evaluate the influence of glucose and wheat bran as co-substrates on the removal of the dye in the medium and investigate the influence of ammonium chloride, ammonium nitrate and ammonium sulfate as the inorganic nitrogen source for the process. Wheat bran was not effective satisfactorily for the removal of dye and organic matter had no desired effect for the removal of ...

  12. Removal of selected azo dyes from textile wastewater by chemical coagulation/flocculation: implication of the dye destabilization mechanism

    OpenAIRE

    Janeczko, M.; GAYDARDZHIEV, Stoyan; Ay, P.

    2006-01-01

    The results of the coagulation/flocculation of six commercially used textile azo dyes coagulated with synthetic primary coagulants are discussed in the paper. Surface charge measurement of coagulated dye-flocs was employed to find a correlation between its sign and the level of colour removal. Additionally, flocs characterization was done with the aim to link data with surface charge and on this basis to outline the predominant mechanism of colour removal. Based on the results obtained, the e...

  13. FACTORS AFFECTING THE REMOVAL OF A BASIC AND AN AZO DYE FROM ARTIFICIAL SOLUTIONS BY ADSORPTION USING ACTIVATED CARBON

    OpenAIRE

    Albroomi, H I; ElSayed, Mohamed; Baraka, A.; Abdelmaged, M A

    2014-01-01

    Decolourisation of wastewater, particularly from textile industries, is one of the major environmental concerns these days. Current methods for removing dyes from wastewater are costly and cannot effectively be used to treat wide range of such wastewater. This work describes the use of commercial available granular activated carbon (GAC) as an efficient adsorbent material for dyes removal. Aqueous solutions of various basic dye Methylene Blue (MB) and azo-dye Tartrazine with concentrations 5-...

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

    Science.gov (United States)

    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.

  15. Non-drug toxicoderma by a respiratory or probable percutaneous route (fluorocarbons, butane, phenyl-azo-beta-naphthol)

    Energy Technology Data Exchange (ETDEWEB)

    Jeanmougin, M.; Bonvalet, D.; Civatte, J.; Ramelet, A.A.; Vilmer, C.

    1984-01-01

    Four cases of cutaneous rash, clinically more or less similar to erythema multiforme have been observed in patient who either stayed in a room with an accidentally high content of fluorocarbons, or had a skin contact with butane or phenyl-azo-beta-naphthol. The cutaneous lesions appear to be secondary to absorption of the toxic product, and probably induced by inhalation rather than by percutaneous penetration. Arguments for the responsibility of the substances rely on anamnestic data.

  16. Iridium mediated phenolic O-H activation and cyclometalation of 2-(naphthyl-1'-azo)-4-methylphenol - Formation of organoiridium complexes

    Indian Academy of Sciences (India)

    Rama Acharyya; Shie-Ming Peng; Gene-Hsiang Lee; Samaresh Bhattacharya

    2009-07-01

    Reaction of 2-(naphthyl-1'-azo)-4-methylphenol with [Ir(PPh3)3Cl] in refluxing ethanol in the presence of a base (NEt3) affords an organoiridium complex of type [Ir(PPh3)2(L)(H)], where L represents the coordinated 2-(naphthyl-1'-azo)-4-methylphenolate ligand. A similar reaction carried out in toluene affords the [Ir(PPh3)2(L)(H)] complex along with a similar complex of type [Ir(PPh3)2(L)Cl]. Structures of both the [Ir(PPh3)2(L)(H)] and [Ir(PPh3)2(L)Cl] complexes have been determined by X-ray crystallography. In both the complexes, 2-(naphthyl-1'-azo)-4-methylphenol is coordinated to iridium, via C-H activation at the 2' position of the naphthyl ring, as a dianionic tridentate C, N, O-donor and the two triphenylphosphines are trans. The organoiridium complexes show intense MLCT transitions in the visible region. Cyclic voltammetry on the [Ir(PPh3)2(L)(H)] and [Ir(PPh3)2(L)Cl] complexes shows a reversible Ir(III)-Ir(IV) oxidation respectively at 0.55 and 0.73 V vs SCE. An irreversible oxidation of the coordinated 2-(naphthyl-1'-azo)-4-methylphenolate ligand is observed above 1.0 V vs SCE and an irreversible reduction of the same is observed near -1.0 V vs SCE.

  17. Decolorization and biodegradation of reactive sulfonated azo dyes by a newly isolated Brevibacterium sp. strain VN-15.

    Science.gov (United States)

    Franciscon, Elisangela; Grossman, Matthew James; Paschoal, Jonas Augusto Rizzato; Reyes, Felix Guillermo Reyes; Durrant, Lucia Regina

    2012-12-01

    Azo dyes constitute the largest and most versatile class of synthetic dyes used in the textile, pharmaceutical, food and cosmetics industries and represent major components in wastewater from these industrial dying processes. Biological decolorization of azo dyes occurs efficiently under low oxygen to anaerobic conditions. However, this process results in the formation of toxic and carcinogenic amines that are resistant to further detoxification under low oxygen conditions. Moreover, the ability to detoxify these amines under aerobic conditions is not a wide spread metabolic activity. In this study we describe the use of Brevibacterium sp. strain VN-15, isolated from an activated sludge process of a textile company, for the sequential decolorization and detoxification of the azo dyes Reactive Yellow 107 (RY107), Reactive Black 5 (RB5), Reactive Red 198 (RR198) and Direct Blue 71 (DB71). Tyrosinase activity was observed during the biotreatment process suggesting the role of this enzyme in the decolorization and degradation process, but no-activity was observed for laccase and peroxidase. Toxicity, measured using Daphnia magna, was completely eliminated.

  18. Isolation and Characterization of Paracoccus sp. GSM2 Capable of Degrading Textile Azo Dye Reactive Violet 5

    Directory of Open Access Journals (Sweden)

    Mallikarjun C. Bheemaraddi

    2014-01-01

    Full Text Available A potential bacterial strain GSM2, capable of degrading an azo dye Reactive Violet 5 as a sole source of carbon, was isolated from textile mill effluent from Solapur, India. The 16S rDNA sequence and phenotypic characteristics indicated an isolated organism as Paracoccus sp. GSM2. This strain exhibited complete decolorization of Reactive Violet 5 (100 mg/L within 16 h, while maximally it could decolorize 800 mg/L of dye within 38 h with 73% decolorization under static condition. For color removal, the most suitable pH and temperature were pH 6.0–9.0 and 25–40°C, respectively. The isolate was able to decolorize more than 70% of five structurally different azo dyes within 38 h. The isolate is salt tolerant as it can bring out more than 90% decolorization up to a salt concentration of 2% (w/v. UV-Visible absorption spectra before and after decolorization suggested that decolorization was due to biodegradation and was further confirmed by FT-IR spectroscopy. Overall results indicate the effectiveness of the strain GSM2 explored for the treatment of textile industry effluents containing various azo dyes. To our knowledge, this could be the first report on biodegradation of Reactive Violet 5 by Paracoccus sp. GSM2.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  1. New tridentate azo-azomethines and their copper(II) complexes: Synthesis, solvent effect on tautomerism, electrochemical and biological studies

    Science.gov (United States)

    Sarigul, Munire; Deveci, Pervin; Kose, Muhammet; Arslan, Ugur; Türk Dagi, Hatice; Kurtoglu, Mukerrem

    2015-09-01

    In this study, three azo-azomethines and their copper(II) complexes were prepared and characterized by analytical and spectroscopic methods. The complexes prepared were found to be mononuclear and the chelation of the ligands to the copper(II) ions occurs through two phenolic oxygens and a nitrogen atom of the azomethine group of the ligand. The tautomeric behaviors of the azo-azomethines in solution were studied by UV-Vis. spectra in three organic solvents with different polarity (CHCl3, DMSO and DMF) at room temperature. The redox behaviors of the azo-azomethines and their Cu(II) complexes were investigated by cyclic voltammetry (CV) in DMSO solution containing 0.1 M tetrabutylammonium tetrafluoroborate (TBATFB) as supporting electrolyte. Additionally, the antibacterial activity was also evaluated by the broth microdilution methods against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. The compounds were found to be less effective against all bacteria tested than two reference antibiotics (ampicillin and gentamicin).

  2. Biomineralization of azo dye bearing wastewater in periodic discontinuous batch reactor: Effect of microaerophilic conditions on treatment efficiency.

    Science.gov (United States)

    Naresh Kumar, A; Nagendranatha Reddy, C; Venkata Mohan, S

    2015-01-01

    The present study illustrates the influence of microaerophilic condition on periodic discontinuous batch reactor (PDBR) operation in treating azo dye containing wastewater. The process performance was evaluated with the function of various dye load operations (50-750 mg/l) by keeping the organic load (1.6 kg COD/m(3)-day) constant. Initially, lower dye operation (50mg dye/l) resulted in higher dye [45 mg dye/l (90%)] and COD [SDR: 1.29 kg COD/m(3)-day (92%)] removal efficiencies. Higher dye load operation (750 mg dye/l) also showed non-inhibitory performance with respect to dye [600 mg dye/l (80%)] and COD [1.25 kg COD/m(3)-day (80%)] removal efficiencies. Increment in dye load showed increment in azo reductase and dehydrogenase activities (39.6 U; 4.96 μg/ml; 750 mg/l). UV-Vis spectroscopy (200-800 nm), FTIR and (1)H NMR studies revealed the disappearance of azo bond (-NN-). First derivative cyclic voltammogram supported the involvement of various membrane bound redox shuttlers, viz., cytochrome-C, cytochrome-bc1 and flavoproteins (FAD (H)).

  3. The influence of target erosion grade in the optoelectronic properties of AZO coatings growth by magnetron sputtering

    Science.gov (United States)

    Zubizarreta, C.; G-Berasategui, E.; Ciarsolo, I.; Barriga, J.; Gaspar, D.; Martins, R.; Fortunato, E.

    2016-09-01

    Aluminum-doped zinc oxide (AZO) transparent conductor coating has emerged as promising substitute to tin-doped indium oxide (ITO) as electrode in optoelectronic applications such as photovoltaics or light emitting diodes (LEDs). Besides its high transmission in the visible spectral region and low resistivity, AZO presents a main advantage over other candidates such as graphene, carbon nanotubes or silver nanowires; it can be deposited using the technology industrially implemented to manufacture ITO layers, the magnetron sputtering (MS). This is a productive, reliable and green manufacturing technique. But to guarantee the robustness, reproducibility and reliability of the process there are still some issues to be addressed, such as the effect and control of the target state. In this paper a thorough study of the influence of the target erosion grade in developed coatings has been performed. AZO films have been deposited from a ceramic target by RF MS. Structure, optical transmittance and electrical properties of the produced coatings have been analyzed as function of the target erosion grade. No noticeable differences have been found neither in optoelectronic properties nor in the structure of the coatings, indicating that the RF MS is a stable and consistent process through the whole life of the target.

  4. Reaction mechanism and degradation course of azo dyes by catalytic wet peroxide oxidation(CWPO)%催化湿式过氧化(CWPO)偶氮染料反应机理及降解历程研究

    Institute of Scientific and Technical Information of China (English)

    张蕾; 马宏瑞

    2011-01-01

    采用浸渍法制备出具有较高催化活性的催化剂CuO/γ-Al2O3,通过XRD、电镜等手段对催化剂进行了表征。降解了几种不同结构的偶氮染料,并通过改变CWPO的反应条件推断了其催化反应机理。采用紫外/可见分光光度计(UV-Vis)和傅里叶红外光谱仪(IR)等手段对染料降解过程进行跟踪和分析,对比染料处理前后紫外可见光谱与红外光谱图的变化,说明染料分子结构中的偶氮键发生断裂,破坏了分子结构的偶氮-苯环共轭发色体系,从而达到了脱色的目的。并借助水杨酸验证了CWPO体系中.OH的产生及CWPO反应机理。%The catalyst CuO/γ-Al2O3 with high catalytic activity by impregnation was prepared,and were examined by XRD、SEM to characterize the catalyst.Azo dyes of several different structures were degraded,and the reaction conditions were changed to study the reaction mechanism of CWPO.The UV/Visible spectrophotometer(UV-Vis) and the Fourier transform infrared spectrometer(IR) were used to track and analyze the degradation process of the dyes.Compared the UV-Vis and IR spectra before and after wastewater treatment,indicating the structure of the azo dye molecules bond was broken,destroyed azo benzene conjugated chromophoric system of the molecular structure,so as to achieve the purpose of bleaching.The salicylic acid was used to infer the ·OH generation and reaction mechanism in the CWPO system.

  5. Using chemical wet-etching methods of textured AZO films on a-Si:H solar cells for efficient light trapping

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Guo-Sheng; Li, Chien-Yu; Huang, Kuo-Chan; Houng, Mau-Phon, E-mail: mphoung@eembox.ncku.edu.tw

    2015-06-15

    In this paper, Al-doped ZnO (AZO) films are deposited on glasses substrate by RF magnetron sputtering. The optical, electrical and morphological properties of AZO films textured by wet-etching with different etchants, H{sub 3}PO{sub 4}, HCl, and HNO{sub 3} are studied. It is found that the textured structure could enhance the light scattering and light trapping ability of amorphous silicon solar cells. The textured AZO film etched with HNO{sub 3} exhibits optimized optical properties (T% ≧ 80% over entire wavelength, haze ratio > 40% at 550 nm wavelength) and excellent electrical properties (ρ = 5.86 × 10{sup −4} Ωcm). Scanning electron microscopy and Atomic force microscopy are used to observe surface morphology and average roughness of each textured AZO films. Finally, the textured AZO films etched by H{sub 3}PO{sub 4}, HCl and HNO{sub 3} were applied to front electrode layer for p–i–n amorphous silicon solar cells. The highest conversion efficiency of amorphous silicon solar cell fabricated on HNO{sub 3}-etched AZO film was 7.08% with open-circuit voltage, short-circuit current density and fill factor of 895 mV, 14.92 mA/cm{sup 2} and 0.56, respectively. It shows a significantly enhancement in the short-circuit current density and conversion efficiency by 16.2% and 20.2%, respectively, compared with the solar cell fabricated on as-grown AZO film. - Highlights: • The textured surface enhances light scattering and light trapping ability. • The HNO{sub 3}-etched AZO film exhibits excellent optical and electrical properties. • The efficiency of a-Si:H solar cell fabricated on HNO{sub 3}-etched AZO film was 7.08%. • The short-circuit current density enhances to 16.2%. • The conversion efficiency enhances to 20.2%.

  6. Effect of AZO Substrates on Self-Seeded Electrochemical Growth of Vertically Aligned ZnO Nanorod Arrays and Their Optical Properties

    Directory of Open Access Journals (Sweden)

    A. Peić

    2012-01-01

    Full Text Available We present a single step and an electrochemical synthesis of vertically aligned ZnO nanorod (NR arrays, directly on transparent aluminium-doped zinc oxide (AZO electrodes. The NRs grow from mild, aqueous-based solution at low temperature, with no need for catalysts or additional seed layer. The use of textured AZO as substrate allows for highly effective growth of hexagonally faceted, single-crystalline ZnO NRs along the wurtzite c-axis. The matching of the crystal lattices initiates a self-seeding route, thus the inherent growth habit of the AZO crystallites advances the vertical growth and alignment of NRs. Moreover, the thickness-dependant grain size of the AZO layer provides a valuable feature for tuning the diameter of ZnO NRs grown atop. In the absence of any seed mediator, the interfacial quality is expected to improve significantly. This should enhance the thermal and electrical transport throughout the whole nanostructured transparent electrode. The NR growth was investigated under systematic manipulation of the synthesis variables in order to optimize growth conditions for highly aligned, single-crystalline NRs with a large aspect ratio and a good optical quality. The structure and optical property of the AZO/ZnO NR ensembles were characterized by atomic force microscopy, scanning electron microscopy, X-ray diffraction, photoluminescence, and ultraviolet-visible transmission spectroscopy.

  7. Boron complexing with H-resorcinol and acidic hydroxyxanthene dyes

    Energy Technology Data Exchange (ETDEWEB)

    Nazarenko, V.A.; Flyantikova, G.V.; Chekirda, T.N. (AN Ukrainskoj SSR, Odessa. Fiziko-Khimicheskij Inst.)

    1984-01-01

    Complex formation of boron with H-resorcinol (hr; 2,4-dihydroxybenzene-azo -8-hydroxynaphtalene-3,6-disulfonic acid) and acidic hydroxyxanthene dyes (hxd: fluorescein, eosine, erathrosine). Mixed-ligand complexes with a ratio of r:hr:hxd=1:1:1 are formed at pH=5-6. The chemism of the complex formation of boron with H-resorcinol and fluorescein has been studied. The stability constant of the complex is 1.12x10/sup 21/, the conditional molar absorptivitis 1.80x10/sup 0/. This complex formation reaction was used for photometric determination of boron in natural water.

  8. 过氧化氢湿式氧化法处理偶氮染料废水的动力学及可生化性影响研究%Kinetic and biodegradability influence of azo dye wastewater treatment by wet peroxide oxidation

    Institute of Scientific and Technical Information of China (English)

    吴志敏; 张丽

    2016-01-01

    The influence factors, biodegradability changes and dynamic characteristics of Acid Red B simu⁃lated dye wastewater by wet peroxide oxidation (WPO) treatment was explored in a 100 mL continuous pres⁃sure reactor. The results showed that WPO was suitable for treating high concentrations of azo dye wastewa⁃ter and the wastewater influent pH was appropriate to keep in neutral. WPO could obviously improve the BOD5/CODCr values of azo dye wastewater and wastewater biodegradability. General dynamics model could bet⁃ter predict the wet oxidation macro process of Acid Red B of dye wastewater.%在100 mL连续釜式反应器中,研究了过氧化氢湿式氧化法(WPO)处理酸性红B染料模拟废水的影响因素、可生化性变化和动力学特征。结果表明,WPO法适于处理浓度较高的偶氮染料废水,废水进水pH宜保持在中性;能明显改善偶氮染料废水的BOD5/CODCr值,提高废水可生化性;通用动力学模型能较好地预测酸性红B染料废水的湿式氧化宏观过程。

  9. Optimization of integrated chemical-biological degradation of a reactive azo dye using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Sudarjanto, Gatut [Advanced Wastewater Management Centre, The University of Queensland, Qld 4072 (Australia); Keller-Lehmann, Beatrice [Advanced Wastewater Management Centre, The University of Queensland, Qld 4072 (Australia); Keller, Jurg [Advanced Wastewater Management Centre, The University of Queensland, Qld 4072 (Australia)]. E-mail: j.keller@awmc.uq.edu.au

    2006-11-02

    The integrated chemical-biological degradation combining advanced oxidation by UV/H{sub 2}O{sub 2} followed by aerobic biodegradation was used to degrade C.I. Reactive Azo Red 195A, commonly used in the textile industry in Australia. An experimental design based on the response surface method was applied to evaluate the interactive effects of influencing factors (UV irradiation time, initial hydrogen peroxide dosage and recirculation ratio of the system) on decolourisation efficiency and optimizing the operating conditions of the treatment process. The effects were determined by the measurement of dye concentration and soluble chemical oxygen demand (S-COD). The results showed that the dye and S-COD removal were affected by all factors individually and interactively. Maximal colour degradation performance was predicted, and experimentally validated, with no recirculation, 30 min UV irradiation and 500 mg H{sub 2}O{sub 2}/L. The model predictions for colour removal, based on a three-factor/five-level Box-Wilson central composite design and the response surface method analysis, were found to be very close to additional experimental results obtained under near optimal conditions. This demonstrates the benefits of this approach in achieving good predictions while minimising the number of experiments required.

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

    Energy Technology Data Exchange (ETDEWEB)

    Spadaro, J.T.; Gold, M.H.; Renganathan, V. (Oregon Graduate Inst. of Science and Technology, Beaverton (United States))

    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.

  11. New azo-decorated N-pyrrolidinylthiazoles: synthesis, properties and an unexpected remote substituent effect transmission.

    Science.gov (United States)

    Boga, Carla; Cino, Silvia; Micheletti, Gabriele; Padovan, Daniele; Prati, Luca; Mazzanti, Andrea; Zanna, Nicola

    2016-08-01

    New 5-azo substituted thiazole derivatives have been obtained, under mild conditions and in good yields, by the reaction between 2-N-pyrrolidinylthiazole and a series of aryldiazonium salts bearing, mainly in the para position, groups with different electronic effects. The NMR spectra of the products show broad signals of the methylene groups in the alpha position to the pyrrolidinyl nitrogen, suggesting a hindered rotation around the C2-N bond, of which a double bond character was also evidenced by X-ray diffraction analyses. The free energies of activation for the rotational processes have been obtained from (1)H NMR experiments and computer simulations at different temperatures and provided good correlation with the σ constants of the substituents on the 'remote' benzene ring. This represents an unexpected and peculiar result since the restricted rotation around the C2-N bond was shown to be influenced by a substituent situated very far away. 2,4-Di-N-pyrrolidinylthiazole showed a much greater reactivity than 2-N-pyrrolidinylthiazole with aryldiazonium salts. PMID:27376825

  12. Photo-Fenton-like degradation of azo dye methyl orange using synthetic ammonium and hydronium jarosite

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhihui [Department of Chemistry, College of Science, Nanjing Agricultural University, Nanjing 210095 (China); Liang, Jianru [Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Zhou, Lixiang, E-mail: lxzhou@njau.edu.cn [Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China)

    2013-01-05

    Highlights: Black-Right-Pointing-Pointer Hydronium and ammonium jarosite could catalyze the oxidation of methyl orange in photo-Fenton-like process. Black-Right-Pointing-Pointer The oxidation process is essentially heterogeneous, not homogeneous. Black-Right-Pointing-Pointer Hydronium jarosite has stronger reactivity than ammonium jarosite. - Abstract: Ammonium and hydronium jarosite were prepared by hydrothermal method with urea as the homogeneous precipitant. X-ray diffraction, field-emission scanning electron microscope, X-ray photoelectron spectrum, UV-vis spectra and fourier transform infrared spectrum were used to characterize the resulting products. The photodegradation efficiency of the prepared ammonium and hydronium jarosite was studied in a photo-Fenton-like process using methyl orange (MO) as target pollutant. The photocatalytic degradation of MO over synthetic ammonium and hydronium jarosite under various conditions, such as catalysts loading, H{sub 2}O{sub 2} concentration and initial pH, has been investigated. Results show that ammonium and hydronium jarosite have satisfactory photocatalysis effect in degradation of MO azo dye, and that the reactivity of hydronium jarosite toward the mineralization of MO was higher than that of ammonium jarosite. The novel ammonium and hydronium jarosite catalysts would be important for industrial applications due to their high photoactivity, little iron leaching and low cost.

  13. Synthesis, structure, redox and spectra of green iridium complexes of tridentate azo-aromatic ligands

    Indian Academy of Sciences (India)

    Manashi Panda; Chayan Das; Chen-Hsiung Hung; Sreebrata Goswami

    2007-01-01

    Reactions of IrCl3$\\cdot$ H2O with the ligands, 2-[(phenylamino)phenylazo]pyridine (HL1a) and 2-[(-tolylamino)phenylazo]pyridine (HL1b) produce [Ir(L1)2]Cl (L1 = L1a, [1]Cl and L1 = L1b, [2]Cl) along with many unidentified products. The iridium complexes have been characterized by various techniques such as X-ray crystallography, mass spectrometry, 1H and 13C NMR, cyclic voltammetry and absorption studies. The complex [1]ClO4 crystallises in triclinic space group. The crystallographic data have been determined. Notably, the Ir-N (azo) lengths are short (av. 1.9875(4) Å) as compared to the remaining four Ir-N lengths (av. 2.052(5) Å). There is significant degree of ligand backbone conjugation in the coordinated ligands, which result in shortening of the C-N lengths on the other side of the middle phenyl ring and also in lengthening of the diazo (N=N) lengths. The complexes display multiple low energy transitions ranging between 1010 and 450 nm. These are electro active and show three reversible redox responses in the potential range, +1.5 V to -1.5 V. The cathodic potential responses are ascribed as ligand reductions, while the redox process at the anodic potential occurs at a mixed metal-ligand (HOMO) orbital.

  14. Degradation of direct azo dye by Cucurbita pepo free and immobilized peroxidase

    Institute of Scientific and Technical Information of China (English)

    Nabila Boucherit; Mahmoud Abouseoud; Lydia Adour

    2013-01-01

    Enzymatic decolourization of the azo dye,Direct Yellow (DY 106) by Cucurbita pepo (courgette) peroxidase (CP) is a complex process,which is greatly affected by pH,temperature,enzyme activity and the concentrations of H2O2 and dye.Courgette peroxidase was extracted and its performance was evaluated by using the free-CP (FCP) and immobilized-CP (ICP) forms in the decolourization of DY106.Immobilization of peroxidase in calcium alginate beads was performed according to a strategy aiming to minimize enzyme leakage and keep its activity at a maximum value by optimizing sodium alginate content,enzyme loading and calcium chloride concentration.The initial conditions it which the highest DY106 decolourization yield was obtained were found at pH 2,temperature 20C,H2O2 dose 1 mmol]L (FCP) and 100 mmol/L (ICP).The highest decolourization rates were obtained for dye concentrations 50 mg/L (FCP) and 80 mg/L (ICP).Under optimal conditions,the FCP was able to decolorize more than 87% of the dye within 2 min.While with ICP,the decolourization yield was 75% within 15 min.The decolourization and removal of DY106 was proved by UV-Vis analysis.Fourier transform infrared (FT-IR) spectroscopy analysis was also performed on DY106 and enzymatic treatment precipitated byproduct.

  15. Biodegradation of carcinogenic textile azo dyes using bacterial isolates of mangrove sediment

    Institute of Scientific and Technical Information of China (English)

    Guru Prasad Srinivasan; Asnar Sikkanthar; Anandajothi Elamaran; Caroline R Delma; Kumaran Subramaniyan

    2014-01-01

    Objective:To evaluate the biodegrading property against carcinogenic azo dyes using bacterial isolates of mangrove sediment. Methods: The bacterial isolates were subjected to submerged fermentation and their growth kinetics were studied. The potential strain was characterized using 16S rDNA sequencing. Results:In the present study, dye degrading bacterial colonies were isolated from the mangrove sediment samples of Parangipettai estuarine area, Tamil Nadu. Of the 30 morphologically different strains isolated, 5 showed antagonistic property. The growth kinetics of the two strains, P1 and G1, which showed potent activity were calculated. One particular isolate (P1) showing promising dye degrading potential in the submerged fermentation was further characterized. The strain was identified as Paenibacillus sp. by 16S rDNA sequencing. Conclusions:This study reveals the less explored microflora of mangrove sediments. The novel strain may further be analyzed and used in the treatment of effluent from dye industry so as to reduce the impact of carcinogenic contaminants.

  16. Testing of some azo dyes and their reduction products for mutagenicity using Salmonella typhimurium TA 1538.

    Science.gov (United States)

    Garner, R C; Nutman, C A

    1977-07-01

    A series of ten azo dyes as well as various single ring aromatic amines substituted on the benzene ring were tested for bacterial mutagenicity with Salmonella typhimurium TA 1538 using a soft-agar overlay method. Two dyes, sudan 2 and chrysoidin induced mutation but only in the presence of a rat liver preparation. Chrysoidin was the more active. Testing of its reduction products, aniline and 1,2,4-triaminobenzene showed a liver metabolite of the latter compound could be responsible for the mutagenic effect, having a comparable mutagenicity with 1,2-diamino-4-nitro-benzene, one of the mutagenic constituents of hair dyes. Structure-activity studies on a series of ring-substituted anilines indicated that mutagenic activity required at least two positions to be substituted with either amino or nitro groups, or one of each. The bacteria as well as the liver enzyme preparation may partake in the activation of these chemicals. The correlation between mutagenicity and carcinogenicity for this group of compounds is discussed.

  17. Characterization of an azo-calix[4]arene-based optical sensor for Europium (III) ions

    Energy Technology Data Exchange (ETDEWEB)

    Echabaane, M., E-mail: mosaab.echabaane@gmail.com [Laboratoire d' interfaces et Materiaux Avances (LIMA) Faculte des sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia); Rouis, A. [Laboratoire d' interfaces et Materiaux Avances (LIMA) Faculte des sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia); Bonnamour, I. [Institut de Chimie and Biochimie Moleculaires and Supramoleculaires (ICBMS), UMR CNRS 5246, 43 Boulevard du 11 Novembre 1918, Universite Claude Bernard Lyon 1, 69100 Villeurbanne (France); Ouada, H. Ben [Laboratoire d' interfaces et Materiaux Avances (LIMA) Faculte des sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia)

    2012-07-01

    Selective and sensitive optical sensor membranes (optodes) were elaborated to detect cations in aqueous solutions. The sensing films are based on chromogenic calix[4]arene derivatives. The optode membranes were studied using UV/Vis absorption spectroscopy measurements. The sensitivity of the optode has been tested for Pb{sup 2+}, Cd{sup 2+}, Mg{sup 2+} and Eu{sup 3+} ions at pH 6.8. The results showed a good selectivity response towards Eu{sup 3+}. Low selectivity coefficients were observed for Cd{sup 2+} and Mg{sup 2+} where Pb{sup 2+} can be considered as interfering ions. The characteristics of this optode such as response time, regeneration, reproducibility and lifetime are discussed. - Highlights: Black-Right-Pointing-Pointer We report optical sensing studies of chromogenic calixarene derivatives. Black-Right-Pointing-Pointer We investigate optical interaction between azo-calix[4]arene and Eu{sup 3+}. Black-Right-Pointing-Pointer We study sensitivity and selectivity of optode films. Black-Right-Pointing-Pointer We describe characteristics of optode films for determination of europium traces.

  18. Case study of the sonochemical decolouration of textile azo dye Reactive Black 5

    Energy Technology Data Exchange (ETDEWEB)

    Vajnhandl, Simona [University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, 2000 Maribor (Slovenia)]. E-mail: simona.vajnhandl@uni-mb.si; Le Marechal, Alenka Majcen [University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, 2000 Maribor (Slovenia)

    2007-03-06

    The decolouration and mineralization of reactive dye C.I. Reactive Black 5, a well-known representative of non-biodegradable azo dyes, by means of ultrasonic irradiation at 20, 279 and 817 kHz has been investigated with emphasis on the effect of various parameters on decolouration and degradation efficiency. Characterization of the used ultrasound systems was performed using calorimetric measurements and oxidative species monitoring using Fricke and iodine dosimeter. Experiments were carried out with low frequency probe type, and a high-frequency plate type transducer at 50, 100 and 150 W of acoustic power and within the 5-300 mg/L initial dye concentration range. Decolouration, as well as radical production, increased with increasing frequency, acoustic power, and irradiation time. Any increase in initial dye concentration results in decreased decolouration rates. Sonochemical decolouration was substantially depressed by the addition of 2-methyl-2-propanol as a radical scavenger, which suggests radical-induced reactions in the solution. Acute toxicity to marine bacteria Vibrio fischeri was tested before and after ultrasound irradiation. Under the conditions employed in this study, no toxic compounds were detected after 6 h of irradiation. Mineralization of the dye was followed by TOC measurements. Relatively low degradation efficiency (50% after 6 h of treatment) indicates that ultrasound is rather inefficient in overall degradation, when used alone.

  19. Predictive modeling of sorption and desorption of a reactive azo dye by pumpkin husk.

    Science.gov (United States)

    Çelekli, Abuzer; Çelekli, Fadime; Çiçek, Erdoğan; Bozkurt, Hüseyin

    2014-04-01

    The use of effective disposal of redundant pumpkin husk (PH) to remove pollutants is an important issue for environmental protection and utilization of resource. The aim of this study was to remove a potentially toxic reactive azo dye, Reactive Red (RR) 120, by widespread PH as a low-cost adsorbent. Particle size, adsorbent dose, pH, temperature, initial dye concentration, and contact time affected the sorption process. Amine, amide, hydroxyl, and carboxyl groups of PH played significant roles on the sorption process. Rapid sorption occurred within the first 2 min and equilibrium was reached within 60 min. Sorption kinetic was well represented by logistic equation. Generated secondary logistic model can be used to describe effects of initial dye concentration, contact time, and temperature by a single equation with high R (2) value. Monolayer sorption capacity was found as 98.61 mg g(-1). Activation energy, thermodynamic, and desorption studies showed that this process was physical, endothermic, and spontaneous. This study indicated that redundant PH as a low-cost adsorbent had a great potential for the removal of RR 120 as an alternative eco-friendly process. PMID:24374618

  20. Exploration of redox method for effective removal of vinyl sulphone based reactive azo dye

    International Nuclear Information System (INIS)

    Study depicted here involved the removal of Reactive Red 195 from synthetic wastewater by some oxidizing and reducing agents involving potassium permanganate (KMnO/sub 4/), hydrogen peroxide (H/sub 2/O/sub 2/) ferrioxalate (Fe(OX)) and sodium sulphite (Na/sub 2/SO/sub 3/) under various experimental conditions. In order to get maximum removal of dye some operational factors like pH, initial concentration of dye and concentration of oxidizing and reducing agents were varied. Results indicated that the efficiency of KMnO/sub 4/, H/sub 2/O/sub 2/, Fe(OX) and Na/sub 2/SO/sub 3/ under optimized conditions was 99.31, 49.67, 52 and 46.15 %, respectively, for removal of dye under study. Effectiveness of these redox reagents for the treatment of colored wastewater was also monitored by chemical oxygen demand (COD) and total organic carbon (TOC) content. There was decrease in COD and TOC values after redox treatment which showed chemical decomposition of complex dye molecule. FT-IR examination of products obtained after treatment under optimized experimental conditions also confirmed the chemical degradation of selected reactive azo dye. (author)

  1. Removal of azo and anthraquinone reactive dyes from industrial wastewaters using MgO nanoparticles

    International Nuclear Information System (INIS)

    In the present investigation, a porous MgO powder was synthesized and tested for the removal of dyes from aqueous solution. The size of the MgO particles was in the range of 38-44 nm, with an average specific surface area of 153.7 m2/g. Adsorption of reactive blue 19 and reactive red 198 was conducted to model azo and anthraquinone dyes at various MgO dosages, dye concentrations, solution pHs and contact times in a batch reactor. Experimental results indicate that the prepared MgO powder can remove more than 98% of both dyes under optimum operational conditions of a dosage of 0.2 g, pH 8 and a contact time of 5 min for initial dye concentrations of 50-300 mg/L. The isotherm evaluations revealed that the Langmuir model attained better fits to the experimental equilibrium data than the Freundlich model. The maximum predicted adsorption capacities were 166.7 and 123.5 mg of dye per gram of adsorbent for RB 19 and RR 198, respectively. In addition, adsorption kinetic data followed a pseudo-second-order rate for both tested dyes.

  2. Optimization of integrated chemical-biological degradation of a reactive azo dye using response surface methodology

    International Nuclear Information System (INIS)

    The integrated chemical-biological degradation combining advanced oxidation by UV/H2O2 followed by aerobic biodegradation was used to degrade C.I. Reactive Azo Red 195A, commonly used in the textile industry in Australia. An experimental design based on the response surface method was applied to evaluate the interactive effects of influencing factors (UV irradiation time, initial hydrogen peroxide dosage and recirculation ratio of the system) on decolourisation efficiency and optimizing the operating conditions of the treatment process. The effects were determined by the measurement of dye concentration and soluble chemical oxygen demand (S-COD). The results showed that the dye and S-COD removal were affected by all factors individually and interactively. Maximal colour degradation performance was predicted, and experimentally validated, with no recirculation, 30 min UV irradiation and 500 mg H2O2/L. The model predictions for colour removal, based on a three-factor/five-level Box-Wilson central composite design and the response surface method analysis, were found to be very close to additional experimental results obtained under near optimal conditions. This demonstrates the benefits of this approach in achieving good predictions while minimising the number of experiments required

  3. All-Nonvacuum-Processed CIGS Solar Cells Using Scalable Ag NWs/AZO-Based Transparent Electrodes.

    Science.gov (United States)

    Wang, Mingqing; Choy, Kwang-Leong

    2016-07-01

    With record cell efficiency of 21.7%, CIGS solar cells have demonstrated to be a very promising photovoltaic (PV) technology. However, their market penetration has been limited due to the inherent high cost of the cells. In this work, to lower the cost of CIGS solar cells, all nonvacuum-processed CIGS solar cells were designed and developed. CIGS absorber was prepared by the annealing of electrodeposited metallic layers in a chalcogen atmosphere. Nonvacuum-deposited Ag nanowires (NWs)/AZO transparent electrodes (TEs) with good transmittance (92.0% at 550 nm) and high conductivity (sheet resistance of 20 Ω/□) were used to replace the vacuum-sputtered window layer. Additional thermal treatment after device preparation was conducted at 220 °C for a few of minutes to improve both the value and the uniformity of the efficiency of CIGS pixel cell on 5 × 5 cm substrate. The best performance of the all-nonvacuum-fabricated CIGS solar cells showed an efficiency of 14.05% with Jsc of 34.82 mA/cm(2), Voc of 0.58 V, and FF of 69.60%, respectively, which is comparable with the efficiency of 14.45% of a reference cell using a sputtered window layer. PMID:27299854

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

    Science.gov (United States)

    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

  5. Biodegradation mechanisms and kinetics of azo dye 4BS by a microbial consortium.

    Science.gov (United States)

    He, Fang; Hu, Wenrong; Li, Yuezhong

    2004-10-01

    A microbial consortium consisting of a white-rot fungus 8-4* and a Pseudomonas 1-10 was isolated from wastewater treatment facilities of a local dyeing house by enrichment, using azo dye Direct Fast Scarlet 4BS as the sole source of carbon and energy, which had a high capacity for rapid decolorization of 4BS. To elucidate the decolorization mechanisms, decolorization of 4BS was compared between individual strains and the microbial consortium under different treatment processes. The microbial consortium showed a significant improvement on dye decolorization rates under either static or shaking culture, which might be attributed to the synergetic reaction of single strains. From the curve of COD values and the UV-visible spectra of 4BS solutions before and after decolorization cultivation with the microbial consortium, it was found that 4BS could be mineralized completely, and the results had been used for presuming the degrading pathway of 4BS. This study also examined the kinetics of 4BS decolorization by immobilized microbial consortium. The results demonstrated that the optimal decolorization activity was observed in pH range between four and 9, temperature range between 20 and 40 degrees C and the maximal specific decolorization rate occurred at 1,000 mg l(-1) of 4BS. The proliferation and distribution of microbial consortium were also microscopically observed, which further confirmed the decolorization mechanisms of 4BS.

  6. Random UV mutagenesis approach for enhanced biodegradation of sulfonated azo dye, Green HE4B.

    Science.gov (United States)

    Joshi, Swati M; Inamdar, Shrirang A; Jadhav, Jyoti P; Govindwar, Sanjay P

    2013-03-01

    The objective of the study was to execute mutant bacteria for efficient biodegradation of sulfonated azo dye, Green HE4B (GHE4B). UV irradiation was used to introduce random mutations in Pseudomonas sp. LBC1. Genetic alterations induced by UV irradiation in selected mutant bacteria were confirmed by random amplification of polymorphic DNA technique. The mutant bacteria named as Pseudomonas sp. 1 F reduced the time required for complete degradation of recalcitrant dye GHE4B by 25 % when compared with the wild one. The biodegradation was monitored by UV-Vis spectrophotometric analysis. Activities of enzymes like laccase, lignin peroxidase, veratryl alcohol oxidase, and NADH dichlorophenol indophenol reductase were found to be boosted in mutant bacteria as a consequence of UV-induced mutation. Matrix-assisted laser desorption/ionization-time of flight analysis of differentially expressed proteins of mutant bacteria suggested active role of antioxidant enzymes in the degradation of the dye. The degradation product was analyzed by Fourier transform infrared spectroscopy, high-performance thin-layer chromatography, and gas chromatography-mass spectrometry. Results revealed few variations in the degradation end products of wild-type and mutant bacteria. Phytotoxicity study underlined the safer biodegradation of GHE4B by mutant Pseudomonas sp. 1 F.

  7. Application of response surface analysis for biodegradation of azo reactive textile dye using Aspergillus foetidus.

    Science.gov (United States)

    Sharma, Praveen; Singh, Lakhvinder

    2012-06-01

    This paper reports the application of experimental design methodology for the optimization of decolourization of azo reactive textile dye Remazol Red RR and reduction of chemical oxygen demand (COD) using fungal isolate Aspergillus foetidus. Response surface methodology (RSM), involving central composite design matrix in three most important input variables; temperature, pH and initial dye concentration was employed. A total of 20 experiments were conducted in the study towards the construction of a quadratic model. This demonstrated the benefits of approach in achieving excellent predictions, while minimizing the number of experiments required. Very high regression coefficient between the variables and the responses indicated excellent evaluation of experimental data. Under optimized conditions fungal isolate was capable to decolourize Remazol Red RR up to 86.21% and COD reduction up to 55.43% was achieved during the experimental setup. Enzymatic activity indicated excellent outcome under the optimal process conditions. The experimental values agreed with the predicted ones, indicating suitability of the model and success of RSM approach in optimizing the process.

  8. Biodegradation of carcinogenic textile azo dyes using bacterial isolates of mangrove sediment

    Directory of Open Access Journals (Sweden)

    Guru Prasad Srinivasan

    2014-02-01

    Full Text Available Objective: To evaluate the biodegrading property against carcinogenic azo dyes using bacterial isolates of mangrove sediment. Methods: The bacterial isolates were subjected to submerged fermentation and their growth kinetics were studied. The potential strain was characterized using 16S rDNA sequencing. Results: In the present study, dye degrading bacterial colonies were isolated from the mangrove sediment samples of Parangipettai estuarine area, Tamil Nadu. Of the 30 morphologically different strains isolated, 5 showed antagonistic property. The growth kinetics of the two strains, P1 and G1, which showed potent activity were calculated. One particular isolate (P1 showing promising dye degrading potential in the submerged fermentation was further characterized. The strain was identified as Paenibacillus sp. by 16S rDNA sequencing. Conclusions: This study reveals the less explored microflora of mangrove sediments. The novel strain may further be analyzed and used in the treatment of effluent from dye industry so as to reduce the impact of carcinogenic contaminants.

  9. Anion recognition ability of a novel azo dye derived from 4-hydroxycoumarin

    Energy Technology Data Exchange (ETDEWEB)

    Chandel, Madhurya; Roy, Sutapa Mondal; Sharma, Darshna [Department of Applied Chemistry, SV National Institute of Technology, Surat, Gujarat (India); Sahoo, Suban K., E-mail: suban_sahoo@rediffmail.com [Department of Applied Chemistry, SV National Institute of Technology, Surat, Gujarat (India); Patel, Amit; Kumari, Premlata [Department of Applied Chemistry, SV National Institute of Technology, Surat, Gujarat (India); Dhale, Ranu S. [School of Chemical Sciences, National Institute of Science Education and Research, Bhubaneswar, Odisha (India); Ashok, Kumar S.K. [School of Advanced Sciences, VIT University, Vellore, Tamil Nadu (India); Nandre, Jitendra P.; Patil, Umesh D. [School of Chemical Sciences, North Maharashtra University, Jalgaon, Maharashtra (India)

    2014-10-15

    The anion recognition ability of a novel azo dye derived from 4-hydroxycuomarin (L) was investigated by experimental (UV–vis, fluorescence and {sup 1}H NMR) and theoretical [(B3LYP/6-31G(d,p)] methods. Among the surveyed anions, the receptor L showed both naked-eye detectable color and spectral changes in the presence of F{sup −}, AcO{sup −} and H{sub 2}PO{sub 4}{sup −} due to the formation of hydrogen bonding complexes followed by deprotonation between these anions and L. - Highlights: • Anion recognition ability of an easy-to-prepare coumarin derivative L was reported. • L showed both naked-eye and spectral responses towards AcO{sup −}, F{sup −} and H{sub 2}PO{sub 4}{sup −}. • Deprotonation mechanism was proposed for the observed spectral responses. • L showed selective ratiometric fluorescence ‘turn-on’ responses towards AcO{sup −} and F{sup −}.

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

    Science.gov (United States)

    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.

  11. Continuous biodegradation of sulfanilic acid in a multi-stage packed bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Salazar-Huerta, A.; Velazquez-Garcia, A.; Cobos-Vasconcelos, D. de los.; Juarez-Ramirez, C.; Ruiz-Ordaz, N.; Galindez-Mayer, J.

    2009-07-01

    Sulfanilic acid SA is an aromatic amine derived from the azo-bond cleavage of several textile dyes. Recalcitrance and toxicity of this amine is high, and with frequency it could be found as an aquatic contaminant; thus biodegradation process for its removal are justified. Although the SA molecule contains carbon, nitrogen and sulphur, its C:N:S proportion is unbalanced for microbial growth in a biodegradation process; thus nutrient complementation should be necessary for its complete removal. (Author)

  12. Anaerobic degradation of azo dye Drimaren blue HFRL in UASB reactor in the presence of yeast extract a source of carbon and redox mediator.

    Science.gov (United States)

    Baêta, B E L; Aquino, S F; Silva, S Q; Rabelo, C A

    2012-04-01

    This paper presents results on anaerobic degradation of the azo dye blue HFRL in a bench scale Upflow anaerobic sludge blanket (UASB) reactor operated at ambient temperature. The results show that the addition of yeast extract (500 mg/L) increased color removal (P dye removal increased along the operational phases and depended on the presence of yeast extract, suggesting progressive biomass acclimatization. Analysis of bacterial diversity by Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) method showed there was biomass selection along the bioreactor operation and no evidence of azo dye degrading bacteria predominance. This strengthens the hypothesis that color removal happens extracellularly by the reduction of azo bond by reduced redox mediators, such as riboflavin, which is present in high amount in the yeast extract.

  13. Impedimetric Sensing Proprieties of ITO Electrodes Functionalized with PEDOT:PSS/Azo-Calix[4]Arene for the Detection of Al3+ Ions Under Light Excitation

    Science.gov (United States)

    Echabaane, M.; Rouis, A.; Mahjoub, M. A.; Bonnamour, I.; Ben Ouada, H.

    2016-08-01

    This study describes an investigation of the sensitivity of the azo-calix[4]arene/poly(3,4-ethylenedioxythiophene)/poly-(styrenesulfonate) (PEDOT:PSS) thin film deposited on the indium tin oxide (ITO) electrode surface toward aluminum ions (Al3+) under light excitation. Thin films were deposited by the spin-coating technique. Adhesion of these films to the ITO surface was highlighted by performing contact angle measurements. Then, interfaces of the azo-calix[4]arene/PEDOT:PSS thin film were characterized by impedance measurements using electrochemical impedance spectroscopy. Obtained impedance spectra were fitted using an equivalent circuit. Finally, evolutions of the different components of this circuit were studied. These evolutions show that the sensitivity of the azo-calix[4]arene/PEDOT:PSS/ITO electrode is remarkably improved under illumination.

  14. Optical and Electrical Properties of Heavy-doped AZO Transparent Conducting Thin Films%重掺杂AZO透明导电薄膜的光电特性

    Institute of Scientific and Technical Information of China (English)

    吕有明; 曹培江; 贾芳; 柳文军; 朱德亮; 马晓翠; 林传强; 刘稳

    2011-01-01

    Al-doped ZnO (AZO) film have been actively investigated for potential applications in solar cells,flat panel displays, transparent heat mirrors and organic light emitting diodes,etc. , because of high transmittance in the visible region, low resistance and better stability. Extensive work has been concentrated on the fabrication and characterization of AZO thin films. All results show that the average transmittance of the visible light is above 80%, the resistivity can be changed from values as low as 10-4 Ω · cm to values as high as 104 Ω · cm. However, a few researches are devoted to the optical and electrical properties in heavy Al doping AZO thin films. In particular, there are hardly any reports regarding the conductivity mechanism of heavily doped AZO thin films. In this paper, AZO thin films with heavy Al doping concentration were grown on quartz (SiO2) substrates by pulsed laser deposition (PLD) method. ZnO mixed with Al203 (mass fraction is 2% ) was used as target.The structure, optical and electrical properties of AZO thin films were investigated by using X-ray diffraction (XRD), transmission spectra, photoluminescence (PL) spectra and Hall effect measurement. XRD patterns indicate that all AZO thin films have the wurtzite structure of ZnO with a strong c-axis preferred orientation.The electrical measurement of AZO thin films show a good conductivity. The highest carrier density and the Hall mobility are 9. O1 × 1020 cm-3 and 33 cm2 · V-1 · s-1, respectively. The conducting mechanism was studied by temperature-dependent Hall-effect measurement. The temperature variation of cartier concentration from shows alike-metallic conducting behavior. All AZO thin films have good optical quality. The optical transmittance is above 80%, the highest transmittance is about 90%. The PL spectrum in AZO thin films is dominated by near band edge (NBE) emission at room temperature. The absorption edge and NBE emission peak of AZO thin films show an obvious

  15. Photo degradation of methyl orange an azo dye by advanced Fenton process using zero valent metallic iron: influence of various reaction parameters and its degradation mechanism.

    Science.gov (United States)

    Gomathi Devi, L; Girish Kumar, S; Mohan Reddy, K; Munikrishnappa, C

    2009-05-30

    Advanced Fenton process (AFP) using zero valent metallic iron (ZVMI) is studied as a potential technique to degrade the azo dye in the aqueous medium. The influence of various reaction parameters like effect of iron dosage, concentration of H(2)O(2)/ammonium per sulfate (APS), initial dye concentration, effect of pH and the influence of radical scavenger are studied and optimum conditions are reported. The degradation rate decreased at higher iron dosages and also at higher oxidant concentrations due to the surface precipitation which deactivates the iron surface. The rate constant for the processes Fe(0)/UV and Fe(0)/APS/UV is twice compared to their respective Fe(0)/dark and Fe(0)/APS/dark processes. The rate constant for Fe(0)/H(2)O(2)/UV process is four times higher than Fe(0)/H(2)O(2)/dark process. The increase in the efficiency of Fe(0)/UV process is attributed to the cleavage of stable iron complexes which produces Fe(2+) ions that participates in cyclic Fenton mechanism for the generation of hydroxyl radicals. The increase in the efficiency of Fe(0)/APS/UV or H(2)O(2) compared to dark process is due to continuous generation of hydroxyl radicals and also due to the frequent photo reduction of Fe(3+) ions to Fe(2+) ions. Though H(2)O(2) is a better oxidant than APS in all respects, but it is more susceptible to deactivation by hydroxyl radical scavengers. The decrease in the rate constant in the presence of hydroxyl radical scavenger is more for H(2)O(2) than APS. Iron powder retains its recycling efficiency better in the presence of H(2)O(2) than APS. The decrease in the degradation rate in the presence of APS as an oxidant is due to the fact that generation of free radicals on iron surface is slower compared to H(2)O(2). Also, the excess acidity provided by APS retards the degradation rate as excess H(+) ions acts as hydroxyl radical scavenger. The degradation of Methyl Orange (MO) using Fe(0) is an acid driven process shows higher efficiency at pH 3. The

  16. Abc Amino Acids: Design, Synthesis, and Properties of New Photoelastic Amino Acids

    Energy Technology Data Exchange (ETDEWEB)

    Standaert, Robert F [ORNL; Park, Dr Seung Bum [Seoul National University

    2006-01-01

    Photoisomerizable amino acids provide a direct avenue to the experimental manipulation of bioactive polypeptides, potentially allowing real-time, remote control of biological systems and enabling useful applications in nanobiotechnology. Herein, we report a new class of photoisomerizable amino acids intended to cause pronounced expansion and contraction in the polypeptide backbone, i.e., to be photoelastic. These compounds, termed Abc amino acids, employ a photoisomerizable azobiphenyl chromophore to control the relative disposition of aminomethyl and carboxyl substituents. Molecular modeling of nine Abc isomers led to the identification of one with particularly attractive properties, including the ability to induce contractions up to 13A in the backbone upon transa?cis photoisomerization. This isomer, designated mpAbc, has substituents at meta and para positions on the inner (azo-linked) and outer rings, respectively. An efficient synthesis of Fmoc-protected mpAbc was executed in which the biaryl components were formed via Suzuki couplings and the azo linkage was formed via amine/nitroso condensation; protected forms of three other Abc isomers were prepared similarly. A decapeptide incorporating mpAbc was synthesized by conventional solid-phase methods and displayed characteristic azobenzene photochemical behavior with optimal conversion to the cis isomer at 360 nm and a thermal cisa?trans half life of 100 min. at 80 AoC.

  17. AZO透明导电薄膜的制备%Preparation of AZO transparent conductive thin films

    Institute of Scientific and Technical Information of China (English)

    刘丹妮; 史永胜; 马猛飞; 杨巍巍; 杨若欣

    2012-01-01

    采用射频磁控溅射法在玻璃衬底上制备了ZnO:AI(AZO)透明导电薄膜,并借助XRD、SEM等表征方法,研究了溅射功率和衬底温度对薄膜结构、表面形貌及光电特性的影响.结果表明,制备薄膜的最佳溅射功率和衬底温度分别为180W、200℃,在此条件下制备的AZO薄膜具有明显的c轴(002)择优取向,其最低方块电阻为18 Ω/□,在可见光范围内的平均透光率超过91%,且透明导电性能优于目前平板显示器的要求,有望取代现在市场上的主流氧化铟锡(ITO)薄膜.%Aluminum doped zinc oxide films were deposited by RF-magnetron sputtering method on glass substrate, the effects of sputtering power and substrate temperature on the structure, surface topography, photoelectric properties of AZO films were investigated by using XRD, SEM, et al. The results show that the best sputtering power and substrate temperature to prepare films are 180 W and 200 ℃ respectively. The AZO film prepared on this condition is highly oriented along c-axis (002), and the lowest sheet resistance is 18 Ω/, the average transmittance in the visible light range is over 91%. Its transparent and conductive properties are superior to the current requirements of flat-panel displays, thus it is expected to replace indium tin oxide (ITO) film which is the mainstream thin film on the market now.

  18. Microbial diversity in a continuous system based on rice husks for biodegradation of the azo dyes Reactive Red 2 and Reactive Black 5.

    Science.gov (United States)

    Forss, Jörgen; Pinhassi, Jarone; Lindh, Markus; Welander, Ulrika

    2013-02-01

    In the present study the degradation of two common azo dyes used in dye houses today, Reactive Black 5 and Reactive Red 2 was evaluated in biofilters. In two experiments, bioreactors performed over 80% decolorization at a hydraulic retention time of only 28.4h with little production of metabolites. Molecular analyses showed a diverse and dynamic bacterial community composition in the bioreactors, including members of the Bacteroidetes, Acinetobacter (Gammaproteobacteria) and Clostridium (Firmicutes) that possess the capacity to reduce azo dyes. Collectively, the results indicate that the development of mixed bacterial communities from natural biomaterials contributes to an efficient and robust degradation performance in bioreactors even at high concentration of dyes.

  19. Synthesis and spectroscopic characterization of some lanthanide(III) nitrate complexes of ethyl 2-[2-(1-acetyl-2-oxopropyl)azo]-4,5-dimethyl-3-thiophenecarboxyate

    OpenAIRE

    CHEMPAKAM JANARDHANAN ATHIRA; YESODHARAN SINDHU; MATHUNNI SUSAMMA SUJAMOL; KOCHUKITTAN MOHANAN

    2011-01-01

    Ethyl 2-[2-(1-acetyl-2-oxopropyl)azo]-4,5-dimethyl-3-thiophenecarboxyate was synthesized by coupling diazotized ethyl 2-amino-4,5-dimethylthiophene-3-carboxylate with acetylacetone. Based on various spectral studies and elemental analysis, an intramolecularly hydrogen-bonded azo-enol structural form was assigned for the ligand. This ligand is versatile in forming a series of lanthanide(III) complexes, viz., lanthanum(III), cerium(III), praseodymium(III), neodymium(III), samarium(III) and gado...

  20. A New Photocatalytic System Using Steel Mesh and Cold Cathode Fluorescent Light for the Decolorization of Azo Dye Orange G

    OpenAIRE

    Ming-Chin Chang; Chin-Pao Huang; Hung-Yee Shu; Yung-Chen Chang

    2012-01-01

    High color and organic composition, the effluents from the textile dyeing and finishing industry, can be treated by photocatalytic oxidation with UV/TiO2. The objective of this study was to prepare a new photocatalytic system by coating nanosized TiO2 particles on steel mesh support and using cold cathode fluorescent light (CCFL) irradiation at 365 nm in a closed reactor for the oxidation of azo dye C.I. Orange G (OG). Various factors such as reaction time, coating temperature, TiO2 dosage, p...

  1. Photometric determination of vanadium as its complex with N-methylanabasine-α'-azo-n-cresol and hydrogen peroxide

    International Nuclear Information System (INIS)

    Using absorption spectra the reactions between vanadium(5, 4) and N-methylanabasine-α'-azo-p-cresol have been studied in the absence and presence of hydrogen peroxide pH 3.5 and 0.6 M HCl. Addition of H2O2 improves the contrast, sensitivity, selectivity, and precision of determination. Independing on the initial oxidation state, vanadium(5) in involved into the ternary complex formed. A photometric procedure of determining vanadium is suggested. The procedure was applied to the analysis of titanomagnetic ores

  2. Investigation into state of N-methyl-anabasine-α'-azo-p-cresol and its complex with indium in solutions

    International Nuclear Information System (INIS)

    The states of N-methylanabasine-α'-azo-p-cresol (MC) at different pH and of its complex with indium have been studied in solutions by the Huckel molecular orbital method and spectrophotometry. The indium complex with MC is formed within the pH range 3.5-6.0. The composition of the complex is 1:1, the apparent molar absorption coefficient is 1.26x104. The most probable structures of the complex as well as the reaction contrast degree determined by calculation agree satisfactorily with experimental data

  3. Ant colony optimization as a descriptor selection in QSPR modeling for prediction of λmax of azo dyes

    Institute of Scientific and Technical Information of China (English)

    Morteza Atabati; Farzaneh Khandani

    2012-01-01

    A quantitative structure-property relationship (QSPR) study was suggested for the prediction of λmax of azo dyes.After optimization of 3D geometry of structures,different descriptors were calculated by the HyperChem and Dragon softwares.A major problem of QSPR is the high dimensionality of the descriptor space; therefore,descriptor selection is the most important step for these studies.In this paper,an ant colony optimization (ACO) algorithm was proposed to select the best descriptors.

  4. Sorption and desorption studies of a reactive azo dye on effective disposal of redundant material.

    Science.gov (United States)

    Çelekli, Abuzer; Bozkurt, Hüseyin

    2013-07-01

    The effective disposal of redundant elephant dung (ED) is important for environmental protection and utilization of resource. The aim of this study was to remove a toxic-azo dye, Reactive Red (RR) 120, using this relatively cheap material as a new adsorbent. The FTIR-ATR spectra of ED powders before and after the sorption of RR 120 and zero point charge (pHzpc) of ED were determined. The sorption capacity of ED for removing of RR 120 were carried out as functions of particle size, adsorbent dose, pH, temperature, ionic strength, initial dye concentration, and contact time. Sorption isotherm, kinetic, activation energy, thermodynamic, and desorption parameters of RR 120 on ED were studied. The sorption process was found to be dependent on particle size, adsorbent dose, pH, temperature, ionic strength, initial dye concentration, and contact time. FTIR-ATR spectroscopy indicated that amine and amide groups have significant role on the sorption of RR 120 on ED. The pHzpc of ED was found to be 7.3. Sorption kinetic of RR 120 on ED was well described by sigmoidal Logistic model. The Langmuir isotherm was well fitted to the equilibrium data. The maximum sorption capacity was 95.71 mg g(-1). The sorption of RR 120 on ED was mainly physical and exothermic according to results of D-R isotherm, Arrhenius equation, thermodynamic, and desorption studies. The thermodynamic parameters showed that this process was feasible and spontaneous. This study showed that ED as a low-cost adsorbent had a great potential for the removal of RR 120 as an alternative eco-friendly process.

  5. Photocatalytic degradation of an azo-dye on TiO2/activated carbon composite material.

    Science.gov (United States)

    Andriantsiferana, C; Mohamed, E F; Delmas, H

    2014-01-01

    A sequential adsorption/photocatalytic regeneration process to remove tartrazine, an azo-dye in aqueous solution, has been investigated. The aim ofthis work was to compare the effectiveness of an adsorbent/photocatalyst composite-TiO2 deposited onto activated carbon (AC) - and a simple mixture of powders of TiO2 and AC in same proportion. The composite was an innovative material as the photocatalyst, TiO2, was deposited on the porous surface ofa microporous-AC using metal-organic chemical vapour deposition in fluidized bed. The sequential process was composed of two-batch step cycles: every cycle alternated a step of adsorption and a step of photocatalytic oxidation under ultra-violet (365 nm), at 25 degreeC and atmospheric pressure. Both steps, adsorption and photocatalytic oxidation, have been investigated during four cycles. For both materials, the cumulated amounts adsorbed during four cycles corresponded to nearly twice the maximum adsorption capacities qmax proving the photocatalytic oxidation to regenerate the adsorbent. Concerning photocatalytic oxidation, the degree of mineralization was higher with the TiO2/AC composite: for each cycle, the value of the total organic carbon removal was 25% higher than that obtained with the mixture powder. These better photocatalytic performances involved better regeneration than higher adsorbed amounts for cycles 2, 3 and 4. Better performances with this promising material - TiO2 deposited onto AC - compared with TiO2 powder could be explained by the vicinity of photocatalytic and AC adsorption sites.

  6. 具有广谱偶氮还原能力柠檬酸菌AzoR-2的分离鉴定和还原特性研究%Isolation,Identification and Characterization of a Broad-Spectrum Azo-reducing Citrobacter Strain AzoR-2

    Institute of Scientific and Technical Information of China (English)

    洪义国; 郭俊; 王敏妮; 许玫英; 孙国萍

    2007-01-01

    从印染活性污泥中分离到1株高效广谱偶氮还原菌AzoR-2,并对该菌株进行了鉴定和偶氮还原特性分析.通过细胞形态和BIOLOG细菌自动鉴定系统的生理生化特性及16S rDNA与β-内酰胺酶基因相结合的分子生物学特性的分析,鉴定该菌株为柠檬酸菌属细菌,定名为Citrobacter sp.AzoR-2.通过对其偶氮还原特性的研究表明,菌株AzoR-2能够在厌氧条件下利用多种有机物和氢气为电子供体还原多种偶氮化合物,具有广谱偶氮还原特征.对电子供体和偶氮键的定量分析表明,还原过程中偶氮键接受的电子全部来自一级电子供体.氧气对其偶氮还原具有强烈的抑制作用.该菌株的偶氮还原系统定位在菌体的细胞膜上,推测该菌株的偶氮还原与菌体膜上的电子传递过程密切相关.菌株AzoR-2的厌氧偶氮还原在碱性pH值范围发生,其反应的最适pH值为7.5.菌株偶氮还原要求的温度范围较宽泛,在20~40℃范围内都显还原活性,最适作用温度为35℃.具有偶氮还原能力的柠檬酸菌在受偶氮染料污染的环境以及在印染废水的脱色中,可以发挥重要作用.

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

    Science.gov (United States)

    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.

  8. DECOLORIZATION OF AZO DYES AND MINERALIZATION OF PHENANTHRENE BY TRAMETES SP. AS03 ISOLATED FROM INDONESIAN MANGROVE FOREST

    Directory of Open Access Journals (Sweden)

    Asep Hidayat

    2014-04-01

    Full Text Available Textile industry contributes the most disposals of synthetic dyes, and about 40% of textile dyes has been generating high amount of colored wastewater. Polycyclic aromatic hydrocarbons (PAHs, such as phenanthrene, is a group of organic compounds, that structurally comprised of two or more benzene rings, which persist in air, water, and soil. The organic pollutants of dyes and PAHs have adversely effects the food chain and are potentially toxic, mutagenic, and carcinogenic to the environment. The objective of this research is to screen and investigate the potential fungus from mangrove forest to degrade azo dyes and phenanthrene.  In this study, fungi were collected from mangrove forest in Riau Province – Sumatra – Indonesia. Previously, Trametes sp. AS03 is one of the fungi isolated from mangrove forest in Riau Province, that was able to decolorize Remazol Brilliant Blue R (RBBR. The capability of Trametes sp. AS03 to decolorize four azo dyes, Remazol B. Violet (V5, Levafix Orange E3GA (Or64, Levafix B. Red E-6BA (R159, and Sumifix S. Scarlet 2GF (R222, were further evaluated. The result shows that Trametes sp. AS03 decolorized 91, 60, 48, and 31 of V5, R222, R159, and Or64, respectively. By showing its capability to decolorize some of the dyes, Trametes sp. AS03 was used to break down phenanthrene. AS03 degraded more than 70% of phenanthrene in 15 days.

  9. Statement on Allura Red AC and other sulphonated mono azo dyes authorised as food and feed additives

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS

    2013-06-01

    Full Text Available The ANS Panel has been asked by EFSA to assess the new scientific information that has become available since the adoption of the opinion on the re-evaluation of the food colouring agent Allura Red AC in 2009, in particular the positive findings from an in vivo comet assay in mice. The findings from this study have been interpreted in conjunction with all the available relevant data from genotoxicity testing, metabolism and carcinogenicity, and in consideration of possible species differences between mouse and rat. These new data have been considered in the context of the overall relevant data available not only for Allura Red AC but also for a number of other structurally related sulphonated mono azo dyes authorised as food additives, namely: Amaranth, Ponceau 4R, Sunset Yellow FCF, Tartrazine and Azorubine/Carmoisine. The Panel concluded that the new data by themselves were insufficient at this time to change the conclusions of the 2009 opinion on the safety of Allura Red AC and that there is currently no reason to revise the ADI. The read-across exercise has highlighted a shared pattern of effects for this class of substances that would warrant further investigation The Panel therefore recommended a repetition of the in vivo comet assay in mice, to be performed in compliance with the most recent and internationally validated experimental protocol, using whole cells and examining a wide range of tissues. These recommendations apply to all the sulphonated mono azo dyes included in this review.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  13. Effects of annealing temperature on ZnO and AZO films prepared by sol-gel technique

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Zi-Neng [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia); Chan, Kah-Yoong, E-mail: kychan@mmu.edu.my [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia); Tohsophon, Thanaporn [Physics Department, Faculty of Science, Srinakharinwirot University, 10110 Bangkok (Thailand)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer Low cost sol-gel spin coating technique was used to fabricate the ZnO films. Black-Right-Pointing-Pointer Influences of annealing temperature on the structural and optical properties of the ZnO and AZO films were investigated. Black-Right-Pointing-Pointer The experimental results reveal that the annealing treatment affects the structural and optical properties of the ZnO films. - Abstract: Zinc oxide (ZnO) films have the potential in the emerging thin-film technologies which can be employed in thin-film solar cells, transistors, sensors and other optoelectronic devices. In this work, low cost sol-gel spin-coating technique was used to synthesize the ZnO films. The influences of annealing temperature on the structural and optical properties of ZnO and aluminum doped ZnO (AZO) films were investigated. The structural properties of the ZnO films such as surface morphology and crystallinity were determined using atomic force microscopy (AFM) and X-ray diffractometry (XRD), respectively. The optical properties of the ZnO films were characterized by the ultraviolet-visible (UV-vis) spectroscopy and Tauc method was adopted to estimate the optical gap. The experimental results reveal that the thermal annealing treatment affects the properties of the ZnO films. The effects of the low range annealing temperature on the sol-gel ZnO films addressed in this investigation will be discussed in this paper.

  14. Biodegradation of Azo Dye Disperse Orange S-RL by a Newly Isolated Strain Acinetobacter sp. SRL8.

    Science.gov (United States)

    Cai, Zhiqiang; Zhang, Wenjie; Ma, Jiangtao; Cai, Jinyan; Li, Shanshan; Zhu, Xiaolin; Yang, Guanghua; Zhao, Xiyue

    2015-06-01

    The strain SRL8, which could decolorize the azo dye disperse orange S-RL (S-RL), was first isolated from sludge and identified as Acinetobacter sp. through physiobiochemical identification and 16S rRNA gene sequences. The effects of temperature, pH, dye concentration, O2, and glucose concentration on S-RL decolorization by the strain SRL8 were studied. The optimal conditions were 30 °C, pH 7.0, 4g·L(-1) of inoculation (wet cells), and microaerophilic incubation. The decolorization percentage for S-RL by the strain SRL8 could reach 90.2% under optimal conditions. The strain SRL8 was highly tolerant to the azo dye SRL up to 300 mg·L(-1) and it had a broad decolorizing spectrum. According to the Monod equation, kinetic parameters of decolorization by SRL8 were calculated. The vmax and Km were 5.57×10(-3) h(-1) and 14.53 mg·L(-1), respectively.

  15. Low-temperature-fabricated ZnO, AZO, and SnO{sub 2} nanoparticle-based dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong Hee; Park, Cheolmin; Choi, Wonkook; Cho, Sungjae; Moon, Byungjoon; Son, Dongick [Korea Institute of Science and Technology, Seoul (Korea, Republic of); Yonsei University, Seoul (Korea, Republic of)

    2014-11-15

    The authors investigated the microstructural and the electrical properties of ZnO, AZO, and SnO{sub 2} based dye-sensitized solar cells (DSSCs) fabricated using a low-temperature-processed (200 .deg. C) dyesensitized ZnO, AZO, and SnO{sub 2} 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 SnO{sub 2} nanoparticle layer which forms a nano porous ZnO, AZO, and SnO{sub 2} 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{sub sc}), the open circuit potential (V{sub oc}), the fill factor (FF), and power conversion efficiency (η), of the DSSC fabricated wander optimized conditions were observed to be 5.10 mA/cm{sup 2}, 0.61 V, 0.46, and 1.43%, respectively.

  16. Cancer risk assessment of azo dyes and aromatic amines from tattoo bands, folders of paper, toys, bed clothes, watch straps and ink

    NARCIS (Netherlands)

    Zeilmaker MJ; Kranen HJ van; Veen MP van; Janus J; LBM

    2000-01-01

    A quantitative assessment was performed to estimate the cancer risk to individuals using tattoo bands, folders of paper, toys, bed clothes, watch straps and ink which are coloured with azo dyes. In these products benzidine and the benzidine related amines o-anisidine, 2,4-toluenediamine, 4,4'-diamin

  17. FIA-Spectrophotometric Method for Determination of Nitrite in Meat Products: An Experiment Exploring Color Reduction of an Azo-Compound

    Science.gov (United States)

    Penteado, Jose C.; Angnes, Lucio; Masini, Jorge C.; Oliveira, Paulo C. C.

    2005-01-01

    This article describes the reaction between nitrite and safranine O. This sensitive reaction is based on the disappearance of color of the reddish-orange azo dye, allowing the determination of nitrite at the mg mL-1 level. A factorial optimization of parameters was carried out and the method was applied for the quantification of nitrite in…

  18. trans/cis-Isomerization of fluorene-bridged azo chromophore with significant two-photon absorbability at near-infrared wavelength.

    Science.gov (United States)

    Chu, Chih-Chien; Chang, Ya-Chi; Tsai, Bo-Kai; Lin, Tzu-Chau; Lin, Ja-Hon; Hsiao, Vincent K S

    2014-12-01

    Azo-containing materials have been proven to possess second-order nonlinear optical (NLO) properties, but their third-order NLO properties, which involves two-photon absorption (2PA), has rarely been reported. In this study, we demonstrate a significant 2PA behavior of the novel azo chromophore incorporated with bilateral diphenylaminofluorenes (DPAFs) as a π framework. The electron-donating DPAF moieties cause a redshifted π-π* absorption band centered at 470 nm, thus allowing efficient blue-light-induced trans-to-cis photoisomerization with a rate constant of 2.04 × 10(-1) min(-1) at the photostationary state (PSS). The open-aperture Z-scan technique that adopted a femtosecond (fs) pulse laser as excitation source shows an appreciably higher 2PA cross-section for the fluorene-derived azo chromophore than that for common azobenzene dyes at near-infrared wavelength (λex =800 nm). Furthermore, the fs 2PA response is quite uniform regardless of the molecular geometry. On the basis of the computational modeling, the intramolecular charge-transfer (ICT) process from peripheral diphenylamines to the central azo group through a fluorene π bridge is crucial to this remarkable 2PA behavior. PMID:25294108

  19. Synthesis of 5-aminotetrazole-1N-oxide and its azo derivative: a key step in the development of new energetic materials.

    Science.gov (United States)

    Fischer, Dennis; Klapötke, Thomas M; Piercey, Davin G; Stierstorfer, Jörg

    2013-04-01

    1-Hydroxy-5-aminotetrazole (1), which is a long-desired starting material for the synthesis of hundreds of new energetic materials, was synthesized for the first time by the reaction of aqueous hydroxylamine with cyanogen azide. The use of this unique precursor was demonstrated by the preparation of several energetic compounds with equal or higher performance than that of commonly used explosives, such as hexogen (RDX). The prepared compounds, including energetic salts of 1-hydroxy-5-aminotetrazole (hydroxylammonium (2, two polymorphs) and ammonium (3)), azo-coupled derivatives (potassium (5), hydroxylammonium (6), ammonium (7), and hydrazinium 5,5'-azo-bis(1-N-oxidotetrazolate (8, two polymorphs)), as well as neutral compounds 5,5'-azo-bis(1-oxidotetrazole) (4) and 5,5'-bis(1-oxidotetrazole)hydrazine (9), were intensively characterized by low-temperature X-ray diffraction, IR, Raman, and multinuclear NMR spectroscopy, elemental analysis, and DSC. The calculated energetic performance, by using the EXPLO5 code, based on the calculated (CBS-4M) heats of formation and X-ray densities confirm the high energetic performance of tetrazole-N-oxides as energetic materials. Last but not least, their sensitivity towards impact, friction, and electrostatic discharge were explored. 5,5'-Azo-bis(1-N-oxidotetrazole) deflagrates close to the DDT (deflagration-to-detonation transition) faster than all compounds that have been investigated in our research group to date.

  20. Reductive decolorization of the azo dye RR2 in the absence and presence of redox mediator and the electrons acceptor nitrate

    NARCIS (Netherlands)

    Brauna, C.H.D.; Mota, S.; Santos, dos A.B.

    2009-01-01

    This paper aimed at evaluating the effect of nitrate on anaerobic azo dye reduction by using mesophilic bioreactors, in the absence and in the presence of redox mediators. Two anaerobic bioreactors were operated in parallel with a hydraulic retention time (HRT) of ten hours; ethanol was used as co-s

  1. Monopolar Electro-Coagulation Process for Azo Dye C.I. Acid Red 18 Removal from Aqueous Solutions

    OpenAIRE

    Ghasem Azarian; Davood Nematollahi; Ali Reza Rahmani; Kazem Godini; Mohammad Bazdar; Hassan Zolghadrnasab

    2014-01-01

    The discharge of wastewaters containing an untreated dye results in aesthetic problems and an increase in gases solubility, which causes light transmission inhibition into water bodies. In spite of advantages of physicochemical and biological methods, these processes produce huge amounts of sludge, toxic by-products and require several oxidant chemicals. By contrast, electrochemical processes because of their high versatility, high efficiency and eco-friendly properties are more acceptable. I...

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

    Science.gov (United States)

    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.

  3. Descoloração redutiva de corantes azo e o efeito de mediadores redox na presença do aceptor de elétrons sulfato Reductive decolourisation of azo dyes and the effect of redox mediators in the presence of the electron acceptor sulfate

    Directory of Open Access Journals (Sweden)

    Mayara Carantino Costa

    2010-01-01

    Full Text Available We investigated the impact of sulphate and the redox mediator Anthraquinone-2,6-disulfonate (AQDS on the decolorization of the azo dyes Congo Red (CR and Reactive Black 5 (RB5. In anaerobic reactors free of extra sulphate dosage, the color removal efficiency decreased drastically when the external electron donor ethanol was removed. In presence of an extra dosage of sulphate, CR decolourisations were 47.8% (free of AQDS and 96.5% (supplemented with AQDS. The decolourisations achieved in both reactors with RB5 were lower than the ones found with CR. Finally, the biogenic sulphide contribution on azo dye reduction was negligiable.

  4. Biodegradación del Colorante Azo Azul Disperso 79 en un Reactor Discontinuo Secuencial Bajo Ambientes Anaerobios/Aerobios.

    Directory of Open Access Journals (Sweden)

    Rosa María Melgoza-Alemán

    2005-01-01

    Full Text Available Se estudió la biodegradación del colorante mono azo azul disperso 79 (AD79 en un reactor discontinuo secuencial (SBR con biomasa suspendida, combinando ambientes anaerobios/aerobios en un solo tanque, mediante fases de no aireación y aireación respectivamente. El objetivo fue obtener agua para ser reutilizada en el proceso textil o bien para riego agrícola. El colorante AD79 es uno de los colorantes azo que más aplicación tiene en la industria textil y se ha observado que por sí mismo no es tóxico, pero en ambientes reductores se biotransforma a aminas aromáticas que se ha comprobado son carcinogénicas a los microorganismos y al hombre. Los resultados mostraron que el proceso anaerobio/aerobio discontinuo secuenciado fue muy eficiente en la remoción del colorante AD79. La biomasa se aclimató a la degradación de colorante a los 45 días de operación. Los tiempos de reacción disminuyeron de 11 a 4 días, con fases de reacción anaerobia de 9 a 3 días y fases de reacción aerobia de 48 a 24 h. La eficiencia de remoción global del colorante en el reactor fue de 92 %. En la etapa anaerobia la eficiencia de biotransformación a aminas fue de 65 %. La mineralización de las aminas producidas por la ruptura del enlace azo fue de 96 %. Se observó un incrementó de la toxicidad después de la fase reductiva, sin embargo después del tratamiento anaerobio/aerobio secuenciado, la toxicidad fue eliminada a niveles no detectados en el efluente, lo que demostró la eficacia del proceso anaerobio/aerobio para eliminar la toxicidad del agua residual.

  5. The oxidation of Ni(II) N-confused porphyrins (NCPs) with azo radical initiators and an unexpected intramolecular nucleophilic substitution reaction via a proposed Ni(III) NCP intermediate.

    Science.gov (United States)

    Jiang, Hua-Wei; Chen, Qing-Yun; Xiao, Ji-Chang; Gu, Yu-Cheng

    2009-07-01

    The oxidation of Ni(II) N-confused porphyrins (NCPs) with azo radical initiators resulted in an unexpected intramolecular nucleophilic substitution reaction via a proposed Ni(III) NCP intermediate, which could be detected by HRMS.

  6. The use HPTLC and Direct Analysis in Real Time-Of-Flight Mass Spectrometry DART-TOF-MS for rapid analysis of degradation by oxidation and sonication of an azo dye

    OpenAIRE

    Djelal, Hayet; Cornée, Carole; Tardivel, Ronan; Lavastre, Olivier; Amrane, Abdelatif

    2013-01-01

    Advanced oxidation processes are efficient for the removal of recalcitrant compounds, like azo-dyes. However, the intermediates produced during their degradation can be more toxic than the parent compounds. Improving the knowledge concerning the degradation pathways may be therefore helpful to optimize the process. In this aim, HPTLC and Direct Analysis in Real Time-Of-Flight Mass Spectrometry DART-TOF-MS were considered and applied to analyze the sono-oxidation of an azo dye, methyl red sodi...

  7. Perspectives d'amélioration du conseil prévisionnel de fertilisation azotée à la parcelle en Wallonie par l'utilisation du logiciel AzoFert®

    Directory of Open Access Journals (Sweden)

    Abras, M.

    2013-01-01

    Full Text Available Prospects for improving the provisional nitrogen fertilization recommendation at field scale in Wallonia using the AzoFert® software. The French software AzoFert® for nitrogen fertilization recommendation is currently under adaptation and validation for soil and climatic conditions in Wallonia by the CRA-W within the INTERREG IV project "SUN" (Sustainable Use of Nitrogen. This adaptation has raised the need for a change of values in the parameter tables and catalogs relating to meadow residues, crop residues, catch crop practices, crops, organic amendments and soil type. Data from 25 trials of increasing nitrogen fertilizer rates conducted by CRA-W between 1996 and 2011 in cereal, potato and vegetable crops located on loam and sandy loam soil were used to validate the AzoFert® software adapted for Wallonia. The difference between nitrogen rates recommended on the one hand by AzoFert® or Azobil® (software currently used in the reference lab for Nitrate [Requasud] at CRA-W and the optimal dose of nitrogen fertilizer assessed in each trial on the other hand shows that, in most cases, AzoFert® gives a recommendation closer to the optimum than Azobil®. The nitrogen uptake measured in the plants collected in the unfertilized control plot also shows a higher correlation with nitrogen supply from the soil assessed by AzoFert® than for plants assessed by Azobil®. The more accurate estimate of the mineralization of organic sources, probably linked to the dynamic soil nitrogen supply approach integrated into AzoFert®, may explain the gain in the greater accuracy of the AzoFert® recommendation in comparison with that of Azobil®.

  8. Semiconductor-mediated photocatalysed degradation of two selected azo dye derivatives, amaranth and bismarck brown in aqueous suspension.

    Science.gov (United States)

    Tariq, M Abu; Faisal, M; Muneer, M

    2005-12-01

    Semiconductor-mediated photocatalysed degradation of two selected azo dye derivatives such as amaranth (1) and bismarck brown (2) has been investigated in aqueous suspension by monitoring the change in substrate concentration employing UV spectroscopic analysis technique as a function of irradiation time. The degradation was studied under different conditions such as types of TiO(2), pH, substrate concentration, catalyst concentration, and in the presence of electron acceptors such as hydrogen peroxide (H(2)O(2)), potassium bromate (KBrO(3)) and ammonium persulphate (NH(4))(2)S(2)O(8) besides air. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 showed comparatively highest photocatalytic activity. The dye derivative, bismarck brown (2) was found to degrade faster than amaranth dye (1).

  9. Decolorization of Textile Dyes and Degradation of Mono-Azo Dye Amaranth by Acinetobacter calcoaceticus NCIM 2890.

    Science.gov (United States)

    Ghodake, Gajanan; Jadhav, Umesh; Tamboli, Dhawal; Kagalkar, Anuradha; Govindwar, Sanjay

    2011-10-01

    Acinetobacter calcoaceticus NCIM 2890 (A. caloaceticus) was found to decolorize 20 different textile dyes of various classes. Decolorization of an azo dye amaranth was observed effectively (91%) at static anoxic condition, whereas agitated culture grew well but showed less decolorization (68%) within 48 h of incubation. Induction of intracellular and extracellular lignin peroxidase, intracellular laccase, dichlorophenol indophenol (DCIP) reductase and riboflavin reductase represented their involvement in the biodegradation of amaranth. The products obtained after degradation of Amaranth were characterized as naphthalene sulfamide, hydroxyl naphthalene diazonium and naphthalene diazonium. The germination and growth of Sorghum vulgare and Phaseolus mungo seeds, and the growth of E. coli and Bacillus substilis were not inhibited by the metabolic products of the dye.

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

    Science.gov (United States)

    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

  11. [Spectrophotometric determination of aromatic amino compounds with J-acid].

    Science.gov (United States)

    Yin, Xiao-hang; Shi, Wen-jian; Shen, Xin; Ma, Jun-tao; Li, Liang

    2015-01-01

    The problems such as chromogenic reaction selectivity, reaction rate, sensitivity and water-solubility of azo compounds were considered. The molecular structures of coupling components were theoretically designed and screened in the present research The reaction conditions and methods of chromogenic reaction were investigated. J-Acid (2-amino-5-naphthol-7-sulfonic acid) as a coupling reagent to determine aromatic amino compounds was established. In the presence of potassium bromide, at room temperature, nitrite reacted with aromatic amino compounds in the medium of thin hydrochloric acid. Then diazonium salt reacted with J-Acid in the aqueous solution of sodium carbonate, forming coloured azo dye, which had a maximum adsorption at 480 nm. The molar adsorption coeffcients of aniline, 4-aminobenzene sulfonic acid and 1-naphthylamine were 3. 95 X 10(4), 3. 24 X 10(4) and 3. 91 X 10(4) L . mol-1 . cm-1 , respectively. Experimental results showed that common coexisting ions on the surface water did not affect the results of determination. J-Acid of spectrophotometry was used to determine the samples of Shanghai Fu Xing Dao canal. Meanwhile, recovery experiments by standard addition method were done. Experiment results showed that the recoveries of aniline were in the range of 98. 5%-102. 1%, and RSD was 2. 08%. J-Acid is a common organic reagent. It is soluble in water and low volatile, and its toxicity is much lower than N-ethylenediamine. spectrophotometric determination of aromatic amino compounds by J-Acid has the advantage of high sensitivity, good selectivity, simple rapid operation and accurate results, and thus it can be used for the determination of trace aromatic amino compounds in the environmental water.

  12. Preparation, spectral, X-ray powder diffraction and computational studies and genotoxic properties of new azo-azomethine metal chelates

    Science.gov (United States)

    Bitmez, Şirin; Sayin, Koray; Avar, Bariş; Köse, Muhammet; Kayraldız, Ahmet; Kurtoğlu, Mükerrem

    2014-11-01

    A new tridentate azo-azomethine ligand, N‧-[{2-hydroxy-5-[(4-nitrophenyl)diazenyl]phenyl}methylidene]benzohydrazidemonohydrate, (sbH·H2O) (1), is prepared by condensation of benzohydrazide and 2-hydroxy-5-[(4-nitrophenyl)diazenyl]benzaldehyde (a) with treatment of a solution of diazonium salt of p-nitroaniline and 2-hydroxybenzaldehyde in EtOH. The five coordination compounds, [Co(sb)2]·4H2O (2), [Ni(sb)2]·H2O (3), [Cu(sb)2]·4H2O (4), [Zn(sb)2]·H2O (5) and [Cd(sb)2]·H2O (6) are prepared by reacting the Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with the ligand. The structures of the compounds are elucidated from the elemental analyses data and spectroscopic studies. It is found the ligand acts as a tridentate bending through phenolic and carbonyl oxygens and nitrogen atom of the Cdbnd Nsbnd group similar to the most of salicylaldimines. Comparison of the infrared spectra of the ligand and its metal complexes confirm that azo-Schiff base behaves as a monobasic tridentate ligand towards the central metal ion with an ONO donor sequence. Upon complexation with the ligand, the Cd(II), and Zn(II) ions form monoclinic structures, while Co(II), Cu(II) and Ni(II) ions form orthorhombic structures. Quantum chemical calculations are performed on tautomers and its metal chelates by using DFT/B3LYP method. Most stable tautomer is determined as tautomer (1a). The geometrical parameters of its metal chelates are obtained as theoretically. The NLO properties of tautomer (1a) and its metal complexes are investigated. Finally, the ligand and its metal complexes are assessed for their genotoxicity.

  13. 改性PAN纤维铁配合物暗态催化偶氮染料降解反应%Modified PAN fiber-Fe ( Ⅲ ) complex catalyzing degradation of azo dyes in dark

    Institute of Scientific and Technical Information of China (English)

    王志超; 董永春; 韩振邦

    2011-01-01

    A modified PAN fiber-Fe (Ⅲ) complex (Fe-AO-PAN) was prepared by a coordinated reaction between amidoximated PAN fiber and ferric chloride solution, and then used as a heterogeneous Fenton catalyst for the degradation of azo dyes with different structures. The relationship between Fe-AOPAN dosage (M), ferric content of Fe-AO-PAN, decolorization ratio (D), and initial degradation rate constant (k) of the dyes in dark was investigated. Moreover, degradation process of the dyes and the effect of inorganic salt on degradation were also studied. The results indicated that the oxidative degradation of the azo dyes in water could be catalyzed effectively by Fe-AO-PAN in dark, and reactive dyes showed higher initial degradation rate constants than acid dyes at the same conditions. Besides,there exists a linear relationship between M and CFe-pAN and D and k within initial reaction 50 min in dark, and increasing quantitatively M and CFe-pAN could accelerate the dye degradation and obtain the same degradation effect as that under irradiation.%利用偕胺肟改性聚丙烯腈(PAN)纤维和三氯化铁的配位反应制备改性PAN纤维铁配合物(Fe-AO-PAN),然后将其作为非均相Fenton反应催化剂应用于不同结构偶氮染料的降解反应中,重点考察Fe-AO-PAN的添加量(M)和铁离子含量(C)与暗态时染料的脱色率(D)和初始反应速率常数(k)之间的关系.此外还研究了暗态时偶氮染料的降解反应过程以及无机盐的影响.结果表明:Fe-AO-PAN暗态时能够催化偶氮染料的降解,并且使活性染料的k值明显高于酸性染料;暗态时Fe-AO-PAN的M和C与染料降解反应50 rain时的D和k值之间存在着线性关系,可通过定量增加Fe-AO-PAN的肘和C来促进暗态时染料的降解反应,达到其在辐射光时的降解效果.

  14. Enhanced degradation of azo dye in wastewater by pulsed discharge plasma coupled with MWCNTs-TiO2/γ-Al2O3 composite photocatalyst.

    Science.gov (United States)

    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

  15. A dinuclear ruthenium(II) complex as turn-on luminescent probe for hypochlorous acid and its application for in vivo imaging

    Science.gov (United States)

    Liu, Zonglun; Gao, Kuo; Wang, Beng; Yan, Hui; Xing, Panfei; Zhong, Chongmin; Xu, Yongqian; Li, Hongjuan; Chen, Jianxin; Wang, Wei; Sun, Shiguo

    2016-06-01

    A dinuclear ruthenium(II) complex Ruazo was designed and synthesized, in which oxidative cyclization of the azo and o-amino group was employed for the detection of hypochlorous acid (HClO) in aqueous solution. The non-emissive Ruazo formed highly luminescent triazole-ruthenium(II) complex in presence of HClO and successfully imaged HClO in living cell and living mouse.

  16. A dinuclear ruthenium(II) complex as turn-on luminescent probe for hypochlorous acid and its application for in vivo imaging

    Science.gov (United States)

    Liu, Zonglun; Gao, Kuo; Wang, Beng; Yan, Hui; Xing, Panfei; Zhong, Chongmin; Xu, Yongqian; Li, Hongjuan; Chen, Jianxin; Wang, Wei; Sun, Shiguo

    2016-01-01

    A dinuclear ruthenium(II) complex Ruazo was designed and synthesized, in which oxidative cyclization of the azo and o-amino group was employed for the detection of hypochlorous acid (HClO) in aqueous solution. The non-emissive Ruazo formed highly luminescent triazole-ruthenium(II) complex in presence of HClO and successfully imaged HClO in living cell and living mouse. PMID:27356618

  17. Solid phase extraction using silica gel modified with azo-dyes derivative for preconcentration and separation of Th(IV) ions from aqueous solutions

    International Nuclear Information System (INIS)

    Azo-dyes derivative (HL) sorbent was synthesized according to the literature to be used in the adsorption and preconcentration of Th(IV) ions from aqueous solution and it was exposed to immobilization, and new solid support material was obtained. For this purpose, azo-dyes derivative (HL) was chemically bonded to silica gel surface immobilized 3-chloropropyl trimethoxysilane, then analyzed by FTIR, BET, SEM and elemental analysis. The influence of the solution pH, initial Th(IV) concentration, amount of sorbent, contact time, temperature and foreign ion effect was investigated. The maximum Th(IV) uptake capacity was found to be 24.85 ± 0.2 mg/g. (author)

  18. Synthesized TiO2/ZSM-5 composites used for the photocatalytic degradation of azo dye: Intermediates, reaction pathway, mechanism and bio-toxicity

    Science.gov (United States)

    Zhou, Kefu; Hu, Xin-Yan; Chen, Bor-Yann; Hsueh, Chung-Chuan; Zhang, Qian; Wang, Jiajie; Lin, Yu-Jung; Chang, Chang-Tang

    2016-10-01

    In this study, a one-step solid dispersion method was used to synthesize titanium dioxide (TiO2)/Zeolite Socony Mobil-5 (ZSM-5) composites with substantially reduced time and energy consumption. A degradation efficiency of more than 95% was achieved within 10 min using 50% PTZ (synthesized TiO2/ZSM-5 composites with TiO2 contents of 50 wt% loaded on ZSM-5) at pH 7 and 25 °C. The possible degradation pathway of azo-dye Reactive Black 5 (RB5) was investigated using gas chromatography-mass spectrometry and ion chromatography (IC). The bonds between the N atoms and naphthalene groups are likely attacked first and cleaved by hydroxyl radicals, ultimately resulting in the decolorization and mineralization of the azo dye. A comparative assessment of the characteristics of abiotic and biotic dye decolorization was completed. In addition, the toxicity effects of the degradation intermediates of azo-dye RB5 on cellular respiratory activity were analyzed. The bio-toxicity results showed that the decay rate constants of CO2 production from the azo-dye RB5 samples at different degradation times increased initially and subsequently decreased, indicating that intermediates of higher toxicity could adhere to the catalyst surface and gradually destroyed by further photocatalytic oxidation. Additionally, EDTA (hole scavengers) and t-BuOH (radical scavengers) were used to detect the main active oxidative species in the system. The results showed that the hydroxyl radicals are the main oxidation species in the photocatalytic process.

  19. Azo···phenyl stacking: a persistent self-assembly motif guides the assembly of fluorinated cis-azobenzenes into photo-mechanical needle crystals.

    Science.gov (United States)

    Bushuyev, Oleksandr S; Tomberg, Anna; Vinden, Joanna R; Moitessier, Nicolas; Barrett, Christopher J; Friščić, Tomislav

    2016-02-01

    We describe a novel, persistent motif of molecular assembly in photo-mechanical crystals and cocrystals of fluorinated cis-azobenzenes. The azo···phenyl stacking, preserved upon either chemical substitution or halogen-bonded cocrystallization, guides the assembly of fluorinated cis-azobenzenes into columnar stacks and drives the formation of crystals with needle-like morphologies optimal for photo-mechanical motion. PMID:26691226

  20. Research progress in the microbial degradation of azo dyes%微生物降解偶氮染料的研究进展

    Institute of Scientific and Technical Information of China (English)

    卢婧; 余志晟; 张洪勋

    2013-01-01

    偶氮染料广泛应用于纺织印染、造纸印刷等行业,产生的染料废水严重污染环境.近年来,利用微生物(细菌、真菌、藻类)对偶氮染料进行脱色降解的研究报道很多.介绍了最近几年染料废水脱色降解研究中涉及到的微生物,并探讨了相关微生物对偶氮染料的脱色降解作用及其机理,旨在为运用微生物对偶氮染料废水进行脱色处理和降解研究提供参考和依据.%Azo dyes are widely used in textile dying,paper printing and other industries.The release of dye wastewater causes serious environmental pollution.In recent years,there has been an intensive research on microbial decolorization of dye wastewater,including bacteria,fungi,algae,etc.The function and mechanism of microbial decolorization and degradation of azo dyes based on the newest progress in the decolorization using microorganisms are discussed,so as to provide some reference and bases for the studies on microbial decolorization and degradation of azo dyes wastewater.

  1. Influence of the composition of in-vitro azo-reducing systems on the degradation kinetics of the model compound amaranth.

    Science.gov (United States)

    Maris, B; Verheyden, L; Samyn, C; Augustijns, P; Kinget, R; Van den Mooter, G

    2002-02-01

    The purpose of this study was to investigate the influence of the composition of in-vitro azo-reducing systems on the degradation kinetics of the model compound amaranth. The degradation kinetics of amaranth were determined under anaerobic conditions both in rat caecal content (ex-vivo) and in a variety of in-vitro degradation media derived from rat caecal content. It was observed that the reducing activity was highly dependent on the preparation method and composition of the degradation medium. In pure rat caecal content, the degradation of amaranth was apparent first order (k = 0.044 +/- 0.002 min(-1)), while dilution of the rat caecal content resulted in an apparent zero-order degradation. Both apparent zero- and first-order degradations were also observed in media made up of diluted rat caecal content to which cofactors such as NADP, D-glucose-6-phosphate, glucose-6-phosphate dehydrogenase and Bz were added. This study demonstrates that in-vitro azo-reducing kinetics are dependent on the composition and mode of preparation of the in-vitro media used. This has to be taken into account when evaluating the degradability of azo-aromatic drug delivery systems in-vitro.

  2. Assessment of the effect of azo dye RP2B on the growth of a nitrogen fixing cyanobacterium--Anabaena sp.

    Science.gov (United States)

    Hu, T L; Wu, S C

    2001-03-01

    Certain nitrogen fixing cyanobacteria are diazotrophic, which profoundly impacts the aquatic ecosystem chemically and biologically. Although certain types are banned due to their carcinogenicity, azo dyes are commonly used in the dyeing or textile industry. This work investigates the effect of azo dye on the growth of cyanobacteria. Anabaena sp. isolated from the Da Jia Brook is an odor producing, nitrogen fixing cyanobacterium. The growth rates of Anabaena sp. in the media with or without nitrogen source were 3.56 x 10(-2) mg/ml day and 2.44 x 10(-2) mg/ml day, respectively. Anabaena sp. could not use azo dye RP2B as the nitrogen source. Experimental results indicated that the growth of Anabaena sp. was inhibited in the medium containing RP2B. The degree of inhibition increased from 50% to 81% with an increasing concentration of RP2B (0-50 mg/l). The IC-50 (inhibitory concentration) of RP2B on the growth of Anabaena sp. was 5 mg/l (as based on dry weight) or 7 mg/l (as measured by chlorophyll a).

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

    Science.gov (United States)

    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

  4. Novel zinc(II)phthalocyanines bearing azo-containing schiff base: Determination of pKa values, absorption, emission, enzyme inhibition and photochemical properties

    Science.gov (United States)

    Kantar, Cihan; Mavi, Vildan; Baltaş, Nimet; İslamoğlu, Fatih; Şaşmaz, Selami

    2016-10-01

    Azo-containing schiff bases are well known and there are many studies about their various properties in literature. However, phthalocyanines bearing azo-containing schiff bases, their spectral, analytical and biological properties are unknown. Therefore, new zinc (II) phthalocyanines bearing azo-containing schiff base were synthesized and investigated to determine pKa values, absorption, emission, enzyme inhibition and photochemical properties. Emission spectra were reported and large Stokes shift values were determined for all compounds, indicating that all molecules exhibit excited state intramolecular proton transfer. These phthalocyanines were the first examples of phthalocyanine showing excited state intramolecular proton transfer. Singlet oxygen quantum yields of zinc (II) phthalocyanines were determined. pKa values and indicator properties of all compounds were investigated by potentiometry. All compounds were assayed for inhibitory activity against bovine milk xanthine oxidase and acetylcholinesterase enzyme in vitro. Compound 2 showed the high inhibitory effect against xanthine oxidase (IC50 = 0.24 ± 0.01 μM). However, phthalocyanine compounds did not show enzyme inhibitor behavior.

  5. Mutagenic and carcinogenic potential of a textile azo dye processing plant effluent that impacts a drinking water source.

    Science.gov (United States)

    Alves de Lima, Rodrigo Otávio; Bazo, Ana Paula; Salvadori, Daisy Maria Fávero; Rech, Célia Maria; de Palma Oliveira, Danielle; de Aragão Umbuzeiro, Gisela

    2007-01-10

    Recently a textile azo dye processing plant effluent was identified as one of the sources of mutagenic activity detected in the Cristais River, a drinking water source in Brazil [G.A. Umbuzeiro, D.A. Roubicek, C.M. Rech, M.I.Z. Sato, L.D. Claxton, Investigating the sources of the mutagenic activity found in a river using the Salmonella assay and different water extraction procedures, Chemosphere 54 (2004) 1589-1597]. Besides presenting high mutagenic activity in the Salmonella/microsome assay, the mutagenic nitro-aminoazobenzenes dyes CI Disperse Blue 373, CI Disperse Violet 93, and CI Disperse Orange 37 [G.A. Umbuzeiro, H.S. Freeman, S.H. Warren, D.P. Oliveira, Y. Terao, T. Watanabe, L.D. Claxton, The contribution of azo dyes in the mutagenic activity of the Cristais river, Chemosphere 60 (2005) 55-64] as well as benzidine, a known carcinogenic compound [T.M. Mazzo, A.A. Saczk, G.A. Umbuzeiro, M.V.B. Zanoni, Analysis of aromatic amines in surface waters receiving wastewater from textile industry by liquid chromatographic with eletrochemical detection, Anal. Lett., in press] were found in this effluent. After approximately 6 km from the discharge of this effluent, a drinking water treatment plant treats and distributes the water to a population of approximate 60,000. As shown previously, the mutagens in the DWTP intake water are not completely removed by the treatment. The water used for human consumption presented mutagenic activity related to nitro-aromatics and aromatic amines compounds probably derived from the cited textile processing plant effluent discharge [G.A. Umbuzeiro, D.A. Roubicek, C.M. Rech, M.I.Z. Sato, L.D. Claxton, Investigating the sources of the mutagenic activity found in a river using the Salmonella assay and different water extraction procedures, Chemosphere 54 (2004) 1589-1597; G.A. Umbuzeiro, H.S. Freeman, S.H. Warren, D.P. Oliveira, Y. Terao, T. Watanabe, L.D. Claxton, The contribution of azo dyes in the mutagenic activity of the Cristais

  6. Adsorption of aromatic compounds from the biodegradation of azo dyes on activated carbon

    Science.gov (United States)

    Faria, P. C. C.; Órfão, J. J. M.; Figueiredo, J. L.; Pereira, M. F. R.

    2008-03-01

    The adsorption of three selected aromatic compounds (aniline, sulfanilic acid and benzenesulfonic acid) on activated carbons with different surface chemical properties was investigated at different solution pH. A fairly basic commercial activated carbon was modified by means of chemical treatment with HNO 3, yielding an acid activated carbon. The textural properties of this sample were not significantly changed after the oxidation treatment. Equilibrium isotherms of the selected compounds on the mentioned samples were obtained and the results were discussed in relation to their surface chemistry. The influence of electrostatic and dispersive interactions involved in the uptake of the compounds studied was evaluated. The Freundlich model was used to fit the experimental data. Higher uptakes are attained when the compounds are present in their molecular form. In general, adsorption was disfavoured by the introduction of oxygen-containing groups on the surface of the activated carbon.

  7. The Effect of Thickness on Electrical and Optical Properties of AZO Films%薄膜厚度对AZO薄膜光电性能的影响

    Institute of Scientific and Technical Information of China (English)

    范丽琴

    2015-01-01

    通过射频磁控溅射技术在玻璃衬底上制备AZO薄膜,研究膜层厚度对AZO薄膜光电特性的影响。发现随着膜层厚度的增加,AZO薄膜在可见光区的平均透射率略微增长,而方块电阻和电阻率却显著递减,导致其品质因子随厚度增加而增加。在薄膜厚度为395 nm时,获得电阻率为3.24×10-3Ωcm,可见光区平均透射率为85.52%,品质因子为25.52×10-4Ω-1的光电性能良好的透明导电薄膜。本文制备的薄膜具有较优的透明导电性,可以广泛应用于太阳能电池、平板显示器等光电领域。%Transparent conducting Al-doped zinc oxide (AZO) iflms were deposited on BK-7 glass substrates by radio frequency magnetron sputtering. The effect of thickness on electrical and optical properties of AZO iflms was studied. Results indicated that the ifgure of merit decreased as the average transmittance in visible spectral region for all samples slowly increased and the resistivity of the film sharply decreased when the thickness of AZO iflms increased. The highest ifgure of merit of 25.52×10-4 Ω-1, with the lowest sheet resistance of 82 Ω/sq and the average transmittance of 85.52% was obtained when the thickness of AZO iflms was 395 nm. As-prepared AZO iflms with good transparent conductive properties can be widely used in various ifelds such as solar cells and lfat panel displays.

  8. Synthesis, Crystal Structure and Properties of a Novel Tetranuclear Nickel(II) Complex with Azo-enolic-2-hydroxybenzamide%Synthesis, Crystal Structure and Properties of a Novel Tetranuclear Nickel(II) Complex with Azo-enolic-2-hydroxybenzamide

    Institute of Scientific and Technical Information of China (English)

    CHEN Shi-Liang; LIU Zheng; HAN Guo-Cheng

    2012-01-01

    A novel tetranuclear nickel(II) complex [NiaL2(DMF)2(H20)2'2DMF] (1, H4L = azo-enolic-2-hydroxybenzamide, DMF = N,N-dimethyl-formamide) has been synthesized and characterized by elemental analysis, UV, IR and X-ray single-crystal diffraction characterization. Complex 1 crystallizes in the monoclinic system, space group P21/n with a = 8.8944(11), b = 14.4583(18), c = 18.097(2) A, fl = 90.00(2), Z = 2 , V = 2327.2(5) A3, C40H48NI2Ni4OI4, Mr = 1155.66, Dc= 1.649 g/cm3,μ=1.672 mm1, F(000) = 1192, R = 0.0392 and wR = 0.0958. The local coordination environment around the nickel ions exist a distorted octahedral and quadrangle geometry in the molecular structure. Complex 1 exhibits strong photoluminescent emission in the ultraviolet region at room temperature. The electrochemical studies reveal that redox of Nia+/Ni2+ in the complex is a quasi-reversible process.

  9. The Kinetic Aspects of the Interaction of Nitrite Ions with Sulfanilic Acid and 1-Naphthylamine in Aqueous and Micellar Media

    Science.gov (United States)

    Korneeva, O. I.; Chernova, R. K.; Doronin, S. Yu.

    2008-04-01

    The kinetics of the reaction of nitrite ions with sulfanilic acid and 1-naphthylamine in aqueous and micellar (sodium dodecyl sulfate) media was studied step-by-step. The diazotization of sulfanilic acid with the nitrite ion was found to occur virtually instantaneously. Anionic surfactant micelles did not influence the rate of this reaction. The calculated effective rate constants and activation energies of the azo coupling reaction between synthesized sulfophenyldiazonium and 1-naphthylamine showed that the passage from water into the micellar medium decelerated the reaction. It was found that sodium dodecyl sulfate micelles played the role of a reagent separator.

  10. The role of Aster amellus Linn. in the degradation of a sulfonated azo dye Remazol Red: a phytoremediation strategy.

    Science.gov (United States)

    Khandare, Rahul V; Kabra, Akhil N; Tamboli, Dhawal P; Govindwar, Sanjay P

    2011-02-01

    Phytoremediation is a novel and promising approach for the treatment of pollutants. This study did explore the potential of Aster amellus Linn. to decolorize a sulfonated azo dye Remazol Red (RR), a mixture of dyes and a textile effluent. Induction in the activities of lignin peroxidase, tyrosinase, veratryl alcohol oxidase and riboflavin reductase was observed during RR decolorization, suggesting their involvement in the metabolism of RR. UV-Visible absorption spectrum, HPLC and FTIR analysis confirmed the degradation of RR. Four metabolites after the degradation of the dye were identified as 2-[(3-diazenylphenyl) sulfonyl] ethanesulfonate, 4-amino-5-hydroxynaphthalene-2,7-disulfonate, naphthalene-2-sulfonate and 3-(1,3,5-triazin-2-ylamino)benzenesulfonate by using GC/MS. Textile effluent and mixture of dyes showed 47% and 62% decrease respectively in American Dye Manufacturers Institute value. BOD of textile effluent and mixture of dyes were reduced by 75% and 48% respectively, COD of industrial effluent and mixture of dyes was reduced by 60% and 75% and TOC was reduced by 54% and 69% respectively after the treatment by A. amellus for 60 h; this indicated that the plant can be used for cleaning textile effluents. Toxicity study revealed the phytotransformation of RR into non-toxic products.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Sidra Ilyas

    2013-01-01

    Full Text Available In the present investigation the fungi, Aspergillus niger and Nigrospora sp. were employed for decolorization of Synazol red HF-6BN. Decolorization study showed that Aspergillus niger and Nigrospora sp. were able to decolorize 88% and 96% Synazol red 6BN, respectively, in 24 days. It was also studied that 86% and 90% Synazol 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[degree sign]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 Synazol 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.

  14. Enhanced decolorization and biodegradation of textile azo dye Scarlet R by using developed microbial consortium-GR.

    Science.gov (United States)

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

    2009-05-01

    A developed consortium-GR, consisting of Proteus vulgaris NCIM-2027 (PV) and Micrococcus glutamicus NCIM-2168 (MG), completely decolorized an azo dye Scarlet R under static anoxic condition with an average decolorization rate of 16,666 microg h(-1); which is much faster than that of the pure cultures (PV, 3571 microg h(-1); MG, 2500 microg h(-1)). Consortium-GR gave best decolorization performance with nearly complete mineralization of Scarlet R (over 90% TOC and COD reduction) within 3h, much shorter relative to the individual strains. Induction in the riboflavin reductase and NADH-DCIP reductase was observed in the consortium, suggesting the involvement of these enzymes during the fast decolorization process. The FTIR and GC-MS analysis showed that 1,4-benzenediamine was formed during decolorization/degradation of Scarlet R by consortium-GR. Phytotoxicity studies revealed no toxicity of the biodegraded products of Scarlet R by consortium-GR. In addition, consortium-GR applied for mixture of industrial dyes showed 88% decolorization under static condition with significant reduction in TOC (62%) and COD (68%) within 72 h, suggesting potential application of this microbial consortium in bioremediation of dye-containing wastewater.

  15. Carcinogenicities of 3-methoxy-4-aminoazobenzene, N-hydroxy-3-methoxy-4-aminoazobenzene and related azo dyes in the mouse.

    Science.gov (United States)

    Watanabe, H K; Hashimoto, Y; Abe, I; Sato, H

    1982-02-01

    The carcinogenicities of 2-methoxy-4-aminoazobenzene and 3-methoxy-4-aminoazobenzene (2-MeO-AAB and 3-MeO-AAB) and their N-hydroxy derivatives (N-OH-2-MeO-AAB and N-OH-3-MeO-AAB) were tested in (C3H X C57BL/6) F1 mice. Topical sc injections, twice weekly for 8 weeks, of 4 or 8 mumol of N-OH-3-MeO-AAB dissolved in 0.1 ml of olive oil containing 10% dimethyl sulfoxide induced fibrosarcomas at the site of application. Similar treatment with 3-MeO-AAB or 2-MeO-AAB as well as N-OH-2-MeO-AAB failed to induce sarcomas. Oral administration of 0.09% 3-MeO-AAB in the diet for 13 months induced hepatic tumors in female mice but not in males. 2-MeO-AAB did not induce tumors in male or female mice. The relationship between carcinogenicity, mutagenicity, the ability to induce unscheduled DNA synthesis, and the metabolism of these azo dyes is discussed.

  16. Adsorption of heavy metal ions and azo dyes by crosslinked nanochelating resins based on poly(methylmethacrylate-co-maleic anhydride

    Directory of Open Access Journals (Sweden)

    M. Ghaemy

    2014-03-01

    Full Text Available Chelating resins are suitable materials for the removal of heavy metals in water treatments. A copolymer, Poly(MMA-co-MA, was synthesized by radical polymerization of maleic anhydride (MA and methyl methacrylate (MMA, characterized and transformed into multifunctional nanochelating resin beads (80–150 nm via hydrolysis, grafting and crosslink reactions. The resin beads were characterized by swelling studies, field emission scanning electron microscopy (FESEM and Fourier transform infrared spectroscopy (FTIR. The main purpose of this work was to determine the adsorption capacity of the prepared resins (swelling ratio ~55% towards metal ions such as Hg2+, Cd2+, Cu2+ from water at three different pH values (3, 6 and 9. Variations in pH and types of metal ions have not significantly affected the chelation capacity of these resins. The maximum chelation capacity of one of the prepared resin beads (Co-g-AP3 for Hg2+ was 63, 85.8 and 71.14 mg/g at pH 3, 6 and 9, respectively. Approximately 96% of the metal ions could be desorbed from the resin. Adsorption capacity of these resins towards three commercial synthetic azo dyes was also investigated. The maximum adsorption of dye AY42 was 91% for the resin Co-g-AP3 at room temperature. This insures the applicability of the synthesized resins for industrial applications.

  17. Decoloration of Azo Dye Sunset Yellow by a Coaxial Insulated-Rod-to-Cylinder Underwater Streamer Discharge System

    Institute of Scientific and Technical Information of China (English)

    温小琼; 王明; 丁振峰; 刘贵师

    2012-01-01

    A coaxial insulated-rod-to-cylinder underwater streamer discharge system capable of injecting plasma into a large volume of water was developed and employed to decolorize azo dye sunset yellow. The rod type anode was covered by an insulator tube with a wall thickness of 0.4 mm. A series of slits with a width of 20 μm to 80 μm and a length of about 4 mm were cut onto the wall of the insulator tube. Depending on the solution conductivity, a cylindrical discharge region with a length of 60 mm and a wall thickness of 5 mm to 11 mm forms in the reactor. The influence of the solution conductivity, pH and pulse frequency on the decoloration of sunset yellow was investigated. The results show that the solution conductivity has little effect, while the solution pH and the pulse frequency have significant influence on the decoloration rate of sunset yellow. The decoloration rate of sunset yellow is increased with the increase in pulse frequency. A lower pH in solution promotes the decoloration of sunset yellow while a higher pH inhibits it.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Xuekun; Li, Ran, E-mail: liran@buaa.edu.cn; Zong, Jingzhen; Zhang, Ying; Li, Haifei; Zhang, Tao, E-mail: zhangtao@buaa.edu.cn

    2014-06-01

    A controllable uniform nanoporous copper (NPC) layer was synthesized on the surface of the ball-milled powder of Mg{sub 65}Cu{sub 25}Y{sub 10} 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.

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

    Science.gov (United States)

    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.

  2. The Effect of High Concentration Guanidinium Azo-Tetrazolate on Thrust and Specific Impulse of a Hybrid Rocket

    Science.gov (United States)

    Tilahun, Dagim; Wright, A.; Foley, P.; Reason, M.

    2001-04-01

    A thrust and impulse study of the hybrid rocket fuel additive, Guanidinium Azo-Tetrazolate (GAT), was conducted at the University of Arkansas at Little Rock (UALR) Hybrid Rocket Facility. GAT is an organic salt with a high percentage of nitrogen. GAT was mixed with the standard hybrid rocket fuel, Hydroxyl-Terminated Polybutadiene (HTPB), in concentrations of 15% and 25%, by mass. The fuel grains with the GAT additive were fired for 4 second runs with oxygen flows of 0.04, 0.06, 0.08, and 0.10 lbm/sec. For each run, average thrust, standard deviation of thrust, total impulse, and specific impulse were measured. Average thrust, standard deviation of thrust, specific impulse and total impulse vs. oxygen flow were plotted. Similar data was collected for plain HTPB/PAPI fuels for comparison. GAT is found to increase the thrust output when added to the standard hybrid rocket fuel, HTPB. 25% GAT fuel produced approximately the same thrust as the 15% GAT fuel. Specific impulse was slightly lower with both 15% and 25% GAT fuels. Standard Deviation of thrust was used as a crude measure of amplitude of oscillations during combustion. GAT-added fuels showed a limited decrease in thrust oscillation amplitude.

  3. A Thrust and Impulse Study of Guanidinium Azo-Tetrazolate as an Additive for Hybrid Rocket Fuel

    Science.gov (United States)

    Patton, J.; Wright, A. M.; Dunn, L.; Alford, B.

    2000-03-01

    A thrust and impulse study of the hybrid rocket fuel additive Guanidinium Azo-Tetrazolate (GAT) was conducted at the University of Arkansas at Little Rock (UALR) Hybrid Rocket Facility. GAT is an organic salt with a high percentage of nitrogen. GAT was mixed with the standard hybrid rocket fuel, Hydroxyl-Terminated Polybutadiene (HTPB), in the concentration of 15%, by mass. The fuel grains with the GAT additive were fired for 4 second runs with the oxygen flows of 0.05, 0.07, 0.09, and 0.12 lbm/sec. For each run average thrust, total impulse, and specific impulse were measured. Average thrust, specific impulse, and total impulse vs. oxygen flow were plotted. Similar data was collected for plain HTPB/PAPI fuels for comparison. GAT was found to increase the thrust output when it was added to the standard hybrid rocket fuel, HTPB. GAT also increased the total impulse during the run. The thrust and total impulse were increased at all flows, but especially at the lower oxygen flow rates. Specific impulse only increased during the lower oxygen flow runs, and decreased slightly for the higher oxygen flow runs.

  4. Heterogeneous electro-Fenton oxidation of azo dye methyl orange catalyzed by magnetic Fe3O4 nanoparticles.

    Science.gov (United States)

    Jiang, Hao; Sun, Yabing; Feng, Jingwei; Wang, Jian

    2016-01-01

    Azo dye methyl orange (MO) degradation by heterogeneous electro-Fenton (EF) with a magnetic nano-Fe3O4 catalyst was investigated. In this study, Fe3O4 was synthesized by a coprecipitation method and characterized by X-ray diffraction and scanning electron microscopy. The influences of the main operating parameters such as current density, pH, catalyst dosage and aeration rate were studied. The results revealed that higher current density, catalyst dosage and aeration rate facilitated the degradation of MO, whereas the degradation efficiency of MO was decreased with an increase in the initial pH. After 90 min EF process, the volume of 500 mL, the initial concentration of 50 mg L(-1) MO solution could be degraded by 86.6% with the addition of 1 g L(-1) Fe3O4 under the current density of 10 mA cm(-2) and pH 3, compared with 69.5% for the electrolytic process alone. Meanwhile, a total organic carbon removal of 32% was obtained, up to 35.5 mg L(-1) accumulated H2O2 and less than 3.5 mg L(-1) Fe leaching were detected. Moreover, based on the results of natural bond orbital (at B3LYP/6-311G (d, p)) and liquid chromatograph-triple quadrupole mass spectrometer analysis, nine intermediates were identified and the proposed degradation pathways were investigated. PMID:27642831

  5. Adsorption of Azo-Dye Orange II from Aqueous Solutions Using a Metal-Organic Framework Material: Iron- Benzenetricarboxylate

    Directory of Open Access Journals (Sweden)

    Elizabeth Rojas García

    2014-12-01

    Full Text Available A Metal-Organic Framework (MOF, iron-benzenetricarboxylate (Fe(BTC, has been studied for the adsorptive removal of azo-dye Orange II from aqueous solutions, where the effect of various parameters was tested and isotherm and kinetic models were suggested. The adsorption capacities of Fe(BTC were much higher than those of an activated carbon. The experimental data can be best described by the Langmuir isotherm model (R2 > 0.997 and revealed the ability of Fe(BTC to adsorb 435 mg of Orange II per gram of adsorbent at the optimal conditions. The kinetics of Orange II adsorption followed a pseudo-second-order kinetic model, indicating the coexistence of physisorption and chemisorption, with intra-particle diffusion being the rate controlling step. The thermodynamic study revealed that the adsorption of Orange II was feasible, spontaneous and exothermic process (−25.53 kJ·mol−1. The high recovery of the dye showed that Fe(BTC can be employed as an effective and reusable adsorbent for the removal of Orange II from aqueous solutions and showed the economic interest of this adsorbent material for environmental purposes.

  6. Decolorization and degradation of Disperse Blue 79 and Acid Orange 10, by Bacillus fusiformis KMK5 isolated from the textile dye contaminated soil.

    Science.gov (United States)

    Kolekar, Yogesh M; Pawar, Shrikant P; Gawai, Kachru R; Lokhande, Pradeep D; Shouche, Yogesh S; Kodam, Kisan M

    2008-12-01

    The release of azo dyes into the environment is a concern due to coloration of natural waters and due to the toxicity, mutagenicity and carcinogenicity of the dyes and their biotransformation products. The dye degrading bacterial strain KMK 5 was isolated from the textile dyes contaminated soil of Ichalkaranji, Maharashtra, India. It was identified as Bacillus fusiformis based on the biochemical and morphological characterization as well as 16S rDNA sequencing. KMK 5 could tolerate and degrade azo dyes, Disperse Blue 79 (DB79) and Acid Orange 10 (AO10) under anoxic conditions. Complete mineralization of DB79 and AO10 at the concentration of 1.5g/l was observed within 48h. This degradation potential increased the applicability of this microorganism for the dye removal.

  7. Metal-Based Antibacterial and Antifungal Agents: Synthesis, Characterization, and In Vitro Biological Evaluation of Co(II), Cu(II), Ni(II), and Zn(II) Complexes With Amino Acid-Derived Compounds

    OpenAIRE

    Zahid H. Chohan; Arif, M.; Akhtar, Muhammad A.; Supuran, Claudiu T.

    2006-01-01

    A series of antibacterial and antifungal amino acid-derived compounds and their cobalt(II), copper(II), nickel(II), and zinc(II) metal complexes have been synthesized and characterized by their elemental analyses, molar conductances, magnetic moments, and IR, and electronic spectral measurements. Ligands (L1)−(L5) were derived by condensation of β-diketones with glycine, phenylalanine, valine, and histidine and act as bidentate towards metal ions (cobalt, copper, nickel, and zinc) via the azo...

  8. Effect of acid orange 7 on nitrification process

    Energy Technology Data Exchange (ETDEWEB)

    He, Yongjie (ManTech Environmental Tech., Inc., Dayton, OH (United States)); Bishop, P.L. (Univ. of Cincinnati, OH (United States). Dept. of Civil and Environmental Engineering)

    The effect of Acid Orange 7 (AO7), an azo dye commonly used in textile, pharmaceutical, food, and cosmetic industries, on the nitrification process is studied using completely stirred tank reactors (CSTR) and batch treatment systems. Azo dyes are of concern because many of the dyes or their metabolic intermediates are carcinogenic. AO7 biodegradation is found to be essentially complete when solids retention times (SRT) are maintained above 7.5 days, but systems with lower SRTs are unstable. It is shown that AO7 inhibits all stages of the nitrification process. Nitrite oxidizers are found to be more sensitive to AO7 than ammonium oxidizers. The results of kinetic studies indicate that the inhibition of ammonium oxidation is typified by noncompetitive inhibition; the presence of AO7 decreases the maximum substrate utilization rate and very slightly increases K[sub s], the half-saturation constant. AO7 is found to be less toxic to nitrification than some metal and phenolic compounds, but more toxic than some common organic compounds such as formalin, methanol, or acetone.

  9. Synthesis and Characterization of Novel Electroactive Polyamide with Azo Groups in the Backbone%主链含偶氮电活性聚酰胺材料的合成与性质

    Institute of Scientific and Technical Information of China (English)

    何立兵; 边秀杰; 晁单明; 李智亮; 李野; 王策; 刘新才

    2011-01-01

    An alternating copolymer, electroactive azo polyamide was prepared by oxidative coupling polymerization and its characteristics were systematically studied. The polyamide showed both electroactivity and photoactivity. A large enhancement in the dielectric constant of the polymer was achieved utilizing the method of doping the conjugated oligoaniline segments with hydrochloric acid.%聚苯胺因其特殊的光学、电学和磁学性质成为最具应用潜力的导电高分子材料[1~4].然而结构上的缺陷和不溶不熔的现象限制了聚苯胺的深入研究和应用[5,6].苯胺齐聚物具有明确的分子结构和良好的溶解性,而且光谱和电学性质与聚苯胺十分相似[7,8],但其缺乏良好的机械性能和环境稳定性,因此制备综合性能优异的含有苯胺齐聚物链段的聚合物备受关注[9],本文从分子设计入手,采用氧化偶联聚合方法,将苯胺齐聚物链段和偶氮苯基团同时引入到具有良好综合性能的聚酰胺主链中,制备出一种兼具光活性和电活性的多功能聚合物材料.

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

    Science.gov (United States)

    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

  11. 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.

    Science.gov (United States)

    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.

  12. Impedance spectroscopic investigation of the effect of thin azo-calix[4]arene film type on the cation sensitivity of the gold electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Mlika, R., E-mail: mlikarym@yahoo.fr [Laboratoire de Physique et Chimie des Interfaces (LPCI), Faculte des Sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia); Rouis, A. [Laboratoire de Physique et Chimie des Interfaces (LPCI), Faculte des Sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia); Bonnamour, I. [Universite de Lyon, Institut de Chimie et Biochimie Moleculaires et Supramoleculaires, Universite Claude Bernar, Lyon 1, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne (France); Ouada, H. Ben [Laboratoire de Physique et Chimie des Interfaces (LPCI), Faculte des Sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia)

    2011-10-10

    In this work, we report the impedance spectroscopic investigation of the effect of the thin film type on the selectivity of gold/azo-calix[4]arene electrodes. For this purpose, two C1 and C3 azo-calix[4]arene derivative molecules, used as thin films, are deposited by spin-coating process on the gold surface. These thin films were first studied using contact angle measurements. This revealed a less hydrophobic character for C3 thin film, which has been attributed to the presence of hydroxyl groups at the lower rim. The sensitivity study, by Electrochemical Impedance Spectroscopy (EIS), towards Cu{sup 2+} and Eu{sup 3+} cations, has showed that the C3 thin film is more sensitive and selective towards Eu{sup 3+} than C1. This best performance is due to the presence of two ester groups acting as clips and leading to more complexation stability. The EIS results were modeled by an appropriate equivalent circuit for the aim of elucidating electrical properties of thin films. This modeling has exposed that C3 thin film presents lower ionic conductivity and limited diffusion phenomenon at the interface. Highlights: {yields} C1 and C3 azo-calix[4]arenes thin films are deposited on the gold surface. {yields} The lower hydrophobicity for C3 was attributed to the presence of hydroxyl groups. {yields} The C3 thin film is more sensitive and selective towards Eu{sup 3+} than C1 one. {yields} This best performance is due to the presence of two ester groups acting as clips.

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

    Science.gov (United States)

    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

  14. Iron promotion of the TiO{sub 2} photosensitization process towards the photocatalytic oxidation of azo dyes under solar-simulated light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Camilo A.; Centeno, Aristobulo [Centro de Investigaciones en Catalisis (CICAT), Escuela de Ingenieria Quimica, Universidad Industrial de Santander (UIS), A.A. 678, Bucaramanga (Colombia); Giraldo, Sonia A., E-mail: sgiraldo@uis.edu.co [Centro de Investigaciones en Catalisis (CICAT), Escuela de Ingenieria Quimica, Universidad Industrial de Santander (UIS), A.A. 678, Bucaramanga (Colombia)

    2011-10-03

    Highlights: {yields} Azo dye photooxidation occurs under strict combination of ultraviolet and visible irradiation of Fe-TiO{sub 2}. {yields} Fe{sup 3+} enhances the TiO{sub 2} photooxidation of azo dyes while decreases that of phenol. {yields} UV irradiation leads to a decrease in photooxidation activity of Fe-TiO{sub 2} photocatalysts. - Abstract: The photocatalytic oxidation of the azo dye Orange-II (Or-II) using Fe loaded TiO{sub 2} (Fe-TiO{sub 2}) was studied under ultraviolet (UV), visible (vis) and simultaneous UV-vis irradiations using a solar light simulator. Photocatalysts were characterized by means of XRD, SEM-EDX, FTIR and DRS. Fe{sup 3+} species, identified in XPS analyses, were responsible of the increased absorption of visible light. Moreover, DRS analyses showed a decrease in the bandgap due to Fe{sup 3+} loading. Photocatalystic tests proved that Fe modification enhanced the TiO{sub 2} photocatalytic activity towards Or-II photodegradation under simultaneous UV-vis irradiation. Even so, the performance of the Fe-TiO{sub 2} samples towards the photodegradation of phenol, under UV irradiation, was lower than TiO{sub 2} suggesting the recombination of the UV photogenerated electron-hole pair. Therefore, results evidence a Fe{sup 3+} promotion of the electron caption in the photosensitization process of TiO{sub 2} by Or-II acting as a sensitizer. Such process leads to the Or-II photooxidation under UV-vis irradiation by losing energy in electron transferring processes to sensitize TiO{sub 2}, and, the formation of reactive oxygen species promoted by the injected electron to the TiO{sub 2} conduction band.

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

    Science.gov (United States)

    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

  16. Cr(VI) and azo dye removal using a hollow-fibre membrane system functionalized with a biogenic Pd-magnetite catalyst.

    Science.gov (United States)

    Coker, V S; Garrity, A; Wennekes, W B; Roesink, H D W; Cutting, R S; Lloyd, J R

    2014-01-01

    This study investigates the application of a hybrid system combining hollow-fibre membrane technology with the reductive abilities of magnetic nanoparticles for the remediation of toxic Cr(VI) and the azo dye, Remazol Black B. Nano-scale biogenic magnetite (Fe3O4), formed by microbial reduction of the mineral ferrihydrite, has a high reductive capacity due to the presence of Fe(II) in the mineral structure. The magnetic nanoparticles (approximately 20 nm) can be arrayed with Pd0 nanoparticles (approximately 5 nm) making a catalytically active nanomaterial. Membrane units, with and without nanoparticles, were challenged with either Cr(VI) or azo dye and some were supplemented with sodium formate, as an electron donor for contaminant reduction promoted by the Pd. The combination of Pd-magnetite with formate resulted in the most effective remediation strategy for both contaminants and the lifetime of the membrane unit was also increased, with 55% (19 days) and 70% (23 days) removal of the azo dye and Cr(VI), respectively. Low flow rates of 0.1 ml/min resulted in improved efficiencies due to increased contact time with the membrane/nanoparticle unit, with 70-75% removal of each contaminant. Chemical analyses of the nanoparticles post-exposure to Cr(VI) in the membrane modules indicated Pd to be more oxidized when Cr removal was maximized, and that the Cr was partially reduced to Cr(III) at the surface of the magnetite. These results have demonstrated that hollow-fibre membrane units can be enhanced for the removal of soluble, redox sensitive contaminants by incorporation of a layer of palladized biogenic nanoparticulate magnetite.

  17. Aerobic biodegradation of Azo dye by Bacillus cohnii MTCC 3616; an obligately alkaliphilic bacterium and toxicity evaluation of metabolites by different bioassay systems.

    Science.gov (United States)

    Prasad, A S Arun; Rao, K V Bhaskara

    2013-08-01

    An obligate alkaliphilic bacterium Bacillus cohnii MTCC 3616 aerobically decolorized a textile azo dye Direct Red-22 (5,000 mg l⁻¹) with 95 % efficiency at 37 °C and pH 9 in 4 h under static conditions. The decolorization of Direct Red-22 (DR-22) was possible through a broad pH (7-11), temperature (10-45 °C), salinity (1-7 %), and dye concentration (5-10 g l⁻¹) range. Decolorization of dye was assessed by UV-vis spectrophotometer with reduction of peak intensity at 549 nm (λ(max)). Biodegradation of dye was analyzed by Fourier transform infrared spectroscopy (FTIR) and high-performance liquid chromatography (HPLC). The FTIR spectrum revealed that B. cohnii specifically targeted azo bond (N=N) at 1,614.42 cm⁻¹ to break down Direct Red-22. Formation of metabolites with different retention times in HPLC analysis further confirmed the degradation of dye. The phytotoxicity test with 5,000 mg l⁻¹ of untreated dye showed 80 % germination inhibition in Vigna mungo, 70 % in Sorghum bicolor and 80 % in Vigna radiata. No germination inhibition was noticed in all three plants by DR-22 metabolites at 5,000 mg l⁻¹. Biotoxicity test with Artemia salina proved the lethality of the azo dye at LC₅₀ of 4 and 8 % for degraded metabolites by causing death of its nauplii compared to its less toxic-degraded metabolites. Bioaccumulation of dye was observed in the mid-gut of A. salina. The cytogenotoxicity assay on the meristematic root tip cells of Allium cepa further confirmed the cytotoxic nature of azo dye (DR-22) with decrease in mitotic index (0.5 % at 500 ppm) and increase in aberrant index (4.56 %) over 4-h exposure period. Genotoxic damages (lagging chromosome, metaphase cluster, chromosome bridges, and dye accumulation in cytoplasm) were noticed at different stages of cell cycle. The degraded metabolites had negligible cytotoxic and genotoxic effects.

  18. Azo anion radical complex of rhodium as a molecular memory switching device: isolation, characterization, and evaluation of current-voltage characteristics.

    Science.gov (United States)

    Paul, Nanda D; Rana, Utpal; Goswami, Sreetosh; Mondal, Tapan K; Goswami, Sreebrata

    2012-04-18

    Two rare examples of azo anion diradical complexes of Rh(III) are reported. These complexes showed excellent memory switching properties with a large ON/OFF ratio and are suitable for RAM/ROM applications. Their electronic structures have been elucidated using a host of physical methods, including X-ray crystallography, variable-temperature magnetic susceptibility measurement, cyclic voltammetry, electron paramagnetic resonance spectroscopy, and density functional theory. The results indicate a predominant triplet state description of the systems with two ferromagnetically coupled radicals. PMID:22462473

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

    OpenAIRE

    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 decolori...

  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

    OpenAIRE

    Harshad Lade; Sanjay Govindwar; Diby Paul

    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...