WorldWideScience

Sample records for azo dye acid

  1. Studies on Dyeing Performance of Novel Acid Azo Dyes and Mordent Acid Azo Dyes Based on 2,4-Dihydroxybenzophenone

    Directory of Open Access Journals (Sweden)

    Bharat C. Dixit

    2009-01-01

    Full Text Available Novel acid azo and mordent acid azo dyes have been prepared by the coupling of diazo solution of different aminonaphthol sulphonic acids and aromatic amino acids with 2,4-dihydroxybenzophenone. The resultant dyes were characterized by elemental analysis as well as IR and 1H NMR spectral studies. The UV-visible spectral data have also been discussed in terms of structure property relationship. The dyeing assessments of all the dyes were evaluated on wool and silk textile fibers. The dyeing of chrome pretreated wool and silk have also been monitored. The result shows that better hue was obtained on mordented fiber. Results of bactericidal studies of chrome pretreated fibers revealed that the toxicity of mordented dyes against bacteria is fairly good. Dyeing on wool and silk fibers resulted in yellowish pink to reddish brown colourations having excellent light fastness and washing fastness.

  2. Modification of azo dyes by lactic acid bacteria.

    Science.gov (United States)

    Pérez-Díaz, I M; McFeeters, R F

    2009-08-01

    The ability of Lactobacillus casei and Lactobacillus paracasei to modify the azo dye, tartrazine, was recently documented as the result of the investigation on red coloured spoilage in acidified cucumbers. Fourteen other lactic acid bacteria (LAB) were screened for their capability to modify the food colouring tartrazine and other azo dyes of relevance for the textile industry. Most LAB modified tartrazine under anaerobic conditions, but not under aerobic conditions in modified chemically defined media. Microbial growth was not affected by the presence of the azo dyes in the culture medium. The product of the tartrazine modification by LAB was identified as a molecule 111 daltons larger than its precursor by liquid chromatography-mass spectrometry. This product had a purple colour under aerobic conditions and was colourless under anaerobic conditions. It absorbed light at 361 and 553 nm. LAB are capable of anabolizing azo dyes only under anaerobic conditions. IMPACT AND SIGNIFICANCE OF THE STUDY: Although micro-organisms capable of reducing the azo bond on multiple dyes have been known for decades, this is the first report of anabolism of azo dyes by food related micro-organisms, such as LAB.

  3. 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.

  4. Anaerobic azo dye reduction

    OpenAIRE

    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 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 dye...

  5. 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

  6. Acid-Base Properties of Azo Dyes in Solution Studied Using Spectrophotometry and Colorimetry

    Science.gov (United States)

    Snigur, D. V.; Chebotarev, A. N.; Bevziuk, K. V.

    2018-03-01

    Colorimetry and spectrophotometry with chemometric data processing were used to study the acid-base properties of azo dyes in aqueous solution. The capabilities of both methods were compared. Ionization constants of all the functional groups of the azo compounds studied could be determined relative to the change in the specific color difference depending on the acidity of the medium. The colorimetric functions of ion-molecular forms of azo compounds used as an analytical signal allow us to obtain complete information on the acid-base equilibrium in a wide acidity range.

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  8. The oxidation of acid azo dye AY 36 by a manganese oxide containing mine waste

    International Nuclear Information System (INIS)

    Clarke, Catherine E.; Kielar, Filip; Johnson, Karen L.

    2013-01-01

    Highlights: ► This study looks at the oxidative breakdown of the amine containing dye acid yellow 36 by a Mn oxide containing mine waste. ► The oxidation proceeds by successive one electron transfers between the dye molecule and the Mn oxide minerals. ► The initial decolorization of the dye is rapid, but does not involve the cleavage of the azo bond. -- Abstract: The oxidative breakdown of acid azo dye acid yellow 36 (AY 36) by a Mn oxide containing mine tailings is demonstrated. The oxidation reaction is pH dependent with the rate of decolorization increasing with decreasing pH. The oxidation reaction mechanism is initiated at the amino moiety and proceeds via successive, one electron transfers from the dye to the Mn oxide minerals. The reaction pathway involves the formation of a number of colorless intermediate products, some of which hydrolyze in a Mn oxide-independent step. Decolorization of the dye is rapid and is observed before the cleavage of the azo-bond, which is a slower process. The terminal oxidation products were observed to be p-benzoquinone and 3-hydroxybenzenesulfonate. The reaction order of the initial decolorization was determined to be pseudo fractional order with respect to pH and pseudo first order with respect to dye concentration and Mn tailings’ surface area

  9. Incorporation of Kojic Acid-Azo Dyes on TiO2 Thin Films for Dye Sensitized Solar Cells Applications

    Directory of Open Access Journals (Sweden)

    Carolynne Zie Wei Sie

    2017-01-01

    Full Text Available Sensitization of heavy metal free organic dyes onto TiO2 thin films has gained much attention in dye sensitized solar cells (DSSCs. A series of new kojic acid based organic dyes KA1–4 were synthesized via nucleophilic substitution of azobenzene bearing different vinyl chains A1–4 with kojyl chloride 4. Azo dyes KA1–4 were characterized for photophysical properties employing absorption spectrometry and photovoltaic characteristic in TiO2 thin film. The presence of vinyl chain in A1–4 improved the photovoltaic performance from 0.20 to 0.60%. The introduction of kojic acid obtained from sago waste further increases the efficiency to 0.82–1.54%. Based on photovoltaic performance, KA4 achieved the highest solar to electrical energy conversion efficiency (η = 1.54% in the series.

  10. A New Nano Silica Gel Supported by Thionyl Chloride as a Solid Acid for the Efficient Diazotization of Aniline Derivatives: Application and Synthesis of Azo Dyes

    Directory of Open Access Journals (Sweden)

    Mohammad Mirjalili

    2012-01-01

    Full Text Available A new nano silicagel supported by thionyl chloride as a solid acid was synthesized and used as a increasing the production yield of dye to affect the efficient diazotization of arylamines. The diazonium salts thus obtained were coupled, using standard experimental procedures, to anilines and naphthols to afford the requisite azo dyes in good yield. The diazotization and subsequent azo-coupling generated the related azo dyes at low temperature in short reaction times with a simple experimental procedure.

  11. Immobilized laccase mediated dye decolorization and transformation pathway of azo dye acid red 27

    OpenAIRE

    Chhabra, Meenu; Mishra, Saroj; Sreekrishnan, Trichur Ramaswamy

    2015-01-01

    Background Laccases have good potential as bioremediating agents and can be used continuously in the immobilized form like many other enzymes. Methods In the present study, laccase from Cyathus bulleri was immobilized by entrapment in Poly Vinyl Alcohol (PVA) beads cross-linked with either nitrate or boric acid. Immobilized laccase was used for dye decolorization in both batch and continuous mode employing a packed bed column. The products of degradation of dye Acid Red 27 were identified by ...

  12. Immobilized laccase mediated dye decolorization and transformation pathway of azo dye acid red 27.

    Science.gov (United States)

    Chhabra, Meenu; Mishra, Saroj; Sreekrishnan, Trichur Ramaswamy

    2015-01-01

    Laccases have good potential as bioremediating agents and can be used continuously in the immobilized form like many other enzymes. In the present study, laccase from Cyathus bulleri was immobilized by entrapment in Poly Vinyl Alcohol (PVA) beads cross-linked with either nitrate or boric acid. Immobilized laccase was used for dye decolorization in both batch and continuous mode employing a packed bed column. The products of degradation of dye Acid Red 27 were identified by LC MS/MS analysis. The method led to very effective (90%) laccase immobilization and also imparted significant stability to the enzyme (more than 70% after 5 months of storage at 4°C). In batch decolorization, 90-95% decolorization was achieved of the simulated dye effluent for up to 10-20 cycles. Continuous decolorization in a packed bed bioreactor led to nearly 90% decolorization for up to 5 days. The immobilized laccase was also effective in decolorization and degradation of Acid Red 27 in the presence of a mediator. Four products of degradation were identified by LC-MS/MS analysis. The immobilized laccase in PVA-nitrate was concluded to be an effective agent in treatment of textile dye effluents.

  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. 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.

  15. Aerobic decolourization of two reactive azo dyes under varying ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-02-01

    Feb 1, 2010 ... Azo dyes generally resist aerobic microbial degra- dation, only organisms with specialized azo dye reducing enzymes were found to degrade azo dyes under fully aerobic ... textile mill, in sterile plastic bottles. Isolation of ...

  16. 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.

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

    International Nuclear Information System (INIS)

    Liu Guangfei; Wang Jing; Lu Hong; Jin Ruofei; Zhou Jiti; Zhang Long

    2009-01-01

    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.

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

    Science.gov (United States)

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

    2010-04-01

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

  19. Decolorization of the azo dye Acid Orange 51 by laccase produced in solid culture of a newly isolated Trametes trogii strain

    OpenAIRE

    Daâssi, Dalel; Zouari-Mechichi, Héla; Frikha, Fakher; Martínez, María Jesús; Nasri, M.; Mechichi, Tahar

    2013-01-01

    This study concerns the decolorization and detoxification of the azo dye Acid Orange 51 (AO51) by crude laccase from Trametes trogii produced in solid culture using sawdust as support media. A three-level Box?Behnken factorial design with four factors (enzyme concentration, 1-hydroxybenzotriazole (HBT) concentration, dye concentration and reaction time) combined with response surface methodology was applied to optimize AO51 decolorization. A mathematical model was developed showing the effect...

  20. 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.

  1. 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.

  2. Integrated and sequential anaerobic/aerobic biodegradation of azo dyes

    NARCIS (Netherlands)

    Tan, N.G.C.

    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

  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)

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

    2011-01-01

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

    International Nuclear Information System (INIS)

    Naveenraj, Selvaraj; Solomon, Rajadurai Vijay; Venuvanalingam, Ponnambalam; Asiri, Abdullah M.; Anandan, Sambandam

    2013-01-01

    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

  5. Acid azo dye remediation in anoxic-aerobic-anoxic microenvironment under periodic discontinuous batch operation: bio-electro kinetics and microbial inventory.

    Science.gov (United States)

    Venkata Mohan, S; Suresh Babu, P; Naresh, K; Velvizhi, G; Madamwar, Datta

    2012-09-01

    Functional behavior of anoxic-aerobic-anoxic microenvironment on azo dye (C.I. Acid black 10B) degradation was evaluated in a periodic discontinuous batch mode operation for 26 cycles. Dye removal efficiency and azo-reductase activity (30.50 ± 1 U) increased with each feeding event until 13th cycle and further stabilized. Dehydrogenase activity also increased gradually and stabilized (2.0 ± 0.2 μg/ml) indicating the stable proton shuttling between metabolic intermediates providing higher number of reducing equivalents towards dye degradation. Voltammetric profiles showed drop in redox catalytic currents during stabilized phase also supports the consumption of reducing equivalents towards dye removal. Change in Tafel slopes, polarization resistance and other bioprocess parameters correlated well with the observed dye removal and biocatalyst behavior. Microbial community analysis documented the involvement of specific organism pertaining to aerobic and facultative functions with heterotrophic and autotrophic metabolism. Integrating anoxic microenvironment with aerobic operation might have facilitated effective dye mineralization due to the possibility of combining redox functions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Preparation, characterization of a ceria loaded carbon nanotubes nanocomposites photocatalyst and degradation of azo dye Acid Orange 7

    Directory of Open Access Journals (Sweden)

    Wen Tao

    2016-06-01

    Full Text Available A ceria loaded carbon nanotubes (CeO2/CNTs nanocomposites photocatalyst was prepared by chemical precipitation, and the preparation conditions were optimized using an orthogonal experiment method. HR-TEM, XRD, UV-Vis/DRS, TGA and XPS were used to characterize the photocatalyst. Nitrogen adsorption-desorption was employed to determine the BET specific surface area. The results indicated that the photocatalyst has no obvious impurities. CeO2 was dispersed on the carbon nanotubes with a good loading effect and high loading efficiency without agglomeration. The catalyst exhibits a strong ability to absorb light in the ultraviolet region and some ability to absorb light in the visible light region. The CeO2/CNTs nanocomposites photocatalyst was used to degrade azo dye Acid Orange 7 (40 mg/L. The optical decolorization rate was 66.58% after xenon lamp irradiation for 4 h, which is better than that of commercial CeO2 (43.13%. The results suggested that CeO2 loading on CNTs not only enhanced the optical decolorization rate but also accelerated the separation of CeO2/CNTs and water.

  7. Photocatalytic Oxidation of Azo Dyes and Oxalic Acid in Batch Reactors and CSTR: Introduction of Photon Absorption by Dyes to Kinetic Models

    Directory of Open Access Journals (Sweden)

    I. Grčić

    2018-04-01

    Full Text Available The possibilities of treating industrial effluents and water purification by advanced oxidation processes have been extensively studied; photocatalysis has emerged as a feasible alternative solution. In order to apply the photocatalytic treatment on a larger scale, relevant modeling approaches are necessary. The scope of this work was to investigate the applicability of recently published kinetic models in different reactor systems (batch and CSTR under UVA or UVC irradiation and in combination with two types of TiO2 catalyst, AEROXIDE® P25 and PC-500 for degradation of azo dyes (C.I. Reactive Violet 2, and C.I. Mordant Yellow 10, oxalic acid and their mixtures. The influences of reactor geometry and irradiation intensities on pollutant oxidation efficiency were examined. The effect of photon absorption by dyes in water matrix was thoroughly studied. Relevant kinetic models were introduced to the mass balance for particular reactor system. Resulting models were sufficient for description of pollutant degradation in batch reactors and CSTR. Experimental results showed 1.15 times higher mineralization extents achieved after 7 cycles in CSTR than in batch photoreactor of similar geometry within the equivalent time-span. The application of CSTR in-series could simplify the photocatalytic water treatment on a larger scale.

  8. 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.

  9. 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.

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

    International Nuclear Information System (INIS)

    Palfi, Tamas; Wojnarovits, Laszlo; Takacs, Erzsebet

    2011-01-01

    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.

  11. 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.

  12. Decolorization of the azo dye Acid Orange 51 by laccase produced in solid culture of a newly isolated Trametes trogii strain.

    Science.gov (United States)

    Daâssi, Dalel; Zouari-Mechichi, Hela; Frikha, Fakher; Martinez, Maria Jesus; Nasri, Moncef; Mechichi, Tahar

    2013-04-01

    This study concerns the decolorization and detoxification of the azo dye Acid Orange 51 (AO51) by crude laccase from Trametes trogii produced in solid culture using sawdust as support media. A three-level Box-Behnken factorial design with four factors (enzyme concentration, 1-hydroxybenzotriazole (HBT) concentration, dye concentration and reaction time) combined with response surface methodology was applied to optimize AO51 decolorization. A mathematical model was developed showing the effect of each factor and their interactions on color removal. The model predicted that Acid Orange 51 decolorization above 87.87 ± 1.27 % could be obtained when enzyme concentration, HBT concentration, dye concentration and reaction time were set at 1 U/mL, 0.75 mM, 60 mg/L and 2 days, respectively. The experimental values were in good agreement with the predicted ones and the models were highly significant, the correlation coefficient (R 2 ) being 0.9. Then the desirability function was employed to determine the optimal decolorization condition for each dye and minimize the process cost simultaneously. In addition, germination index assay showed that laccase-treated dye was detoxified; however in the presence of HBT, the phytotoxicity of the treated dye was increased. By using cheap agro-industrial wastes, such as sawdust, a potential laccase was obtained. The low cost of laccase production may further broaden its application in textile wastewater treatment.

  13. Novel acid mono azo dye compound: Synthesis, characterization, vibrational, optical and theoretical investigations of 2-[(E)-(8-hydroxyquinolin-5-yl)-diazenyl]-4,5-dimethoxybenzoic acid

    Science.gov (United States)

    Saçmacı, Mustafa; Çavuş, Hatice Kanbur; Arı, Hatice; Şahingöz, Recep; Özpozan, Talat

    2012-11-01

    Novel acid mono azo dye, 2-[(E)-(8-hydroxyquinolin-5yl)-diazenyl]-4,5-dimethoxybenzoic acid (HQD), was synthesized by coupling diazonium salt solution of 2-amino-4,5-dimethoxybenzoic acid (DMA) with 8-hydroxyquinoline (HQ). This dye was characterized by UV-vis, IR & Raman, 1H and 13C NMR spectroscopic techniques and elemental analysis. The normal coordinate analysis of HQD was also performed to assign each band in vibrational spectra. DFT (B3LYP and B3PW91) calculations were employed to optimize the geometry, to interpret NMR spectra, to calculate and to determine the stable tautomeric structure of the compound. Natural Bond Orbital (NBO) analysis was performed to investigate intramolecular interactions. The vibrational spectral data obtained from solid phase IR & Raman spectra were assigned based on the results of the theoretical calculations. UV-vis spectroscopic technique was employed to obtain the optical band gap of HQD. The analysis of the optical absorption data revealed the existence of direct and indirect transitions in the optical band gaps. The optical band gaps of HQD have been found 1.95 and 1.90 eV for direct and indirect transitions, respectively.

  14. Enhancing the electrochemical oxidation of acid-yellow 36 azo dye using boron-doped diamond electrodes by addition of ferrous ion

    International Nuclear Information System (INIS)

    Villanueva-Rodriguez, M.; Hernandez-Ramirez, A.; Peralta-Hernandez, J.M.; Bandala, Erick R.; Quiroz-Alfaro, Marco A.

    2009-01-01

    This work shows preliminary results on the electrochemical oxidation process (EOP) using boron-doped diamond (BDD) electrode for acidic yellow 36 oxidation, a common azo dye used in textile industry. The study is centred in the synergetic effect of ferrous ions and hydroxyl free radicals for improving discoloration of azo dye. The assays were carried out in a typical glass cell under potentiostatic conditions. On experimental conditions, the EOP was able to partially remove the dye from the reaction mixture. The reaction rate increased significantly by addition of Fe 2+ (1 mM as ferrous sulphate) to the system and by (assumed) generation of ferrate ion [Fe(VI)] over BDD electrode. Ferrate is considered as a highly oxidizing reagent capable of removing the colorant from the reaction mixture, in synergistic action with the hydroxyl radicals produced on the BDD surface. Further increases in the Fe 2+ concentration lead to depletion of the reaction rate probably due to the hydroxyl radical scavenging effect of Fe 2+ excess in the system.

  15. A comparative investigation on adsorption performances of mesoporous activated carbon prepared from waste rubber tire and activated carbon for a hazardous azo dye-Acid Blue 113

    International Nuclear Information System (INIS)

    Gupta, V.K.; Gupta, Bina; Rastogi, Arshi; Agarwal, Shilpi; Nayak, Arunima

    2011-01-01

    Research highlights: → The system is cheap, efficient and fast for the removal of dyes from waters. → Higher adsorption capacity is due to higher mesoporous volume of the adsorbent. → The rate determining step of the adsorption process is particle diffusion. - Abstract: A mesoporous carbon developed from waste tire rubber, characterized by chemical analysis, FTIR, and SEM studies, was used as an adsorbent for the removal and recovery of a hazardous azo dye, Acid Blue 113. Surface area, porosity, and density were determined. The adsorption of the dye over the prepared adsorbent and a commercial activated carbon was achieved under different pH, adsorbate concentration, sieve size, adsorbent dosage, contact time and temperature conditions. Langmuir and Freundlich adsorption isotherm models were applied and thermodynamic parameters were calculated. Kinetic studies indicated that the adsorption process follow first order kinetics and particle diffusion mechanisms are operative. By percolating the dye solution through fixed-bed columns the bulk removal of the Acid Blue 113 was carried out and necessary parameters were determined to find out the percentage saturation of both the columns. Recovery of the dye was made by eluting 0.1 M NaOH through the column.

  16. Solar photoassisted advanced oxidation process of azo dyes.

    Science.gov (United States)

    Prato-Garcia, D; Buitrón, G

    2009-01-01

    Advanced oxidation processes assisted with natural solar radiation in CPC type reactors (parabolic collector compound), was applied for the degradation of three azo dyes: acid orange (AO7), acid red 151 (AR151) and acid blue 113 (AB113). Fenton, Fenton like and ferrioxalate-type complexes showed to be effective for degrade the azo linkage and moieties in different extensions. Initially, the best dose of reagents (Fe(3 + )-H(2)O(2)) was determined through a factorial experimental design, next, using response surface methodologies, the reagent consumption was reduced up to 40%, maintaining in all cases high decolourisation percentages (>98%) after 60 min. of phototreatment. In this work, it was also studied the effect of concentration changes of the influent between 100-300 mg/L and the operation of the photocatalytic process near neutral conditions (pH 6.0-6.5) by using ferrioxalate type complex (FeOx).

  17. 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

  18. Metabolism of azo dyes by human skin microbiota.

    Science.gov (United States)

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

    2010-01-01

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

  19. Aerobic Biodegradation Characteristic of Different Water-Soluble Azo Dyes

    Directory of Open Access Journals (Sweden)

    Shixiong Sheng

    2017-12-01

    Full Text Available This study investigated the biodegradation performance and characteristics of Sudan I and Acid Orange 7 (AO7 to improve the biological dye removal efficiency in wastewater and optimize the treatment process. The dyes with different water-solubility and similar molecular structure were biologically treated under aerobic condition in parallel continuous-flow mixed stirred reactors. The biophase analysis using microscopic examination suggested that the removal process of the two azo dyes is different. Removal of Sudan I was through biosorption, since it easily assembled and adsorbed on the surface of zoogloea due to its insolubility, while AO7 was biodegraded incompletely and bioconverted, the AO7 molecule was decomposed to benzene series and inorganic ions, since it could reach the interior area of zoogloea due to the low oxidation-reduction potential conditions and corresponding anaerobic microorganisms. The transformation of NH3-N, SO42− together with the presence of tryptophan-like components confirm that AO7 can be decomposed to non-toxic products in an aerobic bioreactor. This study provides a theoretical basis for the use of biosorption or biodegradation mechanisms for the treatment of different azo dyes in wastewater.

  20. 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.

  1. Synthesis and spectral studies of some novel coumarin based disperse azo dyes

    International Nuclear Information System (INIS)

    Amjad, R.; Khan, S.R.; Naeem, M.

    2009-01-01

    Synthesis of some novel coumarin based azo dyes was carried out by diazotization of heterocyclic amines using nitrosyl sulphuric acid and then coupling them with 7-hydroxy-4-methyl Coumarin. The synthesized dyes when applied on polyester fibers showed moderate to good light fastness and very good to excellent fastness to washing, rubbing, perspiration and sublimation. (author)

  2. 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.

  3. 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.

  4. Aerobic decolourization of two reactive azo dyes under varying ...

    African Journals Online (AJOL)

    Bacillus cereus isolated from dye industrial waste, that is, effluent and soil samples was screened for its ability to decolourize two reactive azo dye – cibacron black PSG and cibacron red P4B under aerobic conditions at pH 7 and incubated at 35°C over a five day period. Different carbon and nitrogen sources were used for ...

  5. Evidence for significantly enhancing reduction of Azo dyes in Escherichia coli by expressed cytoplasmic Azoreductase (AzoA) of Enterococcus faecalis.

    Science.gov (United States)

    Feng, J; Heinze, T M; Xu, H; Cerniglia, C E; Chen, H

    2010-05-01

    Although cytoplasmic azoreductases have been purified and characterized from various bacteria, little evidence demonstrating that these azoreductases are directly involved in azo dye reduction in vivo is known. In order to evaluate the contribution of the enzyme to azo dye reduction in vivo, experiments were conducted to determine the effect of a recombinant cytoplasmic azoreductase (AzoA) from Enterococcus faecalis expressed in Escherichia coli on the rate of metabolism of Methyl Red, Ponceau BS and Orange II. The intact cells that contained IPTG induced AzoA had a higher rate of dye reduction with increases of 2 (Methyl Red), 4 (Ponceau BS) and 2.6 (Orange II)-fold compared to noninduced cells, respectively. Metabolites of Methyl Red isolated from induced cultures were identified as N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid through liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) analyses. In conclusion, our data demonstrate that AzoA from Ent. faecalis is capable of increasing the reduction of azo dyes in intact E. coli cells and that cytoplasmic azoreductase is involved in bacterial dye degradation in vivo.

  6. KINETIC BEHAVIOR OF SOME AZO DYES DECOLORIZATION BY VARIATION OF ZINC OXIDE AND TITANIUM DIOXIDE CONCENTRATIONS

    Directory of Open Access Journals (Sweden)

    Wallace J. C. da Silva

    Full Text Available The decolorization of three monoazo dyes (acid orange 7, direct orange 34, and methyl orange, one diazo dye (direct yellow 86 and one tetraazo dye (direct red 80 were mediated by n-type semiconductors as ZnO and TiO2 under pseudo-first order conditions at 30 ºC. The decolorization rate constants of these azo dyes were determined, varying the semiconductor concentration for the majority of them from 1.0 to 10.0 g L-1. In general, the highest rate constants were displayed for ZnO. This work elucidates that the decolorization capacity depends on the charge, structure, and adsorption of the azo dye on the semiconductor surface as well as the agglomeration of the photocatalyst particles.

  7. Optimization for decolorization of azo dye acid green 20 by ultrasound and H2O2 using response surface methodology

    International Nuclear Information System (INIS)

    Zhang Zhanmei; Zheng Huaili

    2009-01-01

    Response surface methodology (RSM) based on Box-Behnken design was successfully applied to the optimization of the operating conditions in decolorization of acid green 20 (AG 20) by ultrasonic irradiation in the presence of H 2 O 2 . The effects of three operating variables, ultrasonic power density, initial pH value of dye solution and H 2 O 2 concentration on the decolorization efficiency of AG 20 were evaluated. A quadratic model for AG 20 decolorization was proposed. Analysis of variance (ANOVA) indicated that the proposed quadratic model could be used to navigate the design space. The proposed model was approximately in accordance with the experimental case with correlation coefficients R 2 and R adj 2 of 0.9995 and 0.9984, respectively. The optimum operating conditions for AG 20 decolorization were found to be 1.08 W/mL of ultrasonic power density, 4.85 of initial pH and 1.94 mM of H 2 O 2 concentration, respectively. The predicted decolorization rate under the optimum conditions determined by RSM was 96.8%. Confirmatory tests were carried out under the optimum conditions and the decolorization rate of 96.3% was observed, which closely agreed with the predicted value. The results confirmed that RSM based on Box-Behnken design was an accurate and reliable method to optimize the operating conditions of AG 20 decolorization.

  8. 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.

  9. Radiation resistance of organic azo dyes in aqueous solutions

    International Nuclear Information System (INIS)

    Khabarov, V.N.; Kozlov, L.L.

    1987-01-01

    The resistance to the action of the ionizing radiation of aqueous and aqueous-alcoholic solutions of organic mono- and diazo dyes was studied. The radiation chemical yield of decolorization of the dye, determined from the kinetic decolorization curves served as a quantitative criterion of the radiation resistance. The influence of pH, addition of ethanol, hydroquinone, thiourea, glucose and oxygen on the radiation resistance of the azo dyes was studied. An attempt was made to relate the efficiency of radiation decolorization to the chemical nature of the dye

  10. Influence of chemical structures on biodegradation of azo dyes by ...

    African Journals Online (AJOL)

    Influence of chemical structures on biodegradation of azo dyes by Pseudomonas sp. NA Oranusi, CJ Ogugbue. Abstract. No Abstract. Global Journal of Environmental Sciences Vol. 5(1) 2006: 19-25. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  11. Azo dye reduction by mesophilic and thermophilic anaerobic consortia

    NARCIS (Netherlands)

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

    2005-01-01

    The reduction of the azo dye model compounds Reactive Red 2 (RR2) and Reactive Orange 14 (RO14) by mesophilic (30 C) and thermophilic (55 C) anaerobic consortia was studied in batch assays. The contribution of fermentative and methanogenic microorganisms in both temperatures was evaluated in the

  12. New azo dyes as colored isoelectric point markers for isoelectric focusing in acidic pH region

    Czech Academy of Sciences Publication Activity Database

    Šťastná, Miroslava; Trávníček, Martin; Šlais, Karel

    2005-01-01

    Roč. 26, č. 1 (2005), s. 53-59 ISSN 0173-0835 R&D Projects: GA AV ČR(CZ) IBS4031201; GA ČR(CZ) GA203/02/1447; GA AV ČR IAA4031302 Keywords : ampholytic dyes * pI markers Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.850, year: 2005

  13. 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

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

    International Nuclear Information System (INIS)

    Vacchi, Francine Inforçato; Albuquerque, Anjaina Fernandes; Vendemiatti, Josiane Aparecida; Morales, Daniel Alexandre; Ormond, Alexandra B.; Freeman, Harold S.; Zocolo, Guilherme Julião; Zanoni, Maria Valnice Boldrin; Umbuzeiro, Gisela

    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: ► Aqueous solutions of Disperse Red 1 were treated with chlorine. ► The chlorination products of Disperse Red 1 were identified using LC–ESI-MS/MS. ► Daphnia and Salmonella/microsome were employed for eco/genotoxicity testing. ► The chlorinated dye was more mutagenic than the dye itself. ► Chlorination should be avoided in effluents containing azo-dyes.

  15. 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...

  16. Understanding effects of chemical structure on azo dye decolorization characteristics by Aeromonas hydrophila

    Energy Technology Data Exchange (ETDEWEB)

    Hsueh, Chung-Chuan [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China); Chen, Bor-Yann, E-mail: bychen@niu.edu.tw [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China); Yen, Chia-Yi [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China)

    2009-08-15

    This novel comparative study tended to disclose how the molecular structures present in seven azo dyes including two types of azo dyes (i.e., naphthol type azo dyes - Reactive Black 5 (RB 5), Reactive Blue 171 (RB 171), Reactive Green 19 (RG19), Reactive Red 198 (RR198), Reactive Red 141 (RR141) and non-naphthol type azo dyes - Direct Yellow 86 (DY86), Reactive Yellow 84 (RY84)) affected color removal capability of Aeromonas hydrophila. Generally speaking, the decolorization rate of naphthol type azo dye with hydroxyl group at ortho to azo bond was faster than that of non-naphthol type azo dye without hydroxyl group, except of RG19. The azo dyes with electron-withdrawing groups (e.g., sulfo group in RR198, RB5 and RR141) would be easier to be decolorized than the azo dyes with the electron-releasing groups (e.g., -NH-triazine in RB171 and RG19). In addition, the azo dyes containing more electron-withdrawing groups (e.g., RR198, RB5 and RR141) showed significantly faster rate of decolorization. The azo dyes with electron-withdrawing groups (e.g., sulfo group) at para and ortho to azo bond (e.g., RR198, RB5 and RR141) could be more preferred for color removal than those at meta (e.g., DY86 and RY84). The former azo dyes with para and ortho sulfo group provided more effective resonance effects to withdraw electrons from azo bond, causing azo dyes to be highly electrophilic for faster rates of reductive biodecolorization. However, since the ortho substituent caused steric hindrance near azo linkage(s), azo dyes with para substituent could be more favorable (e.g., SO{sub 2}(CH{sub 2}){sub 2}SO{sub 4}{sup -} in RR198 and RB5) than those with ortho substituent (e.g., sulfo group at RR141) for decolorization. Thus, the ranking of the position for the electron-withdrawing substituent in azo dyes to escalate decolorization was para > ortho > meta. This study suggested that both the positions of substituents on the aromatic ring and the electronic characteristics of

  17. Degradation of a mono sulfonated azo dye by an integrated bio sorption and anaerobic system

    International Nuclear Information System (INIS)

    Goncalves, L. C.; Campos, R.; Pinheiro, H. M.; Lopes, A.; Ferra, M. I.

    2009-01-01

    A simulated textile effluent containing a mono sulphonated azo dye was fed to an anaerobic bioreactor in which a natural adsorbent, spent brewery grains (SBG), was incorporated. SABG is a by-product of the brewing industry and could act as adsorbent as well an electron shuttle (lignin fraction) in the dye degradation mechanism. Furthermore, it can also work as a conditioner for the anaerobic biomass. The influence of the dye (Acid Orange 7, AO7) concentration (60 and 150 mg/L) and the presence of SBG in the performance of upflow anaerobic sludge blanket reactor (UASB) was evaluated. (Author)

  18. Degradation of a mono sulfonated azo dye by an integrated bio sorption and anaerobic system

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, L. C.; Campos, R.; Pinheiro, H. M.; Lopes, A.; Ferra, M. I.

    2009-07-01

    A simulated textile effluent containing a mono sulphonated azo dye was fed to an anaerobic bioreactor in which a natural adsorbent, spent brewery grains (SBG), was incorporated. SABG is a by-product of the brewing industry and could act as adsorbent as well an electron shuttle (lignin fraction) in the dye degradation mechanism. Furthermore, it can also work as a conditioner for the anaerobic biomass. The influence of the dye (Acid Orange 7, AO7) concentration (60 and 150 mg/L) and the presence of SBG in the performance of upflow anaerobic sludge blanket reactor (UASB) was evaluated. (Author)

  19. 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.

  20. The Comparative Study on the Rapid Decolorization of Azo, Anthraquinone and Triphenylmethane Dyes by Anaerobic Sludge

    Directory of Open Access Journals (Sweden)

    Daizong Cui

    2016-10-01

    Full Text Available An anaerobic sludge (AS, capable of decolorizing a variety of synthetic dyes, was acclimated and is reported here. The sludge presented a much better dye decolorizing ability than that of different individual strains. A broad spectrum of dyes could be decolorized by the sludge. Continuous decolorization tests showed that the sludge exhibited the ability to decolorize repeated additions of dye. The chemical oxygen demand (COD removal rate of the dye wastewater reached 52% after 12 h of incubation. Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE profiles revealed that the microbial community changed as a result of varying initial concentrations of dyes. Phylogenetic analysis indicated that microbial populations in the sludge belonged to the phyla Acidobacteria, Firmicutes, Bacteroidetes, Chloroflexi and Proteobacteria. The degradation products of the three types of dye were identified. For azo dyes, the anaerobic sludge converted Methyl Orange to N,N-dimethylbenzene-1,4-diamine and 4-aminobenzenesulfonic acid; for triphenylmethane dyes, after Malachite Green was decolorized, the analyzed products were found to be a mixture of N,N-dimethylbenzenamine, 3-dimethyl-aminophenol and 4-dimethylaminobenzophenone; for anthraquinone dyes, two products (acetophenone and 2-methylbenzoic acid were observed after Reactive Blue 19 decolorization. Together, these results suggest that the anaerobic sludge has promising potential for use in the treatment of industrial wastewater containing various types of dyes.

  1. The Comparative Study on the Rapid Decolorization of Azo, Anthraquinone and Triphenylmethane Dyes by Anaerobic Sludge.

    Science.gov (United States)

    Cui, Daizong; Zhang, Hao; He, Rubao; Zhao, Min

    2016-10-28

    An anaerobic sludge (AS), capable of decolorizing a variety of synthetic dyes, was acclimated and is reported here. The sludge presented a much better dye decolorizing ability than that of different individual strains. A broad spectrum of dyes could be decolorized by the sludge. Continuous decolorization tests showed that the sludge exhibited the ability to decolorize repeated additions of dye. The chemical oxygen demand (COD) removal rate of the dye wastewater reached 52% after 12 h of incubation. Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) profiles revealed that the microbial community changed as a result of varying initial concentrations of dyes. Phylogenetic analysis indicated that microbial populations in the sludge belonged to the phyla Acidobacteria, Firmicutes, Bacteroidetes, Chloroflexi and Proteobacteria. The degradation products of the three types of dye were identified. For azo dyes, the anaerobic sludge converted Methyl Orange to N , N -dimethylbenzene-1,4-diamine and 4-aminobenzenesulfonic acid; for triphenylmethane dyes, after Malachite Green was decolorized, the analyzed products were found to be a mixture of N , N -dimethylbenzenamine, 3-dimethyl-aminophenol and 4-dimethylaminobenzophenone; for anthraquinone dyes, two products (acetophenone and 2-methylbenzoic acid) were observed after Reactive Blue 19 decolorization. Together, these results suggest that the anaerobic sludge has promising potential for use in the treatment of industrial wastewater containing various types of dyes.

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

    International Nuclear Information System (INIS)

    Hsing, H.-J.; Chiang, P.-C.; Chang, E.-E.; Chen, M.-Y.

    2007-01-01

    The comparison of different advanced oxidation processes (AOPs), i.e. ultraviolet (UV)/TiO 2 , O 3 , O 3 /UV, O 3 /UV/TiO 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 3 /UV and O 3 /UV/TiO 2 processes exhibit remarkable TOC removal capability that can achieve a 65% removal efficiency at pH 7 and O 3 dose = 45 mg/L; (2) the optimum pH and ratio of [H 2 O 2 ]/[Fe 2+ ] found for the Fenton process, are pH 4 and [H 2 O 2 ]/[Fe 2+ ] = 6.58. The optimum [H 2 O 2 ] and [Fe 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 3 3 /UV = O 3 /UV/TiO 2 3 = Fenton 3 /UV 3 /UV/TiO 2 for 30 min of reaction time

  4. Dye-sensitized solar cell based on AZO/Ag/AZO multilayer transparent conductive oxide film

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Jin-He; Li, Ying [School of Materials Science and Engineering, Shanghai University, 149 Yanchang Road, Shanghai 200072 (China); Duong, Thanh-Tung; Choi, Hyung-Jin [Department of Materials Engineering, Chungnam National University, Daeduk Science Town, 305-764 Daejeon (Korea, Republic of); Yoon, Soon-Gil, E-mail: sgyoon@cnu.ac.kr [Department of Materials Engineering, Chungnam National University, Daeduk Science Town, 305-764 Daejeon (Korea, Republic of)

    2013-04-15

    Highlights: ► AZO/Ag/AZO (AAA) multilayer was used for working electrode of DSSC cell. ► The 100 nm-thick Nb-doped TiO{sub 2} layer showed a good blocking effect. ► The DSSC cell by AAA TCO material showed the highest efficiency of about 3.25%. -- Abstract: Niobium-doped TiO{sub 2} blocking layer and Al-doped ZnO (AZO)/Ag/AZO (AAA) TCO layers were grown onto glass substrate using pulsed laser deposition (PLD) and direct current (dc)/radio-frequency (rf) sputtering at room temperature, respectively for dye-sensitized solar cell (DSSC) applications. The 100 nm-thick NTO layer showed a blocking effect for the oxygen diffusion into AAA layer and for the recombination of the electrons. The DSSC cell composed of the NTO (100 nm)/AAA (400 nm) showed the highest photo-electrical efficiency of about 3.25%. An insertion of aluminum foil between serrated clip and AAA (100 nm) TCO improved a photo-conversion efficiency of the DSSC.

  5. Dye-sensitized solar cell based on AZO/Ag/AZO multilayer transparent conductive oxide film

    International Nuclear Information System (INIS)

    Qi, Jin-He; Li, Ying; Duong, Thanh-Tung; Choi, Hyung-Jin; Yoon, Soon-Gil

    2013-01-01

    Highlights: ► AZO/Ag/AZO (AAA) multilayer was used for working electrode of DSSC cell. ► The 100 nm-thick Nb-doped TiO 2 layer showed a good blocking effect. ► The DSSC cell by AAA TCO material showed the highest efficiency of about 3.25%. -- Abstract: Niobium-doped TiO 2 blocking layer and Al-doped ZnO (AZO)/Ag/AZO (AAA) TCO layers were grown onto glass substrate using pulsed laser deposition (PLD) and direct current (dc)/radio-frequency (rf) sputtering at room temperature, respectively for dye-sensitized solar cell (DSSC) applications. The 100 nm-thick NTO layer showed a blocking effect for the oxygen diffusion into AAA layer and for the recombination of the electrons. The DSSC cell composed of the NTO (100 nm)/AAA (400 nm) showed the highest photo-electrical efficiency of about 3.25%. An insertion of aluminum foil between serrated clip and AAA (100 nm) TCO improved a photo-conversion efficiency of the DSSC

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Degradation of azo dyes by sequential Fenton's oxidation and aerobic biological treatment

    International Nuclear Information System (INIS)

    Tantak, Nilesh P.; Chaudhari, Sanjeev

    2006-01-01

    A two stage sequential Fenton's oxidation followed by aerobic biological treatment train was used to achieve decolorization and to enhance mineralization of azo dyes, viz. Reactive Black 5 (RB5), Reactive Blue 13 (RB13), and Acid Orange 7 (AO7). In the first stage, Fenton's oxidation process was used while in the second stage aerobic sequential batch reactors (SBRs) were used as biological process. Study was done to evaluate effect of pH on Fenton's oxidation process. Results reveal that pH 3 was optimum pH for achieving decolorization and dearomatization of dyes by Fenton's process. Degradation of dye was assessed by COD reduction and reduction in aromatic amines (naphthalene chromophores) which was measured by reduction in absorbance at 200 nm. More than 95% of color was removed with Fenton's oxidation process in all dyes. In overall treatment train 81.95, 85.57, and 77.83% of COD reduction was achieved in RB5, RB13, and AO7 dyes, respectively. In the Fenton's oxidation process 56, 24.5, and 80% reduction in naphthalene group was observed in RB5, RB13, and AO7, respectively, which further increased to 81.34, 68.73, and 92% after aerobic treatment. Fenton's oxidation process followed by aerobic SBRs treatment sequence seems to be viable method for achieving significant degradation of azo dye

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

    Directory of Open Access Journals (Sweden)

    G. L. Dotto

    2013-03-01

    Full Text Available 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 experimental data (R²>0.99 and ARE<5.0% and the maximum biosorption capacities were 363.2 and 468.7 mg g-1 for tartrazine and allura red, respectively, obtained at 298 K. The negative values of ΔG and ΔH showed that the biosorption of both dyes was spontaneous, favorable and exothermic. The positive values of ΔS suggested that the system disorder increases during the biosorption process.

  13. Evaluation of biodecolorization of the textile azo dye by halophilic archaea

    Directory of Open Access Journals (Sweden)

    Masoomeh Selseleh Hassan-Kiadehi

    2017-09-01

    Discussion and conclusion: In conclusion, our results indicate that halophilic archaea have very high potential to decolorize azo dyes. Regarding high amounts of salts in textile wastewaters, using such microorganisms which can tolerate the harsh environment in order to decolorize azo dyes, could be a new approach in this field.

  14. Decolourization and degradation of azo Dye, Synozol Red HF6BN ...

    African Journals Online (AJOL)

    Decolourization and degradation of azo Dye, Synozol Red HF6BN, by Pleurotus ostreatus. Sidra Ilyas, Skinder Sultan Sultan, Abdul Rehman. Abstract. The present paper focuses on the use of fungus, Pleurotus ostreatus, to decolorize and degrade azo dye, Synazol Red HF6BN. Decolorization study showed that P.

  15. FACILE SYNTHESIS OF 1-NAPHTHOL AZO DYES WITH NANO ...

    African Journals Online (AJOL)

    Preferred Customer

    a highly efficient and one pot synthesis of azo dyes based on 1-naphthol under ... known and were identified by comparison of their physical and spectroscopic data with those of ... δ: 16.15 (s, 1H), 8.41 (d, J = 7.6 Hz, 1 H), 8.33 (d, J = 8.8 Hz, 2H), 7.8 (d, .... 86. 81. 77. 70. 65. N2. + IO4. -. O2N. 2d. 96. 93. 90. 85. 79. 73. 69.

  16. Biodecolorization of the azo dye Reactive Red 2 by a halotolerant enrichment culture.

    Science.gov (United States)

    Beydilli, M Inan; Pavlostathis, Spyros G

    2007-11-01

    The decolorization of the azo dye Reactive Red 2 (RR2) under anoxic conditions was investigated using a mesophilic (35 degrees C) halotolerant enrichment culture capable of growth at 100 g/L sodium chloride (NaCl). Batch decolorization assays were conducted with the unacclimated halotolerant culture, and dye decolorization kinetics were determined as a function of the initial dye, biomass, carbon source, and an externally added oxidation-reduction mediator (anthraquinone-2,6-disulphonic acid) concentrations. The maximum biomass-normalized RR2 decolorization rate by the halotolerant enrichment culture under batch, anoxic incubation conditions was 26.8 mg dye/mg VSSxd. Although RR2 decolorization was inhibited at RR2 concentrations equal to and higher than 300 mg/L, the halotolerant culture achieved a 156-fold higher RR2 decolorization rate compared with a previously reported, biomass-normalized RR2 decolorization rate by a mixed mesophilic (35 degrees C) methanogenic culture in the absence of NaCl. Decolorization kinetics at inhibitory RR2 levels were described based on the Haldane model (Haldane, 1965). Five repetitive dyeing/decolorization cycles performed using the halotolerant culture and the same RR2 dyebath solution demonstrated the feasibility of biological renovation and reuse of commercial-strength spent reactive azo dyebaths.

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

    Energy Technology Data Exchange (ETDEWEB)

    Athalathil, S.; Stüber, F.; Bengoa, C.; Font, J. [Departament d’Enginyeria Quimica, ETSEQ, Universitat Rovira i Virgili, Av. Paisos Catalans 26, 43007 Tarragona, Catalunya (Spain); Fortuny, A. [Departament d’Enginyeria Quimica, EPSEVG, Universitat Politecnica de Catalunya, Av. Victor Balaguer s/n, 08800 Vilanova i la Geltru, Catalunya (Spain); Fabregat, A., E-mail: azael.fabregat@urv.cat [Departament d’Enginyeria Quimica, ETSEQ, Universitat Rovira i Virgili, Av. Paisos Catalans 26, 43007 Tarragona, Catalunya (Spain)

    2014-02-01

    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 ZnCl{sub 2} 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 m{sup 2}/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.

  18. Influence of generated intermediates’ interaction on heterogeneous Fenton's degradation of an azo dye 1-diazo-2-naphthol-4-sulfonic acid by using sludge based carbon as catalyst

    International Nuclear Information System (INIS)

    Gu, Lin; Huang, Shouqiang; Zhu, Nanwen; Zhang, Daofang; Yuan, Haiping; Lou, Ziyang

    2013-01-01

    Highlights: • End-products have higher tendency to be adsorbed on SC than primarily-formed. • Higher initial H 2 O 2 dosage results in intermediates with strong polarity. • 9 model intermediates differ in their behavior on interactions with catalysts. • Polar surface area dominated their adsorption on SC while K ow acts as a key role on HSC. -- Abstract: Sewage sludge based carbons have recently been used as novel catalyst in heterogeneous Fenton's reactions to degrade azo dye molecules. The carbons, functioning as both catalyst and adsorbent, play an important role in pollutants elimination, especially for those simultaneously generated organic intermediates. Different factors, i.e., H 2 O 2 concentration, may influence the type and properties of those intermediates and may have great impacts on their elimination through the interactions with catalysts’ surface. Thus, techniques including Temperature Programmed Desorption-Mass Spectrometer (TPD-MS), N 2 adsorption isotherm and Scanning Electron Microscope (SEM) were used to probe the ways of the interaction between oxidation products and catalyst by using different initial H 2 O 2 concentrations (10 and 20 mM). The higher Chemical Oxygen Demand (COD) removal with 20 mM H 2 O 2 was found to be related not only to the higher hydroxyl radicals but also the specific interactions between the intermediates and catalyst’ surface. The deep oxidation occurred in the conditions with higher oxidant amount enhances the intermediates’ adsorption on catalyst, thus increasing the COD removal by large margin. Simulated adsorption experiments by using six primarily formed intermediates and three deeply mineralized products on three different catalysts also confirmed the assumption. Results suggested close relations between adsorption capacities and intermediates’ properties such as polar surface area and octanol-water partition coefficient

  19. Effect of Reactive Black 5 azo dye on soil processes related to C and N cycling

    Directory of Open Access Journals (Sweden)

    Khadeeja Rehman

    2018-05-01

    Full Text Available Azo dyes are one of the largest classes of synthetic dyes being used in textile industries. It has been reported that 15–50% of these dyes find their way into wastewater that is often used for irrigation purpose in developing countries. The effect of azo dyes contamination on soil nitrogen (N has been studied previously. However, how does the azo dye contamination affect soil carbon (C cycling is unknown. Therefore, we assessed the effect of azo dye contamination (Reactive Black 5, 30 mg kg−1 dry soil, bacteria that decolorize this dye and dye + bacteria in the presence or absence of maize leaf litter on soil respiration, soil inorganic N and microbial biomass. We found that dye contamination did not induce any change in soil respiration, soil microbial biomass or soil inorganic N availability (P > 0.05. Litter evidently increased soil respiration. Our study concludes that the Reactive Black 5 azo dye (applied in low amount, i.e., 30 mg kg−1 dry soil contamination did not modify organic matter decomposition, N mineralization and microbial biomass in a silty loam soil.

  20. 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.

  1. Degradation of the azo dye Acid Red 1 by anodic oxidation and indirect electrochemical processes based on Fenton's reaction chemistry. Relationship between decolorization, mineralization and products

    International Nuclear Information System (INIS)

    Florenza, Xavier; Solano, Aline Maria Sales; Centellas, Francesc; Martínez-Huitle, Carlos Alberto

    2014-01-01

    Highlights: • Degradation of Acid Red 1 by anodic oxidation, electro-Fenton and photoelectro-Fenton • Quicker and similar decolorization by electro-Fenton and photoelectro-Fenton due to oxidation with ● OH in the bulk • Almost total mineralization by photoelectro-Fenton with Pt or BDD due to fast photolysis of products by UVA light • Detection of 11 aromatic products, 15 hydroxylated compounds, 13 desulfonated derivatives and 7 carboxylic acids • Release of NH 4 + , NO 3 − and SO 4 2− ions, and generation of persistent N-products of low molecular mass - Abstract: Solutions of 236 mg dm −3 Acid Red 1 (AR1), an azo dye widely used in textile dying industries, at pH 3.0 have been comparatively treated by anodic oxidation with electrogenerated H 2 O 2 (AO-H 2 O 2 ), electro-Fenton (EF) and photoelectro-Fenton (PEF) at constant current density (j). Assays were performed with a stirred tank reactor equipped with a Pt or boron-doped diamond (BDD) anode and an air-diffusion cathode for H 2 O 2 generation from O 2 reduction. The main oxidizing agents were hydroxyl radicals produced at the anode from water oxidation in all methods and in the bulk from Fenton's reaction between generated H 2 O 2 and 0.5 mmol dm −3 Fe 2+ in EF and PEF. For each anode, higher oxidation power was found in the sequence AO-H 2 O 2 < EF < PEF. The oxidation ability of the BDD anode was always superior to that of Pt. Faster and similar decolorization efficiency was achieved in EF and PEF owing to the quicker destruction of aromatics with hydroxyl radicals produced in the bulk. The PEF process with BDD was the most potent method yielding almost total mineralization due to the additional rapid photolysis of recalcitrant intermediates like Fe(III)-carboxylate complexes under UVA irradiation. The increase in j always enhanced the decolorization and mineralization processes because of the greater production of hydroxyl radicals, but decreases the mineralization current efficiency

  2. 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.

  3. Transport behaviors of anionic azo dyes at interface between surfactant-modified flax shives and aqueous solution: Synchrotron infrared and adsorption studies

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wenxia [MOE Key Laboratory of Resources and Environmental Systems Optimization, Institute for Energy, Environment and Sustainability Research, UR-NCEPU, North China Electric Power University, Beijing, 102206 (China); Huang, Guohe, E-mail: huang@iseis.org [MOE Key Laboratory of Resources and Environmental Systems Optimization, Institute for Energy, Environment and Sustainability Research, UR-NCEPU, North China Electric Power University, Beijing, 102206 (China); An, Chunjiang; Xin, Xiaying [Institute for Energy, Environment and Sustainable Communities, University of Regina, Regina, S4S 0A2 (Canada); Zhang, Yan [MOE Key Laboratory of Resources and Environmental Systems Optimization, Institute for Energy, Environment and Sustainability Research, UR-NCEPU, North China Electric Power University, Beijing, 102206 (China); Liu, Xia [Canadian Light Source, Saskatoon, S7N 2V3 (Canada)

    2017-05-31

    Highlights: • Surfactant modified flax shives for removing anionic azo dyes. • The equilibrium and kinetic studies for the adsorption of anionic azo dyes. • The migration patterns of dye pollutants at flax shive-water interface. • New insights from synchrotron infrared-assisted characterization. • Potential as biomass adsorbent for the removal of dyes from wastewater. - Abstract: From the viewpoint of sustainability, biomass adsorbent has a high potential in pollution control and there is an emerging interest to investigate the behaviors of pollutants at the interface between biomass adsorbent and solution. This study investigated the performance of cetyltrimethylammonium bromide surfactant-modified flax shives (MFS) for removal of anionic azo dyes from aqueous solution. The equilibrium and kinetic analysis for the adsorption of Acid Orange 7 (AO-7), Acid Red 18 (AR-18) and Acid Black 1 (AB-1) on MFS were conducted. The surface of MFS was characterized by synchrotron infrared and SEM analysis. The absorbed amount of three anionic azo dyes varied with the change of adsorbent dosage, pH and ionic strength. The adsorption isotherm data well fit to the Langmuir model. The adsorption process followed the pseudo-second-order kinetics and the liquid film diffusion models. Thermodynamic studies indicated that the adsorption of three anionic azo dyes was spontaneous. The adsorption of AR-18 and AB-1 onto MFS was endothermic while the adsorption of AO-7 was exothermic. The results can help better understand the behaviors of organic pollutants at biomass adsorbent-water interface. They also present the potential of using MFS as a suitable adsorbent for the removal of anionic azo dyes from wastewater.

  4. Transport behaviors of anionic azo dyes at interface between surfactant-modified flax shives and aqueous solution: Synchrotron infrared and adsorption studies

    International Nuclear Information System (INIS)

    Wang, Wenxia; Huang, Guohe; An, Chunjiang; Xin, Xiaying; Zhang, Yan; Liu, Xia

    2017-01-01

    Highlights: • Surfactant modified flax shives for removing anionic azo dyes. • The equilibrium and kinetic studies for the adsorption of anionic azo dyes. • The migration patterns of dye pollutants at flax shive-water interface. • New insights from synchrotron infrared-assisted characterization. • Potential as biomass adsorbent for the removal of dyes from wastewater. - Abstract: From the viewpoint of sustainability, biomass adsorbent has a high potential in pollution control and there is an emerging interest to investigate the behaviors of pollutants at the interface between biomass adsorbent and solution. This study investigated the performance of cetyltrimethylammonium bromide surfactant-modified flax shives (MFS) for removal of anionic azo dyes from aqueous solution. The equilibrium and kinetic analysis for the adsorption of Acid Orange 7 (AO-7), Acid Red 18 (AR-18) and Acid Black 1 (AB-1) on MFS were conducted. The surface of MFS was characterized by synchrotron infrared and SEM analysis. The absorbed amount of three anionic azo dyes varied with the change of adsorbent dosage, pH and ionic strength. The adsorption isotherm data well fit to the Langmuir model. The adsorption process followed the pseudo-second-order kinetics and the liquid film diffusion models. Thermodynamic studies indicated that the adsorption of three anionic azo dyes was spontaneous. The adsorption of AR-18 and AB-1 onto MFS was endothermic while the adsorption of AO-7 was exothermic. The results can help better understand the behaviors of organic pollutants at biomass adsorbent-water interface. They also present the potential of using MFS as a suitable adsorbent for the removal of anionic azo dyes from wastewater.

  5. Radiolysis of organic triphenylmethane, anthraquinone, xanthene, oxazine, thiazine, and azo dyes in polymers films

    International Nuclear Information System (INIS)

    Khabarov, V.N.; Kozlov, L.L.; Molin, A.A.; Mekhanik, T.V.

    1989-01-01

    The effect of the oxygen in the air and the temperature on radiochemical processes of decolorization of triphenylmethane, anthraquinone, xanthene, oxazine, thiazine, and azo dyes in polymer matrices of different chemical natures was studied. The rate of radiation decolorization for most of the dyes increases in irradiation in the presence of O 2 , which is hypothetically due to oxidation of the dye by singlet oxygen. The organic dyes exhibit the highest radiation stability in polyethylene terephthalate and polystyrene films

  6. Radiolysis of organic triphenylmethane, anthraquinone, xanthene, oxazine, thiazine and azo dyes in polymeric films

    International Nuclear Information System (INIS)

    Khabarov, V.N.; Kozlov, L.L.; Molin, A.A.; Mekhanic, T.V.

    1988-01-01

    Effect of air oxygen and temperature (77 - 323 K) on decolorization radiation-chemical processes of triphenylmethane, anthraquinone, xanthene, oxazine, thiazine and azo dyes in different polymeric matrices is investigated. Radiation decolorization rate for the majority of dyes increases at the irradiation in O 2 presence, which is, presumably, connected with the dye oxidation by the singlet oxygen. The organic dyes manifest the most radiation resistance in polyethyleneterephthalate and polystyrene films

  7. 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.‎

  8. Poly(methylmethacrylate) grafted chitosan: An efficient adsorbent for anionic azo dyes

    International Nuclear Information System (INIS)

    Singh, V.; Sharma, A.K.; Tripathi, D.N.; Sanghi, R.

    2009-01-01

    Present study reports on peroxydisulfate/ascorbic acid initiated synthesis of Chitosan-graft-poly(methylmethacrylate) (Ch-g-PMMA) and its characterization by FTIR, XRD and 13 C NMR. The copolymer remained water insoluble even under highly acidic conditions and was evaluated to be an efficient adsorbent for the three anionic azo dyes (Procion Yellow MX, Remazol Brilliant Violet and Reactive Blue H5G) over a wide pH range of 4-10 being most at pH 7. The adsorbent was also found efficient in decolorizing the textile industry wastewater and was much more efficient than the parent chitosan. Equilibrium sorption experiments were carried out at different pH and initial dye concentration values. The experimental equilibrium data for each adsorbent-dye system were successfully fitted to the Langmuir and Freundlich sorption isotherms. Based on Langmuir model Q max for yellow, violet and blue dyes was 250, 357 and 178, respectively. Thermodynamic parameters of the adsorption processes such as ΔG o , ΔH o , and ΔS o were calculated. The negative values of free energy reflected the spontaneous nature of adsorption. The adsorption kinetic data of all the three dyes could be well represented by pseudo-second-order model with the correlation coefficients (R 2 ) being 0.9922, 0.9997 and 0.9862, for direct yellow, reactive violet and blue dye, respectively with rate constants 0.91 x 10 -4 , 1.82 x 10 -4 and 1.05 x 10 -4 g mg -1 min -1 , respectively. At pH 7, parent chitosan also showed pseudo-second-order kinetics. The temperature dependence of dye uptake and the pseudo-second-order kinetics of the adsorption indicated that chemisorption is the rate-limiting step that controls the process

  9. Synthesis, Characterisation and DFT Calculations of Azo-Imine Dyes

    Directory of Open Access Journals (Sweden)

    Sevil Özkınalı

    2017-11-01

    Full Text Available In this study, azo dyes containing an imine group were synthesised by coupling p-hydroxybenzylidene aniline with the diazonium salts of p-toluidine, 4-aminophenol, aniline, p-chloroaniline, p-fluoroaniline, and p-nitroaniline. The compounds were characterised by melting point, elemental, UV-Vis and IR analyses as well as 1H-NMR and 13C-NMR spectroscopies. Moreover, the experimental data were supplemented with density functional theory (DFT calculations. The experimental data on FT-IR and UV–Vis spectra of the compounds were compared with theoretical results. The DFT calculations were performed to obtain the ground state geometries of the compounds using the B3LYP hybrid functional level with 6-311++g(2d,2p basis set. Frontier molecular orbital energies, band gap energies and some chemical reactivity parameters, such as chemical hardness and electronegativity, were calculated and compared with experimental values. A significant correlation was observed between the dipole moment and polarities of the solvents and the absorption wavelength of the compounds.

  10. Poly(acrylamide) functionalized chitosan: An efficient adsorbent for azo dyes from aqueous solutions

    International Nuclear Information System (INIS)

    Singh, Vandana; Sharma, Ajit Kumar; Sanghi, Rashmi

    2009-01-01

    In the present communication we report on the optimization of persulfate/ascorbic acid initiated synthesis of chitosan-graft-poly(acrylamide) (Ch-g-PAM) and its application in the removal of azo dyes. The optimum yield of the copolymer was obtained using 16 x 10 -2 M acrylamide, 3.0 x 10 -2 M ascorbic acid, 2.4 x 10 -3 M K 2 S 2 O 8 and 0.1 g chitosan in 25 mL of 5% aqueous formic acid at 45 ± 0.2 o C. Ch-g-PAM remained water insoluble even under highly acidic conditions and could efficiently remove Remazol violet and Procion yellow dyes from the aqueous solutions over a pH range of 3-8 in contrast to chitosan (Ch) which showed pH dependent adsorption. The adsorption data of the Ch-g-PAM and Ch for both the dyes were modeled by Langmuir and Freundlich isotherms where the data fitted better to Langmuir isotherms. To understand the adsorption behavior of Ch-g-PAM, adsorption of Remazol violet on to the copolymer was optimized and the kinetic and thermodynamic studies were carried out taking Ch as reference. Both Ch-g-PAM and Ch followed pseudo-second-order adsorption kinetics. The thermodynamic study revealed a positive heat of adsorption (ΔH o ), a positive ΔS o and a negative ΔG o , indicating spontaneous and endothermic nature of the adsorption of RV dye on to the Ch-g-PAM. The Ch-g-PAM was found to be very efficient in removing color from real industrial wastewater as well, though the interfering ions present in the wastewater slightly hindered its adsorption capacity. The data from regeneration efficiencies for ten cycles evidenced the high reusability of the copolymer in the treatment of waste water laden with even high concentrations of dye.

  11. 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.

  12. [The decolorization and biodegrading metabolism of azo dyes by Pseudomonas S-42].

    Science.gov (United States)

    Liu, Z P; Yang, H F

    1989-12-01

    Pseudomonas S-42 was capable of decolorizing azo dyes such as Diamira Brilliant Orange RR(DBO-RR), Direct Brown M (DBM), Eriochrome Brown R(EBR) and so on. The cell suspension, cell-free extract and purified enzyme of Pseud. S-42 could decolorize azo dyes under similar conditions: the optimum pH and temperature laid 7.0 and 37 degrees C respectively. The efficiencies of decolorizing of DBO-RR, DBM, EBR by intact cells stood more than 90%. When the cell concentration was 15 mg(wet)/ml and the reaction time was 5 hours, the decolorizing activity for above three azo dyes by intact cells were 1.75, 2.4, 0.95 micrograms dye/mg cell, respectively. Cell-free extract and purified enzyme could well express the decolorizing activity only under the anaerobic condition and added NADH. Purified enzyme belongs to azoreductase, its molecular weight is about 34,000-2000 daltons, and its Vmax and Km for DBO-RR are 13 mumol.mg protein-1.min-1 and 54 mumol/L. The results of the detection of the biodegrading products of DBO-RR by spectrophotometric and NaNO2 reactional methods showed that the biodegradation of azo dyes was initiated by the reduction cleavage of azo bonds. It was hypothesized that biodegrading metabolism pathway of DBO-RR by Pseudomonas S-42.

  13. 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.

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

    Science.gov (United States)

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

    2016-02-01

    A wide variety of azo dyes are generally added for coloring food products not only to make them visually aesthetic but also to reinstate the original appearance lost during the production process. However, many countries in the world have banned the use of most of the azo dyes in food and their usage is highly regulated by domestic and export food supplies. The regulatory authorities and food analysts adopt highly sensitive and selective analytical methods for monitoring as well as assuring the quality and safety of food products. The present manuscript presents a comprehensive review of various analytical techniques used in the analysis of azo dyes employed in food industries of different parts of the world. A brief description on the use of different extraction methods such as liquid-liquid, solid phase and membrane extraction has also been presented. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Influence of mass transfer and chemical reaction on ozonation of azo dyes

    Energy Technology Data Exchange (ETDEWEB)

    Choi, I.S.; Wiesmann, U. [Dept. of Environmental Engineering, Technical Univ. of Berlin, Berlin (Germany)

    2003-07-01

    Azo dyes can be only mineralised by chemical oxidation. In this paper the oxidation of reactive black 5 (RB 5) and reactive orange 96 (RO 96) with concentrations between 35 and 5700 mgL{sup -1} (RB 5) and between 20 and 2050 mgL{sup -1} (RO 96) is investigated. A lab scale bubble column was used, which was gassed by a mixture of O{sub 2} and O{sub 3}. The oxidation rate was influenced by mass transfer for all dye concentrations used. For lower dye concentrations mass transfer alone was decisive for reaction rate showing an enhancement factor of E {approx} 1. However, in the region of higher dye concentrations, the slope of the decreasing ozone concentration inside the liquid boundary layer increases more and more with increasing dye concentration as a result of a chemical oxidation. Therefore, the enhancement factor depends on the kind and concentration of the azo dyes. For RB 5 as an diazo dye an enhancement factor of E = 9 was observed for 3800 mgL{sup -1}, RO 96 as a mono azo dye with a remarkable higher chemical oxidation rate shows an E = 17 already for 2050 mgL{sup -1}. (orig.)

  16. Decolorization of azo dyes Orange G using hydrodynamic cavitation coupled with heterogeneous Fenton process.

    Science.gov (United States)

    Cai, Meiqiang; Su, Jie; Zhu, Yizu; Wei, Xiaoqing; Jin, Micong; Zhang, Haojie; Dong, Chunying; Wei, Zongsu

    2016-01-01

    The present work demonstrates the application of the combination of hydrodynamic cavitation (HC) and the heterogeneous Fenton process (HF, Fe(0)/H2O2) for the decolorization of azo dye Orange G (OG). The effects of main affecting operation conditions such as the inlet fluid pressure, initial concentration of OG, H2O2 and zero valent iron (ZVI), the fixed position of ZVI, and medium pH on decolorization efficiency were discussed with guidelines for selection of optimum parameters. The results revealed that the acidic conditions are preferred for OG decolorizaiton. The decolorization rate increased with increasing H2O2 and ZVI concentration and decreased with increasing OG initial concentration. Besides, the decolorization rate was strongly dependent on the fixed position of ZVI. The analysis results of degradation products using liquid chromatography-ESI-TOF mass spectrometry revealed that the degradation mechanism of OG proceeds mainly via reductive cleavage of the azo linkage due to the attack of hydroxyl radical. The present work has conclusively established that the combination of HC and HF can be more energy efficient and gives higher decolorization rate of OG as compared with HC and HF alone. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. 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.

  18. Photocatalytic oxidation of a reactive azo dye and evaluation of the ...

    African Journals Online (AJOL)

    The purpose of this study was to investigate the photocatalytic oxidation of a reactive azo dye and determine the improvement in the biodegradability when photocatalytic oxidation was used as a pretreatment step prior to biological treatment. The results obtained from the experiments adding H2O2/TiO2 show that the ...

  19. 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

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

    Directory of Open Access Journals (Sweden)

    B. V. Patel

    2008-01-01

    Full Text Available 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 as acid dyes has been assessed on viscose rayon, wool and cotton fibres.

  1. Radiolysis of Reactive AZO Dyes in Aqueous Solution

    International Nuclear Information System (INIS)

    Bagyo, Agustin NM; Winarti-Andayani; Hendig-Winarno; Ermin-Katrin; Soebianto, Yanti S

    2004-01-01

    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. (author)

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

    International Nuclear Information System (INIS)

    Hsueh, C.-C.; Chen, B.-Y.

    2007-01-01

    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 400 ppm and EBT at 230 ppm were significantly less than those predicted from the Monod kinetic model likely due to accumulated intermediates exceeding the threshold levels for feedback inhibition

  3. Diphenyl (4′-(Aryldiazenylbiphenyl-4-ylamino(pyridin-3-ylmethylphosphonates as Azo Disperse Dyes for Dyeing Polyester Fabrics

    Directory of Open Access Journals (Sweden)

    Mohamed F. Abdel-Megeed

    2013-01-01

    Full Text Available Diphenyl (4′-aminobiphenyl-4-ylamino(pyridin-3-ylmethylphosphonate (1 was synthesized in 88% yield from reaction of pyridine-3-carboxaldehyde with benzidine and triphenylphosphite in the presence of titanium tetrachloride as a catalyst. Diazotization of 1 gave the corresponding diazonium salt 2 which was coupled with several hydroxyl or amino compounds to give the corresponding azo dyes 3–8 in 82–88% yields after crystallization. The dyes produced were applied to polyesters as disperse dyes and their fastness properties were elevated.

  4. Efficient degradation of Azo dyes by a newly isolated fungus Trichoderma tomentosum under non-sterile conditions.

    Science.gov (United States)

    He, Xiao-Ling; Song, Chao; Li, Yuan-Yuan; Wang, Ning; Xu, Lei; Han, Xin; Wei, Dong-Sheng

    2018-04-15

    A fast-growing fungus with remarkable ability to degrade several azo dyes under non-sterile conditions was isolated and identified. This fungus was identified as Trichoderma tomentosum. Textile effluent of ten-fold dilution could be decolorized by 94.9% within 72h before optimization. Acid Red 3R model wastewater with a concentration of 85.5mgL -1 could be decolorized by 99.2% within the same time after optimization. High-level of manganese peroxidase and low-level of lignin peroxidase activities were detected during the process of decolorization from the culture supernatant, indicating the possible involvement of two enzymes in azo dye decolorization. No aromatic amine products were detected from the degradation products of Acid Red 3R by gas chromatography-mass spectrometry (GC/MS) analysis, indicating the possible involvement of a special symmetrical oxidative degradation pathway. Phytotoxicity assay confirmed the lower toxicity toward the test plant seeds of the degradation products when compared to the original dye. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Radiation degradation and hemolytic toxicity evaluation of mono azo reactive dyes

    International Nuclear Information System (INIS)

    Saeed, Q.U.; Bhatti, I.A.; Ashraf, A.

    2017-01-01

    Monoazo reactive dyes have been synthesized and subjected to degradation before their application. Advanced oxidation process has been recognized as a promising radiation technology for the remediation of hazardous organic compounds. Radiation induced degradation of two mono azo reactive dyes have been tried at different absorbed dose, 5 kGy,10 kGy and 15 kGy. Aqueous solutions of these dyes were treated with gamma radiation using Cs 137 radiation source at Nuclear Institute of Agriculture and Biology (NIAB) Faisalabad. Dyes were evaluated spectrophotometrically by UV-visible and fourier transform infra red (FT-IR) spectroscopic techniques before and after irradiation to analyse their percentage decolorization and degradation. Maximum percentage decolorization of 93% and 63% was achieved for mono azo dyes D1 and D2 at 15 kGy absorbed dose. Toxicity study of these dyes was also tested by haemolytic activity assay. Percentage haemolytic activity of untreated dyes was found within permissible limit showing non toxicity of dye solutions. (author)

  6. Bioremediation of acid fast red dye by Streptomyces globosus under ...

    African Journals Online (AJOL)

    Two different azo dyes known as acid fast red (AFR) and Congo red (CR) were examined for their decolorization by five strains of actinomycetes (Streptomyces globosus, Streptomyces alanosinicus, Streptomyces ruber, Streptomyces gancidicus, and Nocardiopsis aegyptia) under shake and static conditions. Streptomyces ...

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

    KAUST Repository

    Kalathil, Shafeer; Chaudhuri, Rajib Ghosh

    2016-01-01

    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.

  8. 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.

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

    KAUST Repository

    Kalathil, Shafeer

    2016-08-04

    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.

  10. 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.

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

    Science.gov (United States)

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

    2010-01-14

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

  12. 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.

  13. Novel bio-electro-Fenton technology for azo dye wastewater treatment using microbial reverse-electrodialysis electrolysis cell

    DEFF Research Database (Denmark)

    Li, Xiaohu; Jin, Xiangdan; Zhao, Nannan

    2017-01-01

    Development of sustanaible technologies for treatment of azo dyes containing wastewaters has long been of great interest. In this study, we proposed an innovative concept of using microbial reverse-electrodialysis electrolysis cell (MREC) based Fenton process to treat azo dye wastewater. In such ......Development of sustanaible technologies for treatment of azo dyes containing wastewaters has long been of great interest. In this study, we proposed an innovative concept of using microbial reverse-electrodialysis electrolysis cell (MREC) based Fenton process to treat azo dye wastewater....... In such MREC-Fenton integrated process, the production of H2O2 which is the key reactant of fenton-reaction was driven by the electrons harvested from the exoelectrogens and salinity-gradient between sea water and fresh water in MREC. Complete decolorization and mineralization of 400 mg L-1 Orange G...

  14. Research on Synthesis of New Azo Calix[4]arene and its Dyeing Properties

    Directory of Open Access Journals (Sweden)

    Tang Jun

    2015-01-01

    Full Text Available With the raw materials of calix[4]arene, benzocaine, tricaine and procaine hydrochloride, three new azo calix[4]arene derivatives—6a, 6b and 6c are synthesized by diazotization–coupling reaction of an aromatic amine, with its yield of 83%, 81% and 83% respectively. The structural characterization is in a way of IR, 1H NMR and elemental analysis. This paper investigates the spectral properties of azo calix[4]arene derivatives under different solution pH conditions through the UV–visible spectroscopy, and researches the dyeing properties through the dyeing curve, color yield test and fastness test. The results show that, with the increase of pH value, the azo calix[4]arene derivatives—6a, 6b and 6c form azo–hydrazone tautomeric isomers with the maximum absorption peak redshift; the dyeing effect of the compound is good, of which the dye–uptake rate of the compound 6a is as high as 78%; the surface depth of color yield is 2.798, and the dry and wet rubbing fastness and the soaping fastness are respectively 4, which is a better disperse dye.

  15. Green synthesis of palladium nanoparticles with carboxymethyl cellulose for degradation of azo-dyes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gang; Li, Yun; Wang, Zhengdong; Liu, Huihong, E-mail: huihongliu@126.com

    2017-02-01

    Palladium nanoparticles (PdNPs) were synthesized through friendly environmental method using PdCl{sub 2} and carboxymethyl cellulose (CMC) in an aqueous solution (pH 6) at controlled water bath (80 °C) for 30 min. CMC functioned as both reducing and stabilizing agent. The characterization through high resolution-transmission electron microscopic (HRTEM) and X-ray Fluorescence Spectrometry (XRF) inferred that the as-synthesized PdNPs were spherical in shape with a face cubic crystal (FCC) structure. The results from dynamic light scattering (DLS) suggested the PdNPs had the narrow size distribution with an average size of 2.5 nm. The negative zeta potential (−52.6 mV) kept the as-synthesized PdNPs stable more than one year. The PdNPs showed the excellent catalytic activity by reducing degradation of azo-dyes, such as p-Aminoazobenzene, acid red 66, acid orange 7, scarlet 3G and reactive yellow 179, in the present of sodium borohydride. - Highlights: • Green synthesis of palladium nanoparticles using carboxymethyl cellulose. • The synthesis of palladium nanoparticles were performed easily. • Carboxymethyl cellulose acts as both reducing and stabilization agents. • The as-synthesized palladium nanoparticles show excellent catalytic activity.

  16. 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.

  17. Analysis of electrode microbial communities in an up-flow bioelectrochemical system treating azo dye wastewater

    International Nuclear Information System (INIS)

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

    2016-01-01

    Bioelectrochemical system (BES) is a rapidly developing technology covering contamination remediation, resource recovery and power generation. Electrode biofilms play a key role in BES operation. In this work, a single chamber up-flow bioelectrochemical system (UBES) was assembled with two preinoculated anodes and two raw cathodes for azo dye wastewater treatment. Microbial community structures of these electrodes after long-term operation (more than 200 days) were carried out by high-throughput Illumina 16S rRNA gene MiSeq sequencing platform. Microorganisms belonging to Enterobacter, Desulfovibrio and Enterococcus, which are capable of bidirectional extracellular electron transfer, were found to be the dominant members in all biofilms. Neither the polarity nor the position of the electrodes obviously altered the microbial community structures. This study provides a feasible strategy to build electrode active biofilms in a BES for azo dye wastewater treatment and gives great inspirations to bring this technology closer to application.

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

    Directory of Open Access Journals (Sweden)

    Alya M. Al-Etaibi

    2016-06-01

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

  19. DFT Study of the Structure, Reactivity, Natural Bond Orbital and Hyperpolarizability of Thiazole Azo Dyes

    Directory of Open Access Journals (Sweden)

    Osman I. Osman

    2017-02-01

    Full Text Available The structure, reactivity, natural bond orbital (NBO, linear and nonlinear optical (NLO properties of three thiazole azo dyes (A, B and C were monitored by applying B3LYP, CAM-B3LYP and ωB97XD functionals with 6-311++G** and aug-cc-pvdz basis sets. The geometrical parameters,dipolemoments,HOMO-LUMO(highest occupied molecular orbital,lowest unoccupied molecular orbital energy gaps, absorption wavelengths and total hyperpolarizabilities were investigated in carbon tetrachloride (CCl4 chloroform (CHCl3, dichloromethane (CH2Cl2 and dimethlysulphoxide (DMSO. The donor methoxyphenyl group deviates from planarity with the thiazole azo moiety by ca. 38◦; while the acceptor dicyanovinyl, indandione and dicyanovinylindanone groups diverge by ca. 6◦. The HOMOs for the three dyes are identical. They spread over the methoxyphenyl donor moiety, the thiazole and benzene rings as π-bonding orbitals. The LUMOs are shaped up by the nature of the acceptor moieties. The LUMOs of the A, B and C dyes extend over the indandione, malononitrile and dicyanovinylindanone acceptor moieties, respectively, as π-antibonding orbitals. The HOMO-LUMO splittings showed that Dye C is much more reactive than dyes A and B. Compared to dyes A and B, Dye C yielded a longer maximum absorption wavelength because of the stabilization of its LUMOs relative to those of the other two. The three dyes show solvatochromism accompanied by significant increases in hyperpolarizability. The enhancement of the total hyperpolarizability of C compared to those of A and B is due to the cumulative action of the long π-conjugation of the indanone ring and the stronger electron-withdrawing ability of the dicyanovinyl moiety that form the dicyanovinylindanone acceptor group. These findings are facilitated by a natural bond orbital (NBO technique. The very high total hyperpolarizabilities of the three dyes define their potent nonlinear optical (NLO behaviour.

  20. Decolorization of direct poly azo dye with nanophotocatalytic UV/NiO process

    Directory of Open Access Journals (Sweden)

    Ali Assadi

    2012-01-01

    Full Text Available Aims: The aim of the present study is to investigate the efficiency of ultraviolet/ nickel oxide (UV/NiO system as one form of advanced oxidation processes (AOP for decolorization of red poly azo. Materials and Methods: This study was conducted as a laboratory scale in a batch mode. Ultraviolet radiation was provided by a low pressure (11 W UV lamp. Effects of various factors including pH, different irradiation durations, different concentration of nickel oxide, and initial dye concentration were evaluated. Results: The results of the UV/NiO system′s assessment showed that UV light alone cannot remove DR 80 dye. Nickel oxide is an effective catalyst in the decolorization of dye with the nanophotocatalytic process. The decolorization efficiency increases with decreasing pH value and the optimum pH value is 4. Fainally, the highest removal efficiency achieved by UV/NiO process for DR 80 dye with concentrations of 25 mg/l and 50 mg/l was 94.3% and 82.2%, respectively. UV/NiO-based decolorization process follows pseudo-second-order reaction kinetics. Conclusions: From the findings of the present study, it can be concluded that UV/NiO process is an effective technique for decolorization of poly azo dye, DR 80, in aqueous solutions.

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

    International Nuclear Information System (INIS)

    Gao, Hejun; Kan, Taotao; Zhao, Siyuan; Qian, Yixia; Cheng, Xiyuan; Wu, Wenli; Wang, Xiaodong; Zheng, Liqiang

    2013-01-01

    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

  2. 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.

  3. 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.

  4. 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)

    Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying; Lee, Hyung-Sool; Wang, Ai-Jie

    2012-01-01

    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.

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

    Science.gov (United States)

    Sala, Mireia; López-Grimau, Víctor; Gutiérrez-Bouzán, Carmen

    2016-01-01

    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. PMID:28773335

  6. UV-visible-DAD and 1H-NMR spectroscopy data fusion for studying the photodegradation process of azo-dyes using MCR-ALS.

    Science.gov (United States)

    Fernández, Cristina; Pilar Callao, M; Larrechi, M Soledad

    2013-12-15

    The photodegradation process of three azo-dyes - Acid Orange 61, Acid Red 97 and Acid Brown 425 - was monitored simultaneously by ultraviolet-visible spectroscopy with diode array detector (UV-vis-DAD) and (1)H-nuclear magnetic resonance ((1)H-NMR). Multivariate curve resolution-alternating least squares (MCR-ALS) was applied to obtain the concentration and spectral profile of the chemical compounds involved in the process. The analysis of the H-NMR data suggests there are more intermediate compounds than those obtained with the UV-vis-DAD data. The fusion of UV-vis-DAD and the (1)H-NMR signal before the multivariate analysis provides better results than when only one of the two detector signals was used. It was concluded that three degradation products were present in the medium when the three azo-dyes had practically degraded. This study is the first application of UV-vis-DAD and (1)H-NMR spectroscopy data fusion in this field and illustrates its potential as a quick method for evaluating the evolution of the azo-dye photodegradation process. © 2013 Elsevier B.V. All rights reserved.

  7. 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

  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. Improved biodegradation of synthetic azo dye by horseradish peroxidase cross-linked on nano-composite support.

    Science.gov (United States)

    Sun, Huaiyan; Jin, Xinyu; Long, Nengbing; Zhang, Ruifeng

    2017-02-01

    A ZnO nanowires/macroporous SiO 2 composite was used as support to immobilize horseradish peroxidase (HRP) by in-situ cross-linking method. Using diethylene glycol diglycidyl ether (DDE) as a long-chained cross-linker, it was adsorbed on the surface of ZnO nanowires before reaction with HRPs, the resulted composite was quite different from the traditional cross-linking enzyme aggregates (CLEAs) on both structure and catalytic performance. The immobilized HRP showed high activity in the decolorization of azo dyes. The effect of various conditions such as the loading amount of HRP, solution pH, temperature, contact time and concentration of dye were optimized on the decolorization. The decolorization percentage of Acid Blue 113 and Acid black 10 BX reached as high as 95.4% and 90.3%, respectively. The immobilized HRP gave the highest decolorization rate under dye concentration as 50mg/L and reaction time of 35min. The immobilized HRP exhibited much better resistance to temperature and pH inactivation than free HRP. The storage stability and reusability were greatly improved through the immobilization, from the decolorization of Acid blue 113 it was found that 80.4% of initial efficiency retained after incubation at 4°C for 60 days, and that 79.4% of decolorization efficiency retained after 12 cycles reuse. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Performance and microbial community structures of hydrolysis acidification process treating azo and anthraquinone dyes in different stages.

    Science.gov (United States)

    Liu, Na; Xie, Xuehui; Yang, Bo; Zhang, Qingyun; Yu, Chengzhi; Zheng, Xiulin; Xu, Leyi; Li, Ran; Liu, Jianshe

    2017-01-01

    In this study, performance of hydrolysis acidification process treating simulated dyeing wastewater containing azo and anthraquinone dyes in different stages was investigated. The decolorization ratio, COD Cr removal ratio, BOD 5 /COD Cr value, and volatile fatty acids (VFAs) production were almost better in stage 1 than that in stage 2. Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS) confirmed the biodegradation of Reactive Black 5 (RB5) and Remazol Brilliant Blue R (RBBR) in hydrolysis acidification process. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analyses revealed that significant difference of microbial community structures existed in stage 1 and 2. The dominant species in stage 1 was related to Bacteroidetes group, while the dominant species in stage 2 was related to Bacteroidetes and Firmicutes groups. From the results, it could be speculated that different dyes' structures might have significant influence on the existence and function of different bacterial species, which might supply information for bacteria screening and acclimation in the treatment of actual dyeing wastewater.

  11. Spatial variation of electrode position in bioelectrochemical treatment system: Design consideration for azo dye remediation.

    Science.gov (United States)

    Yeruva, Dileep Kumar; Shanthi Sravan, J; Butti, Sai Kishore; Annie Modestra, J; Venkata Mohan, S

    2018-05-01

    In the present study, three bio-electrochemical treatment systems (BET) were designed with variations in cathode electrode placement [air exposed (BET1), partially submerged (BET2) and fully submerged (BET3)] to evaluate azo-dye based wastewater treatment at three dye loading concentrations (50, 250 and 500 mg L -1 ). Highest dye decolorization (94.5 ± 0.4%) and COD removal (62.2 ± 0.8%) efficiencies were observed in BET3 (fully submerged electrodes) followed by BET1 and BET2, while bioelectrogenic activity was highest in BET1 followed by BET2 and BET3. It was observed that competition among electron acceptors (electrode, dye molecules and intermediates) critically regulated the fate of bio-electrogenesis to be higher in BET1 and dye removal higher in BET3. Maximum half-cell potentials in BET3 depict higher electron acceptance by electrodes utilized for dye degradation. Study infers that spatial positioning of electrodes in BET3 is more suitable towards dye remediation, which can be considered for scaling-up/designing a treatment plant for large-scale industrial applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Removal of azo and anthraquinone reactive dyes from industrial wastewaters using MgO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Moussavi, Gholamreza, E-mail: Moussavi@modares.ac.ir [Department of Environmental Health, School of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Mahmoudi, Maryam [Department of Environmental Health, School of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

    2009-09-15

    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 m{sup 2}/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.

  13. Fe{sub 3}O{sub 4}@Nico-Ag magnetically recyclable nanocatalyst for azo dyes reduction

    Energy Technology Data Exchange (ETDEWEB)

    Kurtan, U., E-mail: ukurtan@fatih.edu.tr; Amir, Md.; Baykal, A.

    2016-02-15

    Graphical abstract: - Highlights: • Fe{sub 3}O{sub 4}@Nico@Ag magnetic recyclable nanocatalyst (MRC) is more effective for the reduction of azo dyes consisting of MB and MO. • It could be reused several times without significant loss in catalytic activity. • Fe{sub 3}O{sub 4}@Nico@Ag (MRCs) has been successively used for colour reduction of MO, MB, EY, RhB and their mixtures. - Abstract: In this study, we report the successful synthesis of Fe{sub 3}O{sub 4}@Nico-Ag nanocomposite as magnetically recyclable nanocatalyst (MRCs) via reflux process at 80 °C for 5 h followed by reduction of Ag{sup +}. FeCl{sub 3}·6H{sub 2}O, FeCl{sub 2}·4H{sub 2}O, AgNO{sub 3} 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 Fe{sub 3}O{sub 4}@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. Fe{sub 3}O{sub 4}@Nico-Ag MRCs has potential for the treatment of industrial dye pollutants.

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

    International Nuclear Information System (INIS)

    Mandic, Zoran; Nigovic, Biljana; Simunic, Branimir

    2004-01-01

    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

  15. Electrochemical characterization of azo dye (E)-1-(4-((4-(phenylamino)phenyl)diazenyl)phenyl)ethanone (DPA)

    International Nuclear Information System (INIS)

    Surucu, Ozge; Abaci, Serdar; Seferoğlu, Zeynel

    2016-01-01

    Highlights: • Electrochemical characterization of azo dye DPA was performed. • Pencil graphite electrode was used as working electrode. • Cyclic voltammetry was used to determine the effect of scan rate and pH. • Chronoamperometry was used to determine diffusion constant. • Square wave voltammetry verified the results of cyclic voltammetry. - Abstract: An enormous range of possible dyes are available, especially as the starting molecules are readily available and cheap. As other dye classes become less viable from either an environmental or economic reasons, azo dyes come to the forefront. Therefore, electrochemical characterization of a novel synthesized azo dye (E)-1-(4-((4-(phenylamino) phenyl)diazenyl)phenyl)ethanone was achieved for the first time. Cyclic voltammetry, chronoamperometry and square wave voltammetry techniques were used to investigate the electrochemical behavior and electrocatalytic effect of azo dye (E)-1-(4-((4-(phenylamino) phenyl)diazenyl)phenyl)ethanone at pencil graphite electrode. Cyclic voltammograms were utilized to determine the effect of scan rate and pH on the peak current and peak potential. Chronoamperometry technique was used to determine diffusion constant, D and the type of adsorption isotherms. The kinetics parameters which were the apparent electron transfer rate constant, k s and charge transfer coefficient, α were calculated. Square wave voltammetry was used to verify responses of cyclic voltammetry technique.

  16. Synthesis of silver nanoparticles using bacterial exopolysaccharide and its application for degradation of azo-dyes

    Directory of Open Access Journals (Sweden)

    Chinnashanmugam Saravanan

    2017-09-01

    Full Text Available In this study, the synthesis and characterization of exopolysaccharide-stabilized sliver nanoparticles (AgNPs was carried out for the degradation of industrial textile dyes. Characterization of AgNPs was done using surface plasmon spectra using UV–Vis spectroscopy, X-ray diffraction (XRD and Raman spectroscopy. The morphological nature of AgNPs was determined through transmission electron microscopy (TEM, scanning electron microscopy (SEM and atomic force microscopy (AFM, which indicated that the AgNPs were spherical in shape, with an average size of 35 nm. The thermal behaviour of AgNPs revealed that it is stable up to 437.1 °C and the required energy is 808.2J/g in TGA-DTA analysis. Ability of EPS stabilized AgNPs for degradation of azo dyes such as Methyl orange (MO and Congo red (CR showed that EPS stabilized AgNPs were found to be efficient in facilitating the degradation process of industrial textile dyes. The electron transfer takes place from reducing agent to dye molecule via nanoparticles, resulting in the destruction of the dye chromophore structure. This makes EPS-AgNPs a suitable, cheap and environment friendly candidate for biodegradation of harmful textile dyes.

  17. Decolorizing of azo dye Reactive red 24 aqueous solution using exfoliated graphite and H2O2 under ultrasound irradiation.

    Science.gov (United States)

    Li, Mei; Li, Ji-Tai; Sun, Han-Wen

    2008-07-01

    At its natural pH (6.95), the decolorization of Reactive red 24 in ultrasound, ultrasound/H2O2, exfoliated graphite, ultrasound/exfoliated graphite, exfoliated graphite/H2O2 and ultrasound/exfoliated graphite/H2O2 systems were compared. An enhancement was observed for the decolorization in ultrasound/exfoliated graphite/H2O2 system. The effect of solution pH, H2O2 and exfoliated graphite dosages, and temperature on the decolorization of Reactive red 24 was investigated. The sonochemical treatment in combination with exfoliated graphite/H2O2 showed a synergistic effect for the decolorization of Reactive red 24. The results indicated that under proper conditions, there was a possibility to remove Reactive red 24 very efficient from aqueous solution. The decolorization of other azo dyes (Reactive red 2, Methyl orange, Acid red 1, Acid red 73, Acid red 249, Acid orange 7, Acid blue 113, Acid brown 75, Acid green 20, Acid yellow 42, Acid mordant brown 33, Acid mordant yellow 10 and Direct green 1) was also investigated, at their natural pH.

  18. pI-Control in comparative fluorescence gel electrophoresis (CoFGE) using amphoteric azo dyes

    Czech Academy of Sciences Publication Activity Database

    Hanneken, M.; Šlais, Karel; König, S.

    2015-01-01

    Roč. 8, SEP (2015), s. 36-39 ISSN 2212-9685 Institutional support: RVO:68081715 Keywords : comparative fluorescence gel * electrophoresis * protein grid * azo dyes Subject RIV: CB - Analytical Chemistry, Separation http://ac.els-cdn.com/S2212968515000094/1-s2.0-S2212968515000094-main.pdf?_tid=7c92fa40-56e6-11e5-b36a-00000aab0f01&acdnat=1441798543_19612c0d7466780944bc4ae22173da92

  19. Decolourisations and biodegradations of model azo dye solutions using a sequence batch reactor, followed by ultrafiltration

    DEFF Research Database (Denmark)

    Korenak, J.; Ploder, J.; Trček, J.

    2018-01-01

    RNA gene and ITS1-5.8S rDNA-ITS2 sequence analysis, respectively. Serratia marcescens and Klebsiella oxytoca were the most common bacteria with the highest number present during the aerobic and anaerobic phases of the bioprocess. In addition, a high number of Elizabethkingia miricola, Morganella morganii......, Comamonas testosteroni, Trichosporon sp. and Galactomyces sp. were detected. Taken together, our results demonstrated that the sequencing batch reactor system combined with ultrafiltration is an efficient technique for treatment of wastewater containing azo dye. Moreover, the ultrafiltration effectively...

  20. 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.

  1. Facile synthesis of 1-naphthol azo dyes with nano SiO2/HIO4 under solvent-free conditions

    Directory of Open Access Journals (Sweden)

    A.R. Pourali

    2013-09-01

    Full Text Available Nano-silica supported periodic acid (nano-SPIA has been utilized as a heterogeneous reagent for a highly efficient and one pot synthesis of azo dyes based on 1-naphthol under solvent-free conditions at room temperature. This method has some advantages, the reaction workup is very easy and the catalyst can be easily separated from the reaction mixture and one-pot procedure. The related products have been obtained in good to excellent yields, high purity and short reaction times. The structures of the products have been characterized by several techniques using UV-Vis, FT-IR, 1H NMR, 13C NMR and mass spectra.DOI: http://dx.doi.org/10.4314/bcse.v27i3.13

  2. 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

    Directory of Open Access Journals (Sweden)

    B. V. Patel

    2007-01-01

    Full Text Available 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 dyeing performance as acid dyes has been assessed on viscose rayon, wool and cotton fibres.

  3. The effect of NCS- on the radiation-induced decoloration of azo and anthraquinone dyes in N2O-saturated aqueous solutions

    International Nuclear Information System (INIS)

    Suzuki, Nobutake; Hotta, Hiroshi

    1977-01-01

    The radiation-induced decoloration of azo and anthraquinone dyes was studied in N 2 O-saturated aqueous solutions containing NCS - . In the N 2 O-saturated solutions, the decoloration yield, G(-Dye), increased markedly upon the addition of NCS - , which is an efficient scavenger of the OH radical-that is, from 1.46 up to 2.10 for Acid Red 265 and from 0.51 up to 1.51 for Acid Blue 40 upon the addition of 1 mM NCS - . In the nitrogen-saturated solutions, however, the G(-Dye) decreased upon the addition of NCS - . It is concluded that the increase in the G(-Dye) upon the addition of NCS - in the N 2 O-saturated solutions is mainly attributable to the attack of the radical anion (NCS) 2 - on the ring structure of the dyes. This radical anion is formed through the following path: NCS - +OH → NCS+OH - and NCS+NCS - reversible (NCS) 2 - . At low NCS - concentrations, the G(-Dye) decreased for Acid Red 265 and increased for Acid Blue 40. This may be attributable to the larger reactivity of (NCS) 2 - on Acid Blue 40 than on Acid Red 265. (auth.)

  4. Influence of generated intermediates’ interaction on heterogeneous Fenton's degradation of an azo dye 1-diazo-2-naphthol-4-sulfonic acid by using sludge based carbon as catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Lin [School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093 (China); School of Environmental Science and Technology, Shanghai Jiao Tong University, Shanghai 200240 (China); Huang, Shouqiang [School of Environmental Science and Technology, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhu, Nanwen, E-mail: nwzhu@sjtu.edu.cn [School of Environmental Science and Technology, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhang, Daofang, E-mail: Zhangdf-usst@163.com [School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093 (China); Yuan, Haiping; Lou, Ziyang [School of Environmental Science and Technology, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2013-12-15

    Highlights: • End-products have higher tendency to be adsorbed on SC than primarily-formed. • Higher initial H{sub 2}O{sub 2} dosage results in intermediates with strong polarity. • 9 model intermediates differ in their behavior on interactions with catalysts. • Polar surface area dominated their adsorption on SC while K{sub ow} acts as a key role on HSC. -- Abstract: Sewage sludge based carbons have recently been used as novel catalyst in heterogeneous Fenton's reactions to degrade azo dye molecules. The carbons, functioning as both catalyst and adsorbent, play an important role in pollutants elimination, especially for those simultaneously generated organic intermediates. Different factors, i.e., H{sub 2}O{sub 2} concentration, may influence the type and properties of those intermediates and may have great impacts on their elimination through the interactions with catalysts’ surface. Thus, techniques including Temperature Programmed Desorption-Mass Spectrometer (TPD-MS), N{sub 2} adsorption isotherm and Scanning Electron Microscope (SEM) were used to probe the ways of the interaction between oxidation products and catalyst by using different initial H{sub 2}O{sub 2} concentrations (10 and 20 mM). The higher Chemical Oxygen Demand (COD) removal with 20 mM H{sub 2}O{sub 2} was found to be related not only to the higher hydroxyl radicals but also the specific interactions between the intermediates and catalyst’ surface. The deep oxidation occurred in the conditions with higher oxidant amount enhances the intermediates’ adsorption on catalyst, thus increasing the COD removal by large margin. Simulated adsorption experiments by using six primarily formed intermediates and three deeply mineralized products on three different catalysts also confirmed the assumption. Results suggested close relations between adsorption capacities and intermediates’ properties such as polar surface area and octanol-water partition coefficient.

  5. Simultaneous determination of ten illegal azo dyes in feed by ultra-high performance liquid chromatography tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Piątkowska Marta

    2017-09-01

    Full Text Available Introduction: The paper presents the method of simultaneous determination of 10 illegal azo dyes in feed by ultra-high performance liquid chromatography coupled with tandem mass spectrometry technique. Material and Methods: The dyes were extracted with hexane, evaporated to dryness, and analysed. Separation was achieved in 7 min in a gradient elution using acetonitrile (A and 0.1% formic acid (B as a mobile phase. Results: The validation results showed the repeatability of the method, which was evaluated at three levels (50, 500, and 5,000 μg/kg. All the matrix calibration curves for the working ranges were linear (R2 0.9904 to 1.0, the repeatability was between 2.1% and 24%, and recoveries ranged from 77.9% to 120%. The LOD and LOQ were at 1-2 and 5-10 μg/kg for different dyes, respectively. Furthermore, the method was applied in the homogeneity tests of the in-house prepared feed containing Sudan I at the levels of 0.5, 5, and 50 mg/kg. Conclusions: A sensitive, selective, and fast multiresidue method was successfully developed and validated. Its robustness was confirmed by the analysis of an experimental feed containing Sudan I.

  6. 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.

  7. Case study of the sonochemical decolouration of textile azo dye Reactive Black 5

    International Nuclear Information System (INIS)

    Vajnhandl, Simona; Le Marechal, Alenka Majcen

    2007-01-01

    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

  8. Isolation, Screening and Development of Local Bacterial Consortia With Azo Dyes Decolourising Capability

    Directory of Open Access Journals (Sweden)

    Khadijah, O.

    2009-01-01

    Full Text Available A total of 1540 bacterial isolates were isolated and screened for their ability to degrade selected azo dyes. Of these, nine isolates were chosen for further studies based on their ability to degrade a wide spectrum of dyes efficiently and rapidly. Several microbial consortia were developed and tested for their effectiveness. Overall the consortia were able to degrade 70 - 100% colour within 72 hours compared to 60 – 97% colour removed by individual isolates. A microbial consortium labelled C15 showed good growth in agitation culture but the colour removal was best in static culture with 80 - 100% colour removed in less than 72 hours. Based on the 16S rRNA sequencing, two of the bacterial isolates in C15 belong to the Chryseobacterium genus while the other one belongs to Flavobacterium genus.

  9. Synthesis and optical properties of azo -dye-attached novel second-order NLO polymers with high thermal stability

    Science.gov (United States)

    Ushiwata, Takami; Okamoto, Etsuya; Komatsu, Kyoji; Kaino, Toshikuni

    2001-06-01

    Novel second order nonlinear optical (NLO) polymethacrylate or polyacrylate polymers with high glass transition temperatures containing an azo dye attached as side-chain have been prepared using a new approach from polymethacrylic acid or polyacrylic acid as starting materials. Glass transition temperatures of 150 approximately 170 degree Celsius were obtained for Disperse red 1 dye attached polymethacrylic acid. These are attributed to the hydrogen bonding between the residual carboxyl groups in the starting polymers. Poled films by corona poling exhibited large NLO susceptibilities, (chi) (2)33 up to 53 pm/V at a wavelength of 1.3 micrometer. Due to the high glass transition temperatures of the polymers, long-term stability of the optical nonlinearity at 100 degrees Celsius was observed for 200 hrs or more. However residual carboxyl groups caused absorbance decrease mainly by hydrolysis of the ester bonds of the polymers investigated by UV-Vis absorption measurement. The stability of induced polar order of the NLO polymer was enhanced by using aminoalkyl chromophore and imidizing it thermally to introduce imide structure into the polymer main-chain. This imidized polymer exhibited (chi) (2)33 of 45 pm/V at a wavelength of 1.3 micrometer and maintained about 90% of the initial value after 230 hrs or more at 100 degrees Celsius.

  10. 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.

  11. 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.

  12. Removal of Azo Dye from Synthetic Wastewater Using Immobilized Nano-Diatomite Within Calcium Alginate

    Directory of Open Access Journals (Sweden)

    AA Khodabandelou

    2016-03-01

    Full Text Available Introduction: The presence of organic dyes, discharged by textile industries, in aqueous environments can cause detrimental effects on aquatic life and subsequently human health. Therefore, the decolorization of aquatic environments is mandatory to protect the environment. For this reason, in the present study, nano-sized diatomite was immobilized within calcium alginate as a nanocomposite adsorbent for removing organic azo dye (Direct blue 15 from aqueous solutions.  Methods: First of all, Iranian diatomite was grinded in a planetary ball mill equipped with tungsten carbide cup for 20 h to achieve nanoparticles of the diatomite. For the immobilization of nanostructured diatomite, a 2% sodium alginate solution was used. Scanning electron microscopy (SEM, X-ray diffraction (XRD and Fourier transform infra-red (FT-IR spectroscopy were used to characterize immobilized nano-diatomite. Fifty milliliter Erlenmeyer flasks were used as batch flow mode experimental reactors. Working solutions were prepared by the dilution of stock solution (1 g/L to desired concentrations. The effect of different operational parameters including contact time, initial pH, adsorbent dosage and initial dye concentration along with kinetic and isotherm of the adsorption were evaluated. After each experiment, the residual concentration of the dyes was measured spectrophotometrically. Results: As results, the adsorption of organic dye increased with increasing contact time and adsorbent dosage, while increasing initial dye concentrations resulted in decreasing the adsorption. The adsorption of DB-15 was favored at basic PH. The immobilization of diatomite led to enhancing the adsorption of  DB-15 compared to diatomite alone. According to the obtained correlation coefficient, the adsorption of DB-15 obeyed pseudo-second order kinetic model and Langmuir isotherm model. The maximum adsorption capacity of diatomite/alginate nanocomposite for the adsorption of DB-15 were found

  13. Degradation of direct azo dye by Cucurbita pepo free and immobilized peroxidase.

    Science.gov (United States)

    Boucherit, Nabila; Abouseoud, Mahmoud; Adour, Lydia

    2013-06-01

    Enzymatic decolourization of the azo dye, Direct Yellow (DY106) 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 at which the highest DY106 decolourization yield was obtained were found at pH 2, temperature 20 degrees C, 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.

  14. Synthesis of MoO3 nanoparticles for azo dye degradation by catalytic ozonation

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  15. 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.

  16. 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. PMID:26496083

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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 (T g ) of each material. Maximum optical anisotropy was obtained 15 °C below the T g 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. (paper)

  18. Ultrasound enhanced activation of peroxydisulfate by activated carbon fiber for decolorization of azo dye.

    Science.gov (United States)

    Huang, Tianyin; Zhang, Ke; Qian, Yajie; Fang, Cong; Chen, Jiabin

    2018-02-20

    Activated carbon fiber (ACF) has become an emerging activator for peroxydisulfate (PDS) to generate sulfate radical (SO 4 •- ). However, the relative low activation efficiency and poor contaminant mineralization limited its widespread application. Herein, ultrasound (US) was introduced to the ACF activated PDS system, and the synergistic effect of US and ACF in PDS activation and the enhancement of contaminant mineralization were investigated. The synergistic effect of US and ACF was observed in the PDS activation to decolorize orange G (OG). The decolorization efficiency increased with increasing ACF loading and US power, and PDS/OG ratio from 1 to 40. The activation energy was determined to be 24.065 kJ/mol. The radical-induced decolorization of OG took place on the surface of ACF, and both SO 4 •- and hydroxyl radical ( • OH) contributed to OG decolorization. The azo bond and naphthalene ring on OG were destructed to other aromatic intermediates and finally mineralized to CO 2 and H 2 O. The introduction of US in the ACF/PDS system significantly enhanced the mineralization of OG. The combination of US and PDS was highly efficient to activate PDS to decolorize azo dyes. Moreover, the introduction of US remarkably improved the contaminant mineralization.

  19. Linearly and circularly polarized laser photoinduced molecular order in azo dye doped polymer films

    Directory of Open Access Journals (Sweden)

    Saad Bendaoud

    2017-01-01

    Full Text Available Photo-induced behavior of Azo Disperse one (AZD1 doped Poly(Methyl MethAcrylate (PMMA using both linear and circular polarized light is studied. The anisotropy is not erased by the circular polarization light. The circular polarization light combined with relatively long lifetime of the cis state in azo dye doped polymers activate all transverse directions of the angular hole burning through the spot in the film inducing anisotropy. Under circular polarized light, there is no orientation perpendicularly to the helex described by the rotating electric field vector, trans molecules reorients in the propagation direction of the pump beam. The polarization state of the probe beam after propagation through the pumped spot depends strongly on the angle of incidence of both pump and probe beams on the input face. In the case where circular polarized pump and probe beams are under the same angle of incidence, the probe beam “sees” anisotropic film as if it is isotropic. Results of this work shows the possibility to reorient azobenzene-type molecules in two orthogonal directions using alternately linearly and circularly polarized beams.

  20. Decolorization of azo dye and generation of electricity by microbial fuel cell with laccase-producing white-rot fungus on cathode

    International Nuclear Information System (INIS)

    Lai, Chi-Yung; Wu, Chih-Hung; Meng, Chui-Ting; Lin, Chi-Wen

    2017-01-01

    Highlights: • A laccase-producing fungus on cathode of MFC was used to enhance degradation of azo dye. • Laccase-producing fungal cathodes performed better than laccase-free control cathodes. • A maximum power density of 13.38 mW/m"2 and an >90% decolorization of acid orange 7 were obtained. • Growing a fungal culture with continuous laccase production improved MFC’s electricity generation. - Abstract: Wood-degrading white-rot fungi produce many extracellular enzymes, including the multi-copper oxidative enzyme laccase (EC 1.10.3.2). Laccase uses atmospheric oxygen as the electron acceptor to catalyze a one-electron oxidation reaction of phenolic compounds and therefore has the potential to simultaneously act as a cathode catalyst in a microbial fuel cell (MFC) and degrade azo dye pollutants. In this study, the laccase-producing white-rot fungus Ganoderma lucidum BCRC 36123 was planted on the cathode surface of a single-chamber MFC to degrade the azo dye acid orange 7 (AO7) synergistically with an anaerobic microbial community in the anode chamber. In a batch culture, the fungus used AO7 as the sole carbon source and produced laccase continuously, reaching a maximum activity of 20.3 ± 0.3 U/L on day 19 with a 77% decolorization of the dye (50 mg/L). During MFC operations, AO7 in the anolyte diffused across a layer of polyvinyl alcohol-hydrogel that separated the cathode membrane from the anode chamber, and served as a carbon source to support the growth of, and production of laccase by, the fungal mycelium that was planted on the cathode. In such MFCs, laccase-producing fungal cathodes outperformed laccase-free controls, yielding a maximum open-circuit voltage of 821 mV, a closed-circuit voltage of 394 mV with an external resistance of 1000 Ω, a maximum power density of 13.38 mW/m"2, a maximum current density of 33 mA/m"2, and a >90% decolorization of AO7. This study demonstrates the feasibility of growing a white-rot fungal culture with continuous

  1. 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.

  2. Kinetic and equilibrium study of adsorption of di-azo dyes on commercial activated carbon

    International Nuclear Information System (INIS)

    Hyali, E.A.S.A.; Abady, T.G.A.

    2013-01-01

    This research work is concerned with studying the adsorption of a number of di-azo dyes on commercial activated carbon (CAC). The synthesized dyes vary in their structures by the central parts. which are either ortho, meta or para phenvlene diamine. This variation affects the linearity of molecules, their spatial arrangement and electron movement throughout the molecule by resonance. Factors a fleeting adsorption process, such as the efiect of contact time, initial concentration, p1-I of the adsorption medium, adsorbent dose, effect of solvent and temperature were studied. The results indicated that, the adsorption process is fast in the first 10 mm, then gradually decreased with time and approaches maximum within 70-80 min for all the studied dyes. The increase of initial concentration and temperature decreased the adsorption efficiency. The results also shows that, the adsorption is found to be more efficient at low Ph value. The increase of the adsorbent dose increases the adsorption efficiency and decreases its capacity. The variation of solvent (ethanol-water ratio) indicates that the decrease of dielectric constant lowers the adsorption efficiency. The study included application of three adsorption isotherms, Freundlich, Langmuir and Tempkin on the experimental data of the studied systems. The results indicated that, Freundlich isotherm fits better the adsorption data. Kinetic analysis of the adsorption data was also conducted by employing 4 kinetic models; pseudo first order and pseudo second order, Elovich and intra particle diffusion equations. The results obtained conclude that, the studied systems follow the Pseudo second order model. (author)

  3. Analysis of photoinduced birefringence in azo-dye doped films by a fast imaging technique

    International Nuclear Information System (INIS)

    Marino, Iari-Gabriel; Lottici, Pier Paolo

    2010-01-01

    In photo-birefringent films, the relationship ρ(I) between optical retardation ρ and pump irradiance I may be obtained with imaging techniques applied within a pump-probe setup. However, measurement of ρ(I) are reported only at long irradiation times and low time-resolution. In this paper we describe a polariscopic imaging technique with higher sensitivity (by a factor of ∼ 30), where the probe beam is focused on the entrance pupil of the camera ('Maxwellian view'). The technique is applied to an azo-dye doped polymeric film, obtaining the continuous ρ(I) curve after irradiation times from 10 ms to 240 ms. Exponential functions are fitted against the experimental data both as a function of time and irradiance.

  4. Waste Plant Material as a Potential Adsorbent of a Selected Azo Dye

    Directory of Open Access Journals (Sweden)

    Tomczak Elwira

    2017-06-01

    Full Text Available This paper discusses the adsorption of Direct Orange 26 azo dye on sunflower husk - an agricultural waste product. During the study, sorption kinetics and equilibrium as well as sorption capacity of the husk were investigated. The adsorption kinetics was analyzed using pseudo-first and pseudo-second order equations, which indicated a chemical sorption mechanism. The sorption equilibrium was approximated with the two-parameter Freundlich and Langmuir equations and the three-parameter Redlich-Peterson equation. The main experiments were carried out in a laboratory adsorption column under different process conditions. Experimental data were interpreted with the Thomas model, based on the volumetric flow rate, initial composition of the feed solution and mass of the adsorbent. The results of modeling the adsorption equilibrium, adsorption kinetics and adsorption dynamics were evaluated statistically.

  5. Synthesis, dyeing performance on polyester fiber and antimicrobial studies of some novel pyrazolotriazine and pyrazolyl pyrazolone azo dyes

    Directory of Open Access Journals (Sweden)

    Hala F. Rizk

    2017-05-01

    Full Text Available 5-Amino-4-heterylazo-3-phenyl-1H-pyrazoles (2a–d were diazotized and coupled with malononitrile to give pyrazoloazo malononitrile which by heating in glacial acetic acid gave novel pyrazolo[5,1-c][1,2,4]triazine dyes (3a–d. Also, some diazopyrazolyl pyrazolone dyes (4a–h were synthesized by diazotization of 2a–d and coupled with some pyrazolone derivatives. The structure of the synthesized dyes was determined by elemental analysis and spectral data. All the synthesized compounds were applied as disperse dyes and their dyeing performance on polyester fabric was studied. The fastness and colorimetric properties were measured. The results revealed that the monoazo dyes have good fastness and good to moderate affinity to polyester fabric than diazo dyes. In addition, the synthesized dyes were screened for their antimicrobial activities against Staphylococcus aureus, Pseudomonas aeruginosa (Gram positive, Bacillus subtitles, Escherichia coli (Gram negative and Candida albicans, Aspergillus niger (Fungi. The results revealed that most of the prepared dyes have high antibacterial activity.

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

    International Nuclear Information System (INIS)

    Iqbal, M; Wang, W H

    2014-01-01

    Mg-based alloys are light weight and have wide range of applications in the automotive industry. These alloys are widely used because of their very attractive physical and mechanical properties and corrosion resistance. The properties and applications can be further improved by changing the nature of materials from crystalline to amorphous. In this study, melt spun ribbons (MSRs) of Mg 70 Zn 25 Ca 5 Mg 68 Zn 27 Ca 5 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 Mg 70 Zn 25 Ca 5 Mg 68 Zn 27 Ca 5 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Azizi, A., E-mail: armina_84@yahoo.com [Civil and Environmental Engineering Department, Amirkabir University of Technology, Hafez Ave., Tehran15875-4413 (Iran, Islamic Republic of); Alavi Moghaddam, M.R., E-mail: alavim@yahoo.com [Civil and Environmental Engineering Department, Amirkabir University of Technology, Hafez Ave., Tehran15875-4413 (Iran, Islamic Republic of); Maknoon, R., E-mail: rmaknoon@yahoo.com [Civil and Environmental Engineering Department, Amirkabir University of Technology, Hafez Ave., Tehran15875-4413 (Iran, Islamic Republic of); Kowsari, E., E-mail: kowsarie@aut.ac.ir [Department of Chemistry, Amirkabir University of Technology, Hafez Ave., Tehran 15875-4413 (Iran, Islamic Republic of)

    2015-12-15

    Highlights: • Three combined advanced SBR and enhanced Fenton process as post treatment was compared. • Higher biomass concentration, dye, COD and metabolites removal was presented together. • Pseudo zero and pseudo first-order bio-decolorization kinetics were observed in all SBRs. • High reduction of AR18 to intermediate metabolites was monitored by HPLC. - Abstract: 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 10 mg/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.

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

    Science.gov (United States)

    Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying; Lee, Hyung-Sool; Wang, Ai-Jie

    2012-11-15

    Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8±1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 gm(-3) d(-1)) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 gm(-3) d(-1) (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Treatment of an azo dye effluent by peroxi-coagulation and its comparison to traditional electrochemical advanced processes.

    Science.gov (United States)

    do Vale-Júnior, Edilson; da Silva, Djalma R; Fajardo, Ana S; Martínez-Huitle, Carlos A

    2018-04-05

    Peroxi-coagulation (PC) is an interesting new process that has not been widely studied in the literature. This work presents the application of this technology to treat an azo dye synthetic effluent, studying the effect of different parameters including initial pH, current density (j), initial dye concentration and supporting electrolyte. The two former variables significantly affected the colour removal of the wastewater, followed by the initial dye concentration and the kind of electrolyte, in a lesser extent. The optimum operating conditions achieved were initial pH of 3.0, j = 33.3 mA cm -2 , 100 mg L -1 of methyl orange (MO) and Na 2 SO 4 as supporting electrolyte. The performance of PC was also compared to other electrochemical advanced processes, under similar experimental conditions. Results indicate that the kinetic decay of the MO increases in the following order: electrocoagulation (EC) oxidation (EO) with electrogenerated H 2 O 2 oxidant character of the homogenous OH radicals generated by EF and PC approaches. The EO process with production of H 2 O 2 (EO-H 2 O 2 ) is limited by mass transport and the EC, as a separation method, takes longer times to achieve similar removal results. Energy requirements about 0.06 kWh g COD -1 , 0.09 kWh g COD -1 , 0.7 kWh g COD -1 and 0.1 kWh g COD -1 were achieved for PC, EF, EO-H 2 O 2 and EC, respectively. Degradation intermediates were monitored and carboxylic acids were detected for PC and EF processes, being rapidly removed by the former technology. PC emerges as a promising and competitive alternative for wastewaters depollution, among other oxidative approaches. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Boron complexing with H-resorcinol and acidic hydroxyxanthene dyes

    International Nuclear Information System (INIS)

    Nazarenko, V.A.; Flyantikova, G.V.; Chekirda, T.N.

    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 consta nt of the complex is 1.12x10 21 , the conditional molar absorptivitis 1.80x10 0 . This complex formation reaction was used for photometric determination of boron in natural water

  11. 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.

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

    International Nuclear Information System (INIS)

    Prato-Garcia, D.; Buitrón, Germán

    2012-01-01

    Highlights: ► Dosing strategies for a photo-Fenton process were evaluated. ► The dosing strategy had no effect of on the decolorization. ► The type of strategy influenced SUVA index, toxicity reduction and biodegradability. ► A continuous reagents supply was found to be the most adequate strategy. ► 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 1 ), the Fenton's reactants were dosed in a punctual mode, while in the other two strategies (E 2 an E 3 ), the reactants were dosed continuously. In the E 2 strategy the reactants were dosed by varying the duration of the injection time. In the E 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 1 strategy was less effective for aromatic content reduction. Conversely, the continuous addition of the reagents (E 2 and E 3 strategies) improved the aromatic content removal. E 3 strategy was substantially more appropriate than E 1 strategy due to improved the effluent quality in two key areas: toxicity and biodegradability.

  13. 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.

  14. Optimization of integrated chemical-biological degradation of a reactive azo dye using response surface methodology

    International Nuclear Information System (INIS)

    Sudarjanto, Gatut; Keller-Lehmann, Beatrice; Keller, Jurg

    2006-01-01

    The integrated chemical-biological degradation combining advanced oxidation by UV/H 2 O 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 2 O 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

  15. Azo dyes decomposition on new nitrogen-modified anatase TiO2 with high adsorptivity

    International Nuclear Information System (INIS)

    Janus, M.; Choina, J.; Morawski, A.W.

    2009-01-01

    New vis active photocatalyst was obtained by the modification of commercial anatase TiO 2 (Police, Poland) in pressure reactor in an ammonia water atmosphere at 100 o C for 4 h. The photocatalytic activity of new material was tested during three azo dyes decomposition: monoazo (Reactive Read), diazo (Reactive Black) and poliazodye (Direct Green). Obtained photocatalyst had new bands at 1430-1440 cm -1 attributed to the bending vibrations of NH 4 + and at 1535 cm -1 associated with NH 2 groups or NO 2 and NO. UV-vis/DR spectra of photocatalyst had also insignificant decrease in visible region. Fluorescence technique was used for studying the amount of hydroxyl radicals produced on TiO 2 surface during visible light irradiation. The hydroxyl radicals produced react with coumarin present in the solution to form 7-hydroxycoumarin which has fluorescent capacity. Photocatalytic activity of modified TiO 2 was compared with commercial titanium dioxide P25 (Degussa, Germany). The photocatalytic activity of TiO 2 /N was higher than that of unmodified material and P25 under visible light irradiation. The ability for dye adsorption (Reactive Red) on photocatalyst surface was also tested. Unmodified TiO 2 and P25 has isotherm of adsorption by Freundlich model, and nitrogen-modified TiO 2 by Langmuir model. The presence of nitrogen at the surface of TiO 2 significantly increased adsorption capacity of TiO 2 as well as OH· radicals formation under visible radiation.

  16. Fenton oxidative decolorization of the azo dye Direct Blue 15 in aqueous solution

    DEFF Research Database (Denmark)

    Sun, Jian-Hui; Shi, Shao-Hui; Lee, Yi-Fan

    2009-01-01

    In this paper, the application of Fenton oxidation process for the decolorization of an azo dye Direct Blue 15 (DB15) in aqueous solution was investigated. The effect of initial pH, dosage of H2O2, H2O2/Fe2+ and H2O2/dye ratios and the reaction temperature on the decolorization efficiency...... = 60: 1 and temperature = 30 degrees C. Under the optimal conditions, 4.7 x 10(-5) mol/L of the DB15 aqueous solution can be completely decolorized by Fenton oxidation within 50-min reaction time and the decolorization kinetic rate constant k was determined as 0.1694 min(-1). Additionally increasing...... the reaction temperature from 20 to 40 degrees C showed a positive effect on the decolorization efficiency of DB15. The present study can provide guidance to relational industry operators and planners to effectively treat the DB15 contaminated wastewater by Fenton oxidation process. (C) 2009 Elsevier B. V. All...

  17. 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.

  18. Synthesis and antibacterial activity of novel Pyrazolo [3, 4-B] quinoline based heterocyclic azo compounds and their dyeing performance

    International Nuclear Information System (INIS)

    Thaokar, Sanjay F.; Patel, Dinesh M.; Patel, Manish P.; Patel, Ranjan G.

    2007-01-01

    3-Amino-6-methyl-1H- pyrazolo [3, 4-B] quinoline was synthesized in good yield. Monoazo compounds were prepared using this intermediate as diazo component with various heterocyclic coupling components. All the azo compounds were characterized by their percentage yield, melting point, elemental analysis, UV-visible spectra, IR-spectra and dyeing performance on nylon and polyester fibres and by their antibacterial activity against gram positive and gram negative bacteria. (author)

  19. [Decolorization of the azo dye reactive red X-3B by an Al-Cu bimetallic system].

    Science.gov (United States)

    Fan, Jin-hong; Ma, Lu-ming; Wang, Hong-wu; Wu, De-li

    2008-06-01

    The decoloration mechanism and kinetics of the azo dye reactive red X-3B by an Al-Cu bimetallic system were investigated by measuring the dye removal, the TOC removal and the aniline concentration, and by adding EDTA as control experiments. The results showed the colority removal rate of X-3B reached 83% in the near neutral pH medium for 30 min and 96.4% for 120 min, in which, about 34% was due to the X-3B reduced to aniline, and about 20% and 30% was due to the flocculating of aluminum ions and surface adsorption of aluminum-fillings respectively. The decolorization of dyeing wastewater is a gradual reaction process, which first adsorbs a large number of dyeing ingredients and then carries out inner electrolysis reduction, improved effectively by the flocculating action of aluminum ions. The decolorization reaction appears to be a pseudo first-order reaction and increases with rising temperature.

  20. Enhanced degradation of azo dye alizarin yellow R in a combined process of iron-carbon microelectrolysis and aerobic bio-contact oxidation.

    Science.gov (United States)

    Liang, Bin; Yao, Qian; Cheng, Haoyi; Gao, Shuhong; Kong, Fanying; Cui, Dan; Guo, Yuqi; Ren, Nanqi; Lee, Duu-Jong; Wang, Aijie

    2012-06-01

    With the aim of enhanced degradation of azo dye alizarin yellow R (AY) and further removal of the low-strength recalcitrant matter (LsRM) of the secondary effluent as much as possible, our research focused on the combination of aerobic bio-contact oxidation (ABO) with iron/carbon microelectrolysis (ICME) process. The combined ABO (with effective volume of 2.4 l) and ICME (with effectively volume of 0.4 l) process were studied with relatively short hydraulic retention time (HRT) of 4 or 6 h. At the HRT of 6 h with the reflux ratio of 1 and 2, the AY degradation efficiency in the final effluent was >96.5%, and the total organic carbon (TOC) removal efficiency were 69.86% and 79.44%, respectively. At the HRT of 4 h and the reflux ratio of 2, TOC removal efficiency and AY degradation efficiency were 73.94% and 94.89%, respectively. The ICME process obviously enhanced the total AY removal and the generated micromolecule acids and aldehydes then that wastewater backflow to the ABO where they were further biodegraded. The present research might provide the potential options for the advanced treatment azo dyes wastewater with short HRT and acceptable running costs.

  1. Efficiency of Polymeric Membrane Graphene Oxide-TiO2 for Removal of Azo Dye

    Directory of Open Access Journals (Sweden)

    Elahe Dadvar

    2017-01-01

    Full Text Available Achieving the desired standard of drinking water quality has been one of the concerns across water treatment plants in the developing countries. Processes such as grid chamber, coagulation, sedimentation, clarification, filtration, and disinfection are typically used in water purification plants. Among these methods, unit filtration which employs polymers is one of the new technologies. There have been many studies about the use of semiconductive TiO2 with graphene oxide (GO on the base of different polymeric membranes for the removal of azo dyes, especially methylene blue (MB. Polymeric GO-TiO2 membranes have high photocatalytic, antifouling property and permeate the flux removal of organic pollutants. The aim of this study was to investigate the characteristics of different polymeric membranes such as anionic perfluorinated polymer (Nafion, cellulose acetate, polycarbonate (PC, polysulfone fluoride (PSF, and polyvinylidene fluoride (PVDF. The result of this study showed that the GO-TiO2 membrane can be used in the field of water treatment and will be used for the removal of polycyclic aromatic hydrocarbons (PAHs from wastewater.

  2. Electrochemical and optical properties of new soluble dithienylpyrroles based on azo dyes

    International Nuclear Information System (INIS)

    Cihaner, Atilla; Algi, Fatih

    2009-01-01

    Two dithienylpyrroles based on azo dyes, namely 2,5'-dimethyl-[4-(2,5-di-thiophen-2-yl-pyrrol-1-yl)-phenyl]azobenzene (SNS-AB2) and 2,5'-dimethyloxy-[4-(2,5-di-thiophen-2-yl-pyrrol-1-yl)-phenyl]azobenzene (SNS-AB3), were synthesized and their corresponding polymers (PSNS-AB2 and PSNS-AB3) were successfully obtained via electropolymerization. The monomers have lower oxidation potentials (0.75 V and 0.80 V vs. Ag/AgCl for SNS-AB2 and SNS-AB3, respectively) when compared to their analogous. Both monomers exhibited photoisomerism properties under irradiation at 360 nm. During the irradiation process, for example, the color of SNS-AB3 changes from yellow to greenish yellow. The electroactive polymer films have well defined and reversible redox couples with a good cycle stability in both aqueous and organic solutions. The polymer films also exhibited electrochromic behaviors; color changes from yellowish green to dark green for the PSNS-AB2 (λ max = 435 nm and E g = 2.31 eV) and from mustard color to green for PSNS-AB3 (λ max = 430 nm and E g = 2.34 eV). Furthermore, the soluble polymers demonstrated different hues of yellow and green colors

  3. Decolorization of Mordant red 73 azo dye in water using H2O2/UV and photo-Fenton treatment.

    Science.gov (United States)

    Elmorsi, Taha M; Riyad, Yasser M; Mohamed, Zeinhom H; Abd El Bary, Hassan M H

    2010-02-15

    Decolorization of the Mordant red 73 (MR73) azo dye in water was investigated in laboratory-scale experiments using UV/H(2)O(2) and photo-Fenton treatments. Photodegradation experiments were carried out in a stirred batch photoreactor equipped with a low-pressure mercury lamp as UV source at 254 nm. The effect of operating parameters such as pH, [H(2)O(2)](,) [dye] and the presence of inorganic salts (NaNO(3), NaCl and Na(2)CO(3)) were also investigated. The results indicated that complete dye decolorization was obtained in less than 60 min under optimum conditions. Furthermore, results showed that dye degradation was dependent upon pH, [H(2)O(2)] and initial dye concentration. The presence of chloride ion led to large decreases in the photodegradation rate of MR73 while both nitrate and carbonate ions have a slight effect. The photo-Fenton treatment, in the presence of Fe powder as a source of Fe(2+) ions, was highly efficient and resulted in 99% decolorization of the dye in 15 min. Mineralization of MR73 dye was investigated by determining chemical oxygen demand (COD). In a 3h photoperiod "65%" of the dye was mineralized by the H(2)O(2)/UV process, while the photo-Fenton treatment was more efficient producing 85% mineralization over the same 3-h period.

  4. Characterization of pore-expanded amino-functionalized mesoporous silicas directly synthesized with dimethyldecylamine and its application for decolorization of sulphonated azo dyes

    International Nuclear Information System (INIS)

    Yang Hong; Feng Qiyan

    2010-01-01

    With dimethyldecylamine (DMDA) as the expander, a new kind of pore-expanded amino-functionalized mesoporous silicas (PEAFMS) was directly synthesized under mild alkali condition. The characteristics of PEAFMS sample demonstrated that the presence of DMDA markedly augmented the average pore diameter (19.04 nm) and strongly enhanced its decolorization ability. Subsequently, acid mordant dark yellow GG (YGG) and reactive red violet X-2R (RVX) were chosen to assess its adsorption capacity for sulphonated azo dyes. The effect of initial pH was investigated and the decolorization mechanism was illuminated. Three isotherms were conducted and the goodness of fit increased as the following order: Freundlich < Langmuir < Redlich-Peterson. The maximum adsorption capacities of YGG and RVX onto PEAFMS were 1.967 and 0.957 mmol/g, respectively. Adsorption kinetic processes were better predicted by the pseudo-second-order rate equation than the pseudo-first-order one. Adsorption thermodynamic results suggested that the adsorption behavior of both dyes onto PEAFMS was spontaneous with the chemical nature. In addition, the regeneration of PEAFMS was proved to be feasible using NaOH as the strippant. After five cycles, PEAFMS still possessed a favorable adsorption capacity for dyes. It is safely concluded that PEAFMS could be a potential adsorbent for the dye removal from wastewater.

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

    Directory of Open Access Journals (Sweden)

    H Albroomi

    2014-10-01

    Full Text Available 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 5-20 mg l–1 and 10-100 mg l–1, respectively, were shaken with certain amount of GAC to determine the adsorption capacity and removal efficiencies. The effects of adsorbent dose, initial pH, initial dye concentration, agitation speed and contact time on dyes removal efficiencies have been studied. Maximum dye concentration was removed from the solution within 60-90 min after the beginning of every experiment. Adsorption parameters were found to fit well into Langmuir and Freundlich adsorption isotherms models with correlation coefficient (R2 > 0.99 in the concentration range of MB and TZ studied.

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

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jingang, E-mail: hjg@hdu.edu.cn [Institute of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Wu, Mengke; Chen, Jianjun; Liu, Xiuyan; Chen, Tingting [Institute of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Wen, Yue [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Tang, Junhong; Xie, Zhengmiao [Institute of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China)

    2015-12-15

    Highlights: • Henna stem mixed with ceramic media in UAF enhanced the removal of AO7. • Bio-reduction was the main AO7 removal pathway in henna-added UAF. • Adsorption and endogenous reduction were the main removal pathways in the control. • Henna played a multiple role in providing electron donors and redox mediator. - Abstract: 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 (k{sub AO7} and k{sub SA}) were higher in the henna-added UAF (R2) than in the control UAF without henna (R1). The maximum k{sub AO7} in R1 and R2 were 0.0345 and 0.2024 cm{sup −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.

  7. 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.

  8. Effect of an azo dye (DR1) on the dielectric parameters of a nematic liquid crystal system

    International Nuclear Information System (INIS)

    Ozder, S.; Okutan, M.; Koeysal, O.; Goektas, H.; San, S.E.

    2007-01-01

    The dielectric parameters and relaxation properties of azo dye (DR1) doped E7 and pure E7 liquid crystal (LC) have been investigated in a wide frequency range of 10 k-10 MHz through the dielectric spectroscopy method at room temperature. Dielectric anisotropy (Δε) property of the LC changes from the positive type to negative type and dielectric anisotropy values decrease with doping of DR1. The relaxation frequency f r of E7 and E7/DR1 LC was calculated by means of Cole-Cole plots. Influence of bias voltage on the dielectric parameters has also been investigated

  9. Effect of addition of heavy metal ion on decolouration and degradation of azo dye in aqueous solution by gamma irradiation combined with ozone

    International Nuclear Information System (INIS)

    Lee, M.J.; Jin, J.H.; Nho, Y.C.; Arai, H.

    1998-01-01

    In decomposition of azo dyes solution by simultaneous application of gamma-ray and ozone treatment, the effect of addition of heavy metal ion upon decolouration and decomposition was studied. Cupric ion was used as a heavy metal ion. For the aqueous solution with and without addition of cupric ion, the degree of decolouration of 552 nm, the changes of pH, the reduction of TOC and BOD were measured as function of dose under condition of fixed concentration of ozone. It appeared that the addition of cupric ion played a positive role in decomposition of azo dye solution, but played a negative role in decolouration

  10. 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. 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.

  12. Deciphering effects of functional groups and electron density on azo dyes degradation by graphene loaded TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qian [College of Chemical Engineering, HuaQiao University, Xiamen 361021 (China); Liang, Xiao [School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093 (China); Chen, Bor-Yann [Department of Chemical and Materials Engineering, National I-Lan University, 26047, Taiwan (China); Chang, Chang-Tang, E-mail: ctchang@niu.edu.tw [Department of Environmental Engineering, National I-Lan University, 26047, Taiwan (China)

    2015-12-01

    Highlights: • The degradation pathways of RB5, RB171 and RR198 have been identified. • The favorable bond to be broken under photo degradation was deciphered in this research. • The breakages of the bonds were due to the electron density changes around the bonds. • The hydroxyl radicals as the main oxidized species were confirmed by positive hole trapper and ESR. - Abstract: 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 TiO{sub 2}, 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.

  13. Sensitive spectrophotometric determination of aceclofenac following azo dye formation with 4-carboxyl-2,6-dinitrobenzene diazonium ion.

    Science.gov (United States)

    Aderibigbe, Segun A; Adegoke, Olajire A; Idowu, Olakunle S; Olaleye, Sefiu O

    2012-01-01

    The study is a description of a sensitive spectrophotometric determination of aceclofenac following azo dye formation with 4-carboxyl-2,6-dinitrobenzenediazonium ion (CDNBD). Spot test and thin layer chromatography revealed the formation of a new compound distinct from CDNBD and aceclofenac. Optimization studies established a reaction time of 5 min at 30 degrees C after vortex mixing the drug/CDNBD for 10 s. An absorption maximum of 430 nm was selected as analytical wavelength. A linear response was observed over 1.2-4.8 μg/mL of aceclofenac with a correlation coefficient of 0.9983 and the drug combined with CDNBD at stoichiometric ratio of 2 : 1. The method has a limit of detection of 0.403 μg/mL, limit of quantitation of 1.22 μg/mL and is reproducible over a three day assessment. The method gave Sandell's sensitivity of 3.279 ng/cm2. Intra- and inter-day accuracies (in terms of errors) were less than 6% while precisions were of the order of 0.03-1.89% (RSD). The developed spectrophotometric method is of equivalent accuracy (p > 0.05) with British Pharmacopoeia, 2010 potentiometric method. It has the advantages of speed, simplicity, sensitivity and more affordable instrumentation and could found application as a rapid and sensitive analytical method of aceclofenac. It is the first described method by azo dye derivatization for the analysis of aceclofenac in bulk samples and dosage forms.

  14. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. CYP-450 isoenzymes catalyze the generation of hazardous aromatic amines after reaction with the azo dye Sudan III.

    Science.gov (United States)

    Zanoni, Thalita Boldrin; Lizier, Thiago M; Assis, Marilda das Dores; Zanoni, Maria Valnice B; de Oliveira, Danielle Palma

    2013-07-01

    This work describes the mutagenic response of Sudan III, an adulterant food dye, using Salmonella typhimurium assay and the generation of hazardous aromatic amines after different oxidation methods of this azo dye. For that, we used metabolic activation by S9, catalytic oxidation by ironporphyrin and electrochemistry oxidation in order to simulate endogenous oxidation conditions. The oxidation reactions promoted discoloration from 65% to 95% of Sudan III at 1 × 10(-4)molL(-1) and generation of 7.6 × 10(-7)molL(-1) to 0.31 × 10(-4)molL(-1) of aniline, o-anisidine, 2-methoxi-5-methylaniline, 4-aminobiphenyl, 4,4'-oxydianiline; 4,4'-diaminodiphenylmethane and 2,6-dimethylaniline. The results were confirmed by LC-MS-MS experiments. We also correlate the mutagenic effects of Sudan III using S. typhimurium with the strain TA1535 in the presence of exogenous metabolic activation (S9) with the metabolization products of this compound. Our findings clearly indicate that aromatic amines are formed due to oxidative reactions that can be promoted by hepatic cells, after the ingestion of Sudan III. Considering that, the use of azo compounds as food dyestuffs should be carefully controlled. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Evaluation of the adsorbent properties of a zeolite rock modified for the removal of the azo dyes as water pollutants

    International Nuclear Information System (INIS)

    Torres P, J.

    2005-01-01

    At the moment some investigations which make reference to the removal of dyes for diverse adsorbent materials; as well as the factors that influence in the sorption process, considering the type so much of dye as those characteristics of the adsorbent material. In this work were investigated those adsorbent properties of a zeolite rock coming from San Luis Potosi State for the removal of azo dyes, using as peculiar cases the Red 40 (Red Allura) and the Yellow 5 (Tartrazine); for it were determined kinetic parameters and the sorption isotherms, as well as the sorption mechanisms involved in each case, between the dyes and the zeolite rock. In this work also it was considered the characterization before and after to removal of color from the water, through advanced analytical techniques such as the scanning electron microscopy of high vacuum (SEM), elementary microanalysis (EDS) and X-ray diffraction (XRD). The experimental part of the work fundamentally consisted, in the conditioning with a NaCl solution and later on the modification with HDTMA-Br of the natural zeolite rock, for then to put it in contact with solutions of the dyes R-40 and A-5, varying so much the contact times as the concentrations; the quantification of sodium in the liquid phase after the modification of the zeolite rock to determine the capacity of external cation exchange (CICE) it was carried out by means of the atomic absorption spectroscopy technique (EAA), and the quantification of the surfactant and the dyes in the liquid phase, it was carried out by means of the UV-vis spectrophotometry technique. It was found that the kinetic model that better it describes the process of sorption of R-40 and A-5 for the modified zeolite rock with HDTMA-Br, leaving of monocomponent and bi component solutions, it is the pseudo- second order. Inside of the obtained results for the sorption isotherms, as much the dye R-40 as the dye A-5 its presented a better adjustment to the Langmuir model. In what refers

  17. Picric acid sensing and capture by a sterically encumbered azo ...

    Indian Academy of Sciences (India)

    Dhananjayan Kaleeswaran

    2018-01-25

    Jan 25, 2018 ... above observations in mind, here we demonstrate how the presence of bulky ... can affect the azo-polymerization process, PNACs sens- ing ability and CO2 uptake ... on a JEOL model JSM-7600F electron microscope, operat- ing at the .... i PrTAPB is flanked by two isopropyl groups and hence results in a ...

  18. 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,

  19. DMol3/COSMO-RS prediction of aqueous solubility and reactivity of selected Azo dyes: Effect of global orbital cut-off and COSMO segment variation

    CSIR Research Space (South Africa)

    Wahab, OO

    2018-01-01

    Full Text Available Aqueous solubility and reactivity of four azo dyes were investigated by DMol3/COSMO-RS calculation to examine the effects of global orbital cut-off and COSMO segment variation on the accuracies of theoretical solubility and reactivity. The studied...

  20. Kinetics of decolorization of azo dye by bipolar pulsed barrier discharge in a three-phase discharge plasma reactor.

    Science.gov (United States)

    Zhang, Ruobing; Zhang, Chi; Cheng, XingXin; Wang, Liming; Wu, Yan; Guan, Zhicheng

    2007-04-02

    Removal of amaranth, a commercial synthetic azo dye widely used in the dye and food industry, was examined as a possible remediation technology for treating dye-contaminated water. Effects of various parameters such as gas flow rate, solution conductivity, pulse repetition frequency, etc., on decolorization kinetics were investigated. Experimental results show that an aqueous solution of 24 mg/l dye is 81.24% decolorized following 30 min plasma treatment for a 50 kV voltage and 0.75 m(3)/h gas flow rate. Decolorization reaction of amaranth in the plasma reactor is a pseudo first order reaction. Rate constant (k) of decolorization increases quickly with increasing the applied voltage, pulse repetition frequency and the gas flow rate. However, when the applied voltage is beyond 50 kV and increases further, increase rate of k decreases. In addition, k decreases quickly when the solution conductivity increases from 200 to 1481 microS/cm. The decolorization reaction has a high rate constant (k=0.0269 min(-1)) when the solution pH is beyond 10. Rate constant k decreases with the decrease of pH and reaches minimum at a pH of about 5 (k(min)=0.01603 min(-1)), then increases to 0.02105 min(-1) when pH decreases to 3.07. About 15% of the initial TOC can be degraded only in about 120 min non-thermal plasma treatment.

  1. Biosurfactant production from Pseudomonas taiwanensis L1011 and its application in accelerating the chemical and biological decolorization of azo dyes.

    Science.gov (United States)

    Liu, Cong; You, Yanting; Zhao, Ruofei; Sun, Di; Zhang, Peng; Jiang, Jihong; Zhu, Aihua; Liu, Weijie

    2017-11-01

    Dye dispersion and the interaction efficiency between azoreductases and dye molecules are rate-limiting steps for the decolorization of azo dyes. In this study, a biosurfactant-producing strain, Pseudomonas taiwanensis L1011, was isolated from crude oil. To increase the yield of the biosurfactant BS-L1011 from P. taiwanensis L1011, culture conditions were optimized including temperature, initial pH, carbon source, nitrogen source and C/N ratio. A maximum yield of 1.12g/L of BS-L1011 was obtained using D-mannitol as carbon source and yeast extract/urea as compound nitrogen source with C/N ratio of 10/4, pH 7.0 and 28°C. BS-L1011 exhibited a low critical micelle concentration (CMC) of 10.5mg/L and was able to reduce the surface tension of water to 25.8±0.1 mN/m. BS-L1011 was stable over a wide range of temperatures, pH values and salt concentrations. The biosurfactant is reported for the first time to accelerate chemical decolorization of Congo red by sodium hypochlorite, and biological decolorization of Amaranth by Bacillus circulans BWL1061, thus showing a potential in the treatment of dyeing wastewater. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Kinetics of decolorization of azo dye by bipolar pulsed barrier discharge in a three-phase discharge plasma reactor

    International Nuclear Information System (INIS)

    Zhang Ruobing; Zhang Chi; Cheng Xingxin; Wang Liming; Wu Yan; Guan Zhicheng

    2007-01-01

    Removal of amaranth, a commercial synthetic azo dye widely used in the dye and food industry, was examined as a possible remediation technology for treating dye-contaminated water. Effects of various parameters such as gas flow rate, solution conductivity, pulse repetition frequency, etc., on decolorization kinetics were investigated. Experimental results show that an aqueous solution of 24 mg/l dye is 81.24% decolorized following 30 min plasma treatment for a 50 kV voltage and 0.75 m 3 /h gas flow rate. Decolorization reaction of amaranth in the plasma reactor is a pseudo first order reaction. Rate constant (k) of decolorization increases quickly with increasing the applied voltage, pulse repetition frequency and the gas flow rate. However, when the applied voltage is beyond 50 kV and increases further, increase rate of k decreases. In addition, k decreases quickly when the solution conductivity increases from 200 to 1481 μS/cm. The decolorization reaction has a high rate constant (k = 0.0269 min -1 ) when the solution pH is beyond 10. Rate constant k decreases with the decrease of pH and reaches minimum at a pH of about 5 (k min = 0.01603 min -1 ), then increases to 0.02105 min -1 when pH decreases to 3.07. About 15% of the initial TOC can be degraded only in about 120 min non-thermal plasma treatment

  3. Degradation efficiency and mechanism of azo dye RR2 by a novel ozone aerated internal micro-electrolysis filter.

    Science.gov (United States)

    Zhang, Xian-Bing; Dong, Wen-Yi; Sun, Fei-Yun; Yang, Wei; Dong, Jiao

    2014-07-15

    A newly designed ozone aerated internal micro-electrolysis filter (OIEF) was developed to investigate its degradation efficiencies and correlated reaction mechanisms of RR2 dye. Complete decolorization and 82% TOC removal efficiency were stably achieved in OIEF process. Based on the comprehensive experimental results, an empirical equation was proposed to illustrate the effects of initial dye concentration and ozone dosage rate on color removal. The results indicated that OIEF process could be operated at wide pH range without significant treatment efficiencies change, while the optimum pH for RR2 dye degradation was 9.0. There were 15, 8 and 6 kinds of identified intermediates during ozonation, IE and OIEF treatment processes, respectively. Less identified intermediates and their lower concentrations in OIEF may attribute to its rather excellent mineralization performance. It was found that ozonation, Fe(2+)/Fe(3+) catalyzed ozonation, the redox reactions of electro-reduction and electro-oxidation are the most important mechanisms in OIEF process. The catalytic effect of Fe(2+)/Fe(3+) would induce mutual conversion between dissolved Fe(2+) and Fe(3+), and then decrease the dissolution rate of ZVI. The excellent treatment performance proved that the OIEF process is one promising technology applied for reactive azo dyes and other refractory wastewater treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Simultaneous Decolorization and Biohydrogen Production from Xylose by Klebsiella oxytoca GS-4-08 in the Presence of Azo Dyes with Sulfonate and Carboxyl Groups

    Science.gov (United States)

    Cao, Ming-yue; Wang, Peng-tao; Wang, Shi; Yue, Ying-rong; Yuan, Wen-duo; Qiao, Wei-chuan; Wang, Fei

    2017-01-01

    ABSTRACT Biohydrogen production from the pulp and paper effluent containing rich lignocellulosic material could be achieved by the fermentation process. Xylose, an important hemicellulose hydrolysis product, is used less efficiently as a substrate for biohydrogen production. Moreover, azo dyes are usually added to fabricate anticounterfeiting paper, which further increases the complexity of wastewater. This study reports that xylose could serve as the sole carbon source for a pure culture of Klebsiella oxytoca GS-4-08 to achieve simultaneous decolorization and biohydrogen production. With 2 g liter−1 of xylose as the substrate, a maximum xylose utilization rate (URxyl) and a hydrogen molar yield (HMY) of 93.99% and 0.259 mol of H2 mol of xylose−1, respectively, were obtained. Biohydrogen kinetics and electron equivalent (e− equiv) balance calculations indicated that methyl red (MR) penetrates and intracellularly inhibits both the pentose phosphate pathway and pyruvate fermentation pathway, while methyl orange (MO) acted independently of the glycolysis and biohydrogen pathway. The data demonstrate that biohydrogen pathways in the presence of azo dyes with sulfonate and carboxyl groups were different, but the azo dyes could be completely reduced during the biohydrogen production period in the presence of MO or MR. The feasibility of hydrogen production from industrial pulp and paper effluent by the strain if the xylose is sufficient was also proved and was not affected by toxic substances which usually exist in such wastewater, except for chlorophenol. This study offers a promising energy-recycling strategy for treating pulp and paper wastewaters, especially for those containing azo dyes. IMPORTANCE The pulp and paper industry is a major industry in many developing countries, and the global market of pulp and paper wastewater treatment is expected to increase by 60% between 2012 and 2020. Such wastewater contains large amounts of refractory contaminants, such

  5. Efeitos dos parâmetros operacionais na fotodegradação do azo corante direct red 23 na interface dióxido de titânio/água Effects of operational parameters on the photodegradation of direct red 23 azo dye at the titanium dioxide/water interface

    Directory of Open Access Journals (Sweden)

    Débora Nobile Clausen

    2007-01-01

    Full Text Available The decolorization and degradation of direct red 23 azo dye have been investigated in aqueous suspension of titanium dioxide under artificial irradiation. The effects of some operational parameters such as azo dye concentration, catalyst loading, and solution pH were investigated at 30.0 ºC and optimized values were obtained. The first-order kinetic model was used to discuss the results. The UV-Vis spectra changes showed that the azo dye sample, collected after 6 h irradiation, was 98% decolorized while the residual total carbon was 97.9% degraded, indicating simultaneous photodecolorization and degradation.

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

    Science.gov (United States)

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

    2017-07-01

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

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

    International Nuclear Information System (INIS)

    Aravind, Priyadharshini; Selvaraj, Hosimin; Ferro, Sergio; Sundaram, Maruthamuthu

    2016-01-01

    Highlights: • Firstly, the mediated electro-oxidation allows rapid discoloration of the effluent. • Cost effective sunlight-mediated removal of bio-toxic active chlorine species. • Electrochemical pretreatment enhances the biodegradability of textile wastewater. • About 90% COD removal was achieved by a subsequent biodegradation. • By-products from degradation of dyes have shown to be ecofriendly and non-toxic. - Abstract: 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/IrO_2-RuO_2-TiO_2 anodes), lead to discoloration by 92% and 89%, respectively, in 100 min, 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 144 h. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Aravind, Priyadharshini, E-mail: priya.bdu07@gmail.com [Corrosion and Materials Protection Division (CMPD), CSIR—Central electrochemical research institute (CECRI), Karaikudi 630 003 (India); Selvaraj, Hosimin [Corrosion and Materials Protection Division (CMPD), CSIR—Central electrochemical research institute (CECRI), Karaikudi 630 003 (India); Ferro, Sergio [Ecas4 Australia, Unit 8, 1 London Road, Mile End, South Australia 5031 (Australia); Sundaram, Maruthamuthu [Corrosion and Materials Protection Division (CMPD), CSIR—Central electrochemical research institute (CECRI), Karaikudi 630 003 (India)

    2016-11-15

    Highlights: • Firstly, the mediated electro-oxidation allows rapid discoloration of the effluent. • Cost effective sunlight-mediated removal of bio-toxic active chlorine species. • Electrochemical pretreatment enhances the biodegradability of textile wastewater. • About 90% COD removal was achieved by a subsequent biodegradation. • By-products from degradation of dyes have shown to be ecofriendly and non-toxic. - Abstract: 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/IrO{sub 2}-RuO{sub 2}-TiO{sub 2} anodes), lead to discoloration by 92% and 89%, respectively, in 100 min, 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 144 h. 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.

  9. Density functional theory study of adsorption geometries and electronic structures of azo-dye-based molecules on anatase TiO2 surface for dye-sensitized solar cell applications.

    Science.gov (United States)

    Prajongtat, Pongthep; Suramitr, Songwut; Nokbin, Somkiat; Nakajima, Koichi; Mitsuke, Koichiro; Hannongbua, Supa

    2017-09-01

    Structural and electronic properties of eight isolated azo dyes (ArNNAr', where Ar and Ar' denote the aryl groups containing benzene and naphthalene skeletons, respectively) were investigated by density functional theory (DFT) based on the B3LYP/6-31G(d,p) and TD-B3LYP/6-311G(d,p) methods The effect of methanol solvent on the structural and electronic properties of the azo dyes was elucidated by employing a polarizable continuum model (PCM). Then, the azo dyes adsorbed onto the anatase TiO 2 (101) slab surface through a carboxyl group. The geometries and electronic structures of the adsorption complexes were determined using periodic DFT based on the PWC/DNP method. The calculated adsorption energies indicate that the adsorbed dyes preferentially take configuration of the bidentate bridging rather than chelating or monodentate ester-type geometries. Furthermore, the azo compounds having two carboxyl groups are coordinated to the TiO 2 surface more preferentially through the carboxyl group connecting to the benzene skeleton than through that connecting to the naphthalene skeleton. The dihedral angles (Φ B-N ) between the benzene- and naphthalene-skeleton moieties are smaller than 10° for the adsorbed azo compounds containing one carboxyl group. In contrast, Φ B-N > 30° are obtained for the adsorbed azo compounds containing two carboxyl groups. The almost planar conformations of the former appear to strengthen both π-electrons conjugation and electronic coupling between low-lying unoccupied molecular orbitals of the azo dyes and the conduction band of TiO 2 . On the other hand, such coupling is very weak for the latter, leading to a shift of the Fermi level of TiO 2 in the lower-energy direction. The obtained results are useful to the design and synthesize novel azo-dye-based molecules that give rise to higher photovoltaic performances of the dye-sensitized solar cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Photoassisted electrochemical recirculation system with boron-doped diamond anode and carbon nanotubes containing cathode for degradation of a model azo dye

    International Nuclear Information System (INIS)

    Vahid, Behrouz; Khataee, Alireza

    2013-01-01

    In this research work, a photoassisted electrochemical system under recirculation mode and with UV irradiation was designed for treatment of C.I. Acid Blue 92 (AB92) as a model anionic azo dye in aqueous solution. Degradation experiments were carried out with boron-doped diamond (BDD) anode and carbon nanotubes-polytetrafluoroethylene (CNTs-PTFE) cathode in the presence of sulfate as an electrolyte. A comparative study of AB92 degradation by photolysis, electrochemical oxidation and photoassisted electrochemical processes after 45 min of treatment demonstrated that degradation efficiency was 27.89, 37.65 and 95.86%, respectively. Experimental data revealed that the degradation rate of AB92 in all of the processes obeyed pseudo-first-order kinetics and application of photoassisted electrochemical system reduced electrical energy per order (E EO ), considerably. Degradation efficiency of photoassisted electrochemical process enhanced by increasing applied current and flow rate values, but vice versa trend was observed for initial dye concentration and an optimum amount of 6 was obtained for initial pH. The TOC measurement results demonstrated that 93.24% of organic substrates were mineralized after 120 min of photoassisted electrochemical process and GC–Mass analysis was performed for identification of degradation intermediates

  11. 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.

  12. Syntheses of Azo-Imine Derivatives from Vanillin as an Acid Base Indicator

    Directory of Open Access Journals (Sweden)

    Bambang Purwono

    2013-05-01

    Full Text Available Preparations of azo, imine and azo-imine derivatives from vanillin as an indicator of acid-base titration have been carried out. The azo derivative of 4-hydroxy-3-methoxy-5-(phenylazobenzaldehyde 2 was produced by diazotitation reaction of vanillin in 37.04% yield. The azo product was then refluxed with aniline in ethanol to yield azo-imine derivatives, 2-methoxy-6-(phenylazo-4-((phenyliminomethylphenol 1 in 82.21% yield. The imine derivative, 2-methoxy-4-((phenyliminomethyl-phenol 3 was obtained by refluxing of vanillin and aniline mixture in ethanol solvent and produced 82.17% yield. The imine product was then reacted with benzenediazonium chloride salt. However, the products indicated hydrolyzed product of 4-hydroxy-3-methoxy-5-(phenylazobenzaldehyde 2 in 22.15% yield. The 2-methoxy-4-((phenyliminomethylphenol 2 could be used as an indicator for titration of NaOH by H2C2O4 with maximum concentration of H2C2O4 0.1 M while the target compound 1 could be used as titration indicator for titration of NaOH with H2C2O4 with same result using phenolphthalein indicator.

  13. Aerobic sludge granulation for simultaneous anaerobic decolorization and aerobic aromatic amines mineralization for azo dye wastewater treatment.

    Science.gov (United States)

    Yan, Lawrence K Q; Fung, Ka Y; Ng, Ka M

    2018-06-01

    In this study, the capability of using aerobic granules to undergo simultaneous anaerobic decolorization and aerobic aromatic amines degradation was demonstrated for azo dye wastewater treatment. An integrated acclimation-granulation process was devised, with Mordant Orange 1 as the model pollutant. Performance tests were carried out in a batch column reactor to evaluate the effect of various operating parameters. The optimal condition was to use 1.0-1.7 mm (1.51 ± 0.33 mm) granules, 5 g/L biomass, and 4000 mg/L organics as nutrient; and supplement the wastewater with 1  mg/L dissolved oxygen. This led to a dye mineralization of 61 ± 2%, an anaerobic dye removal of 88 ± 1%, and an aerobic aromatic amines removal of 70 ± 3% within 48 h. This study showed that simultaneous anaerobic/aerobic process by aerobic granules could be a possible alternative to the conventional activated sludge process.

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

    Science.gov (United States)

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

    2014-05-01

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

  15. Effect of food azo dye tartrazine on learning and memory functions in mice and rats, and the possible mechanisms involved.

    Science.gov (United States)

    Gao, Yonglin; Li, Chunmei; Shen, Jingyu; Yin, Huaxian; An, Xiulin; Jin, Haizhu

    2011-08-01

    Tartrazine is an artificial azo dye commonly used in human food and pharmaceutical products. The present study was conducted to evaluate the toxic effect of tartrazine on the learning and memory functions in mice and rats. Animals were administered different doses of tartrazine for a period of 30 d and were evaluated by open-field test, step-through test, and Morris water maze test, respectively. Furthermore, the biomarkers of the oxidative stress and pathohistology were also measured to explore the possible mechanisms involved. The results indicated that tartrazine extract significantly enhanced active behavioral response to the open field, increased the escape latency in Morris water maze test and decreased the retention latency in step-through tests. The decline in the activities of catalase, glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) as well as a rise in the level of malonaldehyde (MDA) were observed in the brain of tartrazine-treated rats, and these changes were associated with the brain from oxidative damage. The dose levels of tartrazine in the present study produced a few adverse effects in learning and memory functions in animals. The mechanisms might be attributed to promoting lipid peroxidation products and reactive oxygen species, inhibiting endogenous antioxidant defense enzymes and the brain tissue damage. Tartrazine is an artificial azo dye commonly used in human food and pharmaceutical products. Since the last assessment carried out by the Joint FAO/WHO Expert Committee on Food Additives in 1964, many new studies have been conducted. However, there is a little information about the effects on learning and memory performance. The present study was conducted to evaluate the toxic effect of tartrazine on the learning and memory functions in animals and its possible mechanism involved. Based on our results, we believe that more extensive assessment of food additives in current use is warranted. © 2011 Institute of Food

  16. The effects of halide ions on the radiation-induced decoloration of azo and anthraquinone dyes in N2O-saturated aqueous solutions

    International Nuclear Information System (INIS)

    Suzuki, Nobutake; Tokunaga, Okihiro; Washino, Masamitsu

    1978-01-01

    The radiation-induced decoloration of azo and anthraquinone dyes was studied in N 2 O-saturated aqueous solutions containing halide ions. In the N 2 O-saturated solutions, the decoloration yield, G(-Dye), increased markedly upon the addition of Br - and I - , which are efficient scavengers of the OH radical. In the nitrogen-saturated solutions, however, the G(-Dye) decreased upon the addition of Br - and I - . Such an increase in the G(-Dye) upon the addition of Br - and I - in the N 2 O-saturated solutions is mainly attributable to the attacks of the halide radical anions, Br 2 - and I 2 - , on the ring structure of the dyes. On the other hand, the G(-Dye) was not changed upon the addition of Cl - in the N 2 O-saturated solution. This may be attributable to the very slow rate of the formation of Cl 2 - in a neutral solution. (auth.)

  17. Low-Cost Biodegradation and Detoxification of Textile Azo Dye C.I. Reactive Blue 172 by Providencia rettgeri Strain HSL1

    Directory of Open Access Journals (Sweden)

    Harshad Lade

    2015-01-01

    Full Text Available Present study focuses on exploitation of agricultural waste wheat bran (WB as growth medium for degradation of textile azo dye C.I. Reactive Blue 172 (RB 172 using a single bacterium P. rettgeri strain HSL1 (GenBank accession number JX853768.1. The bacterium was found to completely decolorize 50 mg L−1 of dye RB 172 within 20 h at 30 ± 0.2°C under microaerophilic incubation conditions. Additionally, significant reduction in COD (85% and TOC (52% contents of dye decolorized medium was observed which suggested its mineralization. Induction in the activities of azoreductase (159% and NADH-DCIP reductase (88% provided an evidence for reductive cleavage of dye RB 172. The HPLC, FTIR, and GC-MS analysis of decolorized products confirmed the degradation of dye into various metabolites. The proposed metabolic pathway for biodegradation of RB 172 has been elucidated which showed the formation of 2 intermediate metabolites, namely, 4-(ethenylsulfonyl aniline and 1-amino-1-(4-aminophenyl propan-2-one. The acute and phytotoxicity evaluation of degraded metabolites suggests that bacterial strain favors the detoxification of dye RB 172. Thus, WB could be utilized as a low-cost growth medium for the enrichment of bacteria and their further use for biodegradation of azo dyes and its derivatives containing wastes into nontoxic form.

  18. 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.

  19. 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.

  20. Adsorption of Azo-Dye Orange II from Aqueous Solutions Using a Metal-Organic Framework Material: Iron- Benzenetricarboxylate

    Science.gov (United States)

    Rojas García, Elizabeth; López Medina, Ricardo; May Lozano, Marcos; Hernández Pérez, Isaías; Valero, Maria J.; Maubert Franco, Ana M.

    2014-01-01

    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. PMID:28788289

  1. 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.

  2. Bioremediation of acid fast red dye by Streptomyces globosus under ...

    African Journals Online (AJOL)

    Administrator

    2011-04-25

    Apr 25, 2011 ... Azo dyes are widely used in industries, such as textiles, paper, plastics ... processes have received increasing interest owing to their cost effectiveness and environmental friendliness. (Mabrouk and ... hydrolytic enzymes . In addition it .... A trial for using potato peels for more economic biomass production.

  3. Synthesized TiO{sub 2}/ZSM-5 composites used for the photocatalytic degradation of azo dye: Intermediates, reaction pathway, mechanism and bio-toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Kefu; Hu, Xin-Yan [College of the Environment and Ecology, Xiamen University, Xiamen (China); Chen, Bor-Yann; Hsueh, Chung-Chuan [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan, Taiwan (China); Zhang, Qian [Department of Environmental Engineering, National Taiwan University, Taipei, Taiwan (China); Wang, Jiajie; Lin, Yu-Jung [College of the Environment and Ecology, Xiamen University, Xiamen (China); Chang, Chang-Tang, E-mail: ctchang73222@gmail.com [Department of Environmental Engineering, National I-Lan University, I-Lan, Taiwan (China)

    2016-10-15

    Highlights: • The major photo-catalytic degradation pathway of azo-dye was elaborated according to the identification of by-products from GC–MS and IC analysis. • Comparative assessment on characteristics of abiotic and biotic dye decolorization was analyzed. • EDTA (hole scavengers) and t-BuOH (radical scavengers) were used to determine the main active oxidative species in the system. • The toxicity effects of degradation intermediates of Reactive Black 5 (RB5) on the cellular respiratory activity were assessed. - Abstract: In this study, a one-step solid dispersion method was used to synthesize titanium dioxide (TiO{sub 2})/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 TiO{sub 2}/ZSM-5 composites with TiO{sub 2} 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 CO{sub 2} 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

  4. Kinetics and mechanism of azo dye destruction in advanced oxidation processes

    International Nuclear Information System (INIS)

    Wojnarovits, L.; Palfi, T.; Takacs, E.

    2007-01-01

    The kinetics and mechanism of dye destruction in advanced oxidation processes is discussed on the example of Apollofix Red (Ar-28) radiolysis in aqueous solution. When the reactive intermediate reacts with the color bearing part of the molecule causing with nearly 100% efficiency destruction of the conjugation, the dose dependence, or time dependence of color disappearance is linear. In this case, spectrophotometry can be used to follow-up dye decomposition. Linear dependence was observed when hydrated electrons or hydrogen atoms reacted with the dye. In hydroxyl radical reactions some colored products form with spectra similar to those of the starting dye molecules. For that reason, spectrophotometry gives false result about the intact dye molecule concentration. Analysis by the HPLC reveals logarithmic time dependence in agreement with a theoretical model developed

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

    Science.gov (United States)

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

    2015-07-01

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

  6. Photo-oxidative degradation of Chicago Sky Blue azo dye on transition metal oxide electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Slote, J.; Luo, J.; Hepel, M. [State Univ. of New York at Potsdam, NY (United States). Dept. of Chemistry; Zhong, C.-J. [State Univ. of New York at Binghamton, NY (United States). Dept. of Chemistry

    2003-07-01

    Every day, an average of 128 tons of dye staffs are discharged into waste water, causing environmental harm. The authors discussed the photo-electrical method for separating the semiconductor catalyst particles from the solution and direct control of the interfacial potential as an efficient and convenient method for degrading organic dyes. Photocurrent-potential measurements were made using a standard photoelectrochemical setup. It involved a microcomputer-controlled potentiostat and a 500 watts (W) quartz halogen lamp as the illumination source. The measurement of the photocurrent represented the difference between the current under illumination and current in the dark. Three-electrode electrochemical cells were used for all experiments. The best results concerning the degradation of dyes were obtained with tungsten oxides (WO3) and molybdenum oxides (MoO3) electrodes. Confirmation that the dyes had been fully degraded was obtained by performing absorbance measurements and a high performance liquid chromatography (HPLC) analysis of the samples after degradation. The effect on the rate of decolorisation process of Chicago Sky Blue, a diazo dye, and other dyes, of pH, potential, concentration, and type of supporting electrolyte was examined. The supporting electrolyte was found to have a strong influence on the degradation of diazo dye. Illumination with visible light yielded lower degradation rates than that with ultraviolet-visible light. It appears that Chicago Sky Blue dye sensitizes the semiconductor to expand the absorption of light energy well into visible range, despite the photoelectrochemical degradation of the dye being mainly induced by the ultraviolet light. The authors proposed the mechanisms of the reactions occurring during the photodegradation process. 6 refs., 1 fig.

  7. Structure and reactivity of thiazolium azo dyes: UV-visible, resonance Raman, NMR, and computational studies of the reaction mechanism in alkaline solution.

    Science.gov (United States)

    Abbott, Laurence C; Batchelor, Stephen N; Moore, John N

    2013-03-07

    UV-visible absorption, resonance Raman, and (1)H NMR spectroscopy, allied with density functional theory (DFT) calculations, have been used to study the structure, bonding, and alkaline hydrolysis mechanism of the cationic thiazloium azo dye, 2-[2-[4-(diethylamino)phenyl]diazenyl]-3-methyl-thiazolium (1a), along with a series of six related dyes with different 4-dialkylamino groups and/or other phenyl ring substituents (2a-c, 3a-c) and the related isothiazolium azo dye, 5-[2-[4-(dimethylamino)phenyl]diazenyl]-2-methyl-isothiazolium (4). These diazahemicyanine dyes are calculated to have a similar low-energy structure that is cis, trans at the (iso)thiazolium-azo group, and for which the calculated Raman spectra provide a good match with the experimental data; the calculations on these structures are used to assign and discuss the transitions giving rise to the experimental spectra, and to consider the bonding and its variation between the dyes. UV-visible, Raman, and NMR spectra recorded from minutes to several weeks after raising the pH of an aqueous solution of 1a to ca. 11.5 show that the dominant initial step in the reaction is loss of diethylamine to produce a quinonimine (ca. hours), with subsequent reactions occurring on longer time scales (ca. days to weeks); kinetic analyses give a rate constant of 2.6 × 10(-2) dm(3) mol(-1) s(-1) for reaction of 1a with OH(-). UV-visible spectra recorded on raising the pH of the other dyes in solution show similar changes that are attributed to the same general reaction mechanism, but with different rate constants for which the dependence on structure is discussed.

  8. Photocatalytic Removal of Azo Dye and Anthraquinone DyeUsing TiO2 Immobilised on Ceramic Tiles

    Directory of Open Access Journals (Sweden)

    P. N. Palanisamy

    2011-01-01

    Full Text Available The photocatalytic activity of TiO2 immobilized on different supports; cement and ceramic tile, was studied to decolorize two commercial dyes. The catalyst was immobilised by two different techniques, namely, slurry method on ceramic tile and powder scattering on cement. The degradation of the dyes was carried out using UV and solar irradiation. The comparative efficiency of the catalyst immobilised on two different supports was determined. The photodegradation process was monitored by UV-Vis spectrophotometer. The catalyst immobilised on ceramic tile was found to be better than the catalyst immobilised on cement. Experimental results showed that both illumination and the catalyst were necessary for the degradation of the dyes and UV irradiation is more efficient compared to solar irradiation.

  9. Ultrasound for low temperature dyeing of wool with acid dye.

    Science.gov (United States)

    Ferrero, F; Periolatto, M

    2012-05-01

    The possibility of reducing the temperature of conventional wool dyeing with an acid levelling dye using ultrasound was studied in order to reach exhaustion values comparable to those obtained with the standard procedure at 98 °C, obtaining dyed samples of good quality. The aim was to develop a laboratory method that could be transferred at industrial level, reducing both the energy consumption and fiber damage caused by the prolonged exposure to high temperature without the use of polluting auxiliary agents. Dyeings of wool fabrics were carried out in the temperature range between 60 °C and 80 °C using either mechanical or ultrasound agitation of the bath and coupling the two methods to compare the results. For each dyeing, the exhaustion curves of the dye bath were determined and the better results of dyeing kinetics were obtained with ultrasound coupled with mechanical stirring. Hence the corresponding half dyeing times, absorption rate constants according to Cegarra-Puente modified equation and ultrasonic efficiency were calculated in comparison with mechanical stirring alone. In the presence of ultrasound the absorption rate constants increased by at least 50%, at each temperature, confirming the synergic effect of sonication on the dyeing kinetics. Moreover the apparent activation energies were also evaluated and the positive effect of ultrasound was ascribed to the pre-exponential factor of the Arrhenius equation. It was also shown that the effect of ultrasound at 60 °C was just on the dye bath, practically unaffecting the wool fiber surface, as confirmed by the results of SEM analysis. Finally, fastness tests to rubbing and domestic laundering yielded good values for samples dyed in ultrasound assisted process even at the lower temperature. These results suggest the possibility, thanks to the use of ultrasound, to obtain a well equalized dyeing on wool working yet at 60°C, a temperature process strongly lower than 98°C, currently used in industry

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

    Energy Technology Data Exchange (ETDEWEB)

    Das, Laboni [Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Chatterjee, Suchandra [Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Naik, Devidas B. [Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Adhikari, Soumyakanti, E-mail: asoumya@barc.gov.in [Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2015-11-15

    Highlights: • Demonstration of the role of surfactant in the degradation of the hydrophobic dye. • First direct observation of the formation of “hydrazyl radical-parent” adduct. • Similar products obtained in the reaction of e{sup −}{sub aq} and ·OH radical in TX-100 medium. • Significant reduction in cytotoxicity of irradiated dye in aqueous–organic medium. • New mechanistic pathway could be delineated. - Abstract: A combined methodology involving gamma and pulse radiolysis, product analysis and toxicity studies has been adopted to comprehend the degradation process of a model hydrophobic azo dye, 1-phenylazo-2-naphthol, emphasizing the role of the surfactant, which is an integral part of textile waste. Two new and important findings are underlined in this article. The first is the direct attestation of the hydrazyl radical-parent adduct, formed in the reaction of the dye with e{sup −}{sub aq} followed by protonation and subsequent addition to the unreacted dye molecule. This has been confirmed from concentration dependent studies. Secondly, we have clearly shown that in the reaction of hydroxyl radical with the dye in Triton X-100 media, the initially produced TX radicals cause reductive degradation of the dye. Identification and detailed analysis of HPLC and GCMS data reveals that similar products are formed in both the reactions of e{sup −}{sub aq} and ·OH radicals. Moreover, the cytotoxicity of 10{sup −4} mol dm{sup −3} dye was found to be reduced significantly after irradiation. Thus, the present study not only depicts new pathways for the degradation of hydrophobic azo dye, but also demonstrates the role of a surfactant in the entire process.

  11. Microwave-enhanced UV/H2O2 degradation of an azo dye (tartrazine): optimization, colour removal, mineralization and ecotoxicity.

    Science.gov (United States)

    Parolin, Fernanda; Nascimento, Ulisses Magalhães; Azevedo, Eduardo Bessa

    2013-01-01

    This study optimizes two factors, pH and initial [H2O2], in the ultraviolet (UV)/H2O2/microwave (MW) process through experimental design and assesses the effect of MWs on the colour removal of an azo-dye (tartrazine) solution that was favoured by an acidic pH. The estimated optimal conditions were: initial [H2O2] = 2.0 mmol L(-1) and pH = 2.6, at 30 +/- 2 degrees C. We obtained colour removals of approximately 92% in 24 min of irradiation (EDL, 244.2 W), following zero order kinetics: k = (3.9 +/- 0.52) x 10(-2) a.u. min(-1) and R2 = 0.989. Chemical and biological oxygen demand were significantly removed. On the other hand, the carbon content, biodegradability and ecotoxicity (Lactuca sativa) remained approximately the same. The UV/H2O2/MW process was shown to be eight times faster than other tested processes (MW, H2O2, H2O2/MW, and UV/MW).

  12. Synthesis, characterization and dyeing behavior of heterocyclic acid dyes and mordent acid dyes on wool and silk fabrics

    Directory of Open Access Journals (Sweden)

    Patel Hitendra M.

    2012-01-01

    Full Text Available Novel heterocyclic acid and mordent acid dyes were synthesized by the coupling of diazonium salt solution of different aromatic amines with 2- butyl-3-(4-hydroxybenzoylbenzofuran. The resulting heterocyclic acid dyes were characterized by spectral techniques, i.e., elemental analysis, IR, 1HNMR, 13C-NMR spectral studies and UV- visible spectroscopy. The dyeing performance of all the heterocyclic acid 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.

  13. TiO2/Ag modified penta-bismuth hepta-oxide nitrate and its adsorption performance for azo dye removal

    Institute of Scientific and Technical Information of China (English)

    Eshraq Ahmed Abdullah; Abdul Halim Abdullah; Zulkarnain Zainal; Mohd Zobir Hussein; Tan Kar Ban

    2012-01-01

    A modified hydrophilic penta-bismuth hepta-oxide nitrate (Bi5O7NO3) surface was synthesized via a precipitation method using TiO2 and Ag as modified agents.The synthesized product was characterized by different analytical techniques.The removal efficiency was evaluated using mono- and di-sulphonated azo dyes as model pollutants.Different kinetic,isotherm and diffusion models were chosen to describe the adsorption process.X-ray photoelectron spectroscopy (XPS) results revealed no noticeable differences in the chemical states of modified adsorbent when compared to pure Bi5O7NO3; however,the presence of hydrophilic centres such as TiO2 and Ag developed positively charged surface groups and improved its adsorption performance to a wide range of azo dyes.Dyes removal was found to be a function of adsorbent dosage,initial dye concentration,solution pH and temperature.The reduction of Langrnuir 1,2-mixed order kinetics to the second or first-order kinetics could be successfully used to describe the adsorption of dyes onto the modified adsorbent.Mass transfer can be described by intra-particle diffusion at a certain stage,but it was not the rate limiting step that controlled the adsorption process.Homogenous behavior of adsorbent surface can be explored by applying Langmuir isotherm to fit the adsorption data.

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

    Energy Technology Data Exchange (ETDEWEB)

    Molina, J.; Fernandez, J.; Rio, A.I. del; Bonastre, J. [Departamento de Ingenieria Textil y Papelera, EPS de Alcoy, Universitat Politecnica de Valencia, Plaza Ferrandiz y Carbonell s/n, 03801 Alcoy (Spain); Cases, F., E-mail: fjcases@txp.upv.es [Departamento de Ingenieria Textil y Papelera, EPS de Alcoy, Universitat Politecnica de Valencia, Plaza Ferrandiz y Carbonell s/n, 03801 Alcoy (Spain)

    2012-06-15

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

  15. Azo dyes decomposition on new nitrogen-modified anatase TiO{sub 2} with high adsorptivity

    Energy Technology Data Exchange (ETDEWEB)

    Janus, M., E-mail: mjanus@ps.pl [Szczecin University of Technology, Department of Sanitary Engineering, al. Piastow 50, 70-310 Szczecin (Poland); Szczecin University of Technology, Institute of Chemical and Environment Engineering, Department of Water Technology and Environment Engineering, ul. Pulaskiego 10, 70-322 Szczecin (Poland); Choina, J.; Morawski, A.W. [Szczecin University of Technology, Institute of Chemical and Environment Engineering, Department of Water Technology and Environment Engineering, ul. Pulaskiego 10, 70-322 Szczecin (Poland)

    2009-07-15

    New vis active photocatalyst was obtained by the modification of commercial anatase TiO{sub 2} (Police, Poland) in pressure reactor in an ammonia water atmosphere at 100 {sup o}C for 4 h. The photocatalytic activity of new material was tested during three azo dyes decomposition: monoazo (Reactive Read), diazo (Reactive Black) and poliazodye (Direct Green). Obtained photocatalyst had new bands at 1430-1440 cm{sup -1} attributed to the bending vibrations of NH{sub 4}{sup +} and at 1535 cm{sup -1} associated with NH{sub 2} groups or NO{sub 2} and NO. UV-vis/DR spectra of photocatalyst had also insignificant decrease in visible region. Fluorescence technique was used for studying the amount of hydroxyl radicals produced on TiO{sub 2} surface during visible light irradiation. The hydroxyl radicals produced react with coumarin present in the solution to form 7-hydroxycoumarin which has fluorescent capacity. Photocatalytic activity of modified TiO{sub 2} was compared with commercial titanium dioxide P25 (Degussa, Germany). The photocatalytic activity of TiO{sub 2}/N was higher than that of unmodified material and P25 under visible light irradiation. The ability for dye adsorption (Reactive Red) on photocatalyst surface was also tested. Unmodified TiO{sub 2} and P25 has isotherm of adsorption by Freundlich model, and nitrogen-modified TiO{sub 2} by Langmuir model. The presence of nitrogen at the surface of TiO{sub 2} significantly increased adsorption capacity of TiO{sub 2} as well as OH{center_dot} radicals formation under visible radiation.

  16. Use of active consortia of constructed ternary bacterial cultures via mixture design for azo-dye decolorization enhancement

    International Nuclear Information System (INIS)

    Chen, B.-Y.; Wang, M.-Y.; Lu, W.-B.; Chang, J.-S.

    2007-01-01

    This first-attempt study used constructed bacterial consortia containing Escherichia coli DH5α (a weak decolorizer) and its UV-irradiated mutants (E. coli UVT1 and UV68; strong decolorizers) via equilateral triangle diagram and mixture experimental design to assess color removal during species evolution. The results showed that although strain DH5α was not an effective decolorizer, its presence might still played a significant role in affecting optimal color removal capabilities of mixed consortia (e.g., E. coli DH5α, UVT1 and UV68) for two model azo dyes; namely, reactive red 22 (RR22) and reactive black 5 (RB5). Contour analysis of ternary systems also clearly showed that decolorization of RR22 and RB5 by DH5α-containing active mixed consortia was more effective than mono-cultures of the stronger decolorizer alone (e.g., UVT1). The optimal composition of the mixed consortium (UV68, UVT1, DH5α) achieving the highest specific decolorization rate was (13%:58%:29%) and (0%:74%:26%) for decolorization of RR22 and RB5, respectively, with initial total cell density fixed at OD 600 = 3.5 ± 0.28

  17. Effects of Electrical Stimulation on the Degradation of Azo Dye in Three-Dimensional Biofilm Electrode Reactors

    Directory of Open Access Journals (Sweden)

    Xian Cao

    2017-04-01

    Full Text Available Three-dimensional biofilm electrode reactors (3D-BERs were constructed to degrade the azo dye Reactive Brilliant Red (RBR X-3B. The 3D-BERs with different influent concentrations and external voltages were individually studied to investigate their influence on the removal of X-3B. Experimental results showed that 3D-BERs have good X-3B removal efficiency; even when the influent concentration was 800 mg/L, removal efficiency of 73.4% was still achieved. In addition, the X-3B removal efficiency stabilized shortly after the influent concentration increased. In 3D-BERs, the average X-3B removal efficiency increased from 52.8% to 85.4% when the external voltage rose from 0 to 2 V. We further identified the intermediate products via UV-Vis and gas chromatography-mass spectrometry (GC-MS analyses, and discussed the potential mechanism of degradation. After the conjugate structure of X-3B was destroyed, all of the substances generated mainly consisted of lower-molecular-weight organics.

  18. Remediation of azo dyes by using household used black tea as an ...

    African Journals Online (AJOL)

    In the present study used black tea and its impregnates were used as an adsorbents for the removal of textile dyes such as methylene blue and malachite green. The impregnation technique was adopted for the preparation of metal impregnates. The present study shows that used black tea and its impregnate exhibit ...

  19. Photocatalytic oxidation of a reactive azo dye and evaluation of the ...

    African Journals Online (AJOL)

    driniev

    2004-07-03

    Jul 3, 2004 ... biological oxygen demand (BOD) test. The results ... Toxicity testing of photo- catalytically ... The dye solution contained in a flask was placed on a magnetic ..... opacity of the suspension in the excess of TiO2 particles (Fig. 4).

  20. Spectroscopic, thermal, catalytic and biological studies of Cu(II) azo dye complexes

    Science.gov (United States)

    El-Sonbati, A. Z.; Diab, M. A.; El-Bindary, A. A.; Shoair, A. F.; Hussein, M. A.; El-Boz, R. A.

    2017-08-01

    New complexes of copper(II) with azo compounds of 5-amino-2-(aryl diazenyl)phenol (HLn) are prepared and investigated by elemental analyses, molar conductance, IR, 1H NMR, UV-Visible, mass, ESR spectra, magnetic susceptibility measurements and thermal analyses. The complexes have a square planar structure and general formula [Cu(Ln)(OAc)]H2O. Study the catalytic activities of Cu(II) complexes toward oxidation of benzyl alcohol derivatives to carbonyl compounds were tested using H2O2 as the oxidant. The intrinsic binding constants (Kb) of the ligands (HLn) and Cu(II) complexes (1-4) with CT-DNA are determined. The formed compounds have been tested for biological activity of antioxidants, antibacterial against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and yeast Candida albicans. Antibiotic (Ampicillin) and antifungal against (Colitrimazole) and cytotoxic compounds HL1, HL2, HL3 and complex (1) showed moderate to good activity against S. aureus, E. coli and Candida albicans, and also to be moderate on antioxidants and toxic substances. Molecular docking is used to predict the binding between the ligands with the receptor of breast cancer (2a91).

  1. Biodegradation of Azo Dye RO16 in Different Reactors by Immobilized Irpex lacteus

    Czech Academy of Sciences Publication Activity Database

    Tavčar, M.; Svobodová, Kateřina; Kuplenk, J.; Novotný, Čeněk; Pavko, A.

    2006-01-01

    Roč. 53, - (2006), s. 338-343 ISSN 1318-0207 R&D Projects: GA MŠk(CZ) 1P05ME828; GA AV ČR(CZ) IAA6020411; GA ČR(CZ) GP526/06/P102 Institutional research plan: CEZ:AV0Z50200510 Keywords : irpex lacteus * dye decolorization * trickle bed reactor Subject RIV: EE - Microbiology, Virology Impact factor: 0.703, year: 2006

  2. Photophysical behavior of layer-by-layer electrostatic self-assembled film of azo dye Chromotrope-2R and a polycation

    Energy Technology Data Exchange (ETDEWEB)

    Hansda, Chaitali [Department of Physics, Jadavpur University, Jadavpur, Kolkata 700032 (India); Department of Physics, The University of Burdwan, Golapbag, Burdwan 713104 (India); Dutta, Bipan [Department of Physics, Sammilani Mahavidyalaya, Baghajatin Station, E.M. Bypass, Kolkata 700075 (India); Chakraborty, Utsav; Singha, Tanmoy [Department of Physics, Jadavpur University, Jadavpur, Kolkata 700032 (India); Hussain, Syed Arshad; Bhattacharjee, Debajyoti [Department of Physics, Tripura University, Suryamaninagar 799022, Tripura West (India); Paul, Sharmistha [West Bengal State Council of Science and Technology, Vigyan Chetana Bhavan, Sector-I, Salt Lake, Kolkata 700064 (India); Paul, Pabitra Kumar, E-mail: pabitra_tu@yahoo.co.in [Department of Physics, Jadavpur University, Jadavpur, Kolkata 700032 (India)

    2016-10-15

    This communication reports the fabrication of layer-by-layer electrostatic self-assembled films of an azo dye Chromotrope-2R (CH2R) and a Polycation poly(allylamine hydrochloride) (PAH) onto solid substrate. UV–vis absorption and steady state fluorescence emission spectroscopy successfully confirm the incorporation of dye molecules onto the PAH coated quartz substrate. The adsorption behavior of CH2R onto PAH backbone in LbL films highly depends upon the variation of the microenvironment namely pH of the dye solution from which the film was fabricated. PAH layer onto quartz substrate was able to swell sufficiently in the dye solution at very high pH. The Density functional theory was also utilized here to explain the origin of various spectral transitions from the ground electronic states for both in neutral and anionic form of CH2R. In LbL films the more closure association of dye molecules causes their aggregations which are reflected in their absorption and steady state fluorescence emission spectra when compared to those of pure dye solution. Atomic force microscopic images of LbL films assembled from CH2R aqueous solution at different pH clearly reveal the change in the surface morphology of the films and different degree of association of dye molecules in LbL films deposited at various pH of CH2R.

  3. Photophysical behavior of layer-by-layer electrostatic self-assembled film of azo dye Chromotrope-2R and a polycation

    International Nuclear Information System (INIS)

    Hansda, Chaitali; Dutta, Bipan; Chakraborty, Utsav; Singha, Tanmoy; Hussain, Syed Arshad; Bhattacharjee, Debajyoti; Paul, Sharmistha; Paul, Pabitra Kumar

    2016-01-01

    This communication reports the fabrication of layer-by-layer electrostatic self-assembled films of an azo dye Chromotrope-2R (CH2R) and a Polycation poly(allylamine hydrochloride) (PAH) onto solid substrate. UV–vis absorption and steady state fluorescence emission spectroscopy successfully confirm the incorporation of dye molecules onto the PAH coated quartz substrate. The adsorption behavior of CH2R onto PAH backbone in LbL films highly depends upon the variation of the microenvironment namely pH of the dye solution from which the film was fabricated. PAH layer onto quartz substrate was able to swell sufficiently in the dye solution at very high pH. The Density functional theory was also utilized here to explain the origin of various spectral transitions from the ground electronic states for both in neutral and anionic form of CH2R. In LbL films the more closure association of dye molecules causes their aggregations which are reflected in their absorption and steady state fluorescence emission spectra when compared to those of pure dye solution. Atomic force microscopic images of LbL films assembled from CH2R aqueous solution at different pH clearly reveal the change in the surface morphology of the films and different degree of association of dye molecules in LbL films deposited at various pH of CH2R.

  4. Catalytic role of Au-TiO{sub 2} nanocomposite on enhanced degradation of an azo-dye by electrochemically active biofilms: a quantized charging effect

    Energy Technology Data Exchange (ETDEWEB)

    Kalathil, Shafeer; Lee, Jintae; Cho, Moo Hwan, E-mail: mhcho@ynu.ac.kr [Yeungnam University, School of Chemical Engineering (Korea, Republic of)

    2013-01-15

    A green and sustainable approach to azo dye degradation by an electrochemically active biofilm (EAB) with Au-TiO{sub 2} nanocomposite assistance (average size of Au {approx}8 nm) has been developed with high efficiency and mineralization of toxic intermediates. The EAB-Au-TiO{sub 2} system degraded the dye more rapidly than the EAB without the nanocomposite, which indicated the catalytic role of the Au-TiO{sub 2} nanocomposite on the dye degradation. Toxicity measurements showed that the dye wastewater treated by the EAB-Au-TiO{sub 2} system was almost non-toxic while the dye wastewater treated by the EAB without the nanocomposite showed a high toxicity compared to the parent dye. Quantized charging and Fermi level equilibration within the Au-TiO{sub 2} nanocomposite may be attributed to the excellent catalytic activity of the nanocomposite on the dye degradation. A mechanism of the catalytic activity is also proposed. Redox behavior and quantized charging of the nanocomposite were confirmed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), respectively. The proposed protocol can be effectively utilized in wastewater treatment applications.

  5. Photodegradation of Acid red 18 dye by BiOI/ZnO nanocomposite: A dataset

    Directory of Open Access Journals (Sweden)

    Sahand Jorfi

    2018-02-01

    Full Text Available Dyes are one of the most important existing pollutants in textile industrial wastewater. These compounds are often toxic, carcinogenic, and mutagenic to living organisms, chemically and photochemically stable, and non-biodegradable. Acid red 18 is one of the azo dyes that are currently used in the textile industries. Photocatalytic degradation offers a great potential as an advanced oxidation process, in this study photocatalytic degradation of Acid red 18 by using BiOI/ZnO nanocomposite was evaluated under visible light irradiation. The influence of most essential parameters such as pH and BiOI/ZnO dosage were studied for optimum conditions. The dye removal efficiency was 85.1% at optimum experimental conditions of pH of 7, and BiOI/ZnO dosage of 1.5 g/L. The data had a good agreement with pseudo first-order kinetic model. Thus, the BiOI/ZnO/UV is an efficient process for dye degradation. Keywords: Photodegradation, Nanocomposite, BiOI/ZnO, Degradation, Dye, Acid red 18

  6. Chromed Leather Dyeing Peculiarities when Deliming with Peracetic Acid

    OpenAIRE

    Kęstutis BELEŠKA; Virgilijus VALEIKA; Justa ŠIRVAITYTĖ; Violeta VALEIKIENĖ

    2013-01-01

    The research was aimed to investigate the influence of deliming with peracetic acid on leather dyeing kinetics. Hydrophobic C.I. Acid Red 213 and hydrophilic C.I. Acid Red 423 dyes were used. Sorption of dye depends on hydrophobicity/hydrophility of dye and dyeing temperature. Equilibrium of process is reached faster using hydrophobic C.I. Acid Red 213 at 45 ºC. However, both control and experimental leather fibres adsorb more hydrophilic dye C.I. Acid Red 423 and this fact does not depend on...

  7. Adsorption mechanism and kinetics of azo dye chemicals on oxide nanotubes: a case study using porous CeO_2 nanotubes

    International Nuclear Information System (INIS)

    Wu, Junshu; Wang, Jinshu; Du, Yucheng; Li, Hongyi; Jia, Xinjian

    2016-01-01

    Metal oxide nanotubes are believed to be promising materials with adsorption functionality for water purification due to their synergistic effect of the overall microscale morphology for easy separation and nanoscale surface characters providing enough surface active absorption sites. This work shows the synthesis of uniform hierarchical porous CeO_2 nanotubes via nanowire-directed templating method and describes the adsorption behavior of CeO_2 nanotubes for a typical azo dye Congo red which has resistance to oxidation and decoloration in natural conditions. Fourier transform infrared spectroscopy spectra provided the evidence that Congo red was successfully coated on the surface of CeO_2 nanotubes by both bidentate-type bridge link of Ce"4"+ cations from sulfonate SO_3"− groups and the electrostatic attraction between the protonated surface generated by oxygen vacancies and dissociated sulfonate groups. The adsorption kinetic data fitted well to the pseudo-second-order kinetic equation, whereas the Langmuir isotherm equation exhibited better correlation with the experimental data. The calculated maximum adsorption capacity from the isothermal model was 362.32 mg/g. In addition, the prepared CeO_2 nanotubes exhibited good recyclability and reusability as highly efficient adsorbents for Congo red removal after regeneration. These favorable performances enable the obtained CeO_2 nanotubes to be promising materials for dye removal from aqueous solution.Graphical AbstractCeO_2 nanotubes composed of crystallized nanoparticles exhibit well adsorption ability for a typical azo dye Congo red.

  8. Detection of Azo Dyes in Curry Powder Using a 1064-nm Dispersive Point-Scan Raman System

    Directory of Open Access Journals (Sweden)

    Sagar Dhakal

    2018-04-01

    Full Text Available Curry powder is extensively used in Southeast Asian dishes. It has been subject to adulteration by azo dyes. This study used a newly developed 1064 nm dispersive point-scan Raman system for detection of metanil yellow and Sudan-I contamination in curry powder. Curry powder was mixed with metanil yellow and (separately with Sudan-I, at concentration levels of 1%, 3%, 5%, 7%, and 10% (w/w. Each sample was packed into a nickel-plated sample container (25 mm × 25 mm × 1 mm. One Raman spectral image of each sample was acquired across the 25 mm × 25 mm surface area. Intensity threshold value was applied to the spectral images of Sudan-I mixtures (at 1593 cm−1 and metanil yellow mixtures (at 1147 cm−1 to obtain binary detection images. The results show that the number of detected adulterant pixels is linearly correlated with the sample concentration (R2 = 0.99. The Raman system was further used to obtain a Raman spectral image of a curry powder sample mixed together with Sudan-I and metanil yellow, with each contaminant at equal concentration of 5% (w/w. The multi-component spectra of the mixture sample were decomposed using self-modeling mixture analysis (SMA to extract pure component spectra, which were then identified as matching those of Sudan-I and metanil yellow using spectral information divergence (SID values. The results show that the 1064 nm dispersive Raman system is a potential tool for rapid and nondestructive detection of multiple chemical contaminants in the complex food matrix.

  9. Iron promotion of the TiO2 photosensitization process towards the photocatalytic oxidation of azo dyes under solar-simulated light irradiation

    International Nuclear Information System (INIS)

    Castro, Camilo A.; Centeno, Aristobulo; Giraldo, Sonia A.

    2011-01-01

    Highlights: → Azo dye photooxidation occurs under strict combination of ultraviolet and visible irradiation of Fe-TiO 2 . → Fe 3+ enhances the TiO 2 photooxidation of azo dyes while decreases that of phenol. → UV irradiation leads to a decrease in photooxidation activity of Fe-TiO 2 photocatalysts. - Abstract: The photocatalytic oxidation of the azo dye Orange-II (Or-II) using Fe loaded TiO 2 (Fe-TiO 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 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 3+ loading. Photocatalystic tests proved that Fe modification enhanced the TiO 2 photocatalytic activity towards Or-II photodegradation under simultaneous UV-vis irradiation. Even so, the performance of the Fe-TiO 2 samples towards the photodegradation of phenol, under UV irradiation, was lower than TiO 2 suggesting the recombination of the UV photogenerated electron-hole pair. Therefore, results evidence a Fe 3+ promotion of the electron caption in the photosensitization process of TiO 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 2 , and, the formation of reactive oxygen species promoted by the injected electron to the TiO 2 conduction band.

  10. Bismuth Basic Nitrate as a Novel Adsorbent for Azo Dye Removal

    Directory of Open Access Journals (Sweden)

    E. A. Abdullah

    2012-01-01

    Full Text Available Bismuth basic nitrate (BBN and its TiO2-Ag modified sorbent, PTBA were successfully synthesized via a precipitation method. The structural characteristics of prepared sorbents were determined through different analytical techniques. The potential use of prepared sorbents for organic compounds' removal was evaluated using Methyl Orange and Sunset Yellow dyes as model pollutants in aqueous solutions. The experimental results showed that the presence of TiO2 and Ag particles during the crystal growth of bismuth basic nitrate has an effect on the crystal structure, point of zero charge (pHpzc, pore volume and diameter. The lower binding energy of Ti 2p core level peak indicates the octahedral coordination of TiO2 particles on the PTBA surface. The alteration of hydrophilic-hydrophobic characteristics of sorbent's surface improves the adsorptive performance of the modified sorbent and provides an efficient route for organic contaminants' removal from aqueous solutions.

  11. 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.

  12. Synthesis, spectroscopic and TD-DFT quantum mechanical study of azo-azomethine dyes. A laser induced trans-cis-trans photoisomerization cycle.

    Science.gov (United States)

    Georgiev, Anton; Kostadinov, Anton; Ivanov, Deyan; Dimov, Deyan; Stoyanov, Simeon; Nedelchev, Lian; Nazarova, Dimana; Yancheva, Denitsa

    2018-03-05

    This paper describes the synthesis, spectroscopic characterization and quantum mechanical calculations of three azo-azomethine dyes. The dyes were synthesized via condensation reaction between 4-(dimethylamino)benzaldehyde and three different 4-aminobenzene azo dyes. Quantum chemical calculations on the optimized molecular geometry and electron densities of the trans (E) and cis (Z) isomers and their vibrational frequencies have been computed by using DFT/B3LYP density-functional theory with 6-311++G(d,p) basis set in vacuo. The thermodynamic parameters such as total electronic energy E (RB3LYP), enthalpy H 298 (sum of electronic and thermal enthalpies), free Gibbs energy G 298 (sum of electronic and thermal free Gibbs energies) and dipole moment μ were computed for trans (E) and cis (Z) isomers in order to estimate the ΔE trans→cis , Δμ trans→cis, ΔH trans→cis , ΔG trans→cis and ΔS trans→cis values. After molecular geometry optimization the electronic spectra have been obtained by TD-DFT calculations at same basis set and correlated with the spectra of vapour deposited nanosized films of the dyes. The NBO analysis was performed in order to understand the intramolecular charge transfer and energy of resonance stabilization. Solvatochromism was investigated by UV-VIS spectroscopy in five different organic solvents with increasing polarity. The dynamic photoisomerization experiments have been performed in DMF by pump lasers λ=355nm (mostly E→Z) and λ=491nm (mostly Z→E) in spectral region 300nm - 800nm at equal concentrations and times of illumination in order to investigate the photodynamical trans-cis-trans properties of the CHN and NN chromophore groups of the dyes. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. ISOLATION AND CHARACTERIZATION OF A MOLYBDENUM-REDUCING AND AZO-DYE DECOLORIZING SERRATIA MARCESCENS STRAIN NENI-1 FROM INDONESIAN SOIL

    Directory of Open Access Journals (Sweden)

    Neni Gusmanizar

    2016-01-01

    Full Text Available Heavy metals and organic xenobiotics including dyes are important industrial components with their usage amounting to the millions of tonnes yearly. Their presence in the environment is a serious pollution issue globally. Bioremediation of these pollutants using microbes with multiple detoxification capacity is constantly being sought. In this work we screen the ability of a molybdenum-reducing bacterium isolated from contaminated soil to decolorize various azo and triphenyl methane dyes. The bacterium reduces molybdate to molybdenum blue (Mo-blue optimally at pH 6.0, and temperatures of between 25 and 40oC. Glucose was the best electron donor for supporting molybdate reduction followed by sucrose, trehalose, maltose, d-sorbitol, dmannitol, d-mannose, myo-inositol, glycerol and salicin in descending order. Other requirements include a phosphate concentration of between 5.0 and 7.5 mM and a molybdate concentration between 10 and 20 mM. The absorption spectrum of the Moblue produced was similar to previous Mo-reducing bacterium, and closely resembles a reduced phosphomolybdate. Molybdenum reduction was inhibited by copper, silver and mercury at 2 ppm by 43.8%, 42.3% and 41.7%, respectively. We screen for the ability of the bacterium to decolorize various dyes. The bacterium was able to decolorize the dye Congo Red. Biochemical analysis resulted in a tentative identification of the bacterium as Serratia marcescens strain Neni-1. The ability of this bacterium to detoxify molybdenum and decolorize azo dye makes this bacterium an important tool for bioremediation.

  14. 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

  15. 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.

  16. Treatment of a non-azo dye aqueous solution by CWAO in continuous reactor using a Ni catalyst derived from hydrotalcite-like precursor

    Energy Technology Data Exchange (ETDEWEB)

    Vallet, Ana, E-mail: avallet@quim.ucm.es [Grupo de Catalisis y Procesos de Separacion (CyPS), Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Besson, Michele, E-mail: michele.besson@ircelyon.univ-lyon1.fr [IRCELYON, Institut de recherches sur la catalyse et l' environnement de Lyon, UMR5256 CNRS-Universite Lyon1, 2 Avenue Albert Einstein, F-69626 Villeurbanne Cedex (France); Ovejero, Gabriel; Garcia, Juan [Grupo de Catalisis y Procesos de Separacion (CyPS), Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Ni supported over hydrotalcite calcined precursors as catalyst. Black-Right-Pointing-Pointer Catalytic wet air oxidation in trickle bed reactor for Basic Yellow 11 removal. Black-Right-Pointing-Pointer Dye removal depends on temperature, initial dye concentration and flow rate. Black-Right-Pointing-Pointer The catalyst proved to be stable and efficient for the dye degradation. - Abstract: Catalytic wet air oxidation (CWAO) of a Basic Yellow 11 (BY11) aqueous solution, chosen as a model of a hardly biodegradable non-azo dye was carried out in a continuous-flow trickle-bed reactor, using nickel supported over hydrotalcite precursor calcined at 550 Degree-Sign C. An increase in the reaction temperature (120-180 Degree-Sign C), and a decrease in dye concentration (1000-3000 ppm) or liquid flow rate (0.1-0.7 mL min{sup -1}) enhanced the CWAO performance in a 30 and 19% for the variation of the temperature and concentration respectively. After a small leaching observed within the first hours, the catalyst proved to be very stable during the 65-day reaction. The CWAO process was found to be very efficient, achieving BY11 conversion up to 95% and TOC conversion up to 85% at 0.1 mL min{sup -1} and 180 Degree-Sign C under 5 MPa air.

  17. A comparative study of quantum yield and electrical energy per order (E(Eo)) for advanced oxidative decolourisation of reactive azo dyes by UV light.

    Science.gov (United States)

    Muruganandham, M; Selvam, K; Swaminathan, M

    2007-06-01

    This paper evaluates the quantum yield and electrical energy per order (E(Eo)) efficiency of Reactive Orange 4 (RO4) and Reactive Yellow 14 (RY14) azo dyes by three advanced oxidation processes (AOPs). Both dyes were completely decolourised by all these processes. The relative decolourisation efficiencies of these processes were in the following order: Fe(2+)/H(2)O(2)/UV>UV/TiO(2)>UV/H(2)O(2). The low efficiency of UV/H(2)O(2) process is mainly due to low UV absorption by hydrogen peroxide at the 365nm. The figure of merit E(Eo) values showed that UV/H(2)O(2) process consumes more electrical energy than the other two processes. The electrical energy consumption is in the following order: UV/H(2)O(2)>UV/TiO(2)>Fe(2+)/H(2)O(2)/UV. At low initial dye concentration higher quantum yield was observed in UV/TiO(2) process, whereas in photo-Fenton process higher quantum yield was observed at high initial dye concentration. The structure of dye molecule also influences the quantum yield and E(Eo) value.

  18. Treatment of a non-azo dye aqueous solution by CWAO in continuous reactor using a Ni catalyst derived from hydrotalcite-like precursor

    International Nuclear Information System (INIS)

    Vallet, Ana; Besson, Michèle; Ovejero, Gabriel; García, Juan

    2012-01-01

    Highlights: ► Ni supported over hydrotalcite calcined precursors as catalyst. ► Catalytic wet air oxidation in trickle bed reactor for Basic Yellow 11 removal. ► Dye removal depends on temperature, initial dye concentration and flow rate. ► The catalyst proved to be stable and efficient for the dye degradation. - Abstract: Catalytic wet air oxidation (CWAO) of a Basic Yellow 11 (BY11) aqueous solution, chosen as a model of a hardly biodegradable non-azo dye was carried out in a continuous-flow trickle-bed reactor, using nickel supported over hydrotalcite precursor calcined at 550 °C. An increase in the reaction temperature (120–180 °C), and a decrease in dye concentration (1000–3000 ppm) or liquid flow rate (0.1–0.7 mL min −1 ) enhanced the CWAO performance in a 30 and 19% for the variation of the temperature and concentration respectively. After a small leaching observed within the first hours, the catalyst proved to be very stable during the 65-day reaction. The CWAO process was found to be very efficient, achieving BY11 conversion up to 95% and TOC conversion up to 85% at 0.1 mL min −1 and 180 °C under 5 MPa air.

  19. A comparative study of quantum yield and electrical energy per order (E Eo) for advanced oxidative decolourisation of reactive azo dyes by UV light

    International Nuclear Information System (INIS)

    Muruganandham, M.; Selvam, K.; Swaminathan, M.

    2007-01-01

    This paper evaluates the quantum yield and electrical energy per order (E Eo ) efficiency of Reactive Orange 4 (RO4) and Reactive Yellow 14 (RY14) azo dyes by three advanced oxidation processes (AOPs). Both dyes were completely decolourised by all these processes. The relative decolourisation efficiencies of these processes were in the following order: Fe 2+ /H 2 O 2 /UV > UV/TiO 2 > UV/H 2 O 2 . The low efficiency of UV/H 2 O 2 process is mainly due to low UV absorption by hydrogen peroxide at the 365 nm. The figure of merit E Eo values showed that UV/H 2 O 2 process consumes more electrical energy than the other two processes. The electrical energy consumption is in the following order: UV/H 2 O 2 > UV/TiO 2 > Fe 2+ /H 2 O 2 /UV. At low initial dye concentration higher quantum yield was observed in UV/TiO 2 process, whereas in photo-Fenton process higher quantum yield was observed at high initial dye concentration. The structure of dye molecule also influences the quantum yield and E Eo value

  20. Electrochemical characteriztion of the bioanode during simultaneous azo dye decolorization and bioelectricity generation in an air-cathode single chambered microbial fuel cell

    International Nuclear Information System (INIS)

    Sun Jian; Hu Yongyou; Hou Bin

    2011-01-01

    To achieve high power output based on simultaneously azo dye decolorization using microbial fuel cell (MFC), the bioanode responses during decolorization of a representative azo dye, Congo red, were investigated in an air-cathode single chambered MFC using representative electrochemical techniques. It has been found that the maximum stable voltage output was delayed due to slowly developed anode potential during Congo red decolorization, indicating that the electrons recovered from co-substrate are preferentially transferred to Congo red rather than the bioanode of the MFC and Congo red decolorization is prior to electricity generation. Addition of Congo red had a negligible effect on the Ohmic resistance (R ohm ) of the bioanode, but the charge-transfer resistance (R c ) and the diffusion resistance (R d ) were significantly influenced. The R c and R d firstly decreased then increased with increase of Congo red concentration, probably due to the fact that the Congo red and its decolorization products can act as electron shuttle for conveniently electrons transfer from bacteria to the anode at low concentration, but result in accelerated consumption of electrons at high concentration. Cyclic voltammetry results suggested that Congo red was a more favorable electron acceptor than the bioanode of the MFC. Congo red decolorization did not result in a noticeable decrease in peak catalytic current until Congo red concentration up to 900 mg l -1 . Long-term decolorization of Congo red resulted in change in catalytic active site of anode biofilm.

  1. The influence of Triton X-100 surfactant on the morphology and properties of zinc sulfide nanoparticles for applications in azo dyes degradation

    Energy Technology Data Exchange (ETDEWEB)

    Dumbrava, Anca, E-mail: adumbrava@univ-ovidius.ro [Department of Chemistry and Chemical Engineering, Ovidius University of Constanta, 124 Mamaia Blvd., Constanta 900527 (Romania); Berger, Daniela, E-mail: danaberger01@yahoo.com [University Politehnica of Bucharest, Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, Polizu Street 1-7, Bucharest 011061 (Romania); Prodan, Gabriel [Electron Microscopy Laboratory, Ovidius University of Constanta, 124 Mamaia Blvd., Constanta 900527 (Romania); Matei, Cristian [University Politehnica of Bucharest, Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, Polizu Street 1-7, Bucharest 011061 (Romania); Moscalu, Florin [Department of Physics, Ovidius University of Constanta, 124 Mamaia Blvd., Constanta 900527 (Romania); Diacon, Aurel [University Politehnica of Bucharest, Department of Bioresources and Polymer Science, Polizu Street 1-7, Bucharest 011061 (Romania)

    2017-06-01

    Herein we report the synthesis, by two different routes, of ZnS nanoparticles capped with Triton X-100 (TX), which were characterized by X-ray diffraction, transmission electron microscopy, high resolution electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy, FTIR spectroscopy, UV–visible spectroscopy, photoluminescence spectroscopy, and surface area measurements. The TX-capped ZnS nanopowders have a very good photocatalytic activity and high specific surface area, depending on the synthesis route; e.g. an azo dye solution is almost complete photobleached in only 60 min (a photocatalytic activity of 97.79%) using TX-capped ZnS nanopowder, with specific surface area of 191 m{sup 2}/g, and further a photocatalytic activity of 99.75% was achieved in 120 min. Based on the photocatalytic results, the ZnS nanopowders can be considered suitable catalysts for a green, very efficient and quick strategy for removing of organic pollutants from wastewaters. - Highlights: • Triton X-100 was used as surfactant in ZnS nanopowders synthesis by two methods. • Triton X-capped ZnS nanoparticles with high specific surface area were synthesized. • A very high capacity for bleaching an azo dye solution was evidenced. • Some of ZnS powders properties were crucially modified by the synthesis technique.

  2. The influence of Triton X-100 surfactant on the morphology and properties of zinc sulfide nanoparticles for applications in azo dyes degradation

    International Nuclear Information System (INIS)

    Dumbrava, Anca; Berger, Daniela; Prodan, Gabriel; Matei, Cristian; Moscalu, Florin; Diacon, Aurel

    2017-01-01

    Herein we report the synthesis, by two different routes, of ZnS nanoparticles capped with Triton X-100 (TX), which were characterized by X-ray diffraction, transmission electron microscopy, high resolution electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy, FTIR spectroscopy, UV–visible spectroscopy, photoluminescence spectroscopy, and surface area measurements. The TX-capped ZnS nanopowders have a very good photocatalytic activity and high specific surface area, depending on the synthesis route; e.g. an azo dye solution is almost complete photobleached in only 60 min (a photocatalytic activity of 97.79%) using TX-capped ZnS nanopowder, with specific surface area of 191 m 2 /g, and further a photocatalytic activity of 99.75% was achieved in 120 min. Based on the photocatalytic results, the ZnS nanopowders can be considered suitable catalysts for a green, very efficient and quick strategy for removing of organic pollutants from wastewaters. - Highlights: • Triton X-100 was used as surfactant in ZnS nanopowders synthesis by two methods. • Triton X-capped ZnS nanoparticles with high specific surface area were synthesized. • A very high capacity for bleaching an azo dye solution was evidenced. • Some of ZnS powders properties were crucially modified by the synthesis technique.

  3. The UV and Laser Aging for PMMA/BDK/Azo-dye Polymer Blend Cured by UV Light Beams

    International Nuclear Information System (INIS)

    Ahmad, A A; Omari, A M

    2015-01-01

    A polymeric-based solution blend composed of Azo-dye methyl red (MR) doped with polymethelmethacrelate (PMMA) solution, in addition, to the BenzylDimethylKetal (BDK) photoinitiator was made with optimum molar ratios and deposited on glass substrate by spin coating technique. The samples were then exposed to UV light beams in order to assist the layers polymerization by the proper exposure process. The photo chemical reaction occurred during the UV light polymerization process induces photo refractive changes which were presented as a function of wavelength or photon energy. Two main strong absorption peaks were observed in the films at around 330 nm (3.75 eV) and 500 nm (2.48 eV) for different curing time periods. This phenomenon enhances the films usage for optical data storage media at these two wavelengths. Since the deposited films were then useful as based layers for Read/Write optical data storage media, they were then tested by UV or laser Read/Write beams independently. The optical properties of the films were investigated while exposed to each beam. Finally, their optical properties were investigated as a function of aging time in order to relate the temporary and/or permanent light-exposure effect on the films compared to their optical properties before the light exposure. The films show a low absorbance at 630 nm (1.97 eV) and high absorbance at 480 nm (2.58 eV). This fact makes it possible to record holographic gratings in the polymeric film upon light exposure. In all cases the optical properties were evaluated by using the very sensitive, non destructive surface testing spectroscopic ellipsometry technique. The films were characterized in the spectral range of 300 to 1000 nm using Lorentz oscillator model with one oscillator centred at 4.15 eV. This study has been supported by the SEM and EDAX results to investigate the effect of the UV and visible beams on their optical properties. The results of this research determined the proper conditions for

  4. Removal of binary azo dyes from water by UV-irradiated degradation in TiO2 suspensions

    International Nuclear Information System (INIS)

    Juang, Ruey-Shin; Lin, Su-Hsia; Hsueh, Pei-Ying

    2010-01-01

    Photodegradation and mineralization of single and binary Acid Orange 7 (AO7) and Reactive Red 2 (RR2) under UV irradiation in TiO 2 suspensions was examined. Experiments were conducted as a function of initial pH, TiO 2 dose, and initial dye concentration. First-order derivative spectrophotometric method was used to simultaneously analyze AO7 and RR2 in binary solutions. The Langmuir-Hinshelwood kinetic model was applied to evaluate and compare the apparent rate constants for the photodegradation of both dyes in single and binary solutions. It was shown that photodegradation of both dyes in binary solution was slower than those in single solution under comparable conditions. Moreover, the difference between the apparent rate constants of RR2 and AO7 became smaller in contrast to the cases of single solutions. After 20-min UV irradiation with 0.5 g/L TiO 2 , complete removal of single 0.086 mM AO7 and 0.086 mM RR2 at pH 6.8 was obtained, but only 60% and 45% of binary 0.086 mM AO7 and 0.086 mM RR2 was removed, respectively.

  5. Synthesis and spectroscopic characterization of gallic acid and some of its azo complexes

    Science.gov (United States)

    Masoud, Mamdouh S.; Hagagg, Sawsan S.; Ali, Alaa E.; Nasr, Nessma M.

    2012-04-01

    A series of gallic acid and azo gallic acid complexes were prepared and characterized by elemental analysis, IR, electronic spectra and magnetic susceptibility. The complexes were of different geometries: Octahedral, Tetrahedral and Square Planar. ESR was studied for copper complexes. All of the prepared complexes were of isotropic nature. The thermal analyses of the complexes were studied by DTA and DSC techniques. The thermodynamic parameters and the thermal transitions, such as glass transitions, crystallization and melting temperatures for some ligands and their complexes were evaluated and discussed. The entropy change values, ΔS#, showed that the transition states are more ordered than the reacting complexes. The biological activities of some ligands and their complexes are tested against Gram positive and Gram negative bacteria. The results showed that some complexes have a well considerable activity against different organisms.

  6. Synthesis of mutual azo prodrugs of anti-inflammatory agents and peptides facilitated by α-aminoisobutyric acid.

    Science.gov (United States)

    Kennedy, David A; Vembu, Nagarajan; Fronczek, Frank R; Devocelle, Marc

    2011-12-02

    Reported is the synthesis of azo mutual prodrugs of the nonsteroidal anti-inflammatory agents (NSAIDs) 4-aminophenylacetic acid (4-APAA) or 5-aminosalicylic acid (5-ASA) with peptides, including an antibiotic peptide temporin analogue modified at the amino terminal by an α-aminoisobutyric acid (Aib) residue. These prodrugs are designed for colonic delivery of two agents to treat infection and inflammation by the bacterial pathogen Clostridium difficile . © 2011 American Chemical Society

  7. Synthesis, characterization and degradation activity of Methyl orange Azo dye using synthesized CuO/α-Fe2O3 nanocomposite

    Directory of Open Access Journals (Sweden)

    Mohsen Mehdipour Ghazi

    2017-04-01

    Full Text Available This study investigated the photo-degradation of methyl orange (MO as a type of azo dye using a CuO/α-Fe2O3 nanocomposite. A CuO/α-Fe2O3 powder with a crystalline size in the range of 27-49 nm was successfully prepared using simple co-precipitation along with a sonication method. The characterization of the synthesized sample was done via XRD, FE-SEM, EDS, FTIR and DRS analyses. The Tauc equation revealed that the band gap of the nano composite in the direct mood was 2.05 ev, which is in the visible light range. The effect of operating factors containing dye concentration, photocatalyst dosage and pH on dye degradation efficiency was measured. Response Surface Method (RSM was employed to specify the parameter effects. The photocatalytic activity of the CuO/α-Fe2O3 nanocomposite was evaluated by degradation of MO under visible light irradiation. The results showed that the pH value played a very effective role in the dye degradation process efficiency. Also, the photocatalytic degradation of MO obtained was equal to 88.47% in the optimal values.

  8. Acid-base indicator properties of dyes from local plants I: Dyes from ...

    African Journals Online (AJOL)

    DR. MIKE HORSFALL

    Acid-base indicator properties of dyes from local plants I: Dyes from Basella alba. (Indian spinach) and ... solution, which change colour immediately after the equivalence point has .... The pH ranges over which the dyes change colour were ...

  9. A magenta polypyrrole derivatised with Methyl Red azo dye: synthesis and spectroelectrochemical characterisation

    International Nuclear Information System (INIS)

    Almeida, Andresa K.A.; Dias, Jéssica M.M.; Santos, Diego P.; Nogueira, Fred A.R.; Navarro, Marcelo; Tonholo, Josealdo; Lima, Dimas J.P.; Ribeiro, Adriana S.

    2017-01-01

    Highlights: • A pyrrole (Py) derivative functionalised with methyl red (MRPy) was synthesised. • MRPy was polymerised electrochemically in LiClO_4/CH_3CN with BFEE. • Electrochromic properties of PMRPy and PPy doped with methyl red (PPy/MR) were compared. • Colour of the PMRPy changes from magenta to yellow depending on the pH. • PMRPy films might be applicable in optoelectronic devices or in pH sensors. - Abstract: A pyrrole derivative bearing 2-(4-dimethylaminophenylazo)benzoic acid, also known as Methyl Red (MR), was prepared by a simple synthetic route, and electropolymerised onto ITO/glass electrodes in (C_4H_9)_4NBF_4/CH_3CN in presence of boron trifluoride diethyl etherate (BFEE). Films of polypyrrole (PPy) and PPy doped with MR (PPy/MR) were also deposited onto ITO/glass in order to compare their electrochromic properties with the films of PPy derivatised with MR. Cyclic voltammogram of the poly[3-(N-pyrrolyl)propyl 2-(4-dimethylaminophenylazo)benzoate] (PMRPy) film displayed a redox pair with anodic peak potential (Epa) at ca. 0.53 V and cathodic peak potential (Epc) at 0.25 V vs. Ag/Ag"+, corresponding to the polymer p-doping, whilst the PPy/MR film shows capacitive behaviour with a redox pair in the cathodic region (Epa = −0.36 V and Epc = −0.62 V), similar to the PPy film (Epa = −0.10 V, and Epc = −0.15 V), and an anodic wave in the same potential range of that for PMRPy film. The electrochromic properties of the PMRPy film, such as chromatic contrast (Δ%T = 34.2%), switching time (τ = 10 s) and stability (Δ%T = 15% at the 100th cycle), were enhanced relative to the PPy/MR and PPy films. However, the colour of the PMRPy film changed from yellow (-0.8 V) to magenta (E = 1.0 V) in the first cycle and became light magenta at −0.8 V in the subsequent cycles. PMRPy films were also investigated in phosphate buffer solution (PBS, 2.0 ≤ pH ≤ 9.0) and after exposure to HCl vapour, in which the colour varied from magenta at pH = 2.0 to

  10. Chromed Leather Dyeing Peculiarities when Deliming with Peracetic Acid

    Directory of Open Access Journals (Sweden)

    Kęstutis BELEŠKA

    2013-05-01

    Full Text Available The research was aimed to investigate the influence of deliming with peracetic acid on leather dyeing kinetics. Hydrophobic C.I. Acid Red 213 and hydrophilic C.I. Acid Red 423 dyes were used. Sorption of dye depends on hydrophobicity/hydrophility of dye and dyeing temperature. Equilibrium of process is reached faster using hydrophobic C.I. Acid Red 213 at 45 ºC. However, both control and experimental leather fibres adsorb more hydrophilic dye C.I. Acid Red 423 and this fact does not depend on temperature. The diffusion coefficient of dye C.I. Acid Red 423 calculated according to Weisz model is higher when dyeing conventional leather. The change of deliming method has influence on chromed leather dyeing but this influence is not significant. The adsorption ability of control leather fibres at 30 ºC and 45 ºC is higher using both dyes as compared to the dyeing the experimental one. The increase of dyeing temperature increases the adsorption ability independently on the sort of leather fibres. Such dependence of the adsorption ability on the temperature shows that hydrophobic action and van der Waals forces prevail between dye and fibres during dyeing process. The Gibbs energy changes show that adsorption of both dyes by leather fibres independently on their sort is a spontaneous process. The affinity of both dyes to conventional leather fibres is higher comparing with experimental one. The change of enthalpy is positive in all cases, and it means that the driving force of the dyeing is the change of entropy.DOI: http://dx.doi.org/10.5755/j01.ms.19.2.4431

  11. Colorful and transparent poly(vinyl alcohol) composite films filled with layered zinc hydroxide salts, intercalated with anionic orange azo dyes (methyl orange and orange II)

    International Nuclear Information System (INIS)

    Neves da Silva, Marlon Luiz; Marangoni, Rafael; Cursino, Ana Cristina Trindade; Schreiner, Wido Herwig; Wypych, Fernando

    2012-01-01

    Highlights: ► Zinc hydroxide salts were successfully intercalated with anionic orange azo dyes. ► The anionic dye was co-intercalated with hydrated chloride anions. ► The orange materials were used as fillers for poly(vinyl alcohol). ► Transparent, homogeneous, colorful PVA films were obtained by wet casting. ► Some composites stored at lower humidity exhibited improved mechanical properties. - Abstract: Layered zinc hydroxide salts (zinc LHS) were intercalated with anionic orange azo dyes, namely methyl orange (MO) and orange II (OII), and co-intercalated with hydrated chloride anions. After characterization by X-ray diffraction (XRD), thermal analysis (TGA/DTA), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), the materials were used as fillers for poly(vinyl alcohol) (PVA). Colorful transparent films were obtained by wet casting, revealing good dispersion of the material into the polymer. In the case of zinc LHS/OII, PVA was intercalated between the zinc LHS layers. Evaluation of the mechanical properties of the PVA composite films revealed that the layered colorful materials were able to increase the mechanical properties of the PVA films only when the films were stored under lower relative humidity. As expected, films with higher water content displayed reduced tensile strength and modulus because of the plasticizing effect of water. As for the films stored at 43% relative humidity, more pronounced improvement of modulus was observed for 1 and 4% zinc LHS/OII, and enhanced tensile strength was achieved for 0.5 and 1% zinc LHS/OII. This effect can be attributed to better dispersion of the layered filler and its better adhesion to the PVA matrix.

  12. Adsorption mechanism and kinetics of azo dye chemicals on oxide nanotubes: a case study using porous CeO{sub 2} nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Junshu; Wang, Jinshu, E-mail: wangjsh@bjut.edu.cn; Du, Yucheng; Li, Hongyi; Jia, Xinjian [Beijing University of Technology, School of Materials Science and Engineering (China)

    2016-07-15

    Metal oxide nanotubes are believed to be promising materials with adsorption functionality for water purification due to their synergistic effect of the overall microscale morphology for easy separation and nanoscale surface characters providing enough surface active absorption sites. This work shows the synthesis of uniform hierarchical porous CeO{sub 2} nanotubes via nanowire-directed templating method and describes the adsorption behavior of CeO{sub 2} nanotubes for a typical azo dye Congo red which has resistance to oxidation and decoloration in natural conditions. Fourier transform infrared spectroscopy spectra provided the evidence that Congo red was successfully coated on the surface of CeO{sub 2} nanotubes by both bidentate-type bridge link of Ce{sup 4+} cations from sulfonate SO{sub 3}{sup −} groups and the electrostatic attraction between the protonated surface generated by oxygen vacancies and dissociated sulfonate groups. The adsorption kinetic data fitted well to the pseudo-second-order kinetic equation, whereas the Langmuir isotherm equation exhibited better correlation with the experimental data. The calculated maximum adsorption capacity from the isothermal model was 362.32 mg/g. In addition, the prepared CeO{sub 2} nanotubes exhibited good recyclability and reusability as highly efficient adsorbents for Congo red removal after regeneration. These favorable performances enable the obtained CeO{sub 2} nanotubes to be promising materials for dye removal from aqueous solution.Graphical AbstractCeO{sub 2} nanotubes composed of crystallized nanoparticles exhibit well adsorption ability for a typical azo dye Congo red.

  13. Thermal modification of activated carbon surface chemistry improves its capacity as redox mediator for azo dye reduction.

    Science.gov (United States)

    Pereira, L; Pereira, R; Pereira, M F R; van der Zee, F P; Cervantes, F J; Alves, M M

    2010-11-15

    The surface chemistry of a commercial AC (AC(0)) was selectively modified, without changing significantly its textural properties, by chemical oxidation with HNO(3) (AC(HNO3)) and O(2) (AC(O2)), and thermal treatments under H(2) (AC(H2)) or N(2) (AC(N2)) flow. The effect of modified AC on anaerobic chemical dye reduction was assayed with sulphide at different pH values 5, 7 and 9. Four dyes were tested: Acid Orange 7, Reactive Red 2, Mordant Yellow 10 and Direct Blue 71. Batch experiments with low amounts of AC (0.1 g L(-1)) demonstrated an increase of the first-order reduction rate constants, up to 9-fold, as compared with assays without AC. Optimum rates were obtained at pH 5 except for MY10, higher at pH 7. In general, rates increased with increasing the pH of point zero charge (pH(pzc)), following the trend AC(HNO3) granular biomass, AC(H2) also duplicated and increase 4.5-fold the decolourisation rates of MY10 and RR2, respectively. In this last experiment, reaction rate was independent of AC concentration in the tested range 0.1-0.6 g L(-1). Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Optical, thermal and combustion properties of self-colored polyamide nanocomposites reinforced with azo dye surface modified ZnO nanoparticles

    Science.gov (United States)

    Hajibeygi, Mohsen; Shabanian, Meisam; Omidi-Ghallemohamadi, Mehrdad; Khonakdar, Hossein Ali

    2017-09-01

    New self-colored aromatic-polyamide (PA) nanocomposites containing azo and naphthalene chromophores were prepared with azo-dye surface-modified ZnO nanoparticles (SMZnO) using solution method in dimethylformamide. The X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) results showed the uniform distribution for ZnO nanoparticles in the PA matrix. The UV-vis spectra of PA/ZnO nanocomposites (PANC) showed a blue shift as well as reduction in absorbance intensities and the photoluminescence studies revealed that the increasing intensities of the violet emission in SMZnO loading. From thermo gravimetric analysis (TGA), the temperature at 10% mass loss (T10) increased from 291.8 °C to 387.6 °C for PANC containing 8 mass% of SMZnO, as well as the char yield enhanced significantly, which was about 23.5% higher than the neat PA. The peak heat release rate resulted from microscale combustion calorimeter (MCC), by 8 mass% loading of SMZnO, decreased about 56.9% lower than the neat PA.

  15. Azo dyes degradation using TiO2-Pt/graphene oxide and TiO2-Pt/reduced graphene oxide photocatalysts under UV and natural sunlight irradiation

    Science.gov (United States)

    Rosu, Marcela-Corina; Coros, Maria; Pogacean, Florina; Magerusan, Lidia; Socaci, Crina; Turza, Alexandru; Pruneanu, Stela

    2017-08-01

    The photocatalytic degradation of azo dyes with different structures (amaranth, sunset yellow and tartrazine) using TiO2-Pt nanoparticles (TPt), TiO2-Pt/graphene oxide (TPt-GO) and TiO2-Pt/reduced graphene oxide (TPt-rGO) composites were investigated in the presence of UV and natural sunlight irradiation. The composites were prepared by a combined chemical-thermal method and characterized by Transmission Electron Microscopy (TEM), X-ray powder diffraction (XRD), Infrared (FTIR) and UV-Vis spectroscopy. The modification of TiO2-Pt with graphene oxide shifted its optical absorption edge towards the visible region and increased its photocatalytic activity under UV and natural sunlight irradiation. The efficiency of catalysts on azo dyes degradation (in similar conditions) reached high values (above 99%) under sunlight conditions, proving the remarkable photocatalytic activities of obtained composites. TPt-GO nanocomposite exhibited higher photoactivity than TPt or TPt-rGO, demonstrating degradation efficiencies of 99.56% for amaranth, 99.15% for sunset yellow and 96.23% for tartrazine. The dye photodegradation process follows a pseudo-first-order kinetic with respect to the Langmuir-Hinshelwood reaction mechanism. A direct dependence between azo dyes degradation rate and chemical structure of dyes has been observed.

  16. Preparation and photocatalytic performance of Fe (III)-amidoximated PAN fiber complex for oxidative degradation of azo dye under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Yongchun, E-mail: dye@tjpu.edu.cn [Division of Textile Chemistry and Ecology, School of Textile Science and Engineering, Tianjin Polytechnic University, Tianjin 300160 (China); State Key Laboratory Breeding Base of Photocatalysis, Fuzhou University, Fuzhou, 350002 (China); Han, Zhenbang [Division of Textile Chemistry and Ecology, School of Textile Science and Engineering, Tianjin Polytechnic University, Tianjin 300160 (China); Liu, Chunyan [Division of Textile Chemistry and Ecology, School of Textile Science and Engineering, Tianjin Polytechnic University, Tianjin 300160 (China); State Key Laboratory Breeding Base of Photocatalysis, Fuzhou University, Fuzhou, 350002 (China); Du, Fang [Division of Textile Chemistry and Ecology, School of Textile Science and Engineering, Tianjin Polytechnic University, Tianjin 300160 (China)

    2010-04-15

    Polyacrylonitrile (PAN) fiber was modified with hydroxylamine hydrochloride to introduce amidoxime groups onto the fiber surface. These amidoxime groups were used to react with Fe (III) ions to prepare Fe (III)-amidoximated PAN fiber complex, which was characterized using SEM, XRD, FTIR, XPS, DMA, and DRS respectively. Then the photocatalytic activity of Fe-AO-PAN was evaluated in the degradation of a typical azo dye, C. I. Reactive Red 195 in the presence of H{sub 2}O{sub 2} under visible light irradiation. Moreover, the effect of the Fe content of Fe-AO-PAN on dye degradation was also investigated. The results indicated that Fe (III) ions can crosslink between the modified PAN fiber chains by the coordination of Fe (III) ions with the amino nitrogen atoms and hydroxyl oxygen atoms of the amidoximation groups to form Fe (III)-amidoximated PAN fiber complex, and the Fe content of which is mainly determined by Fe (III) ions and amidoximation groups. Fe (III)-amidoximated PAN fiber complex is found to be activated in the visible light region. Moreover, Fe (III)-amidoximated PAN fiber complex shows the catalytic activity for dye degradation by H{sub 2}O{sub 2} at pH = 6.0 in the dark, and can be significantly enhanced by increasing light irradiation and Fe content, therefore, it can be used as a new heterogeneous Fenton photocatalyst for the effective decomposition of the dye in water. In addition, ESR spectra confirm that Fe (III)-amidoximated PAN fiber complex can generate more {center_dot}OH radicals from H{sub 2}O{sub 2} under visible light irradiation, leading to dye degradation. A possible mechanism of photocatalysis is proposed.

  17. Removal of azo dye using Fenton and Fenton-like processes: Evaluation of process factors by Box-Behnken design and ecotoxicity tests.

    Science.gov (United States)

    Fernandes, Neemias Cintra; Brito, Lara Barroso; Costa, Gessyca Gonçalves; Taveira, Stephânia Fleury; Cunha-Filho, Marcílio Sérgio Soares; Oliveira, Gisele Augusto Rodrigues; Marreto, Ricardo Neves

    2018-06-06

    The conventional treatment of textile effluents is usually inefficient in removing azo dyes and can even generate more toxic products than the original dyes. The aim of the present study was to optimize the process factors in the degradation of Disperse Red 343 by Fenton and Fenton-like processes, as well as to investigate the ecotoxicity of the samples treated under optimized conditions. A Box-Behnken design integrated with the desirability function was used to optimize dye degradation, the amount of residual H 2 O 2 [H 2 O 2residual ], and the ecotoxicity of the treated samples (lettuce seed, Artemia salina, and zebrafish in their early-life stages). Dye degradation was affected only by catalyst concentration [Fe] in both the Fenton and Fenton-like processes. In the Fenton reaction, [H 2 O 2residual ] was significantly affected by initial [H 2 O 2 ] and its interaction with [Fe]; however, in the Fenton-like reaction, it was affected by initial [H 2 O 2 ] only. A. salina mortality was affected by different process factors in both processes, which suggests the formation of different toxic products in each process. The desirability function was applied to determine the best process parameters and predict the responses, which were confirmed experimentally. Optimal conditions facilitated the complete degradation of the dye without [H 2 O 2residual ] or toxicity for samples treated with the Fenton-like process, whereas the Fenton process induced significant mortality for A. salina. Results indicate that the Fenton-like process is superior to the Fenton reaction to degrade Disperse Red 343. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Microbial fuel cell operation using monoazo and diazo dyes as terminal electron acceptor for simultaneous decolourisation and bioelectricity generation.

    Science.gov (United States)

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

    2017-03-05

    Monoazo and diazo dyes [New coccine (NC), Acid orange 7 (AO7), Reactive red 120 (RR120) and Reactive green 19 (RG19)] were employed as electron acceptors in the abiotic cathode of microbial fuel cell. The electrons and protons generated from microbial organic oxidation at the anode which were utilized for electrochemical azo dye reduction at the cathodic chamber was successfully demonstrated. When NC was employed as the electron acceptor, the chemical oxygen demand (COD) removal and dye decolourisation efficiencies obtained at the anodic and cathodic chamber were 73±3% and 95.1±1.1%, respectively. This study demonstrated that the decolourisation rates of monoazo dyes were ∼50% higher than diazo dyes. The maximum power density in relation to NC decolourisation was 20.64mW/m 2 , corresponding to current density of 120.24mA/m 2 . The decolourisation rate and power output of different azo dyes were in the order of NC>AO7>RR120>RG19. The findings revealed that the structure of dye influenced the decolourisation and power performance of MFC. Azo dye with electron-withdrawing group at para substituent to azo bond would draw electrons from azo bond; hence the azo dye became more electrophilic and more favourable for dye reduction. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Hydrogen bonding intermolecular effect on electro-optical response of doped 6PCH nematic liquid crystal with some azo dyes

    Science.gov (United States)

    Kiani, S.; Zakerhamidi, M. S.; Tajalli, H.

    2016-05-01

    Previous studies on the electro-optical responses of dye-doped liquid crystal have shown that dopant material have a considerable effect on their electro-optical responses. Despite the studies carried out on electro-optical properties of dye-doped liquid crystal, no attention has been paid to study of the interaction and structural effects in this procedure. In this paper, linear dyes and with similar structure were selected as dopants. The only difference in used dyes is the functional groups in their tails. So, doping of these dyes into liquid crystals determines the influence of interaction type on electro-optical behaviours of the doped systems. Therefore, in this work, two aminoazobenzene (;A-dye;: hydrogen bond donor) and dimethyl-aminoazobenzene (;B-dye;) dyes with different compositional percentages in liquid crystal host were used. Electro-optical Kerr behaviour, the pre-transition temperature and third order nonlinear susceptibility were investigated. The obtained results effectively revealed that type of interactions between the dye and liquid crystal is determinative of behavioral difference of doped system, compared to pure liquid crystal. Also, pre-transitional behaviour and thereupon Kerr electro-optical responses were affected by formed interactions into doped systems. In other words, it will be shown that addition of any dopants in liquid crystal, regardless of the nature of interactions, cannot cause appropriate electro-optical responses. In fact, type of dye, nature of interactions between dopant and liquid crystalline host as well as concentration of dye are the key factors in selecting the appropriate liquid crystal and dopant dye.

  20. Impacto dos mediadores redox na remoção de cor de corantes azo e antraquinônico por lodo granular anaeróbio sob condições mesofílicas e termofílicas Impact of redox mediators on colour removal of azo and anthraquinone dyes by anaerobic granular sludge under mesophilic and thermophilic conditions

    Directory of Open Access Journals (Sweden)

    André Bezerra dos Santos

    2007-03-01

    Full Text Available Investigou-se o efeito de diferentes mediadores redox (MR na remoção de cor de corantes azo e antraquinônico pelo uso de lodo granular anaeróbio sob condições mesofílicas (30ºC e termofílicas (55ºC. Comprovou-se em experimento em batelada que a adição de concentrações catalíticas de MR pode ter um efeito marcante nas taxas de descoloração do corante azo Reactive Red 2 (RR2, mas o mesmo comportamento não pode ser obtido com o corante antraquinônico Reactive Blue 5 (RB5. Entretanto, com ambos os corantes, o simples aumento da temperatura de incubação para condições termofílicas fez acelerar consideravelmente os processos de descoloração, comparados com condições mesofílicas. Por exemplo, a constante de primeira ordem "k" da redução dos corantes RR2 e RB5, foi aumentada em 6,2 e 11 vezes, respectivamente, à 55ºC quando comparado com 30ºC. Por fim, comprovou-se em experimentos de fluxo contínuo, a boa performance do tratamento termofílico na descoloração redutiva de corantes azo.The effect of different redox mediators (RM on colour removal of azo and anthraquinone dyes was investigated with anaerobic granular sludge under mesophilic (30ºC and thermophilic (55ºC conditions. Batch experiments revealed that an addition of catalytic concentrations of RM provided a remarkable effect on the decolourisation rates of the azo dye Reactive Red 2 (RR2, but the same effect could not be obtained with the anthraquinone dye Reactive Blue 5 (RB5. Nevertheless, for both dyes, the temperature increase to thermophilic conditions was an effective strategy to considerably accelerate the decolourisation process compared to mesophilic conditions. For instance, the first-order rate constant "k" of RR2 and RB5 reduction, was increased in 6.2 and 11-fold, respectively, at 55ºC in comparison with 30ºC. Such an effect of the temperature on the reductive decolourisation of azo dye was also verified in continuous flow experiments.

  1. Investigation of adsorption and inhibitive effect of acid red GRE (183 dye on the corrosion of carbon steel in hydrochloric acid media

    Directory of Open Access Journals (Sweden)

    M. Abd El-raouf

    2015-09-01

    Full Text Available The adsorption and corrosion inhibitive effect of acid red GRE (183 dye on carbon steel alloy in 1 M HCl solutions was studied using various techniques. Results of weight loss, Tafel polarization measurements and electrochemical impedance spectroscopy (EIS techniques show that this compound has fairly good inhibiting properties for steel corrosion in acidic bath; with efficiency around 96% at a concentration of 50 ppm. The inhibition is of a mixed anodic–cathodic nature. Factors affecting the corrosion process have been calculated and discussed. Acid red GRE (183 dye was shown to be an inhibitor in the acidic corrosion. Inhibition efficiency increased with acid red GRE (183 dye concentration but decreased with rise in temperature, corrosion inhibition is attributed to the adsorption of acid red GRE (183 dye on the carbon steel surface via a physical adsorption mechanism. Langmuir isotherm is found to provide an accurate description of the adsorption behavior of the investigated azo compound. The nature of the protective film was investigated using SEM and EDX techniques.

  2. Enhanced accumulation and visible light-assisted degradation of azo dyes in poly(allylamine hydrochloride)-modified mesoporous silica spheres

    International Nuclear Information System (INIS)

    Tao Xia; Liu Bing; Hou Qian; Xu Hui; Chen Jianfeng

    2009-01-01

    A new route for the economic and efficient treatment of azo dye pollutants is reported, in which surface-modified organic-inorganic hybrid mesoporous silica (MS) spheres were chosen as microreactors for the accumulation and subsequent photodegradation of pollutants in defined regions. The surface-modified silica materials were prepared by anchoring the polycationic species such as poly(allylamine hydrochloride) on MS spheres via a simple wet impregnation method. The as-synthesized spheres with well-defined porous structures exhibited 15 times of accumulating capacity for orange II and Congo red compared to that of the pure MS spheres. Diffuse reflectance UV-vis spectroscopy and confocal laser scanning microscopy demonstrated that the accumulated orange II and CR in defined MS spheres were rapidly degraded in the presence of Fenton reagent under visible radiation. Kinetics analysis in recycling degradation showed that the as-synthesized materials might be utilized as environment-friendly preconcentrators/microreactors for the remediation of dye wastewater

  3. Treatment of a non-azo dye aqueous solution by CWAO in continuous reactor using a Ni catalyst derived from hydrotalcite-like precursor.

    Science.gov (United States)

    Vallet, Ana; Besson, Michèle; Ovejero, Gabriel; García, Juan

    2012-08-15

    Catalytic wet air oxidation (CWAO) of a Basic Yellow 11 (BY11) aqueous solution, chosen as a model of a hardly biodegradable non-azo dye was carried out in a continuous-flow trickle-bed reactor, using nickel supported over hydrotalcite precursor calcined at 550°C. An increase in the reaction temperature (120-180°C), and a decrease in dye concentration (1000-3000 ppm) or liquid flow rate (0.1-0.7 mL min(-1)) enhanced the CWAO performance in a 30 and 19% for the variation of the temperature and concentration respectively. After a small leaching observed within the first hours, the catalyst proved to be very stable during the 65-day reaction. The CWAO process was found to be very efficient, achieving BY11 conversion up to 95% and TOC conversion up to 85% at 0.1 mL min(-1) and 180°C under 5 MPa air. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. The Orange Side of Disperse Red 1: Humidity-Driven Color Switching in Supramolecular Azo-Polymer Materials Based on Reversible Dye Aggregation.

    Science.gov (United States)

    Schoelch, Simon; Vapaavuori, Jaana; Rollet, Frédéric-Guillaume; Barrett, Christopher J

    2017-01-01

    Humidity detection, and the quest for low-cost facile humidity-sensitive indicator materials is of great interest for many fields, including semi-conductor processing, food transport and storage, and pharmaceuticals. Ideal humidity-detection materials for a these applications might be based on simple clear optical readout with no power supply, i.e.: a clear color change observed by the naked eye of any untrained observer, since it doesn't require any extra instrumentation or interpretation. Here, the introduction of a synthesis-free one-step procedure, based on physical mixing of easily available commercial materials, for producing a humidity memory material which can be easily painted onto a wide variety of surfaces and undergoes a remarkable color change (approximately 100 nm blue-shift of λ MAX ) upon exposure to various thresholds of levels of ambient humidity is reported. This strong color change, easily visible to as a red-to-orange color switch, is locked in until inspection, but can then be restored reversibly if desired, after moderate heating. By taking advantage of spontaneously-forming reversible 'soft' supramolecular bonds between a red-colored azo dye and a host polymer matrix, a reversible dye 'migration' aggregation appearing orange, and dis-aggregation back to red can be achieved, to function as the sensor. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Ultrasonically facilitated adsorption of an azo dye onto nanostructures obtained from cellulosic wastes of broom and cooler straw.

    Science.gov (United States)

    Safari, Mahdi; Khataee, Alireza; Darvishi Cheshmeh Soltani, Reza; Rezaee, Reza

    2018-07-15

    In the present work, ultrasonically facilitated adsorption (UFA) of a cationic dye [Basic Red 46 (BR46)] was examined using cellulosic nanostructures obtained from broom and cooler straw. Although the exclusive application of the nanostructured broom resulted in the 43.51% adsorption of BR46, the UFA process gave rise to the substantial removal efficiency of about 93%. In the case of the nanostructured straw, the efficiency was increased from 36.9% to 55.7%. The UFA process for both adsorbents reached the equilibrium within 60 min which was shorter than the time for the only adsorption. According to the values of the mean free energy (E), the decolorization via the UFA process applying broom (15.81 kJ/mol) and straw (11.18 kJ/mol) nanostructures was occurred chemically. An insignificant loss in the adsorption capacity of both adsorbents was observed after three regeneration tests by means of 0.05 M hydrochloric acid, indicating the good reusability potential of the as-synthesized cellulosic nanostructures. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. New self-assembled material based on Ru nanoparticles and 4-sulfocalix[4]arene as an efficient and recyclable catalyst for reduction of brilliant yellow azo dye in water: a new model catalytic reaction

    Energy Technology Data Exchange (ETDEWEB)

    Rambabu, Darsi; Pradeep, Chullikkattil P.; Dhir, Abhimanew, E-mail: abhimanew@iitmandi.ac.in [Indian Institute of Technology (India)

    2016-12-15

    New self-assembled material (Ru@SC) with ruthenium nanoparticles (Ru NPs) and 4-sulfocalix[4]arene (SC) is synthesized in water at room temperature. Ru@SC is characterized by thermal gravimetric analysis, FT-IR, powder x-ray diffraction, TEM and SEM analysis. The size of Ru nanoparticles in the self-assembly is approximately 5 nm. The self-assembled material Ru@SC shows an efficient catalytic reduction of toxic ‘brilliant yellow’ (BY) azo dye. The reduced amine products were successfully separated and confirmed by single-crystal XRD, NMR and UV-Vis spectroscopy. Ru@SC showed a better catalytic activity in comparison with commercial catalysts Ru/C (ruthenium on charcoal 5 %) and Pd/C (palladium on charcoal 5 and 10 %). The catalyst also showed a promising recyclability and heterogeneous nature as a catalyst for reduction of ‘BY’ azo dye.

  7. Microbial fuel cell operation using monoazo and diazo dyes as terminal electron acceptor for simultaneous decolourisation and bioelectricity generation

    International Nuclear Information System (INIS)

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

    2017-01-01

    Highlights: • Monoazo and diazo dyes were used as electron acceptor in the abiotic cathode of MFC. • Simultaneous decolourisation and bioelectricity generation were achieved. • Azo dye structures influenced the decolourisation performance. • Positive relation between decolourisation rate and power performance. - Abstract: Monoazo and diazo dyes [New coccine (NC), Acid orange 7 (AO7), Reactive red 120 (RR120) and Reactive green 19 (RG19)] were employed as electron acceptors in the abiotic cathode of microbial fuel cell. The electrons and protons generated from microbial organic oxidation at the anode which were utilized for electrochemical azo dye reduction at the cathodic chamber was successfully demonstrated. When NC was employed as the electron acceptor, the chemical oxygen demand (COD) removal and dye decolourisation efficiencies obtained at the anodic and cathodic chamber were 73 ± 3% and 95.1 ± 1.1%, respectively. This study demonstrated that the decolourisation rates of monoazo dyes were ∼50% higher than diazo dyes. The maximum power density in relation to NC decolourisation was 20.64 mW/m"2, corresponding to current density of 120.24 mA/m"2. The decolourisation rate and power output of different azo dyes were in the order of NC > AO7 > RR120 > RG19. The findings revealed that the structure of dye influenced the decolourisation and power performance of MFC. Azo dye with electron-withdrawing group at para substituent to azo bond would draw electrons from azo bond; hence the azo dye became more electrophilic and more favourable for dye reduction.

  8. Microbial fuel cell operation using monoazo and diazo dyes as terminal electron acceptor for simultaneous decolourisation and bioelectricity generation

    Energy Technology Data Exchange (ETDEWEB)

    Oon, Yoong-Sin [Water Research Group (WAREG), School of Environmental Engineering, Universiti Malaysia Perlis, 02600, Arau, Perlis (Malaysia); Ong, Soon-An, E-mail: ongsoonan@yahoo.com [Water Research Group (WAREG), School of Environmental Engineering, Universiti Malaysia Perlis, 02600, Arau, Perlis (Malaysia); Ho, Li-Ngee [School of Materials Engineering, Universiti Malaysia Perlis, 02600, Arau, Perlis (Malaysia); Wong, Yee-Shian; Oon, Yoong-Ling; Lehl, Harvinder Kaur; Thung, Wei-Eng [Water Research Group (WAREG), School of Environmental Engineering, Universiti Malaysia Perlis, 02600, Arau, Perlis (Malaysia); Nordin, Noradiba [School of Materials Engineering, Universiti Malaysia Perlis, 02600, Arau, Perlis (Malaysia)

    2017-03-05

    Highlights: • Monoazo and diazo dyes were used as electron acceptor in the abiotic cathode of MFC. • Simultaneous decolourisation and bioelectricity generation were achieved. • Azo dye structures influenced the decolourisation performance. • Positive relation between decolourisation rate and power performance. - Abstract: Monoazo and diazo dyes [New coccine (NC), Acid orange 7 (AO7), Reactive red 120 (RR120) and Reactive green 19 (RG19)] were employed as electron acceptors in the abiotic cathode of microbial fuel cell. The electrons and protons generated from microbial organic oxidation at the anode which were utilized for electrochemical azo dye reduction at the cathodic chamber was successfully demonstrated. When NC was employed as the electron acceptor, the chemical oxygen demand (COD) removal and dye decolourisation efficiencies obtained at the anodic and cathodic chamber were 73 ± 3% and 95.1 ± 1.1%, respectively. This study demonstrated that the decolourisation rates of monoazo dyes were ∼50% higher than diazo dyes. The maximum power density in relation to NC decolourisation was 20.64 mW/m{sup 2}, corresponding to current density of 120.24 mA/m{sup 2}. The decolourisation rate and power output of different azo dyes were in the order of NC > AO7 > RR120 > RG19. The findings revealed that the structure of dye influenced the decolourisation and power performance of MFC. Azo dye with electron-withdrawing group at para substituent to azo bond would draw electrons from azo bond; hence the azo dye became more electrophilic and more favourable for dye reduction.

  9. Enhanced solar light photodegradation of brilliant black bis-azo dye in aqueous solution by F, Sm3+ codoped TiO2

    Science.gov (United States)

    Mukonza, Sabastian S.; Nxumalo, Edward N.; Mamba, Bhekie B.; Mishra, Ajay K.

    2017-05-01

    This research focuses on improving the photocatalytic efficiency of TiO2 during the photo-mineralisation of brilliant black (BN) bis-azo dye pollutant in aqueous solution. This was achieved by improving the visible light activity of TiO2 photocatalyst semiconductor through co-doping of fluorine (F) and trivalent samarium ions (Sm3+) into a TiO2 matrix using a modified sol-gel synthesis method. Structural, morphological, and textural properties were evaluated using ultra-violet /visible spectroscopy (UV-visible), Raman spectroscopy, scanning electron microscopy coupled to energy dispersive X-ray spectroscopy (SEM/EDX) and X-ray diffraction spectroscopy (XRD). Photocatalytic and degradation efficiencies were assessed by decolourisation of BN dye in aqueous solution. Complete degradation of BN was attained after an irradiation time of 3 h using F, Sm3+-TiO2 (0.6% Sm3+) compared to 73.4% achieved using pristine TiO2. Pseudo first order kinetics rate constants (Ka) were 2.73×10-2 and 6.6×10-3 min-1 for Sm3+-TiO2 (0.6%Sm3+) and pristine TiO2, respectively, which translates to a remarkably high enhancement factor of 4. The results obtained established that doping of TiO2 by F and Sm3+ enhances the photocatalytic performance of TiO2 during solar light radiation which enables the utilisation of freely available and clean solar energy.

  10. Using Polarized Spectroscopy to Investigate Order in Thin-Films of Ionic Self-Assembled Materials Based on Azo-Dyes

    Science.gov (United States)

    Ahmad, Mariam; Andersen, Frederik; Brend Bech, Ári; Bendixen, H. Krestian L.; Nawrocki, Patrick R.; Bloch, Anders J.; Bora, Ilkay; Bukhari, Tahreem A.; Bærentsen, Nicolai V.; Carstensen, Jens; Chima, Smeeah; Colberg, Helene; Dahm, Rasmus T.; Daniels, Joshua A.; Dinckan, Nermin; El Idrissi, Mohamed; Erlandsen, Ricci; Førster, Marc; Ghauri, Yasmin; Gold, Mikkel; Hansen, Andreas; Hansen, Kenn; Helmsøe-Zinck, Mathias; Henriksen, Mathias; Hoffmann, Sophus V.; Hyllested, Louise O. H.; Jensen, Casper; Kallenbach, Amalie S.; Kaur, Kirandip; Khan, Suheb R.; Kjær, Emil T. S.; Kristiansen, Bjørn; Langvad, Sylvester; Lund, Philip M.; Munk, Chastine F.; Møller, Theis; Nehme, Ola M. Z.; Nejrup, Mathilde Rove; Nexø, Louise; Nielsen, Simon Skødt Holm; Niemeier, Nicolai; Nikolajsen, Lasse V.; Nøhr, Peter C. T.; Skaarup Ovesen, Jacob; Paustian, Lucas; Pedersen, Adam S.; Petersen, Mathias K.; Poulsen, Camilla M.; Praeger-Jahnsen, Louis; Qureshi, L. Sonia; Schiermacher, Louise S.; Simris, Martin B.; Smith, Gorm; Smith, Heidi N.; Sonne, Alexander K.; Zenulovic, Marko R.; Winther Sørensen, Alma; Vogt, Emil; Væring, Andreas; Westermann, Jonas; Özcan, Sevin B.

    2018-01-01

    Three series of ionic self-assembled materials based on anionic azo-dyes and cationic benzalkonium surfactants were synthesized and thin films were prepared by spin-casting. These thin films appear isotropic when investigated with polarized optical microscopy, although they are highly anisotropic. Here, three series of homologous materials were studied to rationalize this observation. Investigating thin films of ordered molecular materials relies to a large extent on advanced experimental methods and large research infrastructure. A statement that in particular is true for thin films with nanoscopic order, where X-ray reflectometry, X-ray and neutron scattering, electron microscopy and atom force microscopy (AFM) has to be used to elucidate film morphology and the underlying molecular structure. Here, the thin films were investigated using AFM, optical microscopy and polarized absorption spectroscopy. It was shown that by using numerical method for treating the polarized absorption spectroscopy data, the molecular structure can be elucidated. Further, it was shown that polarized optical spectroscopy is a general tool that allows determination of the molecular order in thin films. Finally, it was found that full control of thermal history and rigorous control of the ionic self-assembly conditions are required to reproducibly make these materials of high nanoscopic order. Similarly, the conditions for spin-casting are shown to be determining for the overall thin film morphology, while molecular order is maintained. PMID:29462883

  11. Synthesis, Spectral, Thermogravimetric, XRD, Molecular Modelling and Potential Antibacterial Studies of Dimeric Complexes with Bis Bidentate ON–NO Donor Azo Dye Ligands

    Directory of Open Access Journals (Sweden)

    Bipin Bihari Mahapatra

    2013-01-01

    Full Text Available The dimeric complexes of Co(II, Ni(II, Cu(II, Zn(II, Cd(II, and Hg(II with two new symmetrical ON–NO donor bis bidentate (tetradentate azo dye ligands, LH2 = 4,4′-bis(4′-hydroxyquinolinolinylazodiphenylsulphone, and L′H2 = 4,4′-bis(acetoacetanilideazodiphenylsulphone have been synthesized. The metal complexes have been characterised by elemental analytical, conductance, magnetic susceptibility, IR, electronic spectra, ESR, NMR, thermogravimetry, X-ray diffraction (powder pattern spectra, and molecular modelling studies. The Co(II and Ni(II complexes are found to be octahedral, Cu(II complexes are distorted octahedral, and a tetrahedral stereochemistry has been assigned to Zn(II, Cd(II, and Hg(II complexes. The thermogravimetric study indicates that compounds are quite stable. The energy optimized structures are proposed using the semiempirical ZINDO/1 quantum mechanical calculations. The potential antibacterial study of the ligands and some metal complexes has been made with one gram positive bacteria Staphylococcus aureus and one gram negative bacteria E. coli which gives encouraging results. Both the Co(II complexes are found to possess monoclinic crystal system.

  12. Using Polarized Spectroscopy to Investigate Order in Thin-Films of Ionic Self-Assembled Materials Based on Azo-Dyes

    Directory of Open Access Journals (Sweden)

    Miguel R. Carro-Temboury Martin Kühnel

    2018-02-01

    Full Text Available Three series of ionic self-assembled materials based on anionic azo-dyes and cationic benzalkonium surfactants were synthesized and thin films were prepared by spin-casting. These thin films appear isotropic when investigated with polarized optical microscopy, although they are highly anisotropic. Here, three series of homologous materials were studied to rationalize this observation. Investigating thin films of ordered molecular materials relies to a large extent on advanced experimental methods and large research infrastructure. A statement that in particular is true for thin films with nanoscopic order, where X-ray reflectometry, X-ray and neutron scattering, electron microscopy and atom force microscopy (AFM has to be used to elucidate film morphology and the underlying molecular structure. Here, the thin films were investigated using AFM, optical microscopy and polarized absorption spectroscopy. It was shown that by using numerical method for treating the polarized absorption spectroscopy data, the molecular structure can be elucidated. Further, it was shown that polarized optical spectroscopy is a general tool that allows determination of the molecular order in thin films. Finally, it was found that full control of thermal history and rigorous control of the ionic self-assembly conditions are required to reproducibly make these materials of high nanoscopic order. Similarly, the conditions for spin-casting are shown to be determining for the overall thin film morphology, while molecular order is maintained.

  13. Effect of food azo dyes tartrazine and carmoisine on biochemical parameters related to renal, hepatic function and oxidative stress biomarkers in young male rats.

    Science.gov (United States)

    Amin, K A; Abdel Hameid, H; Abd Elsttar, A H

    2010-10-01

    Tartrazine and carmoisine are an organic azo dyes widely used in food products, drugs and cosmetics. The present study conducted to evaluate the toxic effect of these coloring food additives; on renal, hepatic function, lipid profile, blood glucose, body-weight gain and biomarkers of oxidative stress in tissue. Tartrazine and carmoisine were administered orally in two doses, one low and the other high dose for 30 days followed by serum and tissue sample collection for determination of ALT, AST, ALP, urea, creatinine, total protein, albumin, lipid profile, fasting blood glucose in serum and estimation of GSH, catalase, SOD and MDA in liver tissue in male albino rat. Our data showed a significant increase in ALT, AST, ALP, urea, creatinine total protein and albumin in serum of rats dosed with tartrazine and carmoisine compared to control rats and these significant change were more apparent in high doses than low, GSH, SOD and Catalase were decreased and MDA increased in tissue homogenate in rats consumed high tartrazine and both doses of carmoisine. We concluded that tartrazine and carmoisine affect adversely and alter biochemical markers in vital organs e.g. liver and kidney not only at higher doses but also at low doses. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  14. Using Polarized Spectroscopy to Investigate Order in Thin-Films of Ionic Self-Assembled Materials Based on Azo-Dyes.

    Science.gov (United States)

    Kühnel, Miguel R Carro-Temboury Martin; Ahmad, Mariam; Andersen, Frederik; Bech, Ári Brend; Bendixen, H Krestian L; Nawrocki, Patrick R; Bloch, Anders J; Bora, Ilkay; Bukhari, Tahreem A; Bærentsen, Nicolai V; Carstensen, Jens; Chima, Smeeah; Colberg, Helene; Dahm, Rasmus T; Daniels, Joshua A; Dinckan, Nermin; Idrissi, Mohamed El; Erlandsen, Ricci; Førster, Marc; Ghauri, Yasmin; Gold, Mikkel; Hansen, Andreas; Hansen, Kenn; Helmsøe-Zinck, Mathias; Henriksen, Mathias; Hoffmann, Sophus V; Hyllested, Louise O H; Jensen, Casper; Kallenbach, Amalie S; Kaur, Kirandip; Khan, Suheb R; Kjær, Emil T S; Kristiansen, Bjørn; Langvad, Sylvester; Lund, Philip M; Munk, Chastine F; Møller, Theis; Nehme, Ola M Z; Nejrup, Mathilde Rove; Nexø, Louise; Nielsen, Simon Skødt Holm; Niemeier, Nicolai; Nikolajsen, Lasse V; Nøhr, Peter C T; Orlowski, Dominik B; Overgaard, Marc; Ovesen, Jacob Skaarup; Paustian, Lucas; Pedersen, Adam S; Petersen, Mathias K; Poulsen, Camilla M; Praeger-Jahnsen, Louis; Qureshi, L Sonia; Ree, Nicolai; Schiermacher, Louise S; Simris, Martin B; Smith, Gorm; Smith, Heidi N; Sonne, Alexander K; Zenulovic, Marko R; Sørensen, Alma Winther; Sørensen, Karina; Vogt, Emil; Væring, Andreas; Westermann, Jonas; Özcan, Sevin B; Sørensen, Thomas Just

    2018-02-15

    Three series of ionic self-assembled materials based on anionic azo-dyes and cationic benzalkonium surfactants were synthesized and thin films were prepared by spin-casting. These thin films appear isotropic when investigated with polarized optical microscopy, although they are highly anisotropic. Here, three series of homologous materials were studied to rationalize this observation. Investigating thin films of ordered molecular materials relies to a large extent on advanced experimental methods and large research infrastructure. A statement that in particular is true for thin films with nanoscopic order, where X-ray reflectometry, X-ray and neutron scattering, electron microscopy and atom force microscopy (AFM) has to be used to elucidate film morphology and the underlying molecular structure. Here, the thin films were investigated using AFM, optical microscopy and polarized absorption spectroscopy. It was shown that by using numerical method for treating the polarized absorption spectroscopy data, the molecular structure can be elucidated. Further, it was shown that polarized optical spectroscopy is a general tool that allows determination of the molecular order in thin films. Finally, it was found that full control of thermal history and rigorous control of the ionic self-assembly conditions are required to reproducibly make these materials of high nanoscopic order. Similarly, the conditions for spin-casting are shown to be determining for the overall thin film morphology, while molecular order is maintained.

  15. Dielectric Properties of Azo Polymers: Effect of the Push-Pull Azo Chromophores

    Directory of Open Access Journals (Sweden)

    Xuan Zhang

    2018-01-01

    Full Text Available The relationship between the structure and the dielectric properties of the azo polymers was studied. Four azo polymers were synthesized through the azo-coupling reaction between the same precursor (PAZ and diazonium salts of 4-aminobenzoic acid ethyl ester, 4-aminobenzonitrile, 4-nitroaniline, and 2-amino-5-nitrothiazole, respectively. The precursor and azo polymers were characterized by 1H NMR, FT-IR, UV-vis, GPC, and DSC. The dielectric constant and dielectric loss of the samples were measured in the frequency range of 100 Hz–200 kHz. Due to the existence of the azo chromophores, the dielectric constant of the azo polymers increases compared with that of the precursor. In addition, the dielectric constant of the azo polymers increases with the increase of the polarity of the azo chromophores. A random copolymer (PAZ-NT-PAZ composed of the azo polymer PAZ-NT and the precursor PAZ was also prepared to investigate the content of the azo chromophores on the dielectric properties of the azo polymers. It showed that the dielectric constant increases with the increase of the azo chromophores. The results show that the dielectric constant of this kind of azo polymers can be controlled by changing the structures and contents of azo chromophores during the preparation process.

  16. Effect of AZO on GO-NO-GO radiation indicator

    International Nuclear Information System (INIS)

    Hasan Sham; Taiman Kadni; Noriah Mod Ali

    2002-01-01

    The purpose of the study is to evaluate the effect of Azo group dyes as an radiation indicator. Dimethyl Yellow, Alizarin Red, Congo Red, Methyl Violet and Bromophenol Blue dyes were used to compare the capability of each dye to change colour in response to radiation. Sensitivity of single and incorporated dyes were identified by exposing them to 5-50 kGy gamma radiation. The result shows that the Azo group is more sensitive to radiation compare to other groups. (Author)

  17. Optimal decolorization and kinetic modeling of synthetic dyes by Pseudomonas strains.

    Science.gov (United States)

    Yu, J; Wang, X; Yue, P L

    2001-10-01

    Pseudomonas spp were isolated from an anaerobic-aerobic dyeing house wastewater treatment facility as the most active azo-dye degraders. Decolorization of azo dyes and non-azo dyes including anthraquinone, metal complex and indigo was compared with individual strains and a bacterial consortium consisting of the individual strain and municipal sludge (50 50wt). The consortium showed a significant improvement on decolorization of two recalcitrant non-azo dyes, but little effect on the dyes that the individual strains could degrade to a great or moderate extent. Decolorization of Acid violet 7 (monoazo) by a Pseudomonas strain GM3 was studied in detail under various conditions. The optimum decolorization activity was observed in a narrow pH range (7-8), a narrow temperature range (35-40 degrees C), and at the presence of organic and ammonium nitrogen. Nitrate had a severe inhibitory effect on azo dye decolorization: 10 mg/L led to 50% drop in decolorization activity and 1000 mg/L to complete activity depression. A kinetic model is established giving the dependence of decolorization rate on cell mass concentration (first-order) and dye concentration (half order). The rate increased with temperature from 10 to 35 C, which can be predicted by Arrhenius equation with the activation energy of 16.87 kcal/mol and the frequency factor of 1.49 x 10(11) (mg L)1/2/g DCM min.

  18. Synthesis, structural characterization of nano ZnTiO3 ceramic: An effective azo dye adsorbent and antibacterial agent

    Directory of Open Access Journals (Sweden)

    R.S. Raveendra

    2014-12-01

    Full Text Available Nanocrystalline meta-zinc titanate (ZnTiO3 ceramic was prepared using a self-propagating solution combustion synthesis (SCS for the first time using urea as fuel. The product was calcined at 800 °C for 2 h to improve the crystallinity. Powder X-ray diffraction (PXRD, Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM, energy-dispersive X-ray spectroscopy (EDAX, high resolution transmission electron microscopy (HR-TEM and UV–vis absorption spectroscopy were used to characterize the final product. PXRD results show that the ilmenite type rhombohedral structure was formed when the sample was calcined at 800 °C for 2 h. Adsorption experiments were performed with cationic malachite green (MG dye. ∼96% dye was adsorbed onto nanocrystalline ZnTiO3 ceramic at pH 9 for 30 min of the contact time. The optimum adsorbent dose was found to be 0.45 g/L of dye. Langmuir–Hinshelwood model was used to study adsorption kinetics and first order kinetic model best describes the MG adsorption on ZnTiO3. Antibacterial activity was investigated against gram negative Klebsiella aerogenes, Pseudomonas desmolyticum, Escherichia coli, and gram positive Staphylococcus aureus bacteria by agar well diffusion method. Nanocrystalline ZnTiO3 ceramic showed significant effect on all the four bacterial strains at the concentration of 1000 and 1500 μg per well.

  19. Assessment of toxicity and genotoxicity of the reactive azo dyes Remazol Black B and Remazol Orange 3R and effectiveness of electron beam irradiation in the reduction of color and toxic effects

    International Nuclear Information System (INIS)

    Pinheiro, Alessandro de Sa

    2011-01-01

    The textile industries play an important role in national and global economy. But, their activities are considered potentially polluting. The use of large volumes of water and the production of colored wastewater with high organic matter are among the main issues raised, especially during the stage of dyeing and washing of the textile process. The reactive azo dyes are the main colors used in the industry for dyeing of cotton in Brazil and worldwide. Because of its low setting and variations in the fiber production process, about 30% of the initial concentration used in the dyeing baths are lost and will compose the final effluent. These compounds have a low biodegradability, are highly soluble in water and therefore are not completely removed by conventional biological processes. In addition, other processes do not promote degradation but the transference to solid environment. The dyes discarded without treatment in the water body can cause aesthetic modifications, alter photosynthesis and gas solubility, as well as being toxic and genotoxic. The main objectives of this study were to evaluate the toxicity and genotoxicity of two reactive azo dyes (Remazol Black B - RPB and Remazol Orange 3R - R3AR) and the percentage of color and toxicity reduction after the use of electron beam radiation. The acute toxicity assays performed with Vibrio fischeri, Daphnia similis and Biomphalaria glabrata showed different response patterns for dyes. The different chemical forms of dyes were slightly toxic to Vibrio fischeri and only the RPB dye (vinylsulphone) was toxic (EC50 15min = 6,23 mg L-1). In tests with Daphnia similis, the dye RPB was slightly toxic in its pattern form, sulphatoethylsulphone, (CE50 48h = 91,25 mg L -1 ) and showed no toxicity in other chemical forms. However, the RA3R dye was toxic to the dafnids and the vinylsulphone form very toxic (EC50 48h = 0,54 mg L-1). No toxicity was observed in Biomphalaria glabrata assays. Chronic toxicity was assessed with the

  20. Separation of thorium, uranium and rare-earth elements with 2-[(2-arsenophenyl)-azo]-1,8-dihydroxy-7-[(2,4,6-tribromophenyl)azo]-naphthalene-3,6-disulfonic acid by capillary electrophoresis

    International Nuclear Information System (INIS)

    Liu, Bi-feng; Liu, Liang-bin; Cheng, Jie-ke

    1998-01-01

    The separation of thorium, uranium and rare-earth elements (RE) as their 2-[(2-arsenophenyl)-azo]-1,8-dihydroxy-7-[(2,4,6-tribromophenyl)azo]-naphthalene-3,6-disulfonic acid complexes by capillary electrophoresis with direct UV-Vis detection is presented in this paper. The influences of pH value and concentration of electrolyte, voltage and surfactant on separation were investigated and optimized. Under the selected conditions (30mM NaAc-HCl buffer containing 0.5mM cetyltrimethylammonium bromide and 0.2mM chelating reagent, pH 4.30, 12KV, 635nm as detection wavelength), the coexisted ions were separated within 4min, and limits of detection of 37, 39, 199μgl -1 for RE, thorium, uranium with a linear dynamic range of over 2 orders of magnitude were achieved, respectively

  1. Modeling of Reactive Blue 19 azo dye removal from colored textile wastewater using L-arginine-functionalized Fe{sub 3}O{sub 4} nanoparticles: Optimization, reusability, kinetic and equilibrium studies

    Energy Technology Data Exchange (ETDEWEB)

    Dalvand, Arash; Nabizadeh, Ramin [Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Reza Ganjali, Mohammad [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Biosensor Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Khoobi, Mehdi [Medical Biomaterials Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran 14176 (Iran, Islamic Republic of); Nazmara, Shahrokh [Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Hossein Mahvi, Amir, E-mail: ahmahvi@yahoo.com [Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Center for Solid Waste Research, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); National Institute of Health Research, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2016-04-15

    This study aimed to investigate the removal of Reactive Blue 19 from colored wastewater using Fe{sub 3}O{sub 4} magnetic nanoparticles modified with L-arginine (Fe{sub 3}O{sub 4}@L-arginine). In order to investigate the effect of independent variables on dye removal and determining the optimum condition, the Box–Behnken Design (BBD) under Response Surface Methodology (RSM) was employed. Fe{sub 3}O{sub 4}@L-arginine nanoparticles were synthesized and characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and vibrating sample magnetometer. Applying Fe{sub 3}O{sub 4}@L-arginine nanoparticles for dye removal showed that; by increasing adsorbent dose and decreasing pH, dye concentration, and ionic strength dye removal has been increased. In the optimum condition, Fe{sub 3}O{sub 4}@L-arginine nanoparticles were able to remove dye as high as 96.34% at an initial dye concentration of 50 mg/L, adsorbent dose of 0.74 g/L, and pH 3. The findings indicated that dye removal followed pseudo-second-order kinetic (R{sup 2}=0.999) and Freundlich isotherm (R{sup 2}=0.989). Based on the obtained results, as an efficient and reusable adsorbent, Fe{sub 3}O{sub 4}@L-arginine nanoparticles can be successfully applied for dye removal from colored wastewater. - Highlights: • The Fe{sub 3}O{sub 4}@L-arginine removed RB 19 azo dye from wastewater efficiently. • BBD under RSM was used to analyze and optimize the adsorption process. • pH was the most influential parameter in dye removal.

  2. Biofilm inhibition formation of clinical strains of Pseudomonas aeruginosa mutans, photocatalytic activity of azo dye and GC-MS analysis of leaves of Lagerstroemia speciosa.

    Science.gov (United States)

    Sai Saraswathi, V; Kamarudheen, Neethu; Bhaskara Rao, K V; Santhakumar, K

    2017-04-01

    The investigation was conducted to analyse the bioactive compounds from the leaf extracts of L. speciosa by GC-MS. The extracts were screened for antibacterial and antibiofilm activities against potential clinical strains. The bioactive compounds from the leaves of L. speciosa were extracted by soxhlet continuous extraction method and their chemical composition was analysed by Gas Chromatography-Mass Spectroscopy (GC-MS). The antibacterial activity was evaluated against clinical strain like Staphylococcus aureus, Escherichia coli, P. aeruginosa and Salmonella typhi by well diffusion technique. We also screened for antibacterial property against common food borne pathogens namely Listeria monocytogenes and Bacillus cereus at varied concentration 250μml -1 to 1000μml -1 . Thereafter antibiofilm assay was carried out at from 250 to 1000μg/ml against P. aeruginosa (high biofilm forming pathogen) clinical strain by cover slip technique and the morphology of the pathogen was observed using Scanning Electron Microscopy-(SEM). It was observed that diverse class of secondary metabolites were found by GC-MS analysis for all the extracts upon the continuous extraction. It was found that only minimum inhibition was seen in alcoholic extract for antibacterial activity, whereas all other extracts showed negligible activity. P. aeruginosa biofilm inhibited to 93.0±2% and 91±2% at higher concentration (1000μg/ml) for methanolic and ethanolic extract respectively. Absence of extracellular matrix structure and the surface cracking of biofilm were viewed by SEM, which confirmed the antibiofilm activity. Hence this study reveals that L. speciosa showed significant antibiofilm activity against P. aeruginosa due to the phytoconstituents present in the leaf extracts which was well documented in the alcoholic extracts by GC-MS analysis. The methanolic and ethanolic extract showed good photocatalytic activity of 77.44% and 96.66% against azo dye degradation respectively. Further

  3. Advanced oxidation of acid and reactive dyes

    DEFF Research Database (Denmark)

    Arslan-Alaton, I.; Gursoy, B.H.; Schmidt, Jens Ejbye

    2008-01-01

    M) for 10:hsp sp="0.25" min Fenton treatment at pH 3, resulting in reduced chemical oxygen demand and dissolved organic carbon removal efficiencies; only acetate was detected as a stable dye oxidation end product. During anaerobic digestion, 100, 29% and no inhibition in methane production was observed...

  4. CaSnO 3 obtained by modified Pechini method applied in the photocatalytic degradation of an azo dye

    Directory of Open Access Journals (Sweden)

    G. L. Lucena

    Full Text Available Abstract Pure forms of alkaline-earth stannates with perovskite structure (ASnO3, A= Ca2+, Sr2+, Ba2+ have been used as photocatalysts. In this work, CaSnO3 perovskite sample was synthesized by a modified Pechini method at 800 ºC and characterized by X-ray diffraction (XRD, UV-visible spectroscopy, infrared spectroscopy and Raman spectroscopy. The photocatalytic degradation of remazol golden yellow (RNL dye under UV radiation was evaluated. The XRD pattern showed that the synthesis method favored the orthorhombic CaSnO3 crystallization. According to the Raman spectrum, a material with high short-range order was obtained despite of the relatively low synthesis temperature, compared to the solid-state reaction one. The highest photocatalytic activity was attained at pH 3, which presented 51% discoloration and improved activity of 35% compared to discoloration solely due to adsorption (absence of radiation. The point of zero charge (PZC and the photocatalytic results indicated that a direct mechanism prevailed at pH 3, whereas an indirect mechanism prevailed at pH 6.

  5. 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

  6. Rapid degradation of azo dye Direct Black BN by magnetic MgFe{sub 2}O{sub 4}-SiC under microwave radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Jia; Yang, Shaogui, E-mail: yangsg@nju.edu.cn; Li, Na; Meng, Lingjun; Wang, Fei; He, Huan; Sun, Cheng

    2016-08-30

    Highlights: • MgFe{sub 2}O{sub 4}-SiC was first successfully synthesized. • MgFe{sub 2}O{sub 4}-SiC attained the maximum absorbing value of 13.32 dB at 2.57 GHz, which reached extremely high RL value at low frequency range. • Fast decolorization and high TOC removal of azo dye Direct Black BN with complicated structure could occur with MgFe{sub 2}O{sub 4}-SiC under MW radiation. • MgFe{sub 2}O{sub 4}-SiC had better MW absorbing property and higher MW catalytic activity than MnFe{sub 2}O{sub 4}-SiC under the same condition. • MgFe{sub 2}O{sub 4}-SiC was of practical use in the wastewater treatment. - Abstract: A novel microwave (MW) catalyst, MgFe{sub 2}O{sub 4} loaded on SiC (MgFe{sub 2}O{sub 4}-SiC), was successfully synthesized by sol-gel method, and pure MgFe{sub 2}O{sub 4} was used as reference. The MgFe{sub 2}O{sub 4} and MgFe{sub 2}O{sub 4}-SiC catalysts were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), N{sub 2} adsorption analyzer (BET specific surface area), X-ray photoelectron spectroscopy (XPS). The electromagnetic parameters of the prepared catalysts were measured by vector network analyzer. The reflection loss (RL) based on the electromagnetic parameters calculated in Matlab showed MgFe{sub 2}O{sub 4}-SiC attained the maximum absorbing value of 13.32 dB at 2.57 GHz, which reached extremely high RL value at low frequency range, revealing the excellent MW absorption property of MgFe{sub 2}O{sub 4}-SiC. MW-induced degradation of Direct Black BN (DB BN) over as-synthesized MgFe{sub 2}O{sub 4}-SiC indicated that degradation efficiency of DB BN (20 mg L{sup −1}) in 5 min reached 96.5%, the corresponding TOC removal was 65%, and the toxicity of DB BN after degradation by MgFe{sub 2}O{sub 4}-SiC obviously decreased. The good stability and applicability of MgFe{sub 2}O{sub 4}-SiC on the degradation process were also discovered. Moreover, the ionic chromatogram during degradation

  7. Performance variation from triphenylamine- to carbazole-triphenylamine-rhodaniline-3-acetic acid dyes in dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chien-Hsin, E-mail: yangch@nuk.edu.tw [Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan (China); Lin, Wen-Churng [Department of Environmental Engineering, Kun Shan University, Tainan 710, Taiwan (China); Wang, Tzong-Liu; Shieh, Yeong-Tarng; Chen, Wen-Janq; Liao, Shao-Hong; Sun, Yu-Kuang [Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan (China)

    2011-10-17

    Highlights: {yields} We synthesized an organic dye of carbazole-rhodaniline-3-acetic acid-triphenylamine. {yields} A dye-sensitized solar cell is fabricated using this dye with efficiency of 4.64%. {yields} Carbazole donor in the dye molecule provides electron in increasing efficiency. {yields} Two rhodaniline-3-acetic acids play a key role in increasing efficiency. {yields} AC impedance proves this dye's effect on enhancing charge transfer in TiO{sub 2}. - Abstract: Organic dyes have been synthesized which contain an extra-electron donor (carbazole) and electron acceptors (rhodaniline-3-acetic acid) on triphenylamines (TPA). Photophysical, electrochemical, and theoretical computational methods have categorized these compounds. Nanocrystalline TiO{sub 2}-based dye-sensitized solar cells (DSSCs) are fabricated using these dye molecules as light-harvesting sensitizers. The overall efficiency of sensitized cells has 4.64% relative to a cis-di(thiocyanato)-bis(2,2'-bipyridyl)-4,4'-dicarboxylate ruthenium (II) (N3 dye)-sensitized device (7.83%) fabricated and measured under the same conditions. Carbazole-electron donation in the dye molecules plays a key role in the increased efficiency. Two rhodaniline-3-acetic acid groups appear to help convey the charge transfer from the excited dye molecules to the conduction band of TiO{sub 2}, leading to a higher efficiency of devices using such a dye. Electrochemical impedance supports this dye's effect on enhancing charge transfer in TiO{sub 2} (e{sup -}). Computations on this dye compound also indicate the larger charge transfer efficiency in the electronically excited state.

  8. Evaluation of the adsorbent properties of a zeolite rock modified for the removal of the azo dyes as water pollutants; Evaluacion de las propiedades adsorbentes de una roca zeolitica modificada para la remocion de colorantes azoicos como contaminantes del agua

    Energy Technology Data Exchange (ETDEWEB)

    Torres P, J

    2005-07-01

    At the moment some investigations which make reference to the removal of dyes for diverse adsorbent materials; as well as the factors that influence in the sorption process, considering the type so much of dye as those characteristics of the adsorbent material. In this work were investigated those adsorbent properties of a zeolite rock coming from San Luis Potosi State for the removal of azo dyes, using as peculiar cases the Red 40 (Red Allura) and the Yellow 5 (Tartrazine); for it were determined kinetic parameters and the sorption isotherms, as well as the sorption mechanisms involved in each case, between the dyes and the zeolite rock. In this work also it was considered the characterization before and after to removal of color from the water, through advanced analytical techniques such as the scanning electron microscopy of high vacuum (SEM), elementary microanalysis (EDS) and X-ray diffraction (XRD). The experimental part of the work fundamentally consisted, in the conditioning with a NaCl solution and later on the modification with HDTMA-Br of the natural zeolite rock, for then to put it in contact with solutions of the dyes R-40 and A-5, varying so much the contact times as the concentrations; the quantification of sodium in the liquid phase after the modification of the zeolite rock to determine the capacity of external cation exchange (CICE) it was carried out by means of the atomic absorption spectroscopy technique (EAA), and the quantification of the surfactant and the dyes in the liquid phase, it was carried out by means of the UV-vis spectrophotometry technique. It was found that the kinetic model that better it describes the process of sorption of R-40 and A-5 for the modified zeolite rock with HDTMA-Br, leaving of monocomponent and bi component solutions, it is the pseudo- second order. Inside of the obtained results for the sorption isotherms, as much the dye R-40 as the dye A-5 its presented a better adjustment to the Langmuir model. In what refers

  9. Phosphate cellulose with metaphosphoric acid for dye removal

    International Nuclear Information System (INIS)

    Silva, S.C.C.; Silva, F.C.; Lima, L.C.B.; Santos, M.R.M.C.; Osajima, J.A.; Silva Filho, E.C. da

    2014-01-01

    The chemical modification of cellulose is a suitable method used for producing value-added products, making them more efficient and selective for certain applications such as adsorption of dye. Thus the aim of this study was to modify the natural cellulose with metaphosphoric acid, characterized it through the techniques of FTIR and "3"1P NMR and applies it in the adsorption of brilliant green dye, evaluating the kinetic models of pseudo first-order and pseudo second-order and the theoretical models of the Langmuir, Freundlich and Temkin isotherms. The characterizations demonstrated the effectiveness of the modification, the maximum adsorption capacity was 150.0 mg g-1, adjusting better to the kinetic model of pseudo-second order and the theoretical model of Temkin, with the adsorbent showing efficient for removal of brilliant green dye. (author)

  10. Chitosan and chemically modified chitosan beads for acid dyes sorption

    Institute of Scientific and Technical Information of China (English)

    AZLAN Kamari; WAN SAIME Wan Ngah; LAI KEN Liew

    2009-01-01

    The capabilities of chitosan and chitosan-EGDE (ethylene glycol diglycidyl ether) beads for removing Acid Red 37 (AR 37) and Acid Blue 25 (AB 25) from aqueous solution were examined. Chitosan beads were cross-linked with EGDE to enhance its chemical resistance and mechanical strength. Experiments were performed as a function of pH, agitation period and concentration of AR 37 and AB 25. It was shown that the adsorption capacities of chitosan were comparatively higher than chitosan-EGDE for both acid dyes. This is mainly because cross-linking using EGDE reduces the major adsorption sites -NH3+ on chitosan. Langmuir isotherm model showed best conformity compared to Freundlich and BET. The kinetic experimental data agreed very well to the pseudo second-order kinetic model. The desorption study revealed that after three cycles of adsorption and desorption by NaOH and HCl, both adsorbents retained their promising adsorption abilities. FT-IR analysis proved that the adsorption of acid dyes onto chitosan-based adsorbents was a physical adsorption. Results also showed that chitosan and chitosan-EGDE beads were favourable adsorbers and could be employed as low-cost alternatives for the removal of acid dyes in wastewater treatment.

  11. Preparation of nanospinels NiMn{sub x}Fe{sub 2-x}O{sub 4} using sol-gel method and their applications on removal of azo dye from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Khosravi, Iman [Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad 917791436 (Iran, Islamic Republic of); Yazdanbakhsh, Mohammad, E-mail: myazdan@um.ac.ir [Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad 917791436 (Iran, Islamic Republic of); Goharshadi, Elaheh K. [Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad 917791436 (Iran, Islamic Republic of); Center of Nano Research, Ferdowsi University of Mashhad, Mashhad 91799 (Iran, Islamic Republic of); Youssefi, Abbas [Par -e- Tavous Research Institute, Mashhad 91000 (Iran, Islamic Republic of)

    2011-11-01

    Highlights: {yields} The nanospinels, NiMn{sub x}Fe{sub 2-x}O{sub 4} (x = 0.05, 0.1, 0.3, 0.5, 0.7, and 1), prepared by Sol-gel method. {yields} The nanospinels prepared, have been used for removal of approximately 90% of reactive blue 5 within 1 min. {yields} The degradation of RB5 dye, follows merely an adsorption process. - Abstract: In this paper, nanospinels NiMn{sub x}Fe{sub 2-x}O{sub 4} (x = 0.05, 0.1, 0.3, 0.5, 0.7, and 1) were prepared by sol-gel method in the presence of nitrate-metal-ethylene glycol (EG) polymerized complex. The nanospinels were characterized using thermogravimetry analysis (TGA), X-ray powder diffraction (XRD), Fourier infrared spectroscopy (FTIR), and transmission electron microscope (TEM). The adsorption of an azo dye, reactive blue 5 (RB5), from water was determined using the prepared nanospinels. The effect of operational parameters such as the initial dye concentration, the concentration of nanospinels, temperature, and pH on the degradation of dye was investigated. The adsorption process follows second-order kinetics and Arrhenius behavior. Two common models, the Langmuir and Freundlich isotherms were used to investigate the interaction of dye and nanospinels. The isotherm evaluations revealed that the Freundlich model provides better fit to the experimental data than that of the Langmuir model. The photocatalytic degradation of RB5 at pH 1 under UV irradiation was examined. The results showed that the degradation of RB5 dye follows merely an adsorption process.

  12. Effect of the nature of p-substituents in benzene ring of azo compounds based on chromotropic acid on their reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Savvin, S B; Dedkova, V P; Azarashvili, M A; Likhonina, E A

    1988-08-01

    Effect of acceptor and donor substituents in a reagent on degree of contrast and selectivity of spectrophotometric beryllium determination as well as other elements was considered taking derivatives of orthanilic-azo-chromotropic acid as an example. The optimal pH region of aminoorthanilic-azo-chromotropic acid interaction with Be 5-6.5; the optimal wavelength is 640 nm. The solution colour changes from violet-red to blue during complex formation. Selectivity increases after addition of masking substances. Be determination on the background of 4-fold Cu and VO/sup 2+/ amounts 8-fold Al amounts, 2-fold Zn amounts is possible in the presence of 5-fold EDTA amounts unsubstituted reagent is characterized by the lowest degree of contrast and selectivity of reactions with metals.

  13. Kinetics of leather dyeing pretreated with enzymes: role of acid protease.

    Science.gov (United States)

    Kanth, Swarna Vinodh; Venba, Rajangam; Jayakumar, Gladstone Christopher; Chandrababu, Narasimhan Kannan

    2009-04-01

    In the present investigation, kinetics of dyeing involving pretreatment with acid protease has been presented. Application of acid protease in dyeing process resulted in increased absorption and diffusion of dye into the leather matrix. Enzyme treatment at 1% concentration, 60 min duration and 50 degrees C resulted in maximum of 98% dye exhaustion and increased absorption rate constants. The final exhaustion (C(infinity)) for the best fit of CI Acid Black 194 dye has been 98.5% with K and r2 values from the modified Cegarra-Puente isotherm as 0.1033 and 0.0631. CI Acid Black 194 being a 2:1 metal complex acid dye exhibited higher absorption rate than the acid dye CI Acid Black 210. A reduction in 50% activation energy calculated from Arrhenius equation has been observed in enzyme assisted dyeing process of both the dyes that substantiates enhanced dye absorption. The absorption rate constant calculated with modified Cegarra-Puente equation confirm higher rate constants and faster kinetics for enzyme assisted dyeing process. Enzyme treated leather exhibited richness of color and shade when compared with control. The present study substantiates the essential role of enzyme pretreatment as an eco-friendly leather dyeing process.

  14. Influence of ionic strength in the adsorption and during photocatalysis of reactive black 5 azo dye on TiO{sub 2} coated on non woven paper with SiO{sub 2} as a binder

    Energy Technology Data Exchange (ETDEWEB)

    Aguedach, Abdelkahhar [Laboratoire de l' Eau et environnement, Universite Chouaib Doukkali, Faculte des Sciences, BP.20, El Jadida, Maroc (Morocco); Brosillon, Stephan [Laboratoire Science Chimiques de Rennes UMR 6226, Equipe Chimie et Ingenierie des Procedes, Ecole Nationale Superieure de Chimie, Universite Rennes 1, avenue du General Leclerc, 35700 Rennes (France)], E-mail: Stephan.Brosillon@ensc-rennes.fr; Morvan, Jean [Laboratoire Science Chimiques de Rennes UMR 6226, Equipe Chimie et Ingenierie des Procedes, Ecole Nationale Superieure de Chimie, Universite Rennes 1, avenue du General Leclerc, 35700 Rennes (France); Lhadi, El Kbir [Laboratoire de l' Eau et environnement, Universite Chouaib Doukkali, Faculte des Sciences, BP.20, El Jadida, Maroc (Morocco)

    2008-01-31

    Reactive black 5 (RB5), an azo dye, was degraded by using UV-irradiated TiO{sub 2} coated on non woven paper with SiO{sub 2} as a binder. The adsorption capacity of the photocatalyst was studied at natural pH, superior to pH{sub pzc} of the binder, for various ionic strengths. Different salts such as NaCl, KCl, CaCl{sub 2}, LiCl, Ca(NO{sub 3}){sub 2} were used to increase the ionic strength. The presence of salt increased the adsorption capacity. The electrostatic interactions between dye and oxide surface charges (TiO{sub 2}/SiO{sub 2}) is very important in the adsorption phenomena. The effect of the ionic strength of the solution on photocatalyst degradation was studied. The rate of degradation was increased by the presence of salts in the range of the experimental conditions. The increase of the initial decolorization rate was observed in the following order: Ca{sup 2+} > K{sup +} > Na{sup +} > Li{sup +}. Experiments with different anions (Cl{sup -}, NO{sub 3}{sup -}) had shown that nitrate was an indifferent electrolyte for the adsorption and photodegradation of the dye on SiO{sub 2}/TiO{sub 2}.

  15. Influence of ionic strength in the adsorption and during photocatalysis of reactive black 5 azo dye on TiO2 coated on non woven paper with SiO2 as a binder

    International Nuclear Information System (INIS)

    Aguedach, Abdelkahhar; Brosillon, Stephan; Morvan, Jean; Lhadi, El Kbir

    2008-01-01

    Reactive black 5 (RB5), an azo dye, was degraded by using UV-irradiated TiO 2 coated on non woven paper with SiO 2 as a binder. The adsorption capacity of the photocatalyst was studied at natural pH, superior to pH pzc of the binder, for various ionic strengths. Different salts such as NaCl, KCl, CaCl 2 , LiCl, Ca(NO 3 ) 2 were used to increase the ionic strength. The presence of salt increased the adsorption capacity. The electrostatic interactions between dye and oxide surface charges (TiO 2 /SiO 2 ) is very important in the adsorption phenomena. The effect of the ionic strength of the solution on photocatalyst degradation was studied. The rate of degradation was increased by the presence of salts in the range of the experimental conditions. The increase of the initial decolorization rate was observed in the following order: Ca 2+ > K + > Na + > Li + . Experiments with different anions (Cl - , NO 3 - ) had shown that nitrate was an indifferent electrolyte for the adsorption and photodegradation of the dye on SiO 2 /TiO 2

  16. Optical characterization and blu-ray recording properties of metal(II) azo barbituric acid complex films

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.Y. [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)], E-mail: xyli@siom.ac.cn; Wu, Y.Q. [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Key Lab of Functional Inorganic Material Chemistry (Heilongjiang University), Ministry of Education, Haerbin 150080 (China)], E-mail: yqwu@siom.ac.cn; Gu, D.D.; Gan, F.X. [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2009-02-25

    Smooth thin films of nickel(II), cobalt(II) and zinc(II) complexes with azo barbituric acid were prepared by the spin-coating method. Absorption spectra of the thin films on K9 glass substrates in 300-700 nm wavelength region were measured. Optical constants (complex refractive index N = n + ik) of the thin films prepared on single-crystal silicon substrates in 275-695 nm wavelength region were investigated on rotating analyzer-polarizer type of scanning ellipsometer, and dielectric constant {epsilon} ({epsilon} = {epsilon}{sub 1} + i{epsilon}{sub 2}) as well as absorption coefficient {alpha} of thin films were calculated at 405 nm. In addition, static optical recording properties of the cobalt(II) complex thin film with an Ag reflective layer was carried out using a 406.7 nm blue-violet laser and a high numerical aperture (NA) of 0.90. Clear recording marks with high reflectivity contrast (>60%) at proper laser power and pulse width were obtained, and the size of recording mark was as small as 250 nm. The results indicate that these metal(II) complexes are promising organic recording medium for the blu-ray optical storage system.

  17. The comparison of spectra and dyeing properties of new azonaphthalimide with analogues azobenzene dyes on natural and synthetic polymers

    Directory of Open Access Journals (Sweden)

    Mozhgan Hosseinnezhad

    2017-05-01

    Full Text Available The aim of the present research was to prepare new acid dyes based on naphthalimides. In this respect a series of monoazo acid dyes have been obtained using 4-amino-N-methyl (alternatively N-butyl-1,8-naphthalimide, aniline and p-nitroaniline as diazo components. 2-Naphthol-6-sulfonic acid (Schaeffer’s acid and 1-naphthol-8-amino-3,6-disulfonic acid (H-acid were used as coupling components. The spectrophotometric properties of the synthesized dyes were investigated in various solvents and compared with analogues azobenzene dyes. It is found, when acid dyes are applied in various solvents and different pH, additional bathochromically shifted bands of different intensity appear in the electronic spectra. This effect is caused by the occurrence of the equilibrium of azo and hydrazone forms in the dyes. The synthesized acid dyes were applied on wool fabrics in order to consider their dyeing properties, fastnesses and the obtainable color gamut. The synthesized dyes represented that they have the ability of dyeing wool and polyamide fabrics and give red to violet hues with good wash, medium light, and good milling and perspiration fastnesses.

  18. Organic solvent-free air-assisted liquid-liquid microextraction for optimized extraction of illegal azo-based dyes and their main metabolite from spices, cosmetics and human bio-fluid samples in one step.

    Science.gov (United States)

    Barfi, Behruz; Asghari, Alireza; Rajabi, Maryam; Sabzalian, Sedigheh

    2015-08-15

    Air-assisted liquid-liquid microextraction (AALLME) has unique capabilities to develop as an organic solvent-free and one-step microextraction method, applying ionic-liquids as extraction solvent and avoiding centrifugation step. Herein, a novel and simple eco-friendly method, termed one-step air-assisted liquid-liquid microextraction (OS-AALLME), was developed to extract some illegal azo-based dyes (including Sudan I to IV, and Orange G) from food and cosmetic products. A series of experiments were investigated to achieve the most favorable conditions (including extraction solvent: 77μL of 1-Hexyl-3-methylimidazolium hexafluorophosphate; sample pH 6.3, without salt addition; and extraction cycles: 25 during 100s of sonication) using a central composite design strategy. Under these conditions, limits of detection, linear dynamic ranges, enrichment factors and consumptive indices were in the range of 3.9-84.8ngmL(-1), 0.013-3.1μgmL(-1), 33-39, and 0.13-0.15, respectively. The results showed that -as well as its simplicity, fastness, and use of no hazardous disperser and extraction solvents- OS-AALLME is an enough sensitive and efficient method for the extraction of these dyes from complex matrices. After optimization and validation, OS-AALLME was applied to estimate the concentration of 1-amino-2-naphthol in human bio-fluids as a main reductive metabolite of selected dyes. Levels of 1-amino-2-naphthol in plasma and urinary excretion suggested that this compound may be used as a new potential biomarker of these dyes in human body. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. 40 CFR Appendix B to Part 414 - Complexed Metal-Bearing Waste Streams

    Science.gov (United States)

    2010-07-01

    ... 414—Complexed Metal-Bearing Waste Streams Chromium Azo dye intermediates/Substituted diazonium salts + coupling compounds Vat dyes Acid dyes Azo dyes, metallized/Azo dye + metal acetate Acid dyes, Azo...

  20. Adsorption of acid dye onto activated Algerian clay

    OpenAIRE

    D. Bendaho; T. A. Driss; D. Bassou

    2017-01-01

    In this work, activated clay from Algeria was used as adsorbent for the removal of methyl orange (MO) from aqueous solution, for this, the effects of several parameters such as contact time, adsorbent dose, pH value of aqueous solution and temperature on the adsorption of MO were also studied. The results showed that nearly 30 min of contact time are found to be sufficient for the adsorption to reach equilibrium and the adsorption was favourable at lower pH. The acid dye concentration is meas...

  1. A multispectroscopic and molecular docking investigation of the binding interaction between serum albumins and acid orange dye

    Science.gov (United States)

    Naveenraj, Selvaraj; Solomon, Rajadurai Vijay; Mangalaraja, Ramalinga Viswanathan; Venuvanalingam, Ponnambalam; Asiri, Abdullah M.; Anandan, Sambandam

    2018-03-01

    The interaction of Acid Orange 10 (AO10) with bovine serum albumin (BSA) was investigated comparatively with that of human serum albumin (HSA) using multispectroscopic techniques for understanding their toxic mechanism. Further, density functional theory calculations and docking studies have been carried out to gain more insights into the nature of interactions existing between AO10 and serum albumins. The fluorescence results suggest that AO10 quenched the fluorescence of BSA through the combination of static and dynamic quenching mechanism. The same trend was followed in the interaction of AO10 with HSA. In addition to the type of quenching mechanism, the fluorescence spectroscopic results suggest that the binding occurs near the tryptophan moiety of serum albumins and the binding. AO10 has more binding affinity towards BSA than HSA. An AO10-Trp model has been created to explicitly understand the Csbnd Htbnd π interactions from Bader's quantum theory of atoms in molecules analysis which confirmed that AO10 bind more strongly with BSA than that of HSA due to the formation of three hydrogen bonds with BSA whereas it forms two hydrogen bonds in the case of HSA. These obtained results provide an in-depth understanding of the interaction of the acid azo dye AO10 with serum albumins. This interaction study provides insights into the underlying reasons for toxicity of AO10 relevant to understand its effect on bovids and humans during the blood transportation process.

  2. Irradiation treatment of textile dyes: Apollofix-red

    International Nuclear Information System (INIS)

    Wojnarovits, L.; Palfi, T.; Takacs, E.

    2004-01-01

    The UV-VIS absorption spectra of azo dyes in aqueous solutions strongly overlap with the spectra of intermediates produced in reaction with the intermediates of water radiolysis. This overlap complicates the investigation of reaction mechanisms. The paper describes a method for the separation of the two spectra on the example of Apollofix-Red, a triazine and H-acid containing dye. The reactivity of water radiolysis intermediates (e aq - , OH, H, O 2 /HO 2 ) with the dye is also discussed. The most intensive decolouration was found in the reaction of e aq - and H which is due to the fast reaction of these intermediates with the -N=N-azo group of the unreacted molecule and their slow reaction with the transformed molecules. (author)

  3. Ozo-Dyes mixture degradation in a fixed bed biofilm reactor packed with volcanic porous rock

    International Nuclear Information System (INIS)

    Contreras-Blancas, E.; Cobos-Vasconcelos, D. de los; Juarez-Ramirez, C.; Poggi-Varaldo, H. M.; Ruiz-Ordaz, N.; Galindez-Mayer, J.

    2009-01-01

    Textile industries discharge great amounts of dyes and dyeing-process auxiliaries, which pollute streams and water bodies. Several dyes, especially the ones containing the azo group, can cause harmful effects to different organisms including humans. Through bacterial and mammalian tests, azo dyes or their derived aromatic amines have shown cell genotoxicity. The purpose of this work was to evaluate the effect of air flow rate on azo-dyes mixture biodegradation by a microbial community immobilized in a packed bed reactor. (Author)

  4. Ozo-Dyes mixture degradation in a fixed bed biofilm reactor packed with volcanic porous rock

    Energy Technology Data Exchange (ETDEWEB)

    Contreras-Blancas, E.; Cobos-Vasconcelos, D. de los; Juarez-Ramirez, C.; Poggi-Varaldo, H. M.; Ruiz-Ordaz, N.; Galindez-Mayer, J.

    2009-07-01

    Textile industries discharge great amounts of dyes and dyeing-process auxiliaries, which pollute streams and water bodies. Several dyes, especially the ones containing the azo group, can cause harmful effects to different organisms including humans. Through bacterial and mammalian tests, azo dyes or their derived aromatic amines have shown cell genotoxicity. The purpose of this work was to evaluate the effect of air flow rate on azo-dyes mixture biodegradation by a microbial community immobilized in a packed bed reactor. (Author)

  5. Compósitos de poli(álcool vinílico contendo hidroxissais lamelares de zinco, intercalados com corantes aniônicos azo (tropaeolina 0 e tropaeolina 00 Poly(vinyl alcohol composites containing layered hydroxide salts, intercalated with anionic azo dyes (tropaeolin 0 and tropaeolin 0

    Directory of Open Access Journals (Sweden)

    Marlon Luiz Neves da Silva

    2013-01-01

    Full Text Available Hidroxissais lamelares de zinco foram intercalados com corantes aniônicos azo, obtendo-se pigmentos de coloração laranja. Os materiais foram caracterizados por difração de raios X (XRD, espectroscopia vibracional na região do infravermelho com transformada de Fourier (FTIR, análise térmica (TGA/DTA/DSC e espectroscopia fotoeletrônica de raios X (XPS. Após caracterização, os pigmentos lamelares foram dispersos em uma matriz de poli(álcool vinílico - PVA, em concentrações variáveis, em relação à massa de PVA. Filmes homogêneos, transparentes e coloridos foram obtidos pelo método de "casting" úmido e mantidos em dessecador em umidade controlada de 65 % por uma semana e avaliados quanto às suas propriedades mecânicas. Devido às diferentes polaridades dos ânions intercalados, diferentes comportamentos foram observados para os pigmentos quando utilizados como cargas em PVA. Esse trabalho abre uma frente de pesquisas na utilização de hidroxissais lamelares intercalados com corantes aniônicos, como cargas alternativas em materiais compósitos poliméricos.Layered zinc hydroxide salts were intercalated with anionic azo dyes, obtaining orange pigments. The materials were characterized by X-ray diffraction (XRD, Fourier Transform Infrared spectroscopy (FTIR, thermal analysis (TGA/DTA/DSC and X-ray photoelectron spectroscopy (XPS. After characterization, the layered pigments were dispersed into a matrix of poly(vinyl alcohol - PVA, in variable concentrations, in relation to the PVA mass. Homogeneous, transparent and colorful films were obtained by wet casting method and kept in a desiccator at 65% of humidity for one week and evaluated in relation to their mechanical properties. Owing to the different intercalated anions polarities, different behaviors were observed for both pigments when used as fillers in PVA. This work opens a research front in the utilization of layered hydroxide salt intercalated with anionic dyes, as

  6. Using Eggshell in Acid Orange 2 Dye Removal from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Ahmad Reza Yari

    2015-05-01

    Full Text Available Background and purpose: Generated dye wastewater by the textile industry is usually toxic, non-biodegradable and resistant in the environment. Eggshell is one of the inexpensive material and for the reason the vesicular structures can be used as a proper adsorbent for pollutants removal. The aim of this study is to investigate the efficiency of eggshell for removal of acid orange 2 dye from aqueous solution. Materials and Methods: In the experimental study was determined the efficacy of variant variables such as contact time (15, 30, 60, 90 and 120 min, pH (3, 7 and 11, adsorbent dose (10, 25, 50 and 75 g/L, and initial dye concentration (25, 50 and 100 mg/L. The concentration of dye by spectrophotometer ultraviolet/visible in the wavelength 483 nm was examined. Results: The results showed that with increasing contact time and adsorbent dose, the dye removal efficiency was increased, but with increasing pH and initial dye concentration the removal efficiency was decreased. The maximum of removal efficiency of acid orange 2 dye got in the optimum pH: 3, contact time: 90 min, adsorbent dose: 50 g/L and initial dye concentration: 25 mg/L. Adsorption of acid orange 2 dye (R2 = 0.87 follow the Freundlich isotherm. Conclusion: Eggshells can be used as an inexpensive and effective adsorbent for the removal of acid orange 2 dye.

  7. Synthesis and Investigation Absorption Features of Some Novel Hetarylazo Dyes Derived from Calix[4]resorcinarene

    Directory of Open Access Journals (Sweden)

    İzzet Şener

    2013-12-01

    Full Text Available In this study, several derivatives of amines were diazotized and coupled with 3-aminocrotonitrile to give 2-arylhydrazon-3-ketiminocrotononitrile. The synthesized components were then refluxed with hydrazine hydrate in ethanol to give a series of dyes 5-amino-4-arylazo-3-ethyl-1'H-Pyrazole. The synthesized dyes were diazotised and coupled with resorcinarene, which was obtained from condensation of between resorcinol and acetaldehyde, to give a new synthesis of azo dyes based on resorcinarene. The structures of synthesized dyes based on resorcinarene were characterized by spectral methods. The effect of varying solvents, acid and base upon the absorption spectra of resultant dyes has been investigated. Key words: Resorcinarene, Azo Dyes, Absorption Spectra, Solvent Effect, Acid-Base Effect Rezorsinaren Bazlı Azo Boyarmaddelerin Sentezi ve Absorpsiyon Özelliklerinin İncelenmesi Özet: Bu çalışmada, çeşitli amin türevleri diazolanmış ve 3-aminokrotonitril ile kenetlenerek 2-arilhidrazon-3-ketiminokrotononitril bileşikleri elde edilmiştir. Elde edilen bileşikler, hidrazinhidrat ile etanol içerisinde reflaks edilerek bir seri 5-amino-4-arilazo-3-metil-1'H-pirazol boyaları elde edilmiştir. Elde edilen boyalar diazonlarak rezorsinol ve asetaldehit arasındaki kondenzasyondan elde edilen rezorsinaren bileşiği ile kenetlenmiş ve rezorsinaren bazlı azo boyarmaddeler sentezlenmiştir. Sentezlenen rezorsinaren bazlı azoboyarmaddelerin yapıları spektrofotometrik yöntemler kullanılarak incelendi. Sentezlenen boyarmaddelerin görünür bölge absorpsiyon spektrumları üzerine değişik çözücü, asit ve baz etkileri incelendi. Anahtar kelimeler: Rezorsiaren, Azo Boyarmadde, Absorpsiyon Spektrumu, Çözücü Etkisi, Asit-Baz Etkisi

  8. Effect of acidity on the energy level of curcumin dye extracted from Curcuma longa L

    Energy Technology Data Exchange (ETDEWEB)

    Agustia, Yuda Virgantara, E-mail: yuda.mechanical.engineer@student.uns.ac.id; Suyitno,, E-mail: suyitno@uns.ac.id; Sutanto, Bayu, E-mail: bayu.sutanto@student.uns.ac.id [Department of Mechanical Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A, Surakarta (Indonesia); Arifin, Zainal, E-mail: zainal-a@uns.ac.id [Department of Mechanical Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A, Surakarta (Indonesia); Department of Mechanical Engineering, Brawijaya University, Malang (Indonesia)

    2016-03-29

    The purpose of this research is to investigate the effect of acidity on the energy level of curcumin dye. The natural dye, curcumin, was synthesized from Curcuma longa L. using a simple extraction technique. The purification of curcumin dye was conducted in a column of chromatography and its characteristics were studied. Next, the purified curcumin dye was added by benzoic acids until various acidities of 3.0, 3.5, 4.0, 4.5, and 5.0. The absorbance spectra and the functionality groups found in the dyes were detected by ultraviolet-visible spectroscopy and Fourier-transform infrared spectroscopy, respectively. Meanwhile, the energy level of the dyes, E{sub HOMO} and E{sub LUMO} was measured by cyclic voltammetry. The best energy level of curcumin dye was achieved at pH 3.5 where E{sub red} = −0.37V, E{sub LUMO} = −4.28 eV, E{sub ox} = 1.15V, E{sub HOMO} = −5.83 eV, and E{sub band} {sub gap} = 1.55 eV. Therefore, the purified curcumin dye added by benzoic acid was promising for sensitizing the dye-sensitized solar cells.

  9. Effect of acidity on the energy level of curcumin dye extracted from Curcuma longa L

    International Nuclear Information System (INIS)

    Agustia, Yuda Virgantara; Suyitno,; Sutanto, Bayu; Arifin, Zainal

    2016-01-01

    The purpose of this research is to investigate the effect of acidity on the energy level of curcumin dye. The natural dye, curcumin, was synthesized from Curcuma longa L. using a simple extraction technique. The purification of curcumin dye was conducted in a column of chromatography and its characteristics were studied. Next, the purified curcumin dye was added by benzoic acids until various acidities of 3.0, 3.5, 4.0, 4.5, and 5.0. The absorbance spectra and the functionality groups found in the dyes were detected by ultraviolet-visible spectroscopy and Fourier-transform infrared spectroscopy, respectively. Meanwhile, the energy level of the dyes, E_H_O_M_O and E_L_U_M_O was measured by cyclic voltammetry. The best energy level of curcumin dye was achieved at pH 3.5 where E_r_e_d = −0.37V, E_L_U_M_O = −4.28 eV, E_o_x = 1.15V, E_H_O_M_O = −5.83 eV, and E_b_a_n_d _g_a_p = 1.55 eV. Therefore, the purified curcumin dye added by benzoic acid was promising for sensitizing the dye-sensitized solar cells.

  10. Effect of acidity on the energy level of curcumin dye extracted from Curcuma longa L.

    Science.gov (United States)

    Agustia, Yuda Virgantara; Suyitno, Arifin, Zainal; Sutanto, Bayu

    2016-03-01

    The purpose of this research is to investigate the effect of acidity on the energy level of curcumin dye. The natural dye, curcumin, was synthesized from Curcuma longa L. using a simple extraction technique. The purification of curcumin dye was conducted in a column of chromatography and its characteristics were studied. Next, the purified curcumin dye was added by benzoic acids until various acidities of 3.0, 3.5, 4.0, 4.5, and 5.0. The absorbance spectra and the functionality groups found in the dyes were detected by ultraviolet-visible spectroscopy and Fourier-transform infrared spectroscopy, respectively. Meanwhile, the energy level of the dyes, EHOMO and ELUMO was measured by cyclic voltammetry. The best energy level of curcumin dye was achieved at pH 3.5 where Ered = -0.37V, ELUMO = -4.28 eV, Eox = 1.15V, EHOMO = -5.83 eV, and Eband gap = 1.55 eV. Therefore, the purified curcumin dye added by benzoic acid was promising for sensitizing the dye-sensitized solar cells.

  11. Recycling of negative electrodes from spent Ni-Cd batteries as CdO with nanoparticle sizes and its application in remediation of azo dye

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, T.F.M.; Santana, I.L.; Moura, M.N.; Ferreira, S.A.D.; Lelis, M.F.F.; Freitas, M.B.J.G., E-mail: marcosbj@hotmail.com

    2017-07-01

    In this study, negative electrodes from spent Ni-Cd batteries were recycled as CdCO{sub 3}, which was thermally treated to produce synthetized, nanostructured CdO. There is interest in CdO because of its energy band gap, high electrical conductivity and selective catalytic properties. CdO was characterized in this study by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electronic microscopy (TEM). The XRD pattern showed CdO peaks in a crystalline cubic phase, and the average crystallite diameter was 22.21 nm. TEM micrographs showed the formation of clusters containing nanostructures. We also tested the efficiency of CdO catalytic activity in degrading Reactive Black 5 (RB5) dye. Degradation was conducted in conditions of pH = 4.0, pH = 5.97 and pH = 8.0. The degradation efficiency was, respectively, 65.42%, 61.80% and 67.01% after 480 min of reaction. The determining step in the reaction mechanism for dye degradation was the formation of the radical ion OH·. Therefore, the degradation exhibited a first-order reaction. The catalytic activity of CdO and the rate constant values were independent of the pH of the solution. This work presents potential solutions for two environmental problems: recycling Cd and dye degradation. - Graphical abstract: Recycling of spent Ni-Cd batteries as CdO nanoparticles. - Highlights: • This work presents solutions for Cd recycling and dye degradation. • Anodes of Ni-Cd batteries were recycled as CdO with nanometer-sized particles. • CdO presents catalytic activity in the degradation of reactive black dye. • Decoloration of reactive black dye exhibits first-order reaction. • The rate constant values are independent of the pH solution.

  12. Comparative Studies on Dyeability with Direct, Acid and Reactive Dyes after Chemical Modification of Jute with Mixed Amino Acids Obtained from Extract of Waste Soya Bean Seeds

    Science.gov (United States)

    Bhaumik, Nilendu Sekhar; Konar, Adwaita; Roy, Alok Nath; Samanta, Ashis Kumar

    2017-12-01

    Jute fabric was treated with mixed natural amino acids obtained from waste soya bean seed extract for chemical modification of jute for its cataionization and to enhance its dyeability with anionic dyes (like direct, reactive and acid dye) as well enabling soya modified jute for salt free dyeing with anionic reactive dyes maintaining its eco-friendliness. Colour interaction parameters including surface colour strength were assessed and compared for both bleached and soya-modified jute fabric for reactive dyeing and compared with direct and acid dye. Improvement in K/S value (surface colour strength) was observed for soya-modified jute even in absence of salt applied in dye bath for reactive dyes as well as for direct and acid dyes. In addition, reactive dye also shows good dyeability even in acid bath in salt free conditions. Colour fastness to wash was evaluated for bleached and soya-modified jute fabric after dyeing with direct, acid and reactive dyes are reported. Treatment of jute with soya-extracted mixed natural amino acids showed anchoring of some amino/aldemine groups on jute cellulosic polymer evidenced from Fourier Transform Infra-Red (FTIR) Spectroscopy. This amino or aldemine group incorporation in bleached jute causes its cationization and hence when dyed in acid bath for reactive dye (instead of conventional alkali bath) showed dye uptake for reactive dyes. Study of surface morphology by Scanning Electron Microscopy (SEM) of said soya-modified jute as compared to bleached jute was studied and reported.

  13. Novel amphiphilic polymeric ionic liquid-solid phase micro-extraction membrane for the preconcentration of aniline as degradation product of azo dye Orange G under sonication by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Cai, Mei-Qiang; Wei, Xiao-Qing; Du, Chun-Hui; Ma, Xu-Ming; Jin, Mi-Cong

    2014-07-04

    A novel amphiphilic polymeric ionic liquid membrane containing a hydrophilic bromide anion and a hydrophobic carbonyl group was synthesized in dimethylformamide (DMF) systems using the ionic liquid 1-butyl-3-vinylimidazolium bromide (BVImBr) and the methylmethacrylate (MMA) as monomers. The prepared amphiphilic ploy-methylmethacrylate-1-butyl-3-vinylimidazolium bromide (MMA-BVImBr) was characterized by a scanning electron microscope and an infrared spectrum instrument. The results of solid-phase micro-extraction membrane (SPMM) experiments showed that the adsorption capacity of membrane was about 0.76μgμg(-1) for aniline. Based on this, a sensitive method for the determination of trace aniline, as a degradation product of azo dye Orange G under sonication, was developed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The calibration curve showed a good linearity ranging from 0.5 to 10.0μgL(-1) with a correlation coefficient value of 0.9998. The limit of quantification was 0.5μgL(-1). The recoveries ranged from 90.6% to 96.1%. The intra- and inter-day relative standard deviations were less than 8.3% and 10.9%. The developed SPMM-LC-MS/MS method was used successfully for preconcentration of trace aniline produced during the sonication of Orange G solution. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Habibi, Mohammad Hossein; Parhizkar, Janan

    2015-11-05

    Cobalt ferrite nano-composite was prepared by hydrothermal route using cobalt nitrate, iron nitrate and ethylene glycol as chelating agent. The nano-composite was coated on glass by Doctor Blade method and annealed at 300 °C. The structural, optical, and photocatalytic properties have been studied by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and UV-visible spectroscopy (UV-Vis DRS). Powder XRD analysis confirmed formation of CoFe2O4 spinel phase. The estimated particle size from FESEM data was 50 nm. The calculated energy band gaps, obtained by Tauc relation from UV-Vis absorption spectra was 1.3 eV. Photocatalytic degradation of Reactive Red 4 as an azo textile was investigated in aqueous solution under irradiation showed 68.0% degradation of the dye within 100 min. The experimental enhanced activity compare to pure Fe2O3 can be ascribed to the formation of composite, which was mainly attributable to the transfer of electron and hole to the surface of composite and hinder the electron hole recombination. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Ni/MgAlO regeneration for catalytic wet air oxidation of an azo-dye in trickle-bed reaction

    International Nuclear Information System (INIS)

    Vallet, Ana; Ovejero, Gabriel; Rodríguez, Araceli; Peres, José A.; García, Juan

    2013-01-01

    Highlights: ► Ni supported over hydrotalcite calcined precursors as catalyst. ► Catalytic wet air oxidation in trickle bed reactor for Chromotrope 2R removal. ► Dye removal depends on temperature, initial dye concentration and flow rate. ► The catalyst proved to bare-usable after in situ regeneration. -- Abstract: Active nickel catalysts (7 wt%) supported over Mg–Al mixed oxides have been recently developed and it has also been demonstrated that they are also highly selective in Catalytic Wet air Oxidation (CWAO) of dyes. CWAO of Chromotrope 2R (C2R) has been studied using a trickle bed reactor employing temperatures from 100 to 180 °C, liquid flow rates from 0.1 to 0.7 mL min −1 and initial dye concentration from 10 to 50 ppm. Total pressure and air flow were 25 bar and 300 mL min −1 , respectively. The catalyst showed a very stable activity up to 24 h on stream with an average TOC conversion of 82% at 150 °C and T r = 0.098 g Ni min mL −1 . After the reaction, a 1.1 wt% C of carbonaceous deposit is formed onto the catalyst and a diminution of 30% of the surface area with respect of the fresh catalyst was observed. An increase in the space time gave higher TOC conversions up to T r = 0.098 g Ni min mL −1 , attaining values of 80% at 180 °C. The performance of TOC and dye removal does not decrease after two regeneration cycles. In total, a 57 h effective reaction has been carried out with no loss of catalytic activity

  16. Ni/MgAlO regeneration for catalytic wet air oxidation of an azo-dye in trickle-bed reaction

    Energy Technology Data Exchange (ETDEWEB)

    Vallet, Ana [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Ovejero, Gabriel, E-mail: govejero@quim.ucm.es [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Rodríguez, Araceli [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Peres, José A. [Centro de Química de Vila Real, Universidade de Trás-os-Montes e Alto Douro, Apartado 1013, 5001-801 Vila Real (Portugal); García, Juan, E-mail: juangcia@quim.ucm.es [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain)

    2013-01-15

    Highlights: ► Ni supported over hydrotalcite calcined precursors as catalyst. ► Catalytic wet air oxidation in trickle bed reactor for Chromotrope 2R removal. ► Dye removal depends on temperature, initial dye concentration and flow rate. ► The catalyst proved to bare-usable after in situ regeneration. -- Abstract: Active nickel catalysts (7 wt%) supported over Mg–Al mixed oxides have been recently developed and it has also been demonstrated that they are also highly selective in Catalytic Wet air Oxidation (CWAO) of dyes. CWAO of Chromotrope 2R (C2R) has been studied using a trickle bed reactor employing temperatures from 100 to 180 °C, liquid flow rates from 0.1 to 0.7 mL min{sup −1} and initial dye concentration from 10 to 50 ppm. Total pressure and air flow were 25 bar and 300 mL min{sup −1}, respectively. The catalyst showed a very stable activity up to 24 h on stream with an average TOC conversion of 82% at 150 °C and T{sub r} = 0.098 g{sub Ni} min mL{sup −1}. After the reaction, a 1.1 wt% C of carbonaceous deposit is formed onto the catalyst and a diminution of 30% of the surface area with respect of the fresh catalyst was observed. An increase in the space time gave higher TOC conversions up to T{sub r} = 0.098 g{sub Ni} min mL{sup −1}, attaining values of 80% at 180 °C. The performance of TOC and dye removal does not decrease after two regeneration cycles. In total, a 57 h effective reaction has been carried out with no loss of catalytic activity.

  17. Homogenous and heterogenous advanced oxidation of two commercial reactive dyes.

    Science.gov (United States)

    Balcioglu, I A; Arslan, I; Sacan, M T

    2001-07-01

    Two commercial reactive dyes, the azo dye Reactive Black 5 and the copper phythalocyanine dye Reactive Blue 21, have been treated at a concentration of 75 mg l(-1) by titanium dioxide mediated photocatalytic (TiO2/UV), dark and UV-light assisted Fenton (Fe2+/H2O2) and Fenton-like (Fe3+/H2O2) processes in acidic medium. For the treatment of Reactive Black 5, all investigated advanced oxidation processes were quite effective in terms of colour, COD as well as TOC removal. Moreover, the relative growth inhibition of the azo dye towards the marine algae Dunaliella tertiolecta that was initially 70%, did not exhibit an increase during the studied advanced oxidation reactions and complete detoxification at the end of the treatment period could be achieved for all investigated treatment processes. However, for Reactive Blue 21, abatement in COD and UV-VIS absorbance values was mainly due to the adsorption of the dye on the photocatalyst surface and/or the coagulative effect of Fe3+/Fe2+ ions. Although only a limited fraction of the copper phythalocyanine dye underwent oxidative degradation, 47% of the total copper in the dye was already released after 1 h photocatalytic treatment.

  18. Treatment of azo dye-containing wastewater by a Fenton-like process in a continuous packed-bed reactor filled with activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Isabel; Matos, Luis C. [Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Duarte, Filipa [Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); LEPAE - Laboratory for Process, Environmental and Energy Engineering, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto (Portugal); Maldonado-Hodar, F.J. [Department of Inorganic Chemistry, Faculty of Sciences, University of Granada, Av. Fuentenueva, 18071 Granada (Spain); Mendes, Adelio [Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); LEPAE - Laboratory for Process, Environmental and Energy Engineering, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto (Portugal); Madeira, Luis M., E-mail: mmadeira@fe.up.pt [Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); LEPAE - Laboratory for Process, Environmental and Energy Engineering, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto (Portugal)

    2012-10-30

    Highlights: Black-Right-Pointing-Pointer Oxidation with the Fenton's reagent was carried out in a packed-bed reactor. Black-Right-Pointing-Pointer The packed-bed was filled with iron-impregnated activated carbon. Black-Right-Pointing-Pointer The increment of temperature increases the Chicago Sky Blue removal and mineralization. Black-Right-Pointing-Pointer The values of iron leaching were below 0.4 ppm in the outlet effluent. Black-Right-Pointing-Pointer It was possible to reach a dye conversion of 88% in steady-state. - Abstract: In this work, oxidation with a Fenton-like process of a dye solution was carried out in a packed-bed reactor. Activated carbon Norit RX 3 Extra was impregnated with ferrous sulfate and used as catalyst (7 wt.% of iron). The effect of the main operating conditions in the Chicago Sky Blue (CSB) degradation was analyzed. It was found that the increase in temperature leads to a higher removal of the dye and an increased mineralization. However, it also increases the iron leaching, but the values observed were below 0.4 ppm (thus, far below European Union limits). It was possible to reach, at steady-state, a dye conversion of 88%, with a total organic carbon (TOC) removal of ca. 47%, being the reactor operated at 50 Degree-Sign C, pH 3, W{sub cat}/Q = 4.1 g min mL{sup -1} (W{sub cat} is the mass of catalyst and Q the total feed flow rate) and a H{sub 2}O{sub 2} feed concentration of 2.25 mM (for a CSB feed concentration of 0.012 mM). The same performance was reached in three consecutive cycles.

  19. In vitro mutagenicity, NMR metabolite characterization of azo and triphenylmethanes dyes by adherents bacteria and the role of the "cna" adhesion gene in activated sludge.

    Science.gov (United States)

    Ayed, Lamia; Bakir, Karima; Ben Mansour, Hedi; Hammami, Saousen; Cheref, Abdelkrim; Bakhrouf, Amina

    2017-02-01

    Staphylococcus aureus, showing the greatest decolorization ability, was further investigated for Methyl Red (MR) Congo Red (CR), Crystal Violet (CV) and Malachite Green (MG) decolorization using response surface methodology (RSM). The chemometric methods use, based on statistical design of experiments (DOEs) such as RSM is becoming increasingly widespread in several sciences such as analytical chemistry, engineering and environmental chemistry. Stapphylococcus aureus ATCC 25923, Stapphylococcus aureus (S1) and Stapphylococcus aureus (S2), were isolated from textile wastewater plant located in KsarHellal, Tunisia and were tested for their decolorization capacity. PCR technique was utilized to identify the 3 bacterial strains and to detect the adhesin gene "cna". Biodegradation of MR, CR, CV and MG (750 ppm), were investigated under shaking condition in Mineral Salt Medium (MSM) solution at pH 7.5 and temperature 30 °C, using a 3.7 × 10 5  CFU/ml as inoculum size. Our results showed that Staphylococcus aureus had a high decolorization capacity. Nuclear magnetic resonance (NMR) spectroscopy analysis confirmed the biodegradation of dyes. The four dyes mutagenicity with the S9 metabolizing system decreased significantly after biodegradation and totally disappeared. Nuclear magnetic resonance (NMR) spectroscopy analysis confirmed the biodegradation of dyes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Ni/MgAlO regeneration for catalytic wet air oxidation of an azo-dye in trickle-bed reaction.

    Science.gov (United States)

    Vallet, Ana; Ovejero, Gabriel; Rodríguez, Araceli; Peres, José A; García, Juan

    2013-01-15

    Active nickel catalysts (7 wt%) supported over Mg-Al mixed oxides have been recently developed and it has also been demonstrated that they are also highly selective in Catalytic Wet air Oxidation (CWAO) of dyes. CWAO of Chromotrope 2R (C2R) has been studied using a trickle bed reactor employing temperatures from 100 to 180 °C, liquid flow rates from 0.1 to 0.7 mL min(-1) and initial dye concentration from 10 to 50 ppm. Total pressure and air flow were 25 bar and 300 mL min(-1), respectively. The catalyst showed a very stable activity up to 24 h on stream with an average TOC conversion of 82% at 150 °C and T(r)=0.098 g(Ni) min mL(-1). After the reaction, a 1.1 wt% C of carbonaceous deposit is formed onto the catalyst and a diminution of 30% of the surface area with respect of the fresh catalyst was observed. An increase in the space time gave higher TOC conversions up to T(r)=0.098 g(Ni) min mL(-1), attaining values of 80% at 180 °C. The performance of TOC and dye removal does not decrease after two regeneration cycles. In total, a 57 h effective reaction has been carried out with no loss of catalytic activity. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Color removal from acid and reactive dye solutions by electrocoagulation and electrocoagulation/adsorption processes.

    Science.gov (United States)

    Bellebia, S; Kacha, S; Bouberka, Z; Bouyakoub, A Z; Derriche, Z

    2009-04-01

    In this study, electrocoagulation of Marine Blue Erionyl MR (acid dye) and electrocoagulation followed by adsorption of Brilliant Blue Levafix E-BRA (reactive dye) from aqueous solutions were investigated, using aluminum electrodes and granular activated carbon (GAC). In the electrocoagulation and adsorption of dyestuff solutions, the effects of current density, loading charge, pH, conductivity, stirring velocity, contact time, and GAC concentration were examined. The optimum conditions for the electrocoagulation process were identified as loading charges 7.46 and 1.49 F/m3, for a maximum abatement of 200 mg/L reactive and acid dye, respectively. The residual reactive dye concentration was completely removed with 700 mg/L GAC. The results of this investigation provide important data for the development of a combined process to remove significant concentrations of recalcitrant dyes from water, using moderate activated carbon energy and aluminum consumption, and thereby lowering the cost of treatment.

  2. Optical Absorption and Electron Injection of 4-(Cyanomethylbenzoic Acid Based Dyes: A DFT Study

    Directory of Open Access Journals (Sweden)

    Yuehua Zhang

    2015-01-01

    Full Text Available Density functional theory (DFT and time-dependent density functional theory (TDDFT calculations were carried out to study the ground state geometries, electronic structures, and absorption spectra of 4-(cyanomethylbenzoic acid based dyes (AG1 and AG2 used for dye-sensitized solar cells (DSSCs. The excited states properties and the thermodynamical parameters of electron injection were studied. The results showed that (a two dyes have uncoplanar structures along the donor unit and conjugated bridge space, (b two sensitizers exhibited intense absorption in the UV-Vis region, and (c the excited state oxidation potential was higher than the conduction band edge of TiO2 photoanode. As a result, a solar cell based on the 4-(cyanomethylbenzoic acid based dyes exhibited well photovoltaic performance. Furthermore, nine dyes were designed on the basis of AG1 and AG2 to improve optical response and electron injection.

  3. Removal of some basic dyes by poly (Vinyl Alcohol/ acrylic acid)Hydrogel

    International Nuclear Information System (INIS)

    Hegazy, S.A.; Abdel-AAl, S.E.; Abdel-Rehim, H.A.; Khalifa, N.A.; El-Hosseiny, E.M.

    2000-01-01

    A study has made on the preparation and properties of poly (vinyl alcohol/ acrylic acid) hydrogel for the purpose of removal of cationic dyes from aqueous solutions. The effect of dose and monomer concentration on the uptake property of the hydrogel toward dye was studied. The uptake of basic methylene blue-9 dye with PVA/AAc was studied by the batch adsorption technique. The effect of pH on the dye uptake was demonstrated to find out that the suitable pH for maximum uptake occurred at pH 5. It was observed that as the concentration of dye is increased the dye uptake decreased. Furthermore, the uptake of dye by hydrogels increased as the temperature was elevated. The recovery of dye adsorbed is possible by treating the hydrogel with 5% HCl. The results obtained suggested this hydrogel possessed good removal properties towards basic methylene blue-9 dye, and this suggests that such hydrogels could be acceptable for practical uses

  4. Combined cation-exchange and solid phase extraction for the selective separation and preconcentration of zinc, copper, cadmium, mercury and cobalt among others using azo-dye functionalized resin.

    Science.gov (United States)

    Chatterjee, Mousumi; Srivastava, Bhavya; Barman, Milan K; Mandal, Bhabatosh

    2016-04-01

    A facile synthesis of an ion exchange material (FSG-PAN) has been achieved by functionalizing silica gel with an azo-dye. Its composition and structure are well assessed by systematic analysis. Extractor possesses high BET surface area (617.794m(2)g(-1)), exchange capacity and break-through capacity (BTC) (Q0 Zn(II): 225; Cd(II): 918; Hg(II): 384, Cu(II): 269 and Co(II): 388μMg(-1)). The sorption process was endothermic (+ΔH), entropy-gaining (+ΔS) and spontaneous (-ΔG) in nature. Preconcentration factor has been optimized at 172(Zn(II)); 157.2(Cd(II)); 193.6(Hg(II)); 176(Cu(II)); 172.4(Co(II)). Density functional theory calculation has been performed to analyze the sorption pathway. BTC (μMg(-1)) of FSG-PAN was found to be the product of its frontier orbitals and state of sorbed metal ion species, x (at x=1, mononuclear and x>1, a polynuclear species; i.e., BTC=[amount of HOMO]×x). FSG-PAN is used for the selective separation and preconcentration of Zn(II), Cd(II), Hg(II), Cu(II),Co(II) from large volume sample (800mL) of low concentration (0.017-0.40mML(-1)) in presence of foreign ions (50-300mML(-1)) at optimum conditions (pH: 7.0±1.5, flow rate: 2.5mLmin(-1), temperature: 27°C, equilibration-time: 5min). The method was found to be effective for real samples also. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Photocatalytic degradation of textile azo dye over Ce{sub 1-x}Sn {sub x}O{sub 2} series

    Energy Technology Data Exchange (ETDEWEB)

    Borker, Pritam [Department of Chemistry, Goa University, Goa 403 206 (India); Salker, A.V. [Department of Chemistry, Goa University, Goa 403 206 (India)]. E-mail: sal_arun@rediffmail.com

    2006-08-25

    Ce{sub 1-x}Sn {sub x}O{sub 2} (x = 0, 0.1, 0.2, 0.3 and 1.0) have been prepared by co-precipitation method and characterized by XRD, FTIR, BET surface area and TG/DSC methods. The solid state studies such as electrical resistivity, magnetic susceptibility and diffuse reflectance measurements have been carried out and are attempted to correlate with the photocatalytic activity of these compositions. Solar radiation induced degradation of the textile diazo dye Naphthol Blue Black (NBB) has been carried out on these semiconductor compositions. The surface adsorbed oxygen plays an important role in scavenging photogenerated electrons thus preventing the recombination between electron and hole, inducing effective photodegradation.

  6. A review of the chrome mordant dyeing of wool with special reference to the afterchrome process

    CSIR Research Space (South Africa)

    Maasdorp, APB

    1983-11-01

    Full Text Available a -~min*o'- Hydroxyaw Dycs Salicylic Acid Dyes Azo dyes oxidkd to Quinone form when complexed (C.I. Mordant Black 3) e Chrome Fast Brow TV (C.I. Mordant Brow 33) Flavine A (C.I. Mordant Yellow 5) e Solochrome Rcd (C.I. Mordant..., it was decided that they should bedescribed in more detail. In 1858, Peter Greiss, a chemist at a Burton-on-Trent brewery produced the first diizonium salts by treating primary aromatic amines with nitrous acid produced from hydrochloric acid and sodium...

  7. Amino Acid-Assisted Incorporation of Dye Molecules within Calcite Crystals.

    Science.gov (United States)

    Marzec, Bartosz; Green, David C; Holden, Mark A; Coté, Alexander S; Ihli, Johannes; Khalid, Saba; Kulak, Alexander; Walker, Daniel; Tang, Chiu; Duffy, Dorothy M; Kim, Yi-Yeoun; Meldrum, Fiona C

    2018-05-23

    Biomineralisation processes invariably occur in the presence of multiple organic additives, which act in combination to give exceptional control over structures and properties. However, few synthetic studies have investigated the cooperative effects of soluble additives. This work addresses this challenge and focuses on the combined effects of amino acids and coloured dye molecules. The experiments demonstrate that strongly coloured calcite crystals only form in the presence of Brilliant Blue R (BBR) and four of the seventeen soluble amino acids, as compared with almost colourless crystals using the dye alone. The active amino acids are identified as those which themselves effectively occlude in calcite, suggesting a mechanism where they can act as chaperones for individual molecules or even aggregates of dyes molecules. These results provide new insight into crystal-additive interactions and suggest a novel strategy for generating materials with target properties. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Ozonation of acid yellow 17 dye in a semi-batch bubble column

    International Nuclear Information System (INIS)

    Lackey, Laura W.; Mines, Richard O.; McCreanor, Philip T.

    2006-01-01

    A semi-batch bubble column was used to evaluate the effect of ozonation on the removal of acid yellow 17 dye from water. Results indicate that ozonation is very effective at removing acid yellow 17 dye from synthetic textile wastewater. The ozone consumed to apparent dye removal ratio ranged from 2 to 15,000 mg ozone per mg of dye decolorized and was dependent on both ozonation time and apparent dye concentration. The biodegradability of the dye wastewater was evaluated by monitoring changes in 5-day biochemical oxygen demand (BOD 5 ) with respect to chemical oxygen demand (COD). Results indicate that the wastewater biodegradability increased with an increase in ozonation time. Film theory was used to kinetically model the gas-liquid reactions occurring in the reactor. Modeling results indicated that during the first 10-15 min of ozonation, the system could be characterized by a fast, pseudo-first-order regime. With continued ozonation, system kinetics transitioned through a moderate then to a slow regime. Successful modeling of this period required use of a kinetic equation corresponding to a more inclusive condition. Model results are presented

  9. Successful treatment of high azo dye concentration wastewater using combined anaerobic/aerobic granular activated carbon-sequencing batch biofilm reactor (GAC-SBBR): simultaneous adsorption and biodegradation processes.

    Science.gov (United States)

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

    2013-01-01

    The application of a granular activated carbon-sequencing batch biofilm reactor (GAC-SBBR) for treatment of wastewater containing 1,000 mg/L Acid Red 18 (AR18) was investigated in this research. The treatment system consisted of a sequencing batch reactor equipped with moving GAC as biofilm support. Each treatment cycle consisted of two successive anaerobic (14 h) and aerobic (8 h) reaction phases. Removal of more than 91% chemical oxygen demand (COD) and 97% AR18 was achieved in this study. Investigation of dye decolorization kinetics showed that the dye removal was stimulated by the adsorption capacity of the GAC at the beginning of the anaerobic phase and then progressed following a first-order reaction. Based on COD analysis results, at least 77.8% of the dye total metabolites were mineralized during the applied treatment system. High-performance liquid chromatography analysis revealed that more than 97% of 1-naphthyalamine-4-sulfonate as one of the main sulfonated aromatic constituents of AR18 was removed during the aerobic reaction phase. According to the scanning electron microscopic analysis, the microbial biofilms grew in most cavities and pores of the GAC, but not on the external surfaces of the GAC.

  10. Effect of Tannic Acid on the zeta Potential, Sorption, and Surface Free Energy in the Process of Dyeing of Leacril with a Cationic Dye.

    Science.gov (United States)

    Espinosa-Jiménez; Giménez-Martín; Ontiveros-Ortega

    1998-11-01

    The behavior of the surface free energy in the process of dyeing Leacril pretreated with tannic acid and subsequently dyeing with the cationic dye Rhodamine B has been studied. Also the electrokinetic behavior of these systems has been analyzed by studying the zeta potential, which has been obtained by means of the streaming potential technique. Values more significative of the zeta potential of these systems have been obtained using the three models of capillaries existing in the literature. The qualitative behavior of the zeta potential is the same for the three models of capillaries tested in this paper. These models are those of Goring and Mason, Biefer and Mason, and Chang and Robertson. The zeta potential of the systems analyzed is negative in the range of concentration of the dye in the liquid phase from 10(-6) to ca. 10(-4) M of dye. In the range of low concentrations (from 10(-6) to ca. 10(-5) M of dye) the zeta potential of the system untreated Leacril/Rhodamine B increases in absolute value due to increasing hydrophobic attractions between both the hydrophobic chains of the dye and the Leacril fibers in aqueous media. In the system Leacril treated with tannic acid/Rhodamine B, this increase is also due to the presence of hydrogen bonding between the phenolic hydroxyl groups of the tannic acid and the sulfonate and sulfate end groups of Leacril fibers. For concentrations of dye between 10(-5) and 10(-4) M of dye in solution, the zeta potential decreases in absolute value due to the electrostatic attractions between the groups negatively charged in the fiber and the cation of the dye. The zeta potential changes its sign at the highest concentrations of dye used in this work. The adsorption of Rhodamine B onto both untreated Leacril and Leacril treated with tannic acid is favored by the increasing temperature of adsorption. The behavior of the components of the surface free energy obtained by the thin-layer wicking technique led us to consider that the

  11. [Contents mensuration of total alkaloid in Uncaria rhynchophylla by acid dye colorimetry].

    Science.gov (United States)

    Zeng, Chang-qing; Luo, Bei-liang

    2007-08-01

    To investigate the method of determination of total alkaloids Uncaria rhynchophylla. The Contents of total Alkaloid were determined by Acid dye Colorimetry. Acid dye color conditions: pH3.6 buffer 5.0 ml, bromocresol green liquid 5.0 ml; chloroform extraction three times, each time was exeracted for 2 minutes, put it aside for at least 5 minutes for the determination of the best method. Rhynchophylline 6.018 microg - 108.324 microg in the linear range, Recoveriys rate was 97.19%, RSD was 1.34% (n = 6). The method is simple, highly sensitive and reproducible.

  12. CW-laser induced microchannels in dye-polymethacrylic acid films

    OpenAIRE

    M.A. Camacho-López

    2007-01-01

    In this work we report on the formation of microchannels on dye-polymethacrylic acid films using a cw-laser. A focalized beam of a He-Ne laser (632.8 nm emission line) was used to form microchannels on the films. It was found that there exists a laser power density threshold for a pit formation that depends on the dye concentration. The dimensions of the laser-induced channels are dependent on the laser power density. Microchannel formation in the transparent polymethacrylic acid films was no...

  13. Biosorption of Acid Blue 290 (AB 290) and Acid Blue 324 (AB 324) dyes on Spirogyra rhizopus

    International Nuclear Information System (INIS)

    Ozer, Ayla; Akkaya, Goenuel; Turabik, Meral

    2006-01-01

    In this study, the biosorption of Acid Blue 290 and Acid Blue 324 on Spirogyra rhizopus, a green algae growing on fresh water, was studied with respect to initial pH, temperature, initial dye concentration and biosorbent concentration. The optimum initial pH and temperature values for AB 290 and AB 324 biosorption were found to be 2.0, 30 deg. C and 3.0, 25 deg. C, respectively. It was observed that the adsorbed AB 290 and AB 324 amounts increased with increasing the initial dye concentration up to 1500 and 750 mg/L, respectively. The Langmuir, Freundlich, Redlich-Peterson and Koble-Corrigan isotherm models were applied to the experimental equilibrium data and the isotherm constants were determined by using Polymath 4.1 software. The monolayer coverage capacities of S. rhizopus for AB 290 and AB 324 dyes were found as 1356.6 mg/g and 367.0 mg/g, respectively. The intraparticle diffusion model and the pseudo-second order kinetic model were applied to the experimental data in order to describe the removal mechanism of these acidic dyes by S. rhizopus. The pseudo-second order kinetic model described very well the biosorption kinetics of AB 290 and AB 324 dyes. Thermodynamic studies showed that the biosorption of AB 290 and AB 324 on S. rhizopus was exothermic in nature

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

    KAUST Repository

    Guo, Yong; Li, Wengang; Yan, Jingjing; Moosa, Basem; Amad, Maan H.; Werth, Charles; Khashab, Niveen M.

    2012-01-01

    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.

  15. 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.

  16. Batch Removal of Acid Blue 292dye by Biosorption onto Lemna minor: Equilibrium and Kinetic Studies

    Directory of Open Access Journals (Sweden)

    Ali Joghataei

    2016-12-01

    Full Text Available Background: Recently, there has been a great concern about the consumption of dyes because of their toxicity, mutagenicity, carcinogenicity, and persistence in the aquatic environment. Therefore, the aim of this study was to determine the feasibility of using Lemna minor for Acid Blue 292 (AB292 dye removal from aqueous solution and to determine the optimal conditions. Methods: This experimental study was conducted in the batch systems to investigate the effects of parameters such as contact time, initial concentration of dye, pH and Lemna minor biomass dose. Isotherms and kinetic studies of dye adsorption were performed using equilibrium data. Results: According to the results, a maximum removal efficiency of 98.5% was obtained at pH of 3 and the contact time of 90 min; initial dye concentration 10 mg/L and adsorbent dose 3g/L. The adsorption data was best fitted to the Langmuir isotherm and pseudo-second order kinetic model. Conclusion: The results showed that Lemna minor could be used as a cost-effective adsorbent for removing AB292 dye from textile wastewater efficiently.

  17. 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.

  18. Nicotinic acid as a new co-adsorbent in dye-sensitized solar cells

    DEFF Research Database (Denmark)

    Nguyen, Phuong Tuyet; Nguyen, Vinh Son; Pham Phan, Thu Anh

    2017-01-01

    With the aim of introduction a new inexpensive co-adsorbent to improve solar cell performance, the influence of nicotinic acid (NTA) used as a co-adsorbent in dye-sensitized solar cells (DSCs) was investigated. The findings showed that low concentrations of NTA (

  19. Enhanced adsorption of active brilliant red X-3B dye on chitosan molecularly imprinted polymer functionalized with Ti(IV) as Lewis acid.

    Science.gov (United States)

    Deng, Hui; Wei, Zhilai; Wang, XiaoNing

    2017-02-10

    A Ti(IV) functionalized chitosan molecularly imprinted polymer (Ti-CSMIP) was successfully prepared. Ti 4+ as Lewis acidic was used to modify chitosan MIP by producing metal hydroxyl group and protonated surface of adsorbent in aqueous solution to recognize X-3B molecule as a Lewis base. The adsorbent was characterized by FTIR, SEM, XRD, BET, elemental and zeta potential analysis. XRD illustrated Ti-CSMIP exhibited a weak anatase phase when Ti 4+ cross-linked with chitosan. Batch adsorption experiments were performed to evaluate adsorption condition, including sorption isotherm, kinetics and reusability. The maximum adsorption capacity of Ti-CSMIP for X-3B was 161.1mg/g at 293K when solution pH was in the range of 6.0-7.0. Equilibrium data was well analyzed by three-parameter isotherm model, and the kinetics of adsorption followed the pseudo-second kinetics equation. Regeneration experiments indicated a possible application as an effective sorbent for the selective removal of azo anionic dye in aqueous solutions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Removal of rhodamine B (a basic dye) and thoron (an acidic dye) from dilute aqueous solutions and wastewater simulants by ion flotation.

    Science.gov (United States)

    Shakir, Kamal; Elkafrawy, Ahmed Faouzy; Ghoneimy, Hussein Fouad; Elrab Beheir, Shokry Gad; Refaat, Mamdoh

    2010-03-01

    The present work deals with removal, by ion flotation, of two dyes: a basic dye (rhodamine B (RB)) and an acidic one (thoron (TH)) from dilute aqueous solutions and simulated wastewaters. These dyes are widely used for analytical and biological staining purposes. Besides, RB is commonly used in dyeing of various industrial products. Therefore, wastewaters emanating from chemical and radiochemical laboratories, and biomedical and biological research laboratories may be contaminated with RB and TH. Ion flotation of these dyes has been investigated over a wide range of pH using the anionic surfactant, sodium lauryl sulfate (NaLS) and the cationic surfactant, cetyltrimethylammonium bromide (CTAB) as collectors. Successful removals could be achieved for RB and TH with the anionic collector, NaLS, and the cationic collector, CTAB, respectively. In addition to the effects of pH and type of collector on the efficiency of removal of each dye, the effects of collector and dye concentrations, frother dosage, ionic strength, bubbling time period and presence of foreign salts were investigated and the optimal removal conditions have been established. Removals exceeding 99.5 % and 99.9% could be achieved for RB and TH, respectively. The results obtained are discussed with respect to dissociation of dye, type of collector, ionic strength and sign and magnitude of charge of added foreign ions. Kinetics of flotation were also studied. Further studies demonstrate that under optimum conditions the developed flotation processes can be applied for the treatment of dye-contaminated wastewaters simulated to those generated at dyeing industries and radiochemical laboratories. Copyright 2009 Elsevier Ltd. All rights reserved.

  1. Mycoremediation of congo red dye by filamentous fungi

    OpenAIRE

    Bhattacharya, Sourav; Das, Arijit; G, Mangai.; K, Vignesh.; J, Sangeetha.

    2011-01-01

    Azo, anthroquinone and triphenylmethane dyes are the major classes of synthetic colourants, which are difficult to degrade and have received considerable attention. Congo red, a diazo dye, is considered as a xenobiotic compound, and is recalcitrant to biodegradative processes. Nevertheless, during the last few years it has been demonstrated that several fungi, under certain environmental conditions, are able to transfer azo dyes to non toxic products using laccases. The aim of this work was t...

  2. The in situ generation and reactive quench of diazonium compounds in the synthesis of azo compounds in microreactors

    OpenAIRE

    Faith M. Akwi; Paul Watts

    2016-01-01

    Summary In this paper, a micro-fluidic optimized process for the continuous flow synthesis of azo compounds is presented. The continuous flow synthesis of Sudan II azo dye was used as a model reaction for the study. At found optimal azo coupling reaction temperature and pH an investigation of the optimum flow rates of the reactants for the diazotization and azo coupling reactions in Little Things Factory-MS microreactors was performed. A conversion of 98% was achieved in approximately 2.4 min...

  3. High flux and antifouling properties of negatively charged membrane for dyeing wastewater treatment by membrane distillation

    KAUST Repository

    An, Alicia Kyoungjin

    2016-07-25

    This study investigated the applicability of membrane distillation (MD) to treat dyeing wastewater discharged by the textile industry. Four different dyes containing methylene blue (MB), crystal violet (CV), acid red 18 (AR), and acid yellow 36 (AY) were tested. Two types of hydrophobic membranes made of polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) were used. The membranes were characterized by testing against each dye (foulant-foulant) and the membrane–dye (membrane-foulant) interfacial interactions and their mechanisms were identified. The MD membranes possessed negative charges, which facilitated the treatment of acid and azo dyes of the same charge and showed higher fluxes. In addition, PTFE membrane reduced the wettability with higher hydrophobicity of the membrane surface. The PTFE membrane evidenced especially its resistant to dye absorption, as its strong negative charge and chemical structure caused a flake-like (loose) dye–dye structure to form on the membrane surface rather than in the membrane pores. This also enabled the recovery of flux and membrane properties by water flushing (WF), thereby direct-contact MD with PTFE membrane treating 100 mg/L of dye mixtures showed stable flux and superior color removal during five days operation. Thus, MD shows a potential for stable long-term operation in conjunction with a simple membrane cleaning process, and its suitability in dyeing wastewater treatment.

  4. Binding of phenazinium dye safranin T to polyriboadenylic acid: spectroscopic and thermodynamic study.

    Directory of Open Access Journals (Sweden)

    Ankur Bikash Pradhan

    Full Text Available Here, we report results from experiments designed to explore the association of the phenazinium dye safranin T (ST, 3,7-diamino-2,8-dimethyl-5-phenylphenazinium chloride with single and double stranded form of polyriboadenylic acid (hereafter poly-A using several spectroscopic techniques. We demonstrate that the dye binds to single stranded polyriboadenylic acid (hereafter ss poly-A with high affinity while it does not interact at all with the double stranded (ds form of the polynucleotide. Fluorescence and absorption spectral studies reveal the molecular aspects of binding of ST to single stranded form of the polynucleotide. This observation is also supported by the circular dichroism study. Thermodynamic data obtained from temperature dependence of binding constant reveals that association is driven by negative enthalpy change and opposed by negative entropy change. Ferrocyanide quenching studies have shown intercalative binding of ST to ss poly-A. Experiments on viscosity measurements confirm the binding mode of the dye to be intercalative. The effect of [Na⁺] ion concentration on the binding process suggests the role of electrostatic forces in the complexation. Present studies reveal the utility of the dye in probing nucleic acid structure.

  5. Time resolved fluorescence anisotropy of basic dyes bound to poly(methacrylic acid in solution

    Directory of Open Access Journals (Sweden)

    Oliveira Hueder Paulo M. de

    2003-01-01

    Full Text Available Solutions of atactic poly(methacrylic acid, PMAA, with molecular weights in the range of (1.6 to 3.4 x 10(5 g mol-1, and labeled with the fluorescent dyes 9-aminoacridine or Nile blue were studied by photophysical measurements as a function of solvent viscosity and polarity. The conformational behavior of the PMAA chain segments around the fluorescent probe was reported by the change in the rotational diffusion of the dyes. Ethylene glycol swells the polymer chain compared with the more contracted conformation of PMAA in 50% water/ethylene glycol. The change in the rotational relaxation time of the dye bound to PMAA with the decrease of water content in the solvent mixture indicates a progressive expansion of polymer chain to a more open coil form in solution.

  6. Application of AzollaFiliculoides Biomass in Acid Black 1 Dye Adsorption from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Zazouli

    2014-09-01

    Full Text Available Background and purpose: The textile dyes are considered as important pollutants due to the toxicity on human and environment. Therefore, the dye removal from industrial effluents is necessary. This study evaluates the ability of Azolla for the adsorption of acid black 1 (AB1 dye from aqueous solution. Materials and Methods: This was an experimental-laboratory study. The Azolla biomass was sun dried, crushed and sieved to particle sizes in the range of 1-2 mm. Then, it treated with 0.1 M HCl for 5 h, followed by washing with distilled water, and it used as an adsorbent. The effect of study parameter was investigated, and the residues AB1 concentration was measured by DR2800 spectrophotometer at in λmax = 622 nm. Results: The results indicated that the efficiency of AB1 adsorption decreased with increased initial dye concentration. It increased with increased contact time and adsorbent. The highest adsorption efficiency was occurred at pH = 2. The equilibrium data were the best fitted on Langmuir isotherm and pseudo-second-order kinetic model. Conclusion: The Azolla could present high ability in dye removal. Therefore, it can be used as inexpensive and effective adsorbent in textile effluent treatment.

  7. Behaviors and mechanism of acid dyes sorption onto diethylenetriamine-modified native and enzymatic hydrolysis starch

    International Nuclear Information System (INIS)

    Wang Zuohua; Xiang Bo; Cheng Rumei; Li Yijiu

    2010-01-01

    In this paper, different starches were modified by diethylenetriamine. The native starch reacted with diethylenetriamine giving CAS, whereas the enzymatic hydrolysis starch was modified by diethylenetriamine producing CAES. Adsorption capacities of CAES for four acid dyes, namely, Acid orange 7 (AO7), Acid orange 10 (AO10), Acid green 25 (AG25) and Acid red 18 (AR18) have been determined to be 2.521, 1.242, 1.798 and 1.570 mmol g -1 , respectively. In all cases, CAES has exhibited higher sorption ability than CAS, and the increment for these dyes took the sequence of AO7 (0.944 mmol g -1 ) > AO10 (0.592 mmol g -1 ) > AR18 (0.411 mmol g -1 ) > AG25 (0.047 mmol g -1 ). Sorption kinetics and isotherms analysis showed that these sorption processes were better fitted to pseudo-second-order equation and Langmuir equation. Chemical sorption mechanisms were confirmed by studying the effects of pH, ionic strength and hydrogen bonding. Thermodynamic parameters of these dyes onto CAES and CAS were also observed and it indicated that these sorption processes were exothermic and spontaneous in nature.

  8. The effect of dioctyl sodium sulphosuccinate on tartrazine azo reduction by intestinal bacteria.

    Science.gov (United States)

    Allan, R J; Roxon, J J

    1977-03-01

    1. Washed whole-cell suspensions of Proteus vulgaris and micro-organisms from rat faeces, reductively cleave the azo bond of the food dye tartrazine under anaerobic conditions. 2. Dioctyl sodium sulphosuccinate, a common faecal softening laxative, when added to incubations in vitro at concentrations greater than 0.005%, increases tartrazine azo reduction in P. vulgaris whole-cell suspensions. 3. By contrast, concentrations of dioctyl sodium sulphosuccinate greater than 0.005% when added to incubations in vitro of rat faecal preparations, resulted in an inhibition of tartrazine azo reduction.

  9. Nano-dyeing

    Directory of Open Access Journals (Sweden)

    Ning Cui-Juan

    2016-01-01

    Full Text Available Dyeing nanofibers is a frontier of both modern textile engineering and nanotechnology. This paper suggest a feasible method for dyeing nanofibers with a natural red (Roselle Calyx by bubble electrospinning. Reactive dye (Red S3B and acid dye (Red 2B were also used in the experiment for comparison. The dyeing process was finished during the spinning process.

  10. Adsorption of and acidic dye from aqueous solution by surfactant modified bentonite

    International Nuclear Information System (INIS)

    Bouberka, Z.; Khenifi, A.; Belkaid, N.; Ait Mahamed, H.; Haddou, B.; Derriche, Z.

    2009-01-01

    The aim of this paper is to study the adsorption of an acidic dye S. Y. 4 GL (i.e: Supranol yellow 4GL) from aqueous solution on inorgano-organo clay. Bentonite is a kind of natural clay with good exchanging ability. By exchanging its inter lamellar cations with Cetyltrimethylammonium bromide (CTAB) and hydroxy aluminic or chromium poly cations, the properties of natural bentonite can be greatly improved. (Author)

  11. Synthesis and Application of Acid Dyes Based on 3-(4-Aminophenyl-5-benzylidene-2-substituted phenyl-3, 5-dihydroimidazol-4-one

    Directory of Open Access Journals (Sweden)

    Devang N. Wadia

    2008-01-01

    Full Text Available A series of eight novel heterocyclic based monoazo acid dyes were synthesized using various substituted imidazol-4-one as diazo component and coupled with various amino-napthol sulphonic acids. The resultant dyes were characterized using standard spectroscopic methods and then dyeing performance on wool fabric was assessed. Final results concluded that exhaustion (%E of the dyes on wool fibers increased with decreasing pH of application and that fixation (%F of the dyes on wool fibers increased with increasing pH of application and the highest total fixation efficiency was achieved at pH 5. Wash and light fastness properties of prepared dyes showed encouraging results.

  12. Removal of Acid Red 18 dye from Aqueous Solutions Using Nanoscale Zero-Valent Iron

    Directory of Open Access Journals (Sweden)

    Ahmad Reza Yari

    2015-08-01

    Full Text Available Background and Purpose:Organic dyes with a complex structure are often toxic, carcinogenic, mutagenic, non-biodegradation and stable in the environment and if released to the environment without treatment can endanger the environment and human health. The aim was to evaluate the performance nanoscalezero-valent iron (NZVI in the removal of dye acid red 18 (AR18 from aqueous solutions. Materials and Methods:This study was conducted at the laboratory scale. In this study, the removal efficiency of AR18 from a synthetic solution by NZVI was investigated. As well as the effect of solution pH, dye concentration, the concentration of NZVI and contact time in decolorization efficiency was investigated. Results:The results show that in pH = 3, contact time of 80 minutes, dye concentration of 25 mg/l and concentration of NZVI of 2 g/l, the removal efficiency was about 94%. Conclusion:According to the results of experiments, NZVI has high efficiency in removal of AR18 from aqueous solution.

  13. [1,10]Phenanthroline based cyanine dyes as fluorescent probes for ribonucleic acids in live cells

    Science.gov (United States)

    Kovalska, Vladyslava; Kuperman, Marina; Varzatskii, Oleg; Kryvorotenko, Dmytro; Kinski, Elisa; Schikora, Margot; Janko, Christina; Alexiou, Christoph; Yarmoluk, Sergiy; Mokhir, Andriy

    2017-12-01

    A series of monomethine, trimethine- and styrylcyanine dyes based on a [1,10]phenanthroline moiety was synthesized, characterized and investigated as potential fluorescent probes for nucleic acids in cell free settings and in cells. The dyes were found to be weakly fluorescent in the unbound state, whereas upon the binding to dsDNA or RNA their emission intensity raised up to 50 times (for monomethine benzothiazole derivative FT1 complexed with RNA). The strongest fluorescence intensity in assemblies with dsDNA and RNA was observed for the trimethine benzothiazole derivative FT4. The quantum yield of FT4 fluorescence in its complex with dsDNA was found to be 1.5% and the binding constant (K b) was estimated to be 7.9 × 104 M-1 that is a typical value for intercalating molecules. The FT4 dye was found to be cell membrane permeable. It stains RNA rich components—the nucleoli and most probably the cytoplasmic RNA. FT4 bound to RNAs delivers a very strong fluorescence signal, which makes this easily accessible dye a potentially useful alternative to known RNA stains, e.g. expensive SYTO® 83. The advantage of FT4 is its easy synthetic access including no chromatographic purification steps, which will be reflected in its substantially lower price.

  14. Benzothiadiazole oligoene fatty acids: fluorescent dyes with large Stokes shifts

    Directory of Open Access Journals (Sweden)

    Lukas J. Patalag

    2016-12-01

    Full Text Available Herein, we report on the synthesis and characterization of novel fluorescent fatty acids with large Stokes shifts. Three examples consisting of the same number of carbon atoms and thus of similar chain length are presented differing in their degree of unsaturation. As major fluorogenic contributor at the terminus benzo[c][1,2,5]thiadiazole was used. Respective syntheses based on Wittig reactions followed by iodine-mediated isomerization are presented. The absorption properties are modulated by the number of conjugated C=C double bonds of the oligoene chain ranging from one to three. Large Stokes shifts of about 4900–5700 cm−1 and fluorescence quantum yields of up to 0.44 were observed.

  15. Nicotinic acid as a new co-adsorbent in dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Phuong Tuyet, E-mail: ntphuong@hcmus.edu.vn [Faculty of Chemistry, University of Science, Vietnam National University, Ho Chi Minh City (Viet Nam); Nguyen, Vinh Son; Phan, Thu Anh Pham; Le, Tan Nhut Van; Le, Duyen My; Le, Duy Dang; Tran, Vy Anh [Faculty of Chemistry, University of Science, Vietnam National University, Ho Chi Minh City (Viet Nam); Huynh, Tuan Van [Faculty of Physics and Engineering Physics, University of Science, Vietnam National University, Ho Chi Minh City (Viet Nam); Lund, Torben [Department of Science, Systems and Models, Roskilde University DK-4000 (Denmark)

    2017-01-15

    Highlights: • Adsorption of Nicotinic acid on TiO{sub 2} surface is characterized by IR and XPS analysis. • The blocking effect of Nicotinic acid toward electron transfer on TiO{sub 2} electrode is indicated by recent developed method of cyclic voltammetry. • Low concentration of Nicotinic acid (<10 mM) helps to increase the amount of dye loading on TiO{sub 2} surface. • The use of Nicotinic acid at optimum concentration improves the efficiency of the resulting DSC from 3.14 to 5.02%. • Nicotinic acid enhances the cell performance by the same extend as other standard co-adsorbents at optimum concentrations. - Abstract: With the aim of introduction a new inexpensive co-adsorbent to improve solar cell performance, the influence of nicotinic acid (NTA) used as a co-adsorbent in dye-sensitized solar cells (DSCs) was investigated. The findings showed that low concentrations of NTA (<10 mM) increased the N719 ruthenium dye loading on the TiO{sub 2} electrode surface by 10–12%, whereas higher concentrations of NTA lowered the dye loading. The adsorption of NTA onto the TiO{sub 2} electrode surface was studied by attenuated total reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, and the blocking effect of NTA toward electron transfer between the electrode and 1,4-dicyanonaphthalene (redox couple electrolyte probe) was investigated by cyclic voltammetry. Subsequently, the performance of NTA in functional DSCs was evaluated by current–voltage (J–V) DSC characterization and compared with that of DSCs fabricated with two well-established co-adsorbents i.e., chenodeoxycholic acid (CDA) and octadecylphosphonic acid (OPA). The findings showed that under optimized co-adsorbent concentration (1 mM NTA, 0.03 mM CDA, 0.015 mM OPA), the efficiency of the corresponding solar cells increased to the same extent. Specifically, the use of NTA at optimum concentration improved the efficiency of the resulting DSC from 3.14 to 5.02%.

  16. New azo coupling reactions for visible spectrophotometric determination of salbutamol in bulk and pharmaceutical preparations

    International Nuclear Information System (INIS)

    Dhahir, S. A.

    2011-01-01

    The purpose of the present study was to develop a new, simple, cheap, fast, accurate, and sensitive colorimetric methods that can be used for the determination of salbutamol sulphate drug in pure from as well as in pharmaceutical formulations. The method is based on the reaction 2-chloro-4-nitroaniline with nitrite in acid medium to form diazonium ion, which is coupled with of salbutamol in basic medium to form azo dyes, showing yellow color and absorption maxima at 463 nm. Beer's law is obeyed in the concentration of 4-48μg/ml. The molar absorptivity and san dell's sensitivity are 5.27x103 L mole-1 cm-1, 0.015 μgcm-2, respectively. The optimum reaction conditions and other analytical parameters were evaluated. (author).

  17. Effect of Isotopic Substitution on Elementary Processes in Dye-Sensitized Solar Cells: Deuterated Amino-Phenyl Acid Dyes on TiO2

    Directory of Open Access Journals (Sweden)

    Sergei Manzhos

    2013-03-01

    Full Text Available We present the first computational study of the effects of isotopic substitution on the operation of dye-sensitized solar cells. Ab initio molecular dynamics is used to study the effect of deuteration on light absorption, dye adsorption dynamics, the averaged over vibrations driving force to injection (∆Gi and regeneration (∆Gr, as well as on promotion of electron back-donation in dyes NK1 (2E,4E-2-cyano-5-(4-dimethylaminophenylpenta-2,4-dienoic acid and NK7 (2E,4E-2-cyano-5-(4-diphenylaminophenylpenta-2,4-dienoic acid adsorbed in monodentate molecular and bidentate bridging dissociative configurations on the anatase (101 surface of TiO2. Deuteration causes a red shift of the absorption spectrum of the dye/TiO2 complex by about 5% (dozens of nm, which can noticeably affect the overlap with the solar spectrum in real cells. The dynamics effect on the driving force to injection and recombination (the difference between the averaged <∆Gi,r> and ∆Gi,requil at the equilibrium configuration is strong, yet there is surprisingly little isotopic effect: the average driving force to injection <∆Gi> and to regeneration <∆Gr> changes by only about 10 meV upon deuteration. The nuclear dynamics enhance recombination to the dye ground state due to the approach of the electron-donating group to TiO2, yet this effect is similar for deuterated and non-deuterated dyes. We conclude that the nuclear dynamics of the C-H(D bonds, mostly affected by deuteration, might not be important for the operation of photoelectrochemical cells based on organic dyes. As the expectation value of the ground state energy is higher than its optimum geometry value (by up to 0.1 eV in the present case, nuclear motions will affect dye regeneration by recently proposed redox shuttle-dye combinations operating at low driving forces.

  18. Removal of Acid Yellow 17 Dye by Fenton Oxidation Process

    Science.gov (United States)

    Khan, Jehangeer; Sayed, Murtaza; Ali, Fayaz; Khan, Hasan Mahmood

    2018-05-01

    In the present research work the degradation of acid yellow 17 (AY 17) by H2O2/Fe2+ was investigated. The effect of various conditions such as pH value, temperature, conc. of H2O2, Fe2+, conc. of AY 17 were studied. Additionally the scavenging effects of various anions such as Cl-, SO42-, CO32- and HCO3-, on percent degradation of AY 17 were examined. It was found that these anions decrease percent degradation as well as rate of degradation reaction. The optimum conditions were determined as [AY 17]=[Fe2+]=0.06 mM [H2O2]=0.9 mM, and pH 3.0 for 60 min of reaction time. It was found that at optimum conditions 89% degradation of AY17 was achieved. The degradation kinetics of AY17 followed pseudo-first-order reaction kinetics. Thermodynamic studies under natural conditions showed positive value of ΔH (enthalpy) which indicates the degradation process is endothermic.

  19. Decoloration and degradation of Reactive Red-120 dye by electron beam irradiation in aqueous solution

    International Nuclear Information System (INIS)

    Paul, Jhimli; Rawat, K.P.; Sarma, K.S.S.; Sabharwal, S.

    2011-01-01

    The decoloration and degradation of aqueous solution of the reactive azo dye viz. Reactive Red-120 (RR-120) was carried out by electron beam irradiation. The change in decoloration percentage, removal of chemical oxygen demand (COD) and total organic carbon (TOC), solution pH and five-day biochemical oxygen demand (BOD 5 ) were investigated with respect to the applied dose. However, the concentration of the dye in the solution showed a great influence on all these observables. During the radiolysis process, it was found that the decoloration of dye was caused by the destruction of the chromophore group of the dye molecule, whereas COD and TOC removal were depended on the extent of mineralization of the dye. The decrease in pH during the radiolysis process indicated the fragmentation of the large dye molecule into smaller organic components mostly like smaller organic acids. The BOD 5 /COD ratio of the unirradiated dye solution was in the range of 0.1-0.2, which could be classified as non-biodegradable wastewater. However, the BOD 5 /COD ratio increased upon irradiation and it indicated the transformation of non-biodegradable dye solution into biodegradable solution. This study showed that electron beam irradiation could be a promising method for treatment of textile wastewater containing RR-120 dye.

  20. Effects of kainic acid lesions in lateral geniculate nucleus: activity dependence of retrograde axonal transport of fluorescent dyes.

    Science.gov (United States)

    Woodward, W R; Coull, B M

    1988-06-28

    Kainic acid lesions in the dorsal lateral geniculate nucleus of rats block the retrograde axonal transport of fluorescent dyes in corticogeniculate neurons without affecting the retrograde transport of D-aspartate or the orthograde transport of radiolabelled proteins in these neurons. This blocking of dye transport does not appear to be a consequence of kainic acid-induced damage to axon terminals in the geniculate since retinal ganglion cells are still able to transport dyes retrograde. A more likely explanation for these results is that fluorescent dye transport requires electrical activity in neurons, and elimination of the geniculate afferents to visual cortex reduces impulse traffic in cortical output fibers to a level below that required to support detectable dye transport. This interpretation is supported by the observation that kainic acid lesions also reduce retrograde transport of dyes in cortical neurons which project to the superior colliculus. Electrical stimulation in the subcortical white matter restores the transport of dye compounds in corticogeniculate neurons: evidence consistent with an activity-dependent mechanism of retrograde transport for these substances. These results provide evidence that axon terminals of retinal ganglion cells and corticogeniculate neurons survive in kainate-lesioned geniculates and are capable of normal neuronal function.

  1. Removal of hazardous dye Ponceau-S by using Chitin:

    African Journals Online (AJOL)

    Sr030111Bin Comp

    Key words: Chitin, Ponceau-S, organic bioadsorbent, colored organic, industrial effluents. ..... of cationic azo dye by TiO2/bentonite nanocomposite, J. Photochem. ... effluents to freshwater and estuarine algae, crustaceans and fishes. Environ.

  2. Structural and spectral comparisons between isomeric benzisothiazole and benzothiazole based aromatic heterocyclic dyes

    Science.gov (United States)

    Wang, Yin-Ge; Wang, Yue-Hua; Tao, Tao; Qian, Hui-Fen; Huang, Wei

    2015-09-01

    A pair of isomeric heterocyclic compounds, namely 3-amino-5-nitro-[2,1]-benzisothiazole and 2-amino-6-nitrobenzothiazole, are used as the diazonium components to couple with two N-substituted 4-aminobenzene derivatives. As a result, two pairs of isomeric aromatic heterocyclic azo dyes have been produced and they are structurally and spectrally characterized and compared including single-crystal structures, electronic spectra, solvatochromism and reversible acid-base discoloration, thermal stability and theoretically calculations. It is concluded that both benzisothiazole and benzothiazole based dyes show planar molecular structures and offset π-π stacking interactions, solvatochromism and reversible acid-base discoloration. Furthermore, benzisothiazole based aromatic heterocyclic dyes exhibit higher thermal stability, larger solvatochromic effects and maximum absorption wavelengths than corresponding benzothiazole based ones, which can be explained successfully by the differences of their calculated isomerization energy, dipole moment and molecular band gaps.

  3. Biological decolorization of xanthene dyes by anaerobic granular biomass.

    Science.gov (United States)

    Apostol, Laura Carmen; Pereira, Luciana; Pereira, Raquel; Gavrilescu, Maria; Alves, Maria Madalena

    2012-09-01

    Biodegradation of a xanthene dyes was investigated for the first time using anaerobic granular sludge. On a first screening, biomass was able to decolorize, at different extents, six azo dye solutions: acid orange 7, direct black 19, direct blue 71, mordant yellow 10, reactive red 2 and reactive red 120 and two xanthene dyes--Erythrosine B and Eosin Y. Biomass concentration, type of electron donor, induction of biomass with dye and mediation with activated carbon (AC) were variables studied for Erythrosine B (Ery) as model dye. Maximum color removal efficiency was achieved with 4.71 g VSS L⁻¹, while the process rates were independent of the biomass concentration above 1.89 g VSS L⁻¹. No considerable effects were observed when different substrates were used as electron donors (VFA, glucose or lactose). Addition of Ery in the incubation period of biomass led to a fivefold increase of the decolorization rate. The rate of Ery decolorization almost duplicated in the presence of commercial AC (0.1 g L⁻¹ AC₀). Using different modified AC samples (from the treatment of AC₀), a threefold higher rate was obtained with the most basic one, AC(H₂), as compared with non-mediated reaction. Higher rates were obtained at pH 6.0. Chemical reduction using Na₂S confirmed the recalcitrant nature of this dye. The results attest that decolorization of Ery is essentially due to enzymatic and adsorption phenomena.

  4. Newer approach of using alternatives to (Indium doped) metal electrodes, dyes and electrolytes in dye sensitized solar cell

    Science.gov (United States)

    Patni, Neha; Sharma, Pranjal; Pillai, Shibu G.

    2018-04-01

    This work demonstrates the PV study of dye sensitised solar cells by fabricating the (PV) cell using the ITO, FTO and AZO glass substrate. Dyes used for the fabrication were extracted from beetroot and spinach and a cocktail dye by mixing both of the dyes was also prepared. Similarly the three dufferent electrolytes used were iodide-triiodide couple, polyaniline and mixture of polyaniline and iodide couple. Mixed dye and mixed electrolyte has emerged as the highest efficient cell. The electrical characterisation shows that the highest power conversion efficiency of 1.86% was achieved by FTO substrate, followed by efficiency of 1.83% by AZO substrate and efficiency of 1.63% with ITO substrate using mixed dye and mixed electrolyte approach. This justifies that FTO and AZO shows better efficiency and hence proposed to be used as an alternative to indium free system.

  5. Ultra-fast catalytic reduction of dyes by ionic liquid recoverable and reusable mefenamic acid derived gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, Syeda Sara [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Sirajuddin, E-mail: drsiraj03@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Solangi, Amber Rehana [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Agheem, Mohammad Hassan [Center for Pure and Applied Geology, University of Sindh, Jamshoro 76080 (Pakistan); Junejo, Yasmeen; Kalwar, Nazar Hussain; Tagar, Zulfiqar Ali [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)

    2011-06-15

    Highlights: {yields} Gold nanoparticles (AuNps) have been fabricated by a simple chemical method. {yields} AuNps were capped successfully in one step by mefenamic acid (MA). {yields} MA capped AuNps catalytically reduced the mixture of 3 dyes in just 15 s. {yields} AuNps were recovered by ionic liquid and reused for dye(s) reduction effectively. - Abstract: We synthesized mefenamic acid (MA) derived gold nanoparticles (MA-AuNps) in aqueous solution (MA-Au sol). Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of the sol at 1, 5, 15 and 60 min showed changes in size and shape of formed AuNps. Fourier Transform Infrared (FTIR) Spectroscopy revealed the interaction between AuNps and MA. Each Au sol exhibited exceptional catalytic activity for the reduction of Methylene Blue (MB), Rose Bengal (RB) and Eosin B (EB) dye individually as well as collectively. However, complete reduction of dye(s) was accomplished by Au sol of 5 min in just 15 s. The catalytic performance of Ma-Au sol was far superior to that adsorbed on glass. AuNps were recovered with the help of water insoluble room temperature ionic liquid and reused with enhanced catalytic potential. This finding is a novel, rapid and highly economical alternative for environmental safety against pollution by dyes and extendable for control of other reducible contaminants as well.

  6. Ultra-fast catalytic reduction of dyes by ionic liquid recoverable and reusable mefenamic acid derived gold nanoparticles

    International Nuclear Information System (INIS)

    Hassan, Syeda Sara; Sirajuddin; Solangi, Amber Rehana; Agheem, Mohammad Hassan; Junejo, Yasmeen; Kalwar, Nazar Hussain; Tagar, Zulfiqar Ali

    2011-01-01

    Highlights: → Gold nanoparticles (AuNps) have been fabricated by a simple chemical method. → AuNps were capped successfully in one step by mefenamic acid (MA). → MA capped AuNps catalytically reduced the mixture of 3 dyes in just 15 s. → AuNps were recovered by ionic liquid and reused for dye(s) reduction effectively. - Abstract: We synthesized mefenamic acid (MA) derived gold nanoparticles (MA-AuNps) in aqueous solution (MA-Au sol). Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of the sol at 1, 5, 15 and 60 min showed changes in size and shape of formed AuNps. Fourier Transform Infrared (FTIR) Spectroscopy revealed the interaction between AuNps and MA. Each Au sol exhibited exceptional catalytic activity for the reduction of Methylene Blue (MB), Rose Bengal (RB) and Eosin B (EB) dye individually as well as collectively. However, complete reduction of dye(s) was accomplished by Au sol of 5 min in just 15 s. The catalytic performance of Ma-Au sol was far superior to that adsorbed on glass. AuNps were recovered with the help of water insoluble room temperature ionic liquid and reused with enhanced catalytic potential. This finding is a novel, rapid and highly economical alternative for environmental safety against pollution by dyes and extendable for control of other reducible contaminants as well.

  7. POTENTIAL USE OF WOOL WASTE AS ADSORBENT FOR THE REMOVAL OF ACID DYES FROM WASTEWATER

    Directory of Open Access Journals (Sweden)

    BUCIŞCANU Ingrid

    2016-05-01

    Full Text Available At present, great amounts of raw wool are treated as waste and raise disposal problems. In the sustainable development context , wool is regarded as a biodegradable renewable resource and due to its complex chemical composition and fiber morphology, can find different useful applications. It is the aim of this paper to investigate the potential use of raw wool waste as a non-conventional adsorbent for Acid Red 337(AcR ,currently used for leather and wool dyeing. Two wool-based adsorbents were prepared, namely scoured coarse wool (Wool-S and wool activated with alcoholic solution of sodium hydroxide (Wool-A. Adsorbent dosage, dye concentration, pH and treatment time were factors taken in consideration for the assessment of the sorbate-adsorbent interaction. The removal efficiency (R % is mainly dependent on the solution pH and on the activation treatment applied to wool: at pH 3, the removal efficiency reaches the highest values of 42% on Wool-S and 99% on Wool-A. The adsorption rate is slow and needs almost 6 h to reach equilibrium. The experimental data best fitted the Langmuir equilibrium adsorption model, which proves that the adsorbent possess surface active sites to which the dye sorbate binds in monomolecular layer. Raw wool waste is a potential cheap, biodegradable and effective adsorbent for colored wastewater treatment.

  8. SYNTHESIS OF AZO COMPOUNDS DERIVATIVE FROM EUGENOL AND ITS APPLICATION AS A TITRATION INDICATOR

    Directory of Open Access Journals (Sweden)

    Bambang Purwono

    2010-06-01

    Full Text Available The synthesis of azo compounds from eugenol has been carried out by diazotation reaction. The diazonium salt was produced by reaction of aniline and sodium nitrite in acid condition at 0-5 °C temperature to yield benzenediazonium chloride salt. The salt was then reacted with eugenol to produce the azo derivatives. The azo product was analyzed by IR, 1H-NMR, dan GC-MS spectrometer. The results showed that the reaction of benzenediazonium chloride with eugenol gave 4-allyl-2-methoxy-6-hydroxyazobenzene in 34.27% yield for 30 minutes reaction. The derivative of azo compound was dissolved in ethanol and then the color changing was observed in range of pH 9.8-11.1 from yellow to red. Application for titration indicator for acetic acid titrated with sodium hydroxide showed error less than 3.20% compared with phenol phtaline indicator.   Keywords: Eugenol, Azo compound, titration indicator

  9. Batch and column studies on biosorption of acid dyes on fresh water macro alga Azolla filiculoides.

    Science.gov (United States)

    Padmesh, T V N; Vijayaraghavan, K; Sekaran, G; Velan, M

    2005-10-17

    The biosorption of Acid red 88 (AR88), Acid green 3 (AG3) and Acid orange 7 (AO7) by deactivated fresh water macro alga Azolla filiculoides was investigated in batch mode. Langmuir and Freundlich adsorption models were used for the mathematical description of the batch biosorption equilibrium data and model constants were evaluated. The adsorption capacity was pH dependent with a maximum value of 109.0 mg/g at pH 7 for AR88, 133.5 mg/g at pH 3 for AG3 and 109.6 mg/g at pH 3 for AO7, respectively, was obtained. The pseudo first and second order kinetic models were also applied to the experimental kinetic data and high correlation coefficients favor pseudo second order model for the present systems. The ability of A. filiculoides to biosorb AG3 in packed column was also investigated. The column experiments were conducted to study the effect of important design parameters such as initial dye concentration (50-100 mg/L), bed height (15-25 cm) and flow rate (5-15 mL/min) to the well-adsorbed dye. At optimum bed height (25 cm), flow rate (5 mL/min) and initial dye concentration (100 mg/L), A. filiculoides exhibited 28.1mg/g for AG3. The Bed Depth Service Time model and the Thomas model were used to analyze the experimental data and the model parameters were evaluated.

  10. Study of application properties of novel trisazo hetero bi-functional reactive dyes based on j-acid derivatives for cotton

    International Nuclear Information System (INIS)

    Mokhtari, Javad; Akbarzadeh, A; Phillips, D A S; Taylor, J A

    2009-01-01

    Three novel trisazo hetero bi-functional reactive dyes based on J-acid derivatives were prepared using the diazonium salt of [4-(4-sulphophenylazo-)-2,5-dimethylazobenzene-2-sulphonic acid] and a hetero bi-functional coupling component, derived from 1-hydroxy-6-aminonapthalene-3-sulphonic acid (J-acid), 1-hydroxy-6- methylaminonapthalene-3-sulphonic acid (methyl J-acid), and 1-hydroxy-6-aminonaphthalene-3,5-disulphonic acid (sulpho J-acid). On balance, the dye derived from sulpho J-acid displayed the most attractive set of technical properties, building up and fixing more efficiently than those derived from J-acid and methyl J-acid. In addition, the sulpho J-acid based dye offered better migration and, therefore, level dyeing and ease of wash off. (author)

  11. Acidity Constants Determination of Triazine Dye Derivative in the presence of some Surfactants by Multiwavelength Spectrophotometric and Spectrofluorimetric

    Directory of Open Access Journals (Sweden)

    Ali Yeganeh Faal

    2014-03-01

    Full Text Available In this work, acidity constants protonated form of 4.4'-bis astilbene-2,2'-disulfonic-disodium salts (TRIAZ have been determined spectrophotometrically and spectrofluorimetrically at 25◦C and ionic strength of 0.1M KNO3. A program based on MCR-ALS applied for determination of acidity constants. The results show that the peak values of dye are influenced by the presence of anionic, cationic, and nonionic surfactants. The effects of sodium dodecyl sulfate (SDS, Triton X-100 (TX-100 and cetyl trimethyl ammonium bromide (CTAB as a surface-active agent on the acidic and basic forms, and the spectral properties of dye were studied. Also, we determined the critical micelle concentration (CMC for these surfactants by spectrophotometric and spectrofluorimetric triazine dye probes. In addition, by using of evolving factor analysis (EFA and multivariate curve resolution alternative least squares (MCR-ALS methods, acidity constants were acquired.

  12. The in situ generation and reactive quench of diazonium compounds in the synthesis of azo compounds in microreactors.

    Science.gov (United States)

    Akwi, Faith M; Watts, Paul

    2016-01-01

    In this paper, a micro-fluidic optimized process for the continuous flow synthesis of azo compounds is presented. The continuous flow synthesis of Sudan II azo dye was used as a model reaction for the study. At found optimal azo coupling reaction temperature and pH an investigation of the optimum flow rates of the reactants for the diazotization and azo coupling reactions in Little Things Factory-MS microreactors was performed. A conversion of 98% was achieved in approximately 2.4 minutes and a small library of azo compounds was thus generated under these reaction conditions from couplers with aminated or hydroxylated aromatic systems. The scaled up synthesis of these compounds in PTFE tubing (i.d. 1.5 mm) was also investigated, where good reaction conversions ranging between 66-91% were attained.

  13. The in situ generation and reactive quench of diazonium compounds in the synthesis of azo compounds in microreactors

    Directory of Open Access Journals (Sweden)

    Faith M. Akwi

    2016-09-01

    Full Text Available In this paper, a micro-fluidic optimized process for the continuous flow synthesis of azo compounds is presented. The continuous flow synthesis of Sudan II azo dye was used as a model reaction for the study. At found optimal azo coupling reaction temperature and pH an investigation of the optimum flow rates of the reactants for the diazotization and azo coupling reactions in Little Things Factory-MS microreactors was performed. A conversion of 98% was achieved in approximately 2.4 minutes and a small library of azo compounds was thus generated under these reaction conditions from couplers with aminated or hydroxylated aromatic systems. The scaled up synthesis of these compounds in PTFE tubing (i.d. 1.5 mm was also investigated, where good reaction conversions ranging between 66–91% were attained.

  14. Colorimetric Nucleic Acid Detection on Paper Microchip Using Loop Mediated Isothermal Amplification and Crystal Violet Dye.

    Science.gov (United States)

    Roy, Sharmili; Mohd-Naim, Noor Faizah; Safavieh, Mohammadali; Ahmed, Minhaz Uddin

    2017-11-22

    Nucleic acid detection is of paramount importance in monitoring of microbial pathogens in food safety and infectious disease diagnostic applications. To address these challenges, a rapid, cost-effective label-free technique for nucleic acid detection with minimal instrumentations is highly desired. Here, we present paper microchip to detect and quantify nucleic acid using colorimetric sensing modality. The extracted DNA from food samples of meat as well as microbial pathogens was amplified utilizing loop-mediated isothermal amplification (LAMP). LAMP amplicon was then detected and quantified on a paper microchip fabricated in a cellulose paper and a small wax chamber utilizing crystal violet dye. The affinity of crystal violet dye toward dsDNA and positive signal were identified by changing the color from colorless to purple. Using this method, detection of Sus scrofa (porcine) and Bacillus subtilis (bacteria) DNA was possible at concentrations as low as 1 pg/μL (3.43 × 10 -1 copies/μL) and 10 pg/μL (2.2 × 10 3 copies/μL), respectively. This strategy can be adapted for detection of other DNA samples, with potential for development of a new breed of simple and inexpensive paper microchip at the point-of-need.

  15. Production and characterization of laccase from Cyathus bulleri and its use in decolourization of recalcitrant textile dyes.

    Science.gov (United States)

    Salony; Mishra, S; Bisaria, V S

    2006-08-01

    Many fungi (particularly the white rot) are well suited for treatment of a broad range of textile dye effluents due to the versatility of the lignin-degrading enzymes produced by them. We have investigated decolourization of a number of recalcitrant reactive azo and acid dyes using the culture filtrate and purified laccase from the fungus Cyathus bulleri. For this, the enzyme was purified from the culture filtrate to a high specific activity of 4,022 IU mg(-1) protein, produced under optimized carbon, nitrogen and C/N ratio with induction by 2,6-dimethylaniline. The protein was characterized as a monomer of 58+/-5.0 kDa with carbohydrate content of 16% and was found to contain all three Cu(II) centres. The three internal peptide sequences showed sequence identity (80-92%) with laccases of a number of white rot fungi. Substrate specificity indicated highest catalytic efficiency (k(cat)/K(M)) on guaiacol followed by 2,2'-azino-bis(3-ethylthiazoline-6-sulfonic acid) (ABTS). Decolourization of a number of reactive azo and acid dyes was seen with the culture filtrate of the fungus containing predominantly laccase. In spite of no observable effect of purified laccase on other dyes, the ability to decolourize these was achieved in the presence of the redox mediator ABTS, with 50% decolourization in 0.5-5.4 days.

  16. Fe-tannic acid complex dye as photo sensitizer for different morphological ZnO based DSSCs

    Science.gov (United States)

    Çakar, Soner; Özacar, Mahmut

    2016-06-01

    In this paper we have synthesized different morphological ZnO nanostructures via microwave hydrothermal methods at low temperature within a short time. We described different morphologies of ZnO at different Zn(NO3)2/KOH mole ratio. The ZnO nanostructures were characterized via X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and UV-vis spectrophotometry. All ZnO structures have hexagonal wurtzite type structures. The FESEM images showed various morphologies of ZnO such as plate, rod and nanoparticles. Dye sensitized solar cells have been assembled by these different morphological structures photo electrode and tannic acid or Fe-tannic acid complex dye as sensitizer. We have achieved at maximum efficiencies of photovoltaic cells prepared with ZnO plate in all dye systems. The conversion efficiencies of dye sensitized solar cells are 0.37% and 1.00% with tannic acid and Fe-tannic acid complex dye, respectively.

  17. Adsorption of Acid Yellow-73 and Direct Violet-51 Dyes from Textile Wastewater by Using Iron Doped Corncob Charcoal

    Directory of Open Access Journals (Sweden)

    Mujtaba Baqar

    2015-06-01

    Full Text Available The presence of synthetic dyes in textile industry wastewater lead to deterioration of precious fresh water resources, making the need to remove dyes crucial for environmental protection. Recently, different techniques have been employed to remove these dyes from water resources. Among them, biosorption has gained tremendous popularity due to its eco-friendly nature and inexpensive method. In this study, the removal potential of two acid dyes, i.e. yellow-73 and direct violet-51, was assessed from textile effluent samples using iron modified corncob charcoal. The adsorption efficiency ranged between 93.93 ­ 97.96 % and 92.2 - 95.4 % for acid yellow-73 and direct violet-51, respectively. Furthermore, study highlights optimum parameters for successful adsorption of these dyes, such as stirring time (numbers, pH (numbers, temperature (numbers, and adsorbent dosage (numbers. Keeping in consideration these findings, we recommend the use of Iron Doped Corncob Charcoal (IDCC as a low-cost, efficient alternative for wastewater treatment, primarily minimizing the detrimental effects of hazardous dyes.

  18. Use of Polymeric and Natural Materials for the Removal of Irradiated Direct and acid Dyes from Effluents

    International Nuclear Information System (INIS)

    Dessouki, A.M.; Abdel-Aal, S.E.; Gad, Y.H.

    2000-01-01

    Wastewater effluents from textile plants typically contain appreciable quantities of organic dyes that are resistant to degrade by ordinary treatment processes and constitute a highly visible form of pollution in the receiving waters. Carbon absorption as well as ionizing radiation are used as treatment processes. However, each method alone did not achieve the complete removal of these pollutants. A combined treatment is more effective. The two direct dyes(Direct orange S, Isma fast yellow Rl) were degraded by radiation 76% and 70% ,respectively. Also, the acid dye Sandolane Rubanole E-3 GSL (Acid red 37) was degraded almost to the same extent. Addition of O 2 or H 2 O-2 resulted in a remarkable enhancement in the degradation process. The effect of ph, gamma-dose and dye concentration was studied. Polymeric ion exchangers proved to be more effective in the removal process than clays. However, granular activated carbon (GAC) was the best adsorbent for the direct dyes. Clays proved to be very good adsorbents for two basic dyes than their weak adsorption behavior of the direct ones

  19. Computational models for structure-hydrophobicity relationships of 4-carboxyl-2,6-dinitrophenyl azo hydroxynaphthalenes.

    Science.gov (United States)

    Idowu, Olakunle S; Adegoke, Olajire A; Idowu, Abiola; Olaniyi, Ajibola A

    2007-01-01

    Some phenyl azo hydroxynaphthalene dyes (e.g., sunset yellow) are certified as approved colorants for food, cosmetics, and drug formulations. The hydrophobicity of 4 newly synthesized azo dyes of the phenyl azo hydroxynaphthalene class was investigated, as a training set, with the goal of developing models for quantitative structure-property relationships (QSPR). Retention behavior of the molecules reversed-phase thin-layer chromatography (RPTLC) was investigated using liquid paraffin-coated silica gel as the stationary phase. Mobile phases consisted of aqueous mixtures of methanol, acetone, and dimethylformamide (DMF). Basic hydrophobicity parameter (Rmw), specific hydrophobic surface area (S), and isocratic chromatographic hydrophobicity index (phio) were computed from the chromatographic data. The hydrophobicity index (Rm) decreased linearly with increasing concentration of organic modifiers. Extrapolated Rmw values obtained by using DMF and acetone differ significantly from the value obtained by using methanol as organic modifier [P dyes and may also play useful roles in computer-assisted molecular discovery of nontoxic azo dyes.

  20. Synthesis, structure and study of azo-hydrazone tautomeric equilibrium of 1,3-dimethyl-5-(arylazo)-6-amino-uracil derivatives

    Science.gov (United States)

    Debnath, Diptanu; Roy, Subhadip; Li, Bing-Han; Lin, Chia-Her; Misra, Tarun Kumar

    2015-04-01

    Azo dyes, 1,3-dimethyl-5-(arylazo)-6-aminouracil (aryl = -C6H5 (1), -p-CH3C6H4 (2), -p-ClC6H4 (3), -p-NO2C6H4 (4)) were prepared and characterized by UV-vis, FT-IR, 1H NMR, 13C NMR spectroscopic techniques and single crystal X-ray crystallographic analysis. In the light of spectroscopic analysis it evidences that of the tautomeric forms, the azo-enamine-keto (A) form is the predominant form in the solid state whereas in different solvents it is the hydrazone-imine-keto (B) form. The study also reveals that the hydrazone-imine-keto (B) form exists in an equilibrium mixture with its anionic form in various organic solvents. The solvatochromic and photophysical properties of the dyes in various solvents with different hydrogen bonding parameter were investigated. The dyes exhibit positive solvatochromic property on moving from polar protic to polar aprotic solvents. They are fluorescent active molecules and exhibit high intense fluorescent peak in some solvents like DMSO and DMF. It has been demonstrated that the anionic form of the hydrazone-imine form is responsible for the high intense fluorescent peak. In addition, the acid-base equilibrium in between neutral and anionic form of hydrazone-imine form in buffer solution of varying pH was investigated and evaluated the pKa values of the dyes by making the use of UV-vis spectroscopic methods. The determined acid dissociation constant (pKa) values increase according to the sequence of 2 > 1 > 3 > 4.

  1. Effect of organic load on decolourization of textile wastewater containing acid dyes in upflow anaerobic sludge blanket reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wijetunga, Somasiri, E-mail: swije2001@yahoo.com [Laboratory of Environmental Biotechnology, School of Biotechnology, Southern Yangtze University, 170 Huihe Road, Wuxi 214036 (China); Li Xiufen [Laboratory of Environmental Biotechnology, School of Biotechnology, Southern Yangtze University, 170 Huihe Road, Wuxi 214036 (China); Jian Chen, E-mail: jchen@sytu.edu.cn [Laboratory of Environmental Biotechnology, School of Biotechnology, Southern Yangtze University, 170 Huihe Road, Wuxi 214036 (China)

    2010-05-15

    Textile wastewater (TW) is one of the most hazardous wastewater for the environment when discharged without proper treatment. Biological treatment technologies have shown encouraging results over the treatment of recalcitrant compounds containing wastewaters. Upflow anaerobic sludge blanket reactor (UASB) was evaluated in terms of colour and the reduction of chemical oxygen demand (COD) with different organic loads using TW containing dyes belonging to different chemical groups. The study was performed using six different dye concentrations (10 mg/L, 25 mg/L, 50 mg/L, 100 mg/L, 150 mg/L, 300 mg/L) with three COD levels ({approx}1000 mg/L, {approx}2000 mg/L, {approx}3000 mg/L). Decolourization, COD removal and reactor stability were monitored. Over 85% of colour removal was observed with all dye concentrations with three organic loads. Acid Red 131 and Acid Yellow 79 were decolourized through biodegradation while Acid Blue 204 was decolourized due to adsorption onto anaerobic granules. COD removal was high in all dye concentrations, regardless of co-substrate levels. The reactor did not show any instability during the study. The activity of granules was not affected by the dyes. Methanothrix like bacteria were the dominant group in granules before introducing TW, however, they were reduced and cocci-shape microorganism increased after the treatment of textile wastewater.

  2. Effect of organic load on decolourization of textile wastewater containing acid dyes in upflow anaerobic sludge blanket reactor

    International Nuclear Information System (INIS)

    Wijetunga, Somasiri; Li Xiufen; Jian Chen

    2010-01-01

    Textile wastewater (TW) is one of the most hazardous wastewater for the environment when discharged without proper treatment. Biological treatment technologies have shown encouraging results over the treatment of recalcitrant compounds containing wastewaters. Upflow anaerobic sludge blanket reactor (UASB) was evaluated in terms of colour and the reduction of chemical oxygen demand (COD) with different organic loads using TW containing dyes belonging to different chemical groups. The study was performed using six different dye concentrations (10 mg/L, 25 mg/L, 50 mg/L, 100 mg/L, 150 mg/L, 300 mg/L) with three COD levels (∼1000 mg/L, ∼2000 mg/L, ∼3000 mg/L). Decolourization, COD removal and reactor stability were monitored. Over 85% of colour removal was observed with all dye concentrations with three organic loads. Acid Red 131 and Acid Yellow 79 were decolourized through biodegradation while Acid Blue 204 was decolourized due to adsorption onto anaerobic granules. COD removal was high in all dye concentrations, regardless of co-substrate levels. The reactor did not show any instability during the study. The activity of granules was not affected by the dyes. Methanothrix like bacteria were the dominant group in granules before introducing TW, however, they were reduced and cocci-shape microorganism increased after the treatment of textile wastewater.

  3. Synthesis of highly phosphonic acid functionalized benzene-bridged periodic mesoporous organosilicas for use as efficient dye adsorbents

    International Nuclear Information System (INIS)

    Deka, Juti Rani; Liu, Chia-Ling; Wang, Tzu-Hua; Chang, Wei-Chieh; Kao, Hsien-Ming

    2014-01-01

    Highlights: • Synthesis of highly phosphonic acid functionalized benzene-bridged PMOs. • Phosphonic acid loaded PMOs as adsorbent for cationic and anionic dyes. • Due to electrostatic interaction the adsorbent has high dye adsorption capacity. • π–π stacking interaction between benzene and dye enhances adsorption capacity. • Intraparticle diffusion played a dominant role in the adsorption process. - Abstract: Periodic mesoporous organosilicas (PMOs) with benzene bridging groups in the silica wall were functionalized with a tunable content of phosphonic acid groups. These bifunctional materials were synthesized by co-condensation of two different organosilane precursors, that is, 1,4-bis(triethoxysilyl)benzene (BTEB) and sodium 3-(trihydroxysilyl)propyl methyl phosphate (SPMP), under acidic conditions using nonionic surfactant Brij-S10 as template. The materials exhibited well-ordered mesostructures and were characterized by X-ray diffraction, nitrogen sorption, TEM, TGA, FTIR, and solid-state NMR measurements. The materials thus obtained were employed as adsorbents to remove different types of dyes, for example, cationic dyes methylene blue and phenosafranine, anionic orange II, and amphoteric rhodamine B, from aqueous solutions. The materials exhibited a remarkably high adsorption capacity than activated carbon due to their ordered mesostructures, a large number of phosphonic acid groups, and high surface areas. The adsorption was mainly governed by electrostatic interaction, but also involved π–π stacking interaction as well as hydrogen bonding. The adsorption kinetics can be better fitted by the pseudo-second order model. The adsorption process was controlled by the mechanisms of external mass transfer and intraparticle diffusion. The materials retained more than 97% dye removal efficiency after use for five consecutive cycles

  4. Accurate distance determination of nucleic acids via Förster resonance energy transfer: implications of dye linker length and rigidity.

    Science.gov (United States)

    Sindbert, Simon; Kalinin, Stanislav; Nguyen, Hien; Kienzler, Andrea; Clima, Lilia; Bannwarth, Willi; Appel, Bettina; Müller, Sabine; Seidel, Claus A M

    2011-03-02

    In Förster resonance energy transfer (FRET) experiments, the donor (D) and acceptor (A) fluorophores are usually attached to the macromolecule of interest via long flexible linkers of up to 15 Å in length. This causes significant uncertainties in quantitative distance measurements and prevents experiments with short distances between the attachment points of the dyes due to possible dye-dye interactions. We present two approaches to overcome the above problems as demonstrated by FRET measurements for a series of dsDNA and dsRNA internally labeled with Alexa488 and Cy5 as D and A dye, respectively. First, we characterize the influence of linker length and flexibility on FRET for different dye linker types (long, intermediate, short) by analyzing fluorescence lifetime and anisotropy decays. For long linkers, we describe a straightforward procedure that allows for very high accuracy of FRET-based structure determination through proper consideration of the position distribution of the dye and of linker dynamics. The position distribution can be quickly calculated with geometric accessible volume (AV) simulations, provided that the local structure of RNA or DNA in the proximity of the dye is known and that the dye diffuses freely in the sterically allowed space. The AV approach provides results similar to molecular dynamics simulations (MD) and is fully consistent with experimental FRET data. In a benchmark study for ds A-RNA, an rmsd value of 1.3 Å is achieved. Considering the case of undefined dye environments or very short DA distances, we introduce short linkers with a propargyl or alkenyl unit for internal labeling of nucleic acids to minimize position uncertainties. Studies by ensemble time correlated single photon counting and single-molecule detection show that the nature of the linker strongly affects the radius of the dye's accessible volume (6-16 Å). For short propargyl linkers, heterogeneous dye environments are observed on the millisecond time scale. A

  5. Utilization of chemically modified citrus reticulata peels for biosorptive removal of acid yellow-73 dye from water

    International Nuclear Information System (INIS)

    Rehman, R.; Salman, M.; Mahmud, T.; Kanwal, F.; Zaman, W.

    2013-01-01

    Textile effluents contain several varieties of natural and synthetic dyes, which are non-biodegradable. Acid Yellow-73 is one of them. In this research work, adsorptive removal of this dye was investigated using chemically modified Citrus reticulata peels, in batch mode. It was noted that adsorption of dye on Citrus reticulata peels increased by increasing contact time and decreased in basic pH conditions. Langmuir and Freundlich isothermal models were followed by equilibrium data, but the first isotherm fitted the data better, showing that chemisorption occurred more as compared to physiosorption, showing maximum adsorption capacity 96.46 mg.g-1.L-1. The thermodynamic study showed that adsorption of Acid Yellow-73 on chemically modified Citrus reticulata peels was favorable in nature, following pseudo-second order kinetics. (author)

  6. Synthesis of surfactant-coated cobalt ferrite nanoparticles for adsorptive removal of acid blue 45 dye

    Science.gov (United States)

    Waheed Mushtaq, Muhammad; Kanwal, Farah; Imran, Muhammad; Ameen, Naila; Batool, Madeeha; Batool, Aisha; Bashir, Shahid; Mustansar Abbas, Syed; Rehman, Ata ur; Riaz, Saira; Naseem, Shahzad; Ullah, Zaka

    2018-03-01

    Cobalt ferrite (CoFe2O4) nanoparticles (NPs) are synthesized by wet chemical coprecipitation method using metal chlorides as precursors and potassium hydroxide (KOH) as a precipitant. The tergitol-1x (T-1x) and didecyldimethyl ammonium bromide (DDAB) are used as capping agents and their effect is investigated on particle size, size distribution and morphology of cobalt ferrite nanoparticles (CFNPs). The Fourier transform infrared spectroscopy confirms the synthesis of CFNPs and formation of metal-oxygen (M-O) bond. The spinel phase structure, morphology, polydispersity and magnetic properties of ferrite nanoparticles are investigated by x-ray diffraction, scanning electron microscopy, dynamic light scattering and vibrating sample magnetometry analyses, respectively. The addition of capping agents effects the secondary growth of CFNPs and reduces their particle size, as is investigated by dynamic light scattering and atomic force microscopy. The results evidence that the DDAB is more promising surfactant to control the particle size (∼13 nm), polydispersity and aggregation of CFNPs. The synthesized CFNPs, CFNPs/T-1x and CFNPs/DDAB are used to study their adsorption potential for removal of acid blue 45 dye, and a maximum adsorptive removal of 92.25% is recorded by 0.1 g of CFNPs/DDAB at pH 2.5 and temperature 20 ± 1 °C. The results show that the dye is physically adsorbed by magnetic NPs and follows the Langmuir isotherm model.

  7. Determinação de corantes marcadores do tipo azo e antraquinona em combustíveis por cromatografia líquida com detecção eletroquímica Determination of azo and anthraquinone dyes in fuels sample using hplc with electrochemical detection

    Directory of Open Access Journals (Sweden)

    Magno Aparecido Gonçalves Trindade

    2010-01-01

    Full Text Available An analytical method based on high-performance liquid chromatography with electrochemical detection has been developed and applied to the determination of Solvent blue 14 (SA-14 and Solvent red 24 (SV-24 in fuel samples. The dyes were better separated on C18 column, using a mobile phase composed of acetonitrile and ammonium acetate (90:10, v/v. Detection was carried out at an oxidation potential of +0.85V. The detector response was linear at concentration range of 7.50×10-8 - 1.50×10-6 mol L-1 (r = 0.997 for SA-14 and SV-24, respectively. The method was used to quantify these dyes in fuels samples with satisfactory accuracy and precision.

  8. Equilibrium studies on sorption of an anionic dye onto acid activated ...

    African Journals Online (AJOL)

    ISHIOMA

    Batch studies were conducted to evaluate the adsorption capacity of the dye, Congo red on the sorbent with respect to the ... pollution, but dyes are visible even in small quantities due .... in plastic bags, and stored in desiccators for use.

  9. Thermal and electrothermal sensitivity of polyglutamic acid with incorporated carbocyanine dyes in Langmuir-Blodgett films

    Energy Technology Data Exchange (ETDEWEB)

    Popova, G. [Mendeleyev University of Chemical Technology of Russia, Miusskaya sq., 9, Moscow 125047 (Russian Federation)], E-mail: galina@muctr.edu.ru; Spitsyn, A; Vantsyan, M [Mendeleyev University of Chemical Technology of Russia, Miusskaya sq., 9, Moscow 125047 (Russian Federation); Matveeva, N [Lukin Institute Phys. Problems, Zelenograd (Russian Federation); Yudin, S; Palto, S [Crystallography Institute Rus., Leninsky prosp., 57, 117336 Moscow (Russian Federation)

    2008-03-31

    Light-and electrosensitive carbocyanine dyes were incorporated into polyglutamic acid via covalent and non-covalent bonding. The reversible colour change on heating the Langmuir-Blodgett films of polyaminoacid has been studied by absorption spectroscopy and electroconductivity techniques. Characteristic shifts of the absorption spectrum are explained by formation of aggregates and hydrogen bonds. It was shown that H-aggregates and dimers are formed in Langmuir-Blodgett films; each type of assemblies contributes to the absorption spectrum. At elevated temperatures the ratio between concentrations of monomers, dimers and H-aggregates varies due to a breakdown of a part of aggregates into monomers. The change in molecular polarizability was also noticed. Electroconductivity of Langmuir-Blodgett films is observed in longitudinal and transverse directions. Electrochromic effect is noticed under weak electric current by change from red to colourless with iodine doping.

  10. Interface Modification of Dye-sensitized Solar Cells with Pivalic Acid to Enhance the Open-circuit Voltage

    KAUST Repository

    Li, Xin

    2009-01-01

    Pivalic acid (PVA) was used as a new coadsorbent to dye-sensitized solar cells (DSCs) to modify the interface between the TiO2 films and electrolyte. The addition of PVA improved the light-to-electricity conversion efficiency of devices by 8% by enhancing the open-circuit voltage. Copyright © 2009 The Chemical Society of Japan.

  11. Formic acid enhanced effective degradation of methyl orange dye in aqueous solutions under UV-Vis irradiation.

    Science.gov (United States)

    Wang, Jingjing; Bai, Renbi

    2016-09-15

    Developing efficient technologies to treat recalcitrant organic dye wastewater has long been of great research and practical interest. In this study, a small molecule, formic acid (FA), was applied as a process enhancer for the degradation of methyl orange (MO) dye as a model recalcitrant organic pollutant in aqueous solutions under the condition of UV-Vis light irradiation and air aeration at the ambient temperature of 25 °C. It was found that the decolouration of the dye solutions can be rapidly achieved, reducing the time, for example, from around 17.6 h without FA to mostly about less than 2 h with the presence of FA. The mineralization rate of MO dye reached as high as 81.8% in 1.5 h in the case of initial MO dye concentration at 25 mg L(-1), which is in contrast to nearly no mineralization of the MO dye for a similar system without the FA added. The study revealed that the generation of the H2O2 species in the system was enhanced and the produced OH radicals effectively contributed to the degradation of the MO dye. Process parameters such as the initial concentration of MO dye, FA dosage and solution pH were all found to have some effect on the degradation efficiency under the same condition of UV-Vis light irradiation and air aeration. The MO dye degradation performance was found to follow a first-order reaction rate to the MO dye concentration in most cases and there existed a positive correlation between the reaction rate constant and the initial FA concentration. Compared to the traditional H2O2/UV-Vis oxidation system, the use of FA as a process-enhancing agent can have the advantages of low cost, easy availability, and safe to use. The study hence demonstrates a promising approach to use a readily available small molecule of FA to enhance the degradation of recalcitrant organic pollutants, such as MO dye, especially for their pre-treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. A Novel Preparation Method of Two Polymer Dyes with Low Cytotoxicity

    Directory of Open Access Journals (Sweden)

    Dongjun Lv

    2017-02-01

    Full Text Available A new preparation method of polymer dyes was developed to improve both the grafting degree of the azo dyes onto O-carboxymethyl chitosan (OMCS and the water solubility of prepared polymer dyes. Firstly, the coupling compound of two azo edible colorants, sunset yellow (SY and allura red (AR, was grafted onto OMCS, and then coupled with their diazonium salt. The chemical structure of prepared polymer dyes was determined by Fourier transform-infrared spectroscopy and 1H-NMR, and the results showed that the two azo dyes were successfully grafted onto OMCS. The grafting degree onto OMCS and the water solubility of polymer dyes were tested, and the results showed that they were both improved as expected. The UV-vis spectra analysis results showed that the prepared polymer dyes showed similar color performance with the original azo dyes. Eventually, the cytotoxicity of prepared polymer dyes was tested and compared with the original azo dyes by a cytotoxicity test on human liver cell lines LO2, and the results showed that their grafting onto OMCS significantly reduced the cytotoxicity.

  13. Comparative studies on dyeing rate migration and wash fastness ...

    African Journals Online (AJOL)

    Migration and diffusion properties of synthesized azo dyes from 2-aminothiazole derivatives applied on commercial grade undyed cellulose acetate (CA) and cellulose triacetate (CTA) were investigated using dyeing conditions of 2% on weight of fabric (owf), 50:1 liquor ratio and subjected to ISO3 and ISO4 standard wash ...

  14. Hierarchical porous photoanode based on acid boric catalyzed sol for dye sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Maleki, Khatereh [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box: 14395-553, Tehran (Iran, Islamic Republic of); Abdizadeh, Hossein [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box: 14395-553, Tehran (Iran, Islamic Republic of); Center of Excellence for High Performance Materials, University of Tehran, Tehran (Iran, Islamic Republic of); Golobostanfard, Mohammad Reza, E-mail: Mohammadreza.Golbostanfard@gmail.com [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box: 14395-553, Tehran (Iran, Islamic Republic of); Adelfar, Razieh [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box: 14395-553, Tehran (Iran, Islamic Republic of)

    2017-02-01

    Highlights: • Acid boric can thoroughly leads to the hierarchical porous titania structure. • Boron is introduced into titania lattice which causes slight blueshift of bandgap. • The optimized sol parameters are H{sub 3}BO{sub 3}/TTiP = 0.45, DI/TTiP = 4.5, and 0.17 M. • Optimized paste parameters is not changed compared to conventional pastes. • The DSSC based on H{sub 3}BO{sub 3} catalyzed sol shows promising efficiency of 2.91%. - Abstract: The hierarchical porous photoanode of the dye sensitized solar cell (DSSC) is synthesized through non-aqueous sol-gel method based on H{sub 3}BO{sub 3} as an acid catalyst and the efficiencies of the fabricated DSSC based on these photoanodes are compared. The sol parameters of 0.17 M, water mole ratio of 4.5, acid mole ratio of 0.45, and solvent type of ethanol are introduced as optimum parameters for photoanode formation without any detectable cracks. The optimized hierarchical photoanode mainly contains anatase phase with slight shift toward higher angles, confirming the doping of boron into titania structure. Moreover, the porous structure involves two ranges of average pore sizes of 20 and 635 nm. The diffuse reflectance spectroscopy (DRS) shows the proper scattering and blueshift in band gap. The paste parameters of solid:liquid, TiO{sub 2}:ethyl cellulose, and terpineol:ethanol equal to 11:89, 3.5:7.5, and 25:64, respectively, are assigned as optimized parameters for this novel paste. The photovoltaic properties of short circuit current density, open circuit voltage, fill factor, and efficiency of 5.89 mA/cm{sup 2}, 703 mV, 0.7, and 2.91% are obtained for the optimized sample, respectively. The relatively higher short circuit current of the main sample compared to other samples is mainly due to higher dye adsorption in this sample corresponding to its higher surface area and presumably higher charge transfer confirmed by low R{sub S} and R{sub ct} in electrochemical impedance spectroscopy data. Boric acid as

  15. Adsorptive removal of acid blue 113 and tartrazine by fly ash from single and binary dye solutions

    Energy Technology Data Exchange (ETDEWEB)

    Pura, S.; Atun, G. [Istanbul University, Avcilar (Turkey). Dept. of Chemistry

    2009-07-01

    Adsorption of two acid dyestuffs, acid blue 113 (AB) and tartrazine (TA), has been studied from their single and binary solutions by using fly ash (FA) as an adsorbent. The S shaped isotherms observed for dye adsorption from single solutions show that both acid dyes are not preferred at a low concentration region whereas adsorption of the dyes from binary solutions is enhanced via solute-solute interactions. Although the L-shaped isotherm is observed in binary solutions adsorbability of AB decreases in concentrated solutions with respect to single one, time dependency of adsorption is well described with a pseudo-second-order kinetic model as well as the linear relation of Bt vs. t plots (not passing through origin) indicates that film diffusion is effective on dye adsorption. Modeled isotherm curves using isotherm parameters of the Freundlich and Dubinin-Radushkevich (D-R) equations adequately fit to experimental equilibrium data. Equilibrium adsorption of AB in binary solutions has been quite well predicted by the extended Freundlich and the Sheindorf-Rebuhn-Sheintuch (SRS) models. In general, the isotherm curves constructed in the temperature range of 298-328K show that the optimum temperature is 318K for AB removal from both single and binary solutions.

  16. Time-resolved fluorescence of cationic dyes covalently bound to poly(methacrylic acid) in rigid media

    Energy Technology Data Exchange (ETDEWEB)

    Paulo Moises de Oliveira, Hueder [Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, Sao Carlos, SP (Brazil); Gehlen, Marcelo Henrique [Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, Sao Carlos, SP (Brazil)]. E-mail: marcelog@iqsc.usp.br

    2006-12-15

    Atactic poly(methacrylic acid) labeled with acridine and Nile blue (NB) were studied by photophysical techniques in bulk solid state and in solution-cast films over different surfaces (glass, ITO, and polymethylmethacrylate). In the systems with both dyes, energy transfer from acridine to NB occurs with an efficiency depending on the type of substrate (solid or film). The films are more disordered fluorescent rigid media than the bulk chromophoric or bichromophoric polymers, and this effect is ascribed to inhomogeneous distribution of the dyes in the film. This effect enhances dye bimolecular interactions and increases the energy transfer rates between acridine donor and NB acceptor. Bimodal distributions of donor fluorescence lifetimes are observed.

  17. Decolorization of dyes by recombinase CotA from Escherichia coli ...

    African Journals Online (AJOL)

    The CotA laccase could efficiently decolorize anthraquinone and azo dyes in 24 h. The decolourization capacity of this recombinant laccase suggested that it could be a useful biocatalyst for the treatment of dye-containing effluents. Key words: Recombinant CotA laccase, Escherichia coli, purification, dye decolorization.

  18. Dodecylsulfate and dodecybenzenesulfonate intercalated hydrotalcites as adsorbent materials for the removal of BBR acid dye from aqueous solutions

    Directory of Open Access Journals (Sweden)

    Mohamed Bouraada

    2016-07-01

    Full Text Available Two modified layered double hydroxides (HT have been synthesized by intercalating both sodium dodecylsulfate (SDS and sodium dodecylbenzenesulfonate (SDBS surfactants into Mg-Al layered double hydroxides using the calcination–rehydratation method. The prepared materials HT-SDS and HT-SDBS were characterized by X-ray diffraction, FTIR, thermal analysis and BET. The obtained materials were used for Brilliant Blue R (BBR dye removal from aqueous solution. Batch studies were carried out to address various experimental parameters such as kinetic, pH, sorption isotherm and temperature. Sorption experiments of acid dye BBR from aqueous solution by HT-SDS and HT-SDBS were investigated in the batch system. Kinetic studies indicate that the sorption of BBR follows the pseudo-second-order model. Sorption capacities of HT-SDS (357.1 mg/g for BBR dye were much higher than those of HT-SDBS (204.1 mg/g. The intercalated Mg-Al layered double hydroxides with SDS and SDBS could possibly be used to remove anionic dyes of relatively high concentrations, whereas HT-CO3 may only be used to remove anionic dyes of low concentrations.

  19. Continuous biodegradation of sulfanilic acid in a multi-stage packed bed reactor

    International Nuclear Information System (INIS)

    Salazar-Huerta, A.; Velazquez-Garcia, A.; Cobos-Vasconcelos, D. de los.; Juarez-Ramirez, C.; Ruiz-Ordaz, N.; Galindez-Mayer, J.

    2009-01-01

    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)

  20. Spectrophotometric Determination of Gemifloxacin Mesylate, Moxifloxacin Hydrochloride, and Enrofloxacin in Pharmaceutical Formulations Using Acid Dyes

    Directory of Open Access Journals (Sweden)

    Ayman A. Gouda

    2014-01-01

    Full Text Available Simple, rapid, and extractive spectrophotometric methods were developed for the determination of some fluoroquinolones antibiotics: gemifloxacin mesylate (GMF, moxifloxacin hydrochloride (MXF, and enrofloxacin (ENF in pure forms and pharmaceutical formulations. These methods are based on the formation of ion-pair complexes between the basic drugs and acid dyes, namely, bromocresol green (BCG, bromocresol purple (BCP, bromophenol blue (BPB, bromothymol blue (BTB, and methyl orange (MO in acidic buffer solutions. The formed complexes were extracted with chloroform and measured at 420, 408, 416, 415, and 422 nm for BCG, BCP, BPB, BTB, and MO, respectively, for GMF; at 410, 415, 416, and 420 nm for BCP, BTB, BPB, and MO, respectively, for MXF; and at 419 and 414 nm for BCG and BTB, respectively, in case of ENF. The analytical parameters and their effects are investigated. Beer’s law was obeyed in the ranges 1.0–30, 1.0–20, and 2.0–24 μg mL−1 for GMF, MXF, and ENF, respectively. The proposed methods have been applied successfully for the analysis of the studied drugs in pure forms and pharmaceutical formulations. Statistical comparison of the results with the reference methods showed excellent agreement and indicated no significant difference in accuracy and precision.

  1. Sonochemical degradation of Basic Blue 41 dye assisted by nanoTiO2 and H2O2

    International Nuclear Information System (INIS)

    Abbasi, Mahmood; Asl, Nima Razzaghi

    2008-01-01

    The sonolysis of Basic Blue 41 dye in aqueous solution was performed at 35 kHz using ultrasonic power of 160 W and aqueous temperature of 25 + 1 o C within 180 min. The TiO 2 nanoparticles were used as a catalyst to assist the sonication process. The effect of experimental parameters such as pH, H 2 O 2 concentration and initial dye concentration on the reaction were investigated. It was recognized that in lower pH values the dye removal rate decreased. However, dye removal increased via increase in H 2 O 2 concentration and lowering the initial dye concentration. All intermediate compounds were detected by integrated gas chromatography-mass spectrometry (GC/MS) and also ion chromatograph (IC). During the decolorization, all nitrogen atoms and aromatic groups of Basic Blue 41 were converted to urea, nitrate, formic acid, acetic acid and oxalic acid, etc. Kinetic studies revealed that the degradation process followed pseudo-first order mechanism with the correlation coefficient (R 2 ) of 0.9918 under experimental conditions. The results showed that power ultrasound can be regarded as an appropriate tool for degradation of azo dyes to non-toxic end products

  2. Efficient removal of Acid Green 25 dye from wastewater using activated Prunus Dulcis as biosorbent: Batch and column studies.

    Science.gov (United States)

    Jain, Suyog N; Gogate, Parag R

    2018-03-15

    Biosorbent synthesized from dead leaves of Prunus Dulcis with chemical activation during the synthesis was applied for the removal of Acid Green 25 dye from wastewater. The obtained biosorbent was characterized using Brunauer-Emmett-Teller analysis, Fourier transform-infrared spectroscopy and scanning electron microscopy measurements. It was demonstrated that alkali treatment during the synthesis significantly increased surface area of biosorbent from 67.205 to 426.346 m 2 /g. The effect of various operating parameters on dye removal was investigated in batch operation and optimum values of parameters were established as pH of 2, 14 g/L as the dose of natural biosorbent and 6 g/L as the dose of alkali treated biosorbent. Relative error values were determined to check fitting of obtained data to the different kinetic and isotherm models. It was established that pseudo-second order kinetic model and Langmuir isotherm fitted suitably to the obtained batch experimental data. Maximum biosorption capacity values were estimated as 22.68 and 50.79 mg/g for natural biosorbent and for alkali activated Prunus Dulcis, respectively. Adsorption was observed as endothermic and activation energy of 6.22 kJ/mol confirmed physical type of adsorption. Column experiments were also conducted to probe the effectiveness of biosorbent for practical applications in continuous operation. Breakthrough parameters were established by studying the effect of biosorbent height, flow rate of dye solution and initial dye concentration on the extent of dye removal. The maximum biosorption capacity under optimized conditions in the column operation was estimated as 28.57 mg/g. Thomas and Yoon-Nelson models were found to be suitably fitted to obtained column data. Reusability study carried out in batch and continuous column operations confirmed that synthesized biosorbent can be used repeatedly for dye removal from wastewater. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. COMPARATIVE STUDIES OF PHYSICAL CHARACTERISTICS OF RAW AND MODIFIED SAWDUST FOR THEIR USE AS ADSORBENTS FOR REMOVAL OF ACID DYE

    Directory of Open Access Journals (Sweden)

    Jivan Singh

    2011-05-01

    Full Text Available The present paper aims to investigate the physical characteristics of sawdust relative to its use as an adsorbent for removal of an acid dye (Orange G from aqueous solutions. The raw sawdust was sieved to have a uniform size and was activated by sulphuric acid by refluxing the content at 60 oC for 4 h. Surface morphology and surface functional groups of both raw and modified sawdust samples were investigated by Scanning Electron Microscope (SEM, Energy Dispersive X-ray Analysis (EDX, Fourier Transformation Infrared (FTIR, and elemental analysis. All these analyses displayed significant change in the structure of the sawdust. The data obtained from batch adsorption experiments for the removal of the selected dye confirmed that adsorption characteristics of the modified sawdust were better than those of raw sawdust.

  4. Removal of Acid Black 194 dye from water by electrocoagulation with aluminum anode.

    Science.gov (United States)

    Vidal, Jorge; Villegas, Loreto; Peralta-Hernández, Juan M; Salazar González, Ricardo

    2016-01-01

    Application of an electrocoagulation process (EC) for the elimination of AB194 textile dye from synthetic and textile wastewater (effluent) contaminated with AB194 dye, was carried out using aluminum anodes at two different initial pH values. Tafel studies in the presence and absence of the dye were performed. The aluminum species formed during the electrolysis were quantified by atomic absorption, and the flocs formed in the process were analyzed by HPLC-MS. Complete removal of AB194 from 1.0 L of solution was achieved applying low densities current at initial pH values of 4.0 and 8.0. The removal of AB194 by EC was possible with a short electrolysis time, removing practically 100% of the total organic carbon content and chemical oxygen demand. The final result was completely discolored water lacking dye and organic matter. An effluent contaminated with 126 mg L(-1) AB194 dye from a Chilean textile industry was also treated by EC under optimized experimental conditions, yielding discolored water and considerably decreasing the presence of organic compounds (dye + dyeing additives), with very low concentrations of dissolved Al(3+). Analysis of flocs showed the presence of the original dye without changes in its chemical structure.

  5. Acid Treatment of Titania Pastes to Create Scattering Layers in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Trystan Watson

    2012-01-01

    Full Text Available In dye-sensitized solar cells (DSC scattering layers are used to increase the path length of light incident on the TiO2 film. This is typically achieved by the deposition of an additional TiO2 layer on top of an existing transparent film and designed to trap light. In this work we show that a simple acid pretreatment can lead to the formation of a scattering “skin” on the surface of a single TiO2 film performing a similar function to a scattering layer without any additional depositions. This is important in increasing manufacturing throughput for DSCs as further TiO2 depositions require additional materials and heat treatment. The pretreatment leads to self-assembly of a scattering layer of TiO2 which covers the surface on short-term immersion (<30 min and penetrates the bulk layer upon longer immersion. The method has been shown to increase the efficiency of the device by 20%.

  6. EXTRACTION OF MONOAZO DYES BY HYDROPHILIC EXTRACTANTS FROM AQUEOUS SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Y. I. Korenman

    2012-01-01

    Full Text Available The extraction of mono azo dyes E102, E122, E110, E124, E129 from aqueous solutions with hydrophilic solvents (alcohols, esters, ketones and polymers (poly-N-vinylamides, polyethylene glycol was studied. The main regularities of extraction are established. The distribution coefficients and degree of extraction of dyes was estimate. The influence of the nature of solvents and polymers on the extraction of dyes from aqueous solutions are established.

  7. Synthesis and characterization of 5-amino-2-((3-hydroxy-4-((3-hydroxyphenyl phenyl diazenyl phenol and its Cu(II complex – a strategy toward developing azo complexes for reduction of cytotoxicity

    Directory of Open Access Journals (Sweden)

    Durba Ganguly

    2014-12-01

    Full Text Available A major drawback of azo compounds is their associated toxicity, often carcinogenic, which is related to the reduction of the azo bond. This study intends to re-investigate this behavior by studying 5-amino-2-((3-hydroxy-4-((3-hydroxyphenyl phenyl diazenyl phenol (AHPD, a compound containing two azo bonds. Interaction of AHPD and its dimeric Cu(II complex with bacterial strains Escherichia coli and Staphylococcus aureus revealed the complex was less toxic. Reductive cleavage of the azo bond in AHPD and the complex followed using cytochrome c reductase (a model azo-reductase as well as azo-reductase enzymes obtained from bacterial cell extracts. Degradation of the azo bond was less in the complex allowing us to correlate the observed cytotoxicity. Cyclic voltammetry on AHPD and the complex support observations of enzyme assay experiments. These were particularly useful in realizing the formation of amines as an outcome of the reductive cleavage of azo bonds in AHPD that could not be identified through an enzyme assay. Results suggest that complex formation of azo compounds could be a means to control the formation of amines responsible for cytotoxicity. Studies carried out on bacterial cells for mere simplicity bear significance for multicellular organisms and could be important for human beings involved with the preparation and utilization of azo dyes.

  8. Assessment of the biosorption characteristics of a macro-fungus for the decolorization of Acid Red 44 (AR44) dye

    International Nuclear Information System (INIS)

    Akar, Tamer; Tosun, Ilknur; Kaynak, Zerrin; Kavas, Emine; Incirkus, Gonul; Akar, Sibel Tunali

    2009-01-01

    This study focuses on the possible use of macro-fungus Agaricus bisporus to remove Acid Red 44 dye from aqueous solutions. Batch equilibrium studies were carried out as a function of pH, biomass amount, contact time and temperature to determine the decolorization efficiency of biosorbent. The highest dye removal yield was achieved at pH 2.0. Equilibrium occurred within about 30 min. Biosorption data were successfully described by Langmuir isotherm model and the pseudo-second-order kinetic model. The maximum monolayer biosorption capacity of biosorbent material was found as 1.19 x 10 -4 mol g -1 . Thermodynamic parameters indicated that the biosorption of Acid Red 44 onto fungal biomass was spontaneous and endothermic in nature. Fourier transform infrared spectroscopy and scanning electron microscopy were used for the characterization of possible dye-biosorbent interaction and surface structure of biosorbent, respectively. Finally the proposed biosorbent was successfully used for the decolorization of Acid Red 44 in synthetic wastewater conditions.

  9. 40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Copper complex of (substituted... Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine salt... substances identified generically as copper complex of (substituted sulfonaphthyl azo substituted phenyl...

  10. Ultra-fast catalytic reduction of dyes by ionic liquid recoverable and reusable mefenamic acid derived gold nanoparticles.

    Science.gov (United States)

    Hassan, Syeda Sara; Sirajuddin; Solangi, Amber Rehana; Agheem, Mohammad Hassan; Junejo, Yasmeen; Kalwar, Nazar Hussain; Tagar, Zulfiqar Ali

    2011-06-15

    We synthesized mefenamic acid (MA) derived gold nanoparticles (MA-AuNps) in aqueous solution (MA-Au sol). Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of the sol at 1, 5, 15 and 60 min showed changes in size and shape of formed AuNps. Fourier Transform Infrared (FTIR) Spectroscopy revealed the interaction between AuNps and MA. Each Au sol exhibited exceptional catalytic activity for the reduction of Methylene Blue (MB), Rose Bengal (RB) and Eosin B (EB) dye individually as well as collectively. However, complete reduction of dye(s) was accomplished by Au sol of 5 min in just 15s. The catalytic performance of Ma-Au sol was far superior to that adsorbed on glass. AuNps were recovered with the help of water insoluble room temperature ionic liquid and reused with enhanced catalytic potential. This finding is a novel, rapid and highly economical alternative for environmental safety against pollution by dyes and extendable for control of other reducible contaminants as well. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Adsorption of Acid Red 18 by Activated Carbon Prepared from Cedar Tree: Kinetic and Equilibrium Study

    Directory of Open Access Journals (Sweden)

    M. R. Samarghandi

    2012-10-01

    Full Text Available Introduction: Textile effluents are one of the main environmental pollution sources and contain toxic compounds which threat the environment. For that reason, the activated carbon prepared from Cedar Tree was used for removal of Acid Red 18 as an Azo Dye. Material and Methods: Activated carbon was prepared by chemical activation and was used in batch system for dye removal. Effect of various experimental parameters such as pH (3 to11, initial dye concentration (50, 75 and 100 mg/L, contact time (1 to 120 min and adsorbent dosage (2 to 10 g/L were investigated. Equilibrium data was fitted onto Langmuir and Freundlich isotherm model. In addition, pseudo first order and pseudo second order models were used to investigate the kinetic of adsorption process. Results: Results shows that dye removal was increase with increase in adsorbent dosage, contact time and initial dye concentration. In addition, higher removal efficiency was observed in low pH (pH=3. At 120 min contact time, pH=3, 6 g/L adsorbent dosage and 100 mg/L of initial dye concentration, more than 95% of dye was removed. Equilibrium data was best fitted onto Freundlich isotherm model. According to Langmuir constant, maximum sorption capacity was observed to be 51/28 mg/L. in addition pseudo second order model best describe the kinetic of adsorption of Acid Red 18 onto present adsorbent. Conclusion: The results of present work well demonstrate that prepare activated carbon from Pine Tree has higher adsorption capacity toward Acid Red 18 Azo dye and can be used for removal of dyes from textile effluents.

  12. Biosorption of the metal-complex dye Acid Black 172 by live and heat-treated biomass of Pseudomonas sp. strain DY1: Kinetics and sorption mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Du, Lin-Na; Wang, Bing [College of Life Science, Zhejiang University, 310058, Hangzhou, Zhejiang Province (China); Li, Gang [Department of Agriculture and Biotechnology, Wenzhou Vocational College of Science and Technology, 325006 Wenzhou, Zhejiang Province (China); Wang, Sheng [College of Life Science, Zhejiang University, 310058, Hangzhou, Zhejiang Province (China); Crowley, David E., E-mail: crowley@ucr.edu [Department of Environmental Science, University of California, Riverside, CA 92521 (United States); Zhao, Yu-Hua, E-mail: yhzhao225@zju.edu.cn [College of Life Science, Zhejiang University, 310058, Hangzhou, Zhejiang Province (China)

    2012-02-29

    Highlights: Black-Right-Pointing-Pointer The maximum amount of Acid Black 172 sorption was about 2.98 mmol/g biomass. Black-Right-Pointing-Pointer Amine groups played a major role in the biosorption of Acid Black 172. Black-Right-Pointing-Pointer The reasons of increased dye sorption by heat-treated biomass were proposed. - Abstract: The ability of Pseudomonas sp. strain DY1 to adsorb Acid Black 172 was studied to determine the kinetics and mechanisms involved in biosorption of the dye. Kinetic data for adsorption fit a pseudo-second-order model. Increased initial dye concentration could significantly enhance the amount of dye adsorbed by heat-treated biomass in which the maximum amount of dye adsorbed was as high as 2.98 mmol/g biomass, whereas it had no significant influence on dye sorption by live biomass. As treated temperature increased, the biomass showed gradual increase of dye sorption ability. Experiments using potentiometric titration and Fourier transform infrared spectroscopy (FTIR) indicated that amine groups (NH{sub 2}) played a prominent role in biosorption of Acid Black 172. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM) analysis indicated that heat treatment of the biomass increased the permeability of the cell walls and denatured the intracellular proteins. The results of biosorption experiments by different cell components confirmed that intracellular proteins contributed to the increased biosorption of Acid Black 172 by heat-treated biomass. The data suggest that biomass produced by this strain may have application for removal of metal-complex dyes from wastewater streams generated from the dye products industry.

  13. Occupational exposure to allergens in oxidative hair dyes

    Directory of Open Access Journals (Sweden)

    Polona Zaletel

    2013-05-01

    Full Text Available Oxidative hair dyes are the most important hair dying products. Hairdressers are exposed to the allergens found in oxidative hair dyes during the process of applying dyes to the hair, when cutting freshly dyed hair, or as a consequence of prior contamination of the working environment. pphenylenediamine, toluene-2,5-diamine and its sulphate are the most common ingredients in oxidative hair dyes that cause allergic contact dermatitis in hairdressers. Cross-reactivity of p-phenylenediamine with para-amino benzoic acid, sulphonamides, sulphonylurea, dapsone, azo dyes, benzocaine, procaine, and black henna temporary tattoos is possible. Allergic contact dermatitis is classified as delayed-type hypersensitivity, according to Coombs and Gell. Skin changes typically appear on the hands after previous sensitization to causative allergens. Combined with the patient’s overall medical and work history and clinical picture, epicutaneous testing is the basic diagnostic procedure for confirming the diagnosis and identifying the causative allergens. The simplest and most effective measure for preventing the occurrence of allergic contact dermatitis in hairdressers is prevention. Preventive measures should be applied as early as in the beginning stage of vocational guidance for this profession. It is important to include health education in the process of professional training and to implement general technical safety measures, in order to reduce sensitization to allergens in hairdressing. Here, special emphasis must be given to the correct use of protective gloves. Legislation must limit the concentration of allergenic substances in hair dyes, based on their potential hazards documented by scientific research.

  14. Degradation of Acid Orange 7 Dye in Two Hybrid Plasma Discharge Reactors

    Science.gov (United States)

    Shen, Yongjun; Lei, Lecheng; Zhang, Xingwang; Ding, Jiandong

    2014-11-01

    To get an optimized pulsed electrical plasma discharge reactor and to increase the energy utilization efficiency in the removal of pollutants, two hybrid plasma discharge reactors were designed and optimized. The reactors were compared via the discharge characteristics, energy transfer efficiency, the yields of the active species and the energy utilization in dye wastewater degradation. The results showed that under the same AC input power, the characteristics of the discharge waveform of the point-to-plate reactor were better. Under the same AC input power, the two reactors both had almost the same peak voltage of 22 kV. The peak current of the point-to-plate reactor was 146 A, while that of the wire-to-cylinder reactor was only 48.8 A. The peak powers of the point-to-plate reactor and the wire-to-cylinder reactor were 1.38 MW and 1.01 MW, respectively. The energy per pulse of the point-to-plate reactor was 0.2221 J, which was about 29.4% higher than that of the wire-to-cylinder reactor (0.1716 J). To remove 50% Acid Orange 7 (AO7), the energy utilizations of the point-to-plate reactor and the wire-to-cylinder reactor were 1.02 × 10-9 mol/L and 0.61 × 10-9 mol/L, respectively. In the point-to-plate reactor, the concentration of hydrogen peroxide in pure water was 3.6 mmol/L after 40 min of discharge, which was higher than that of the wire-to-cylinder reactor (2.5 mmol/L). The concentration of liquid phase ozone in the point-to-plate reactor (5.7 × 10-2 mmol/L) was about 26.7% higher than that in the wire-to-cylinder reactor (4.5 × 10-2 mmol/L). The analysis results of the variance showed that the type of reactor and reaction time had significant impacts on the yields of the hydrogen peroxide and ozone. The main degradation intermediates of AO7 identified by gas chromatography and mass spectrometry (GCMS) were acetic acid, maleic anhydride, p-benzoquinone, phenol, benzoic acid, phthalic anhydride, coumarin and 2-naphthol. Proposed degradation pathways were

  15. Degradation of Acid Orange 7 Dye in Two Hybrid Plasma Discharge Reactors

    International Nuclear Information System (INIS)

    Shen Yongjun; Ding Jiandong; Lei Lecheng; Zhang Xingwang

    2014-01-01

    To get an optimized pulsed electrical plasma discharge reactor and to increase the energy utilization efficiency in the removal of pollutants, two hybrid plasma discharge reactors were designed and optimized. The reactors were compared via the discharge characteristics, energy transfer efficiency, the yields of the active species and the energy utilization in dye wastewater degradation. The results showed that under the same AC input power, the characteristics of the discharge waveform of the point-to-plate reactor were better. Under the same AC input power, the two reactors both had almost the same peak voltage of 22 kV. The peak current of the point-to-plate reactor was 146 A, while that of the wire-to-cylinder reactor was only 48.8 A. The peak powers of the point-to-plate reactor and the wire-to-cylinder reactor were 1.38 MW and 1.01 MW, respectively. The energy per pulse of the point-to-plate reactor was 0.2221 J, which was about 29.4% higher than that of the wire-to-cylinder reactor (0.1716 J). To remove 50% Acid Orange 7 (AO7), the energy utilizations of the point-to-plate reactor and the wire-to-cylinder reactor were 1.02 × 10 −9 mol/L and 0.61 × 10 −9 mol/L, respectively. In the point-to-plate reactor, the concentration of hydrogen peroxide in pure water was 3.6 mmol/L after 40 min of discharge, which was higher than that of the wire-to-cylinder reactor (2.5 mmol/L). The concentration of liquid phase ozone in the point-to-plate reactor (5.7 × 10 −2 mmol/L) was about 26.7% higher than that in the wire-to-cylinder reactor (4.5 × 10 −2 mmol/L). The analysis results of the variance showed that the type of reactor and reaction time had significant impacts on the yields of the hydrogen peroxide and ozone. The main degradation intermediates of AO7 identified by gas chromatography and mass spectrometry (GCMS) were acetic acid, maleic anhydride, p-benzoquinone, phenol, benzoic acid, phthalic anhydride, coumarin and 2-naphthol. Proposed degradation

  16. DECOLORISATION OF AQUEOUS SOLUTIONS OF SYNTHETIC DYES BY Lentinus polychrous Lév. CULTIVATED ON CASSAVA RHIZOME

    Directory of Open Access Journals (Sweden)

    Jirachaya Boonyarit

    2015-02-01

    Full Text Available Cassava rhizomes are left in fields after harvesting. This agricultural waste is rich in lignocellulosic material which is a substrate for white rot fungi. Disposal of synthetic dyes poses a problem to the environment and it needs to be addressed. The ability of Lentinus polychrous Lév., a white rot fungus, grown on the cassava rhizome chips, to decolorise three kinds of synthetic dye was studied. The effects of the initial moisture content of cassava rhizome used for fungal cultivation, the temperature during the decolorisation, and the pH of synthetic dye solution on the extent of decolorisation were investigated. The decolorisations of Reactive blue 49, Navy blue and Acid blue 62 were affected by the initial moisture content of cassava rhizome. The highest extents of decolorisation of these dyestuffs were observed when the fungus was cultivated at 70% initial moisture content. Temperatures of 30, 37 and 45oC did not alter the extent of decolorisation of the dyestuffs. The most extensive decolorisations of Reactive blue 49 and Acid blue 62 (anthraquinone dyes were at pH 3.0 while that of Navy blue (azo dye was at pH 7.0. Adsorption was the main mechanism of decolorisation of Navy blue. However, both enzymic degradation and adsorption were involved in the decolorisations of Reactive blue 49 and Acid blue 62.

  17. Efficient removal of malachite green dye using biodegradable graft copolymer derived from amylopectin and poly(acrylic acid).

    Science.gov (United States)

    Sarkar, Amit Kumar; Pal, Aniruddha; Ghorai, Soumitra; Mandre, N R; Pal, Sagar

    2014-10-13

    This article reports on the application of a high performance biodegradable adsorbent based on amylopectin and poly(acrylic acid) (AP-g-PAA) for removal of toxic malachite green dye (MG) from aqueous solution. The graft copolymer has been synthesized and characterized using various techniques including FTIR, GPC, SEM and XRD analyses. Biodegradation study suggests that the co-polymer is biodegradable in nature. The adsorbent shows excellent potential (Qmax, 352.11 mg g(-1); 99.05% of MG has been removed within 30 min) for removal of MG from aqueous solution. It has been observed that point to zero charge (pzc) of graft copolymer plays significant role in adsorption efficacy. The adsorption kinetics and isotherm follow pseudo-second order and Langmuir isotherm models, respectively. Thermodynamics parameters suggest that the process of dye uptake is spontaneous. Finally desorption study shows excellent regeneration efficiency of adsorbent. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Biosorption of Acid Dye in Single and Multidye Systems onto Sawdust of Locust Bean (Parkia biglobosa Tree

    Directory of Open Access Journals (Sweden)

    Abdur-Rahim Adebisi Giwa

    2016-01-01

    Full Text Available Properties of raw sawdust of Parkia biglobosa, as a biosorbent for the removal of Acid Blue 161 dye in single, binary, and ternary dye systems with Rhodamine B and Methylene Blue dyes in aqueous solution, were investigated. The sawdust was characterized using Scanning Electron Microscopy, Fourier Transform Infrared spectrophotometry, X-ray diffraction, and pH point of zero charge. Batch adsorption experiments were carried out to determine the equilibrium characteristics, thermodynamics, and kinetics of the sorption processes. The data obtained were subjected to various isotherm and kinetics equations. The results showed that the adsorption processes were described by different isotherm models depending on the composition of the system; they were all spontaneous (ΔG ranges from −0.72 to −5.36 kJ/mol and endothermic (range of ΔH is 11.37–26.31 kJ/mol and with increased randomness with ΔS values of 55.55 and 98.78 J·mol/K for single and ternary systems, respectively. Pseudo-second-order kinetics model gave better fit for all the sorption systems studied irrespective of the differences in composition, with the initial and overall rate constants higher for the mixtures than for the single system (6.76 g·mg−1min−1. The presence of Rhodamine B and Methylene Blue had a synergetic effect on the maximum monolayer capacity of the adsorbent for Acid Blue 161 dye.

  19. Novel colorimetric sensors for cyanide based on azo-hydrazone tautomeric skeletons.

    Science.gov (United States)

    Adegoke, Olajire A; Adesuji, Temitope E; Thomas, Olusegun E

    2014-07-15

    The monoazo dyes, 4-carboxyl-2, 6-dinitrophenylazohydroxynaphthalenes dyes (AZ-01, AZ-03 and AZ-04), were evaluated as a highly selective colorimetric chemosensor for cyanide ion. The recognition of cyanide ion gave an obvious colour change from light yellow to brownish red and upon dilution with acetone produced a purple to lilac colour. Optimum conditions for the reaction between the azo dyes and cyanide ion were established at 30°C for 5 min, and different variables affecting the reaction were carefully studied and optimised. Under the optimum conditions, linear relationships between the CN(-) concentrations and light absorption were established. Using these azo-hydrazone molecular switch entities, excellent selectivity towards the detection of CN(-) in aqueous solution over miscellaneous competitive anions was observed. Such selectivity mainly results from the possibility of nucleophilic attack on the azo-hydrazone chemosensors by cyanide anions in aqueous system, which is not afforded by other competing anions. The cyanide chemosensor method described here should have potential application as a new family probes for detecting cyanide in aqueous solution. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Azo compounds as a family of organic electrode materials for alkali-ion batteries.

    Science.gov (United States)

    Luo, Chao; Borodin, Oleg; Ji, Xiao; Hou, Singyuk; Gaskell, Karen J; Fan, Xiulin; Chen, Ji; Deng, Tao; Wang, Ruixing; Jiang, Jianjun; Wang, Chunsheng

    2018-02-27

    Organic compounds are desirable for sustainable Li-ion batteries (LIBs), but the poor cycle stability and low power density limit their large-scale application. Here we report a family of organic compounds containing azo group (N=N) for reversible lithiation/delithiation. Azobenzene-4,4'-dicarboxylic acid lithium salt (ADALS) with an azo group in the center of the conjugated structure is used as a model azo compound to investigate the electrochemical behaviors and reaction mechanism of azo compounds. In LIBs, ADALS can provide a capacity of 190 mAh g -1 at 0.5 C (corresponding to current density of 95 mA g -1 ) and still retain 90%, 71%, and 56% of the capacity when the current density is increased to 2 C, 10 C, and 20 C, respectively. Moreover, ADALS retains 89% of initial capacity after 5,000 cycles at 20 C with a slow capacity decay rate of 0.0023% per cycle, representing one of the best performances in all organic compounds. Superior electrochemical behavior of ADALS is also observed in Na-ion batteries, demonstrating that azo compounds are universal electrode materials for alkali-ion batteries. The highly reversible redox chemistry of azo compounds to alkali ions was confirmed by density-functional theory (DFT) calculations. It provides opportunities for developing sustainable batteries.

  1. Azo compound degradation kinetics and halonitromethane formation kinetics during chlorination.

    Science.gov (United States)

    Fu, Jing; Wang, Xiaomao; Bai, Weiliang; Yang, Hongwei; Xie, Yuefeng F

    2017-05-01

    The chlorination of azo compounds can produce halonitromethanes (HNMs), which have attracted increasing concern due to their high genotoxicity. By impacting the speciation of chlorine and azo compounds, pH impacts apparent second-order rate constants of Methyl Orange (MO, 27.5-1.4 × 10 3  M -1  s -1 ), Acid Orange II (AO, 16.7-99.3 M -1  s -1 ), and Acid Red 1 (AR 1, 3.7-72.5 M -1  s -1 ) (pH range 6.3-9.0). The two-compartment first-order model successfully described the chloropicrin (TCNM) formation kinetics, suggesting that both fast- and slow-reacting precursors of TCNM are generated from the chlorination of azo compounds. The ratios between fast and slow formation rate constants for MO and AO were 15.6-5.4 × 10 2 , while that of AR 1 was 9.8-19.4 (pH range 6.5-9.0). The fraction of the fast-reacting TCNM precursors decreased with increasing pH for MO and AO; while that for AR 1 decreased when pH increased from 6.5 to 8.0, and then increased when pH increased from 8.0 to 9.0. The impact of pH on TCNM formation was also precursor-specific. The highest molar yields of TCNM predicted from the model in this study were 2.4%, 2.5%, and 1.5% for MO, AO, and AR 1, respectively. The study demonstrates that azo compounds are important HNM precursors, and pose a potential threat to drinking water safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Ultrasound assisted extraction of natural dye from jackfruit's wood (Artocarpus heterophyllus): The effect of ethanol concentration as a solvent

    Science.gov (United States)

    Febriana, Ike Dayi; Gala, Selfina; Mahfud, Mahfud

    2017-05-01

    Azo dye are synthetic organic dyes which has an azo group (- N = N -) as chromophore. Azo dye is resistand to decomposition process and harmfull for the environment and human being. Natural dye can be used as substitution of azo dye at textile industry. Natural dye are eco - friendly and can be applied for dyeing of fibrous material. Natural dye can be obtained from natural origin such as leaves, wood, or roots. The wood of jackfruit (Artocarpus heterophyllus) can used as natural source of natural dye. Ultrasound assisted extraction (UAE) is a new method that can be used to extract natural dye from jackfruit's wood. The aim of this research are to study about influence of ethanol concentration as solvent and extraction kinetic. Jackfruit's wood dust from sawmill used for the experimentation were sifted by sieve 35 mesh. Ethanol 96% used as solvent of this experiment and varied the concentration in volume to volume ratio (v/v). Experiment were carried out from 20 to 50 minutes. The result of this experiment shows that ethanol concentration influenced yield of extraction from jackfruit's wood. Concentration of ethanol will be affected polarity of solvent. The Peleg model was used to describe about kinetic model of natural dye extraction. Value of k1 and k2 constant are 0.003835 and 0.04186 respectively.

  3. Characterisation of acid dyes in forensic fibre analysis by high-performance liquid chromatography using narrow-bore columns and diode array detection.

    Science.gov (United States)

    Laing, D K; Gill, R; Blacklaws, C; Bickley, H M

    1988-06-17

    A gradient elution high-performance liquid chromatographic (HPLC) system with a diode array detector and a short narrow-bore (40 x 1 mm I.D.) column has been used to characterise a number of acid dyes. The resolution and reproducibility of the HPLC system have been evaluated and the detection limits for various dyes have been estimated. Comparisons are made with current methods of fibre dyestuff examination used in forensic science. The system has been applied to the analysis of dye extracted from single fibres. Using diode array detection, both chromatographic and spectral data can be produced in a single operation from casework sized samples.

  4. Study of Modern Nano Enhanced Techniques for Removal of Dyes and Metals

    Directory of Open Access Journals (Sweden)

    Samavia Batool

    2014-01-01

    Full Text Available Industrial effluent often contains the significant amount of hexavalent chromium and synthetic dyes. The discharge of wastewater without proper treatment into water streams consequently enters the soil and disturbs the aquatic and terrestrial life. A range of wastewater treatment technologies have been proposed which can efficiently reduce both Cr(VI and azo dyes simultaneously to less toxic form such as biodegradation, biosorption, adsorption, bioaccumulation, and nanotechnology. Rate of simultaneous reduction of Cr(VI and azo dyes can be enhanced by combining different treatment techniques. Utilization of synergistic treatment is receiving much attention due to its enhanced efficiency to remove Cr(VI and azo dye simultaneously. This review evaluates the removal methods for simultaneous removal of Cr(VI and azo dyes by nanomicrobiology, surface engineered nanoparticles, and nanophotocatalyst. Sorption mechanism of biochar for heavy metals and organic contaminants is also discussed. Potential microbial strains capable of simultaneous removal of Cr(VI and azo dyes have been summarized in some details as well.

  5. Nonlinear optical properties of natural laccaic acid dye studied using Z-scan technique

    CSIR Research Space (South Africa)

    Zongo, S

    2015-08-01

    Full Text Available . The experiments were performed by using single beam Z-scan technique at 532 nm with 10 ns, 10 Hz Nd:YAG laser pulses excitation. From the open-aperture Z-scan data, we derived that the laccaic dye samples exhibit strong two photon absorption (2PA). The nonlinear...

  6. Ponceau 6R dye decoloration and chromate reduction simultaneously in acid medium

    Directory of Open Access Journals (Sweden)

    Seddique M. Ahmed

    2015-07-01

    Full Text Available The degradation efficiency and kinetic degradation reaction of Ponceau 6R dye using potassium chromate have been investigated under various experimental conditions: different concentrations of H2SO4 and temperatures. The immediate change of the red coloration (λmax = 518 nm to colorless was observed after addition of inorganic oxidizing agent (K2CrO4 into the protonated form of Ponceau 6R dye after 48 h. This observation could be attributed to the highest oxidized form of this dye obtained (the quinoid one, which undergoes a hydrolysis reaction to produce p-hydroquinone (H2Q by a mechanism similar to Schiff-base hydrolysis. The cationic form of this matrix is a crucial feature for the hydrolysis process. A kinetic model for oxidation of Ponceau 6R by the combination of chromate was developed based on experimental results. The observed kinetic reaction coefficient was determined and correlated as a function of UV spectral intensity of Ponceau 6R at 518 nm. The degradation rate follows pseudo-first order kinetics with respect to dye concentration.

  7. Laser-induced removal of a dye C.I. Acid Red 87 using n-type WO{sub 3} semiconductor catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Qamar, M. [Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, KFUPM Box 741, Dhahran 31261 (Saudi Arabia); Gondal, M.A., E-mail: magondal@kfupm.edu.sa [Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, KFUPM Box 741, Dhahran 31261 (Saudi Arabia); Laser Research Laboratory, Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Hayat, K. [Chemistry Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Yamani, Z.H. [Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, KFUPM Box 741, Dhahran 31261 (Saudi Arabia); Laser Research Laboratory, Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Hooshani, K. [Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, KFUPM Box 741, Dhahran 31261 (Saudi Arabia); Chemistry Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2009-10-30

    Water contamination by organic substances such as dyes is of great concern worldwide due to their utilization in many industrial processes and environmental concerns. To cater the needs for waste water treatment polluted with organic dyes, laser-induced photocatalytic process was investigated for removal of a dye derivative namely Acid Red 87 using n-type WO{sub 3} semiconductor catalyst. The degradation was investigated in aqueous suspensions of tungsten oxide under different experimental conditions using laser instead of conventional UV lamp as an irradiation source. The degradation process was monitored by measuring the change in dye concentration as a function of laser irradiation time by employing UV spectroscopic analysis. The degradation of dye was studied by varying different parameters such as laser energy, reaction pH, substrate concentration, catalyst concentration, and in the presence of electron acceptors such as hydrogen peroxide (H{sub 2}O{sub 2}), and potassium bromate (KBrO{sub 3}). The degradation rates were found to be strongly dependent on all the above-mentioned parameters. Our experimental results revealed that the dye degradation process was very fast (within few minutes) under laser irradiation as compared to conventional setups using broad spectral lamps (hours or days) and this laser-induced photocatalytic degradation method could be an effective means to eliminate the pollutants present in liquid phase. The experience gained through this study could be beneficial for treatment of waste water contaminated with organic dyes and other organic pollutants.

  8. Selective solid phase extraction and pre-concentration of heavy metals from seawater by physically and chemically immobilized 4-amino-3-hydroxy-2-(2-chlorobenzene)-azo-1-naphtalene sulfonic acid silica gel

    International Nuclear Information System (INIS)

    Mahmoud, M.E.; Soayed, A.A.; Hafez, O.F.

    2003-01-01

    4-Amino-3-hydroxy-2 - (2-chlorobenzene)-azo-l-naphthalene sulfonic acid (AHCANSA) was used as a chelating modifier to improve the reactivity of the silica gel surface in terms of selective binding and extraction of heavy metal ions. The surface cover-age values were found to be 0.488 and 0.473 mmol g -1 for the newly modified physically adsorbed silica gel phase (I) and chemically immobilized-AHCANSA phase (II), respectively. The modified silica gel phases (I, II) were tested for stability in different acidic buffer solutions (pH 1-6) and found to be highly resistant to hydrolysis and leaching by buffer solutions above pH 2. The application of these two phases as solid extractors for a series of mono-, di-, and tri-valent metal ions from aqueous solutions was also performed with different controlling factors such as the pH value of metal ion solutions and equilibrium shaking time. The mmol g -1 metal capacity values determined by silica gel phases (I, II) were found to confirm high affinity and selectivity characters for binding with heavy metal ions such as Cr 3+ , Ni 2+ , Cu 2+ , Zn 2+ , Cd 2+ and Pb 2+ in a range of 0.250-0.483. The tested alkali and alkaline earth metals, Na + , K + , Mg 2+ and Ca 2+ , were found to exhibit little interaction and binding ability with the modified silica gel phases. The selectivity characters incorporated into the modified silica gel phases were further utilized and applied in solid phase extraction and pre-concentration of trace concentration levels (∼1.0 μg mL -1 and 2.00-2.50 ng mL -1 ) from real seawater samples. The percentage recovery values determined for Cr 3+ , Cu 2+ , Zn 2+ , Cd 2+ and Pb 2+ were found to be in the range of 95.2-98.1 ± 2.0-5.0 %, and the pre-concentration recovery values for the same tested heavy metal ions were found to be in the range of 92.5-97.1 ± 3.0-6.0 % for the two newly modified silica gel phases with a pre-concentration factor of 500. Refs. 25 (author)

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

    International Nuclear Information System (INIS)

    Theuring, Martin; Vehse, Martin; Maydell, Karsten von; Agert, Carsten

    2014-01-01

    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

  10. Aerobic biodegradation of a sulfonated phenylazonaphthol dye by a bacterial community immobilized in a multistage packed-bed BAC reactor.

    Science.gov (United States)

    Ruiz-Arias, Alfredo; Juárez-Ramírez, Cleotilde; de los Cobos-Vasconcelos, Daniel; Ruiz-Ordaz, Nora; Salmerón-Alcocer, Angélica; Ahuatzi-Chacón, Deifilia; Galíndez-Mayer, Juvencio

    2010-11-01

    A microbial community able to aerobically degrade the azo dye Acid Orange 7 was selected from riparian or lacustrine sediments collected at sites receiving textile wastewaters. Three bacterial strains, pertaining to the genera Pseudomonas, Arthrobacter, and Rhizobium, constitute the selected community. The biodegradation of AO7 was carried out in batch-suspended cell culture and in a continuously operated multistage packed-bed BAC reactor. The rapid decolorization observed in batch culture, joined to a delay of about 24 h in COD removal and cell growth, suggests that enzymes involved in biodegradation of the aromatic amines generated after AO7 azo-bond cleavage (1-amino-2-naphthol [1-A2N] and 4-aminobenzenesulfonic acid [4-ABS]), are inducible in this microbial consortium. After this presumptive induction period, the accumulated byproducts, measured through COD, were partially metabolized and transformed in cell mass. At all azo dye loading rates used, complete removal of AO7 and 1-A2N was obtained in the multistage packed-bed BAC reactor (PBR).; however, the overall COD (eta ( COD )) and 4-ABS (eta ( ABS )) removal efficiencies obtained in steady state continuous culture were about 90%. Considering the toxicity of 1-A2N, its complete removal has particular relevance. In the first stages of the packed-bed BAC reactor (Fig. 4a-c), major removal was observed. In the last stage, only a slight removal of COD and 4-ABS was obtained. Comparing to several reported studies, the continuously operated multistage packed-bed BAC reactor showed similar or superior results. In addition, the operation of large-packed-bed BAC reactors could be improved by using several shallow BAC bed stages, because the pressure drop caused by bed compaction of a support material constituted by small and fragile particles can be reduced.

  11. Determination of fast ozone oxidation rate for textile dyes by using a continuous quench-flow system.

    Science.gov (United States)

    Gomes, Arlindo C; Nunes, José C; Simões, Rogério M S

    2010-06-15

    To study the fast kinetic decolourisation of textile dyes by ozone a continuous quench-flow system was used. This system has not been used before for these purposes. Reaction times in the range of 7-3000 ms were explored. The reaction was quenched with potassium iodide, which proved to be very effective, and the indigo method was used to follow the ozone concentration. Dyes from the most representative chemical classes currently used in the textile industry, i.e. azo and anthraquinone, were selected. Using the initial slope method, the effect of dye and ozone concentrations was researched and the kinetic equations thus established. Using tert-butyl alcohol, as radical scavenger, and pH close to 2.5, the second-order rate constant of the reactant dyes at 280 K varies in the range of 1.20x10(4)-7.09x10(5)M(-1)s(-1); the Acid Orange 7 exhibiting thus its lowest value, the Acid Blue 45 its highest value and the Acid Green 25 and 27 and Direct Yellow 4 intermediate values (approximately 1.6x10(5)M(-1)s(-1)). Without radical scavenger and the pH close to 4, the reaction rate increases one order of magnitude, but, on the reverse, the efficiency of ozone to decolourisation decreases. Copyright 2010 Elsevier B.V. All rights reserved.

  12. Kinetic of Azo Dyes Decolourization by Enterobacteriaceae Species ...

    African Journals Online (AJOL)

    It was observed that the riboflavin addition at 19.95 n moles ml-1 in the reaction mixture, rate of decolourization was suddenly change from 0.019 ÄA/minutes to 0.20 ÄA/minutes, which is extremely high by 10 fold fast and subsequently remains faster i.e 0.2 ÄA/minutes without further additional RF in the same assay mixture.

  13. Photo refractive effect in an Azo-dye doped polymer

    International Nuclear Information System (INIS)

    Khoshsima, H.

    1997-01-01

    Photo refractive, todays, is the frontier of nonlinear optics. The higher nonlinear properties, the more photo refractive effect will appear. In this experimental study, applying the experimental arrangement for Degenerate Four Wave Minx ing, we got benefit of P.V.K base polymer made complex with T.N.F, that is basically charge carrier. D.M.N.P.A.A chromophore molecules are used to produce second order nonlinear optics effect. Under the best experimental condition, the measured diffraction efficiency was about 70%

  14. Decolorization of the azo dye reactive black 5 using laccase ...

    African Journals Online (AJOL)

    The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to print, save, and work with PDFs, Highwire Press provides a helpful Frequently Asked Questions about PDFs.

  15. Phytoremediation of textile dyes and effluents: Current scenario and future prospects.

    Science.gov (United States)

    Khandare, Rahul V; Govindwar, Sanjay P

    2015-12-01

    Phytoremediation has emerged as a green, passive, solar energy driven and cost effective approach for environmental cleanup when compared to physico-chemical and even other biological methods. Textile dyes and effluents are condemned as one of the worst polluters of our precious water bodies and soils. They are well known mutagenic, carcinogenic, allergic and cytotoxic agents posing threats to all life forms. Plant based treatment of textile dyes is relatively new and hitherto has remained an unexplored area of research. Use of macrophytes like Phragmites australis and Rheum rhabarbarum have shown efficient removal of Acid Orange 7 and sulfonated anthraquinones, respectively. Common garden and ornamental plants namely Aster amellus, Portulaca grandiflora, Zinnia angustifolia, Petunia grandiflora, Glandularia pulchella, many ferns and aquatic plants have also been advocated for their dye degradation potential. Plant tissue cultures like suspension cells of Blumea malcolmii and Nopalea cochenillifera, hairy roots of Brassica juncea and Tagetes patula and whole plants of several other species have confirmed their role in dye degradation. Plants' oxidoreductases such as lignin peroxidase, laccase, tyrosinase, azo reductase, veratryl alcohol oxidase, riboflavin reductase and dichlorophenolindophenol reductase are known as key biodegrading enzymes which break the complex structures of dyes. Schematic metabolic pathways of degradation of different dyes and their environmental fates have also been proposed. Degradation products of dyes and their fates of metabolism have been reported to be validated by UV-vis spectrophotometry, high performance liquid chromatography, high performance thin layer chromatography, Fourier Transform Infrared Spectroscopy, gas chromatograph-mass spectroscopy and several other analytical tools. Constructed wetlands and various pilots scale reactors were developed independently using the plants of P. australis, Portulaca grandiflora, G. pulchella

  16. Removal of Acid Red 14 from Contaminated Water Using UV/S2O82- Advanced Oxidation Process

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Rasoulifard

    2012-10-01

    Full Text Available The present study investigates the degradation of Acid Red 14 (AR14, commonly used as a textile dye in aqueous medium through the oxidation process by UV /S2O82- under a set of variables concentration of S2O82-, Ag+, AR14 and temperature. Commonly Ag+, heat and UV light can excite S2O82− to sulfate radical form (SO4−•, a stronger oxidant (E0 = 2.60 V than S2O82−, to enhance significantly the oxidation of contaminants. Also the changes in the absorption spectra of AR14 solutions during the photoxidation process showed that decrease of absorption peak of the dye at λmax = 514 nm indicates a rapid degradation of the azo dye. The results of this study suggest that the oxidative treatment of AR14 by peroxydisulfate with UV is a viable option for removal of the textile dyes from effluents.

  17. Synthesis of Potato Starch-Acrylic-Acid Hydrogels by Gamma Radiation and Their Application in Dye Adsorption

    Directory of Open Access Journals (Sweden)

    Md. Murshed Bhuyan

    2016-01-01

    Full Text Available Several kinds of acrylic-acid-grafted-starch (starch/AAc hydrogels were prepared at room temperature (27°C by applying 5, 10, 15, 20, and 25 kGy of gamma radiation to 15% AAc aqueous solutions containing 5, 7.5, and 15% of starch. With increment of the radiation dose, gel fraction became higher and attained the maximum (96.5% at 15 kGy, above which the fraction got lowered. On the other hand, the gel fraction monotonically increased with the starch content. Swelling ratios were lower for the starch/AAc hydrogels prepared with higher gamma-ray doses and so with larger starch contents. Significant promotions of the swelling ratios were demonstrated by hydrolysis with NaOH: 13632±10% for 15 kGy radiation-dosed [5% starch/15% AAc] hydrogel, while the maximum swelling ratio was ~200% for those without the treatment. The authors further investigated the availability of the starch/AAc hydrogel as an adsorbent recovering dye waste from the industrial effluents by adopting methylene blue as a model material; the hydrogels showed high dye-capturing coefficients which increase with the starch ratio. The optimum dye adsorption was found to be 576 mg per g of the hydrogel having 7.5 starch and 15% AAc composition. Two kinetic models, (i pseudo-first-order and (ii pseudo-second-order kinetic models, were applied to test the experimental data. The latter provided the best correlation of the experimental data compared to the pseudo-first-order model.

  18. A family of uranium-carboxylic acid hybrid materials: synthesis, structure and mixed-dye selective adsorption

    International Nuclear Information System (INIS)

    Xue Gao; Jian Song; Yong Heng Xing; Feng Ying Bai; Li Xian Sun; Zhan Shi

    2016-01-01

    Four uranyl complexes (UO_2)_2(pht)_2(Hpac)_2(H_2O)_2 (pht = phthalic acid and Hpac = nicotinic acid) (1), (UO_2)(pac)_2(H_2O)_2 (2), [(UO_2)(CMA)_3][H_2N(CH_3)_2] (CMA = cinnamic acid) (3) and (UO_2)_2(C_2O_4)(μ_2- OH)_2(H_2O)_2H_2O (4) were synthesized by the reaction of UO_2(CH_3COO)_2.2H_2O as the metal source with phthalic acid, nicotinic acid, cinnamic acid or oxalic acid as the ligand. They were characterized by elemental analysis, IR, UV-vis, XRD, single crystal X-ray diffraction and thermal gravimetric analysis. The structural analysis showed that complexes 1, 2 and 3 were discrete structures, and by hydrogen bonding interactions, the adjacent molecular units are connected to form a three-dimensional (3D) supramolecular network structure for complex 1 and one-dimensional (1D) chains for complexes 2 and 3. Meanwhile, in the structure of complex 4, a tetrameric SBU (UO_2)_4(μ_2-OH)_4(H_2O)_4 is linked to a 2D layer through a bridging oxalic acid ligand, and furthermore extends the 2D layer into a 3D supramolecular architecture by hydrogen bonding interactions. In order to extend their functional properties, their photoluminescence, surface photovoltage and mixed-dye selective adsorption properties have been studied for the first time. Through experiments, we found that the adsorption performance of complex 3 was better than others, and the amount of adsorbed RhB was 4.22 mg.g"-"1. (authors)

  19. 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…

  20. Hierarchically porous silicon–carbon–nitrogen hybrid materials towards highly efficient and selective adsorption of organic dyes

    Science.gov (United States)

    Meng, Lala; Zhang, Xiaofei; Tang, Yusheng; Su, Kehe; Kong, Jie

    2015-01-01

    The hierarchically macro/micro-porous silicon–carbon–nitrogen (Si–C–N) hybrid material was presented with novel functionalities of totally selective and highly efficient adsorption for organic dyes. The hybrid material was conveniently generated by the pyrolysis of commercial polysilazane precursors using polydivinylbenzene microspheres as sacrificial templates. Owing to the Van der Waals force between sp2-hybridized carbon domains and triphenyl structure of dyes, and electrostatic interaction between dyes and Si-C-N matrix, it exhibites high adsorption capacity and good regeneration and recycling ability for the dyes with triphenyl structure, such as methyl blue (MB), acid fuchsin (AF), basic fuchsin and malachite green. The adsorption process is determined by both surface adsorption and intraparticle diffusion. According to the Langmuir model, the adsorption capacity is 1327.7 mg·g−1 and 1084.5 mg·g−1 for MB and AF, respectively, which is much higher than that of many other adsorbents. On the contrary, the hybrid materials do not adsorb the dyes with azo benzene structures, such as methyl orange, methyl red and congro red. Thus, the hierarchically porous Si–C–N hybrid material from a facile and low cost polymer-derived strategy provides a new perspective and possesses a significant potential in the treatment of wastewater with complex organic pollutants. PMID:25604334

  1. Molecular and excited state properties of isomeric scarlet disperse dyes

    Science.gov (United States)

    Lim, Jihye; Szymczyk, Malgorzata; Mehraban, Nahid; Ding, Yi; Parrillo-Chapman, Lisa; El-Shafei, Ahmed; Freeman, Harold S.

    2018-06-01

    This work was part of an investigation aimed at characterizing the molecular and excited state properties of currently available disperse dyes developed to provide stability to extensive sunlight exposures when adsorbed on poly(ethylene terephthalate) (PET) fibers. Having completed the characterization of yellow, magenta, and cyan disperse dyes for PET-based fabrics used outdoors, our attention turned to the colors designed to enhance the color gamut of a standard 4-member (cyan/yellow/magenta/black) color set. The present study pertained specifically to the characterization of commercially available scarlet dyes. In this regard, HPLC analysis showed that a scarlet product used for PET coloration was mainly a 70/30 mixture of dyes, and the use of HRMS and single crystal X-ray diffraction analyses indicated that these two dyes were azo compounds derived from isomeric pyridine-based couplers which differed in the location of the primary amino (sbnd NH2) and anilino (sbnd NHPh) groups attached to the pyridine ring. One dye structure has the sbnd NHPh group para to the azo group (Sc2), while the other has that group in the ortho position (Sc3). The presence of either ortho substituent provides photostabilization through intramolecular H-bonding with the azo moiety. Further, results from molecular modeling studies showed that the lower excited state oxidation potential of Sc3 relative to that of Sc2 allows Sc3 to function as an energy quencher for the excited state of Sc2 - through thermodynamically favorable electron transfer.

  2. Enhancement of zinc oxide-mediated solar light decoloration of Acid Yellow 99 dye by addition of β-CD

    Science.gov (United States)

    Pitchaimuthu, Sakthivel; Rajalakshmi, Subramanian; Kannan, Nagarathinam; Velusamy, Ponnusamy

    2015-06-01

    In the current work, the commercially available ZnO photocatalyst was used to investigate the photodecoloration of Acid yellow 99 (AY99) dye under solar light radiation. Promising enhancement of photodecoloration of AY99 dye was also achieved by the addition of β-cyclodextrin (β-CD) with the ZnO (ZnO-β-CD). The effects of process parameters such as initial concentration, pH, catalyst loading, and illumination time on the extent of decoloration were investigated. The optimum catalyst loading was observed at 2.0 g/L. The higher photoactivity of ZnO-β-CD/solar light system than ZnO/solar light system can be ascribed due to the ligand to metal charge transfer (LMCT) from β-CD to ZnII. The complexation patterns have been confirmed with UV-visible and FT-IR spectroscopy and the interaction between ZnO and β-CD has been characterized by FE-SEM, powder XRD analysis, and UV-visible diffuse reflectance spectroscopy.

  3. Quaternized triethanolamine-sebacoyl moieties in highly branched polymer architecture as a host for the entrapment of acid dyes in aqueous solutions

    Directory of Open Access Journals (Sweden)

    Meriem Bendjelloul

    2017-03-01

    Full Text Available This paper reports the synthesis of a hyperbranched polymer by a cost-effective one-step copolymerization of A3 and B2 monomers, namely, triethanolamine and sebacoyl chloride, respectively, followed by methylation of tertiary amine groups. The structure of the hyperbranched polymer QTEAS as an efficient material for the removal of acid dyes was demonstrated by Fourier transform infrared spectroscopy (FTIR, cross polarization magic angle spinning (CPMAS 13C NMR, thermogravimetric analysis (TGA, powder X-ray diffraction (DRX and scanning electron microscopy (SEM. The removal of indigo carmine (IC and Evans blue (EB was expected to be driven by the electrostatic attraction between positively charged quaternary ammonium groups within the hyperbranched polymer and the negatively charged dyes. The removal process was found to be closely connected to the total number of sulfonate groups on the surface of the dyes. Nonetheless, the ionic strength does not affect the dyes' removal efficiency by the hyperbranched polymer. The sorption capacities at saturation of the monolayer qmax were determined to be 213.22 mg g−1 and 214.13 mg g−1, for IC and EB, respectively, thus showing the greater affinity of QTEAS sorbent for both dyes. Despite its extended molecular structure, EB is removed with the same effectiveness as IC. Finally, the great efficiency of the highly branched polymer for dye removal from colored wastewater was clearly demonstrated.

  4. Solar energy conversion and storage by using Rose Extract as natural dye and nitrilotriacetic acid as reductant in photogalvanic cell

    Science.gov (United States)

    Yadav, Sushil Kumar

    2018-05-01

    Photogalvanic effect was studied in Photogalvanic cell containing Rose Extract was used as Natural Dye (Photosensitizer), Nitrilotriacetic acid (NTA) as Reductant. The observed value of photopotential and photocurrent generated by this cell were 872 mV and 176 µA, respectively. The observed power at power point was 82.18 µW and the conversion efficiency was 0.79 %. The fill factor 0.4678 was experimentally determined at the power point of the cell. The photogalvanic cell can be used in dark for 42 min., showing the storage capacity of the cell against charging time was 200 min. The effect of different parameters on electrical output of the cell was observed and a mechanism has also been proposed for the generation of photocurrent in photogalvanic cell.

  5. Hair dye-incorporated poly-γ-glutamic acid/glycol chitosan nanoparticles based on ion-complex formation

    Directory of Open Access Journals (Sweden)

    Lee HY

    2011-11-01

    Full Text Available Hye-Young Lee1,*, Young-IL Jeong2,*, Ki-Choon Choi31Anyang Science University, Anyang, Gyeonggi, South Korea; 2Chonnam National University Hwasun Hospital, Jeonnam, South Korea; 3Grassland and Forages Research Center, National Institute of Animal Science, Rural Development Administration, Chungnam, South Korea*These authors contributed equally to this work.Background: p-Phenylenediamine (PDA or its related chemicals are used more extensively than oxidative hair dyes. However, permanent hair dyes such as PDA are known to have potent contact allergy reactions in humans, and severe allergic reactions are problematic.Methods: PDA-incorporated nanoparticles were prepared based on ion-complex formation between the cationic groups of PDA and the anionic groups of poly(γ-glutamic acid (PGA. To reinforce PDA/PGA ion complexes, glycol chitosan (GC was added. PDA-incorporated nanoparticles were characterized using field-emission scanning electron microscopy, Fourier-transform infrared (FT-IR spectroscopy, dynamic light scattering, and powder X-ray diffractometry (XRD.Results: Nanoparticles were formed by ion-complex formation between the amine groups of PDA and the carboxyl groups of PGA. PDA-incorporated nanoparticles are small in size (<100 nm, and morphological observations showed spherical shapes. FT-IR spectra results showed that the carboxylic acid peak of PGA decreased with increasing PDA content, indicating that the ion complexes were formed between the carboxyl groups of PGA and the amine groups of PDA. Furthermore, the intrinsic peak of the carboxyl groups of PGA was also decreased by the addition of GC. Intrinsic crystalline peaks of PDA were observed by XRD. This crystalline peak of PDA was completely nonexistent when nanoparticles were formed by ion complex between PDA, PGA, and GC, indicating that PDA was complexed with PGA and no free drug existed in the formulation. During the drug-release experiment, an initial burst release of PDA was

  6. Treatment of a Textile Effluent from Dyeing with Cochineal Extracts Using Trametes versicolor Fungus

    Directory of Open Access Journals (Sweden)

    Gabriela Arroyo-Figueroa

    2011-01-01

    Full Text Available Trametes versicolor (Tv fungus can degrade synthetic dyes that contain azo groups, anthraquinone, triphenylmethane polymers, and heterocyclic groups. However, no references have been found related to the degradation of natural dyes, such as the carminic acid that is contained in the cochineal extract. Experiments to determine the decolorization of the effluent used in the cotton dyeing process with cochineal extract by means of Tv fungus were done. Treatments to determine decolorization in the presence or absence of Kirk's medium, glucose, and fungus, with an addition of 50% (v v-1 of nonsterilized effluent were performed. Physicochemical characterization was performed at the start and end of the treatment. Degradation kinetics were determined. A direct relationship was found between the dry weight of fungi, pH, and the decolorization system, with higher decolorization at lower pH levels (pH ~4.3. High decolorization (81% ± 0.09; 88% ± 0.17; and 99% ± 0.04 for three of the eight treatments (Kirk's medium without glucose, Kirk's medium with glucose, and without medium with glucose, respectively was found. Toxicity tests determined an increase in the initial effluent toxicity (7.33 TU compared with the final treatment (47.73 TU in a period of 11 days. For this system, a degradation sequence of the carminic acid structure present in the effluent by the Tv fungus is suggested, in which it is seen that metabolites still containing aromatic structures are generated.

  7. Treatment of a textile effluent from dyeing with cochineal extracts using Trametes versicolor fungus.

    Science.gov (United States)

    Arroyo-Figueroa, Gabriela; Ruiz-Aguilar, Graciela M L; López-Martínez, Leticia; González-Sánchez, Guillermo; Cuevas-Rodríguez, Germán; Rodríguez-Vázquez, Refugio

    2011-05-05

    Trametes versicolor (Tv) fungus can degrade synthetic dyes that contain azo groups, anthraquinone, triphenylmethane polymers, and heterocyclic groups. However, no references have been found related to the degradation of natural dyes, such as the carminic acid that is contained in the cochineal extract. Experiments to determine the decolorization of the effluent used in the cotton dyeing process with cochineal extract by means of Tv fungus were done. Treatments to determine decolorization in the presence or absence of Kirk's medium, glucose, and fungus, with an addition of 50% (v v-1) of nonsterilized effluent were performed. Physicochemical characterization was performed at the start and end of the treatment. Degradation kinetics were determined. A direct relationship was found between the dry weight of fungi, pH, and the decolorization system, with higher decolorization at lower pH levels (pH ~4.3). High decolorization (81% ± 0.09; 88% ± 0.17; and 99% ± 0.04) for three of the eight treatments (Kirk's medium without glucose, Kirk's medium with glucose, and without medium with glucose, respectively) was found. Toxicity tests determined an increase in the initial effluent toxicity (7.33 TU) compared with the final treatment (47.73 TU) in a period of 11 days. For this system, a degradation sequence of the carminic acid structure present in the effluent by the Tv fungus is suggested, in which it is seen that metabolites still containing aromatic structures are generated.

  8. A kinetic study of textile dyeing wastewater degradation by Penicillium chrysogenum.

    Science.gov (United States)

    Durruty, Ignacio; Fasce, Diana; González, Jorge Froilán; Wolski, Erika Alejandra

    2015-06-01

    The potential of Penicillium chrysogenum to decolorize azo dyes and a real industrial textile wastewater was studied. P. chrysogenum was able to decolorize and degrade three azo dyes (200 mg L(-1)), either independently or in a mixture of them, using glucose as a carbon source. A kinetic model for degradation was developed and it allowed predicting the degradation kinetics of the mixture of the three azo dyes. In addition, P. chrysogenum was able to decolorize real industrial wastewater. The kinetic model proposed was also able to predict the decolorization of the real wastewater. The calibration of the proposed model makes it a useful tool for future wastewater facilities' design and for practical applications.

  9. Structural evolution, electrical and optical properties of AZO films ...

    Indian Academy of Sciences (India)

    Administrator

    Aluminum-doped zinc oxide (AZO) target was fabricated using AZO ... All AZO films show c-axis preferred orientation and hexagonal structure. With increasing film thick- ness from 153 to 1404 nm, the crystallinity was improved and the angle of (002) peak was close to ... For observing grain boundary and size, the target was.

  10. Application of H2O2 and H2O2/Fe0 in removal of Acid Red 18 dye from aqueous solutions

    Directory of Open Access Journals (Sweden)

    Nazari Shahram

    2013-08-01

    Full Text Available Background & Aims of the Study: Organic dyes with a complex structure are often toxic, carcinogenic, mutagenic, non-biodegradation and stable in the environment and if released to the environment without treatment can endanger the environment and human health. The aim of this study was to evaluate the performance of H2O2 and H2O2/Fe0 Iron in removal of dye Acid Red 18 from aqueous solutions. Materials & Methods: This study was conducted at the laboratory scale. In this study, the removal efficiency of Acid Red 18 from a synthetic solution by H2O2 and H2O2/Fe0 was investigated. As well as Effect of solution pH, dye concentration, Concentration of Nanoscale Zero-Valent Iron, H2O2 and contact time in decolorization efficiency was investigated. Results: Results show that in pH=3, Contact time of 80 minutes, dye concentration of 50 mg/l and Concentration of Nanoscale Zero-Valent Iron of 2 g/l and H2O2 concentration equal to 200 mmol/l, the removal efficiency was about 98%. Conclusions: According to the results of experiments, H2O2/Fe0 has high efficiency in removal of Acid Red 18 from aqueous solution.

  11. Azoreductase and dye detoxification activities of Bacillus velezensis strain AB.

    Science.gov (United States)

    Bafana, Amit; Chakrabarti, Tapan; Devi, Sivanesan Saravana

    2008-01-01

    Azo dyes are known to be a very important and widely used class of toxic and carcinogenic compounds. Although lot of research has been carried out for their removal from industrial effluents, very little attention is given to changes in their toxicity and mutagenicity during the treatment processes. Present investigation describes isolation of a Bacillus velezensis culture capable of degrading azo dye Direct Red 28 (DR28). Azoreductase enzyme was isolated from it, and its molecular weight was found to be 60 kDa. The enzyme required NADH as cofactor and was oxygen-insensitive. Toxicity and mutagenicity of the dye during biodegradation was monitored by using a battery of carefully selected in vitro tests. The culture was found to degrade DR28 to benzidine and 4-aminobiphenyl, both of which are potent mutagens. However, on longer incubation, both the compounds were degraded further, resulting in reduction in toxicity and mutagenicity of the dye. Thus, the culture seems to be a suitable candidate for further study for both decolourization and detoxification of azo dyes, resulting in their safe disposal.

  12. Dye sensitized solar cell of TiO{sub 2} nanoparticle/nanorod composites prepared via low-temperature synthesis in oleic acid

    Energy Technology Data Exchange (ETDEWEB)

    Saji, Viswanathan S. [Department of Printed Electronics Engineering, Sunchon National University, Chonnam 540-742 (Korea, Republic of); Pyo, Myoungho, E-mail: mho@sunchon.ac.k [Department of Printed Electronics Engineering, Sunchon National University, Chonnam 540-742 (Korea, Republic of)

    2010-09-01

    Titania (TiO{sub 2}) nanorods (NRs) and nanoparticles (NPs) were synthesized using oleic acid as a surfactant and employed as photoanodes for dye sensitized solar cell (DSSC) fabrication. The synthesized NRs and NPs were characterized using transmission electron microscopy and X-ray diffraction. The photovoltaic performances were compared between NRs, NPs, and their composites. The results showed that the power conversion efficiencies ({eta}) of the composites depend on the relative compositions of NRs and NPs in photoanodes, reaching the greatest at 10% NR content. {eta} of the pure NRs DSSC was lower than that of the NPs DSSC. Electrochemical impedance spectroscopy revealed that the highest {eta} at 10% NRs is mainly due to reduced charge transport resistance at the TiO{sub 2}/dye/electrolyte interface and electrolyte diffusion resistance, overcoming the reduction of the number of adsorbed dye molecules.

  13. Adsorption Behavior of High Stable Zr-Based MOFs for the Removal of Acid Organic Dye from Water

    Directory of Open Access Journals (Sweden)

    Ke-Deng Zhang

    2017-02-01

    Full Text Available Zirconium based metal organic frameworks (Zr-MOFs have become popular in engineering studies due to their high mechanical stability, thermostability and chemical stability. In our work, by using a theoretical kinetic adsorption isotherm, we can exert MOFs to an acid dye adsorption process, experimentally exploring the adsorption of MOFs, their external behavior and internal mechanism. The results indicate their spontaneous and endothermic nature, and the maximum adsorption capacity of this material for acid orange 7 (AO7 could be up to 358 mg·g−1 at 318 K, estimated by the Langmuir isotherm model. This is ascribed to the presence of an open active metal site that significantly intensified the adsorption, by majorly increasing the interaction strength with the adsorbates. Additionally, the enhanced π delocalization and suitable pore size of UiO-66 gave rise to the highest host–guest interaction, which further improves both the adsorption capacity and separation selectivity at low concentrations. Furthermore, the stability of UiO-66 was actually verified for the first time, through comparing the structure of the samples before and after adsorption mainly by Powder X-ray diffraction and thermal gravimetric analysis.

  14. 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.

  15. Sequential study on reactive blue 29 dye removal from aqueous solution by peroxy acid and single wall carbon nanotubes: experiment and theory

    Directory of Open Access Journals (Sweden)

    Jahangiri-Rad Mahsa

    2013-01-01

    Full Text Available Abstract The majority of anthraquinone dye released to the environment come from antrapogenic sources. Several techniques are available for dyes' removal. In this study removal of reactive blue 29 (RB29 by an advanced oxidation process sequenced with single wall carbon nanotubes was investigated. Advanced oxidation process was optimized over a period of 60 minutes by changing the ratio of acetic acid to hydrogen peroxide, the compounds which form peroxy acid. Reduction of 20.2% -56.4% of reactive blue 29 was observed when the ratio of hydrogen peroxide/acetic acid/dye changed from 344/344/1 to 344/344/0.08 at different times (60, 120 and 180 min. The optimum ratio of acetic acid/hydrogen peroxide/dye was found to be 344/344/0.16 over 60 min. The resultant then was introduced for further removal by single wall carbon nanotubes(SWCNTs as adsorbent. The adsorption of reactive blue 29 onto SWCNTs was also investigated. Langmuir, Freundlich and BET isotherms were determined and the results revealed that the adsorption of RB29 onto SWCNTs was well explained by BET model and changed to Freundlich isotherm when SWCNTs was used after the application of peroxy a