Chlorination treatment of aqueous samples reduces, but does not eliminate, the mutagenic effect of the azo dyes Disperse Red 1, Disperse Red 13 and Disperse Orange 1

The treatment of textile effluents by the conventional method based on activated sludge followed by a chlorination step is not usually an effective method to remove azo dyes, and can generate products more mutagenic than the untreated dyes. The present work evaluated the efficiency of conventional chlorination to remove the genotoxicity/mutagenicity of the azo dyes Disperse Red 1, Disperse Orange 1, and Disperse Red 13 from aqueous solutions. The comet and micronucleus assays with HepG2 cells and the Salmonella mutagenicity assay were used. The degradation of the dye molecules after the same treatment was also evaluated, using ultraviolet and visible absorption spectrum measurements (UV-vis), high performance liquid chromatography coupled to a diode-array detector (HPLC-DAD), and total organic carbon removal (TOC) analysis. The comet assay showed that the three dyes studied induced damage in the DNA of the HepG2 cells in a dose-dependent manner. After chlorination, these dyes remained genotoxic, although with a lower damage index (DI). The micronucleus test showed that the mutagenic activity of the dyes investigated was completely removed by chlorination, under the conditions tested. The Salmonella assay showed that chlorination reduced the mutagenicity of all three dyes in strain YG1041, but increased the mutagenicity of Disperse Red 1 and Disperse Orange 1 in strain TA98. With respect to chemical analysis, all the solutions showed rapid discoloration and a reduction in the absorbance bands characteristic of the chromophore group of each dye. However, the TOC was not completely removed, showing that chlorination of these dyes is not efficient in mineralizing them. It was concluded that conventional chlorination should be used with caution for the treatment of aqueous samples contaminated with azo dyes. (C) 2010 Elsevier B.V. All rights reserved.

Polymethine cyanine dyes in beta-cyclodextrin solution: multiple equilibria and chemical oxidation

Absorption and fluorescence spectroscopy, electrochemical techniques, and semiempirical calculations were employed to characterize the multiple complexation equilibria between two polymethine cyanine dyes (IR-786 and Indocyanine green-ICG, 5) and beta-cyclodextrin (beta-CD, L), as well as the chemical reactivity of the complexed and uncomplexed species against the oxidizing agents hypochlorite (HC) and hydrogen peroxide (HP). IR-786 dimerization is favored with the increase in beta-CD concentration in the form of (SL)(2) complexes. In the case of ICG, free dimers (D) and SL complexes are favored. Both IR-786 and ICG react and discolor in the presence of HC and HP. For IR-786, the reaction with HP and HC proceeds with observed rate constants of 10(-3) and 0.28 s(-1) and second-order rate constants (k(2)) of similar to 10(-3) and 10(4) M(-1) s(-1), respectively. The intermediate species observed in the bleaching reactions of IR-786 and ICG were shown, by cyclic voltammetry and VIS absorption, to result from one electron oxidation. IR-786 complexed with beta-CD is protected against bleaching in the presence of HP and HC by factors of 20 and 4, respectively. This protection was not observed in ICG complexes. Superdelocalizability profile of both dyes and frontier orbital analysis indicates that beta-CD does not protect ICG from oxidation by HP or HC, whereas the 2:2 IR-786/beta-Cd complex is able to avoid the oxidation of IR-786. We concluded that the decrease in the chemical reactivity of the dyes against oxidant agents in the presence of beta-CD is due to the formation of (SL)(2) complexes. Copyright (C) 2010 John Wiley & Sons, Ltd.

Single-wall carbon nanotubes modified with organic dyes: Synthesis, characterization and potential cytotoxic effects

This work deals with the covalent functionalization of single-wall carbon nanotubes (SWNTs) with phenosafranine (PS) and Nile Blue (NB) dyes. These dyes can act as photosensitizers in energy and electron transfer reactions, with a potential to be applied in photodynamic therapy. Several changes in the characteristic Raman vibrational features of the dyes suggest that a covalent modification of the nanotubes with the organic dyes occurs. Specifically, the vibrational modes assigned to the NH(2) moieties of the dyes are seen to disappear in the SWNT-dye nanocomposites, corroborating the bond formation between amine groups in the dyes and carboxyl groups in the oxidized nanotubes. The X-ray absorption (XANES) data also show, that the intense band at 398.6 eV attributed to 1s -> 2p pi* transition of the nitrogen of the aromatic PS ring, is shifted due to the bonding with the carbonic structure of the SWNTs. The cytotoxicity data of dyes-modified SWNT composites in the presence and absence of light shows that the SWNT-NB (4 mu g/mL) composite presents a good photodynamic effect, namely a low toxicity in the dark, higher toxicity in the presence of light and also a reduced dye photobleaching by auto-oxidation. (C) 2010 Elsevier B.V. All rights reserved.

Characterization of Adherent Umbilical Cord Blood Stromal Cells Regarding Passage, Cell Number, and Nano-biomarking Utilization

Adherent umbilical cord blood stromal cells (AUCBSCs) are multipotent cells with differentiation capacities. Therefore, these cells have been investigated for their potential in cell-based therapies. Quantum Dots (QDs) are an alternative to organic dyes and fluorescent proteins because of their long-term photostability. In this study we determined the effects of the cell passage on AUCBSCs morphology, phenotype, and differentiation potential. QDs labeled AUCBSCs in the fourth cell passage were differentiated in the three mesodermal lineages and were evaluated using cytochemical methods and transmission electron microscopy (TEM). Gene and protein expression of the AUCBSCs immunophenotypic markers were also evaluated in the labeled cells by real-time quantitative PCR and flow cytometry. In this study we were able to define the best cellular passage to work with AUCBSCs and we also demonstrated that the use of fluorescent QDs can be an efficient nano-biotechnological tool in differentiation studies because labeled cells do not have their characteristics compromised.

New porphyrins tailored as biodiesel fluorescent markers

This work reports the synthesis, characterization, and evaluation of new porphyrins tailored to become biodiesel fluorescent markers. The compounds were obtained by the synthetic modification of the commercially available porphyrin 5,10,15,20-meso-tetrakis(pentafluorophenyl)porphyrin (TPPF(20)) using ethanol and hexadecan-1-ol (cetylic alcohol) as nucleophilic reagents. The stability of the marked biodiesel fuel solutions was investigated every 15 days for a total period of 3 months, and under different storage temperature and light exposure condition, simulating the conventional stock conditions. The influence of the different substituents of the porphyrins on the fluorescence properties of the biodiesel fuel markers was also assessed. The resulting porphyrins were highly soluble in biodiesel fuel and displayed strong fluorescence characterized by two strong emission bands. The fluorescent markers did not affect the biodiesel physical properties and were stable in storage conditions for at least 3 months at a concentration of 4 ppm. The best storage condition was found to be absence of light and 6 degrees C; the limit of detection by photoluminescence technique had magnitude of 10(-13) mol L(-1). The synthesized porphyrins were characterized by nuclear magnetic resonance ((1)H-NMR and (19)F-NMR), mass spectrometry (HRMS), ultraviolet visible absorption spectroscopy, and photoluminescence spectroscopy. (C) 2011 Elsevier Ltd. All rights reserved.

Treatment of wastewater from a cotton dyeing process with UV/H(2)O(2) using a photoreactor covered with reflective material

Wastewater containing several dyes, including sulfur black from the dyeing process in a textile mill, was treated using a UV/H(2)O(2) process. The wastewater was characterized by a low BOD/ COD ratio, intense color and high acute toxicity to the algae species Pseudokirchneriella subcaptata. The influence of the pH and H(2)O(2) concentration on the treatment process was evaluated by a full factorial design 2(2) with three replicates of the central experiment. The removal of aromatic compounds and color was improved by an increase in the H(2)O(2) concentration and a decrease in pH. The best results were obtained at pH 5.0 and 6 g L(-1). With these conditions and 120 min of UV irradiation, the removal of the color, aromatic compounds and COD were 74.1, 55.1 and 44.8%, respectively. Under the same conditions, but using a photoreactor covered with aluminum foil, the removal of the color, aromatic compounds and COD were 92.0, 77.6 and 59.4%, respectively. Moreover, the use of aluminum foil reduced the cost of the treatment by 40.8%. These results suggest the potential application of reflective materials as a photoreactor accessory to reduce electric energy consumption during the UV/H(2)O(2) process.

Comparison of oxidation efficiency of disperse dyes by chemical and photoelectrocatalytic chlorination and removal of mutagenic activity

Degradation of Disperse Orange 1, Disperse Red 1 and Disperse Red 13 dyes has been performed using electrochemical oxidation on Pt electrode, chemical chlorination and photoelectrochemical oxidation on Ti/TiO(2) thin film electrodes in NaCl or Na(2)SO(4) medium. 100% discoloration was obtained for all tested methods after 1 h of treatment. Faster color removal was obtained by photoelectrocatalytic oxidation in 0.1 mol L(-1) NaCl pH 4.0 under UV light and an applied potential of +1.0V (vs SCE reference electrode), which indicates also values around 60% of TOC removal. The conventional chlorination method and electrochemical oxidation on Pt electrode resulted in negligible reduction of TOC removal. All dyes showed positive mutagenic activity in the Salmonella/microsome assay with the strain TA98 in the absence and presence of S9 (exogenous metabolic activation). Nevertheless, there is complete reduction of the mutagenic activity after 1 h of photoelectrocatalytic oxidation, suggesting that this process would be good option to remove disperse azo dyes from aqueous media. (C) 2008 Elsevier Ltd. All rights reserved.

The azo dye Disperse Orange 1 induces DNA damage and cytotoxic effects but does not cause ecotoxic effects in Daphnia similis and Vibrio fischeri

Azo dyes constitute the largest group of colorants used in industry and can pass through municipal waste water plants nearly unchanged due to their resistance to aerobic treatment, which potentially exposes humans and local biota to adverse effects. Unfortunately, little is known about their environmental fate. Under anaerobic conditions, some azo dyes are cleaved by microorganisms forming potentially carcinogenic aromatic amines. In the present study, the azo dye Disperse Orange 1, widely used in textile dyeing, was tested using the comet, Salmonella/microsome mutagenicity, cell viability, Daphnia similis and Microtox (R) assays. The human hepatoma cell line (HepG2) was used in the comet assay and for cell viability. In the mutagenicity assay. Salmonella typhimurium strains with different levels of nitroreductase and o-acetyltransferase were used. The dye showed genotoxic effects with respect to HepG2 cells at concentrations of 0.2, 0.4, 1.0, 2.0 and 4.0 mu g/mL. In the mutagenicity assay, greater responses were obtained with the strains TA98 and YG1041, suggesting that this compound mainly induces frameshift mutations. Moreover, the mutagenicity was greatly enhanced with the strains overproducing nitroreductase and o-acetyltransferase, showing the importance of these enzymes in the mutagenicity of this dye. In addition, the compound induced apoptosis after 72 h in contact with the HepG2 cells. No toxic effects were observed for either D. similis or Vibrio fischeri. (C) 2011 Elsevier B.V. All rights reserved.

The azo dyes Disperse Red 1 and Disperse Orange 1 increase the micronuclei frequencies in human lymphocytes and in HepG2 cells

The use of azo dyes by different industries can cause direct and/or indirect effects oil human and environmental health due to the discharge of industrial effluents that contain these toxic compounds. Several studies have demonstrated the genotoxic effects of various azo dyes, but information on the DNA damage caused by Disperse Red 1 and Disperse Orange 1 is unavailable, although these dyes are used in dyeing processes in many countries. The aim of the present study was to evaluate the mutagenic activity of Disperse Red 1 and Disperse Orange 1 using the micronucleus (MN) assay in human lymphocytes and in HepG2 cells. In the lymphocyte assay. it was found that the number of MN induced by the lowest concentration of each dye (0.2 mu g/mL) was similar to that of the negative control. At the other concentrations, a dose response MN formation was observed up to 1.0 mu g/mL. At higher dose levels, the number of MN decreased. For the HepG2 cells the results were similar. With both dyes a dose dependent increase in the frequency of MN was detected. However for the HepG2, the threshold for this increase was 2.0 mu g/mL, while at higher doses a reduction in the MN number was observed. The proliferation index was also calculated in order to evaluate acute toxicity during the test. No differences were detected between the different concentrations tested and the negative control. (C) 2009 Elsevier B.V. All rights reserved.

Heterogeneous photocatalytic degradation of acid dyes in aqueous TiO2 suspensions: Kinetics and toxicity

This work assesses the photocatalytic (TiO2/UV) degradation of a simulated acid dye bath (Yellow 3, Red 51, Blue 74, and auxiliary chemicals). Color and phytotoxicity removal were monitored by spectrophotometry and lettuce (Lactuca sativa) seeds as the test organism, respectively. Mineralization was determined by DOC analyses. Photocatalytic, photolytic, and adsorption experiments were performed, showing that adsorption was negligible. After 240 minutes of irradiation, it was achieved 96% and 78% of color removal with photocatalysis and photolysis, respectively. 37% of mineralization occurred with photocatalysis only. The dye bath was rendered completely non-toxic after 60 minutes of photocatalytic treatment; the same result was only achieved with photolysis after 90 minutes. A kinetic model composed of two first-order in series reactions was used. The first photocatalytic decolorization rate constant was k(1) = 0.062 min(-1) and the second k(2) = 0.0043 min(-1), approximately two times greater than the photolytic ones.

Fatigue and workability in Brazilian textile companies in different corporate social responsibility score groups

The aim of this study was to evaluate working conditions in the textile industry for different stages of Corporate Social Responsibility (CSR) development, and workers` perception of fatigue and workability. A cross-sectional study was undertaken with 126 workers in the production areas of five Brazilian textile plants. The corporate executive officers and managers of each company provided their personal evaluations of CSR. Companies were divided into 2 groups (higher and lower) of CSR scores. Workers completed questionnaires on fatigue, workability and working conditions. Ergonomic job analysis showed similar results for working conditions, independent of their CSR score. Multivariate analysis models were developed for fatigue and workability, indicating that they are both associated to factors related to working conditions and individual workers` characteristics and life styles. Work organization, (what, how, when, where and for how long the work is done), is also an associated factor for fatigue. This study suggests that workers` opinions should be taken into greater consideration when companies develop their CSR programs, in particular for those relating to working conditions. Relevance to industry: This paper underlines the importance of considering working conditions and workers` opinions of them, work organization and individual workers` characteristics and life styles in order to restore or to maintain workability and to reduce fatigue, independently of how developed a company may be in the field of Corporate Social Responsibility. (C) 2010 Elsevier B.V. All rights reserved.

Study of the spectroscopic properties and first hyperpolarizabilities of disperse azo dyes derived from 2-amino-5-nitrothiazole

The solvatochromism and other spectroscopic and photophysical characteristics of four azo disperse dyes, derived from 2-amino-5-nitrothiazole, were evaluated and interpreted with the aid of experimental data and quantum mechanical calculations. For the non-substituted compound two conformers, E and Z, were proposed for the isolated molecules, being the second one considerably less stable. The optimization of these structures in combination with a SCRF methodology (IEFPCM, Simulating the molecules in a continuum dielectric with characteristics of methanol), suggests that the Z form is not stable in solution. This same behaviour is expected for the substituted compounds, which is corroborated by experimental data presented in previous investigations [A.E.H. Machado, L.M. Rodrigues, S. Gupta, A.M.F. Oliveira-Campos, A.M.S. Silva, J. Mol. Struct. 738 (2005) 239-245]. For the substituted compounds, two forms derived from E conformer (A and R) are possible. Quantum mechanical data suggest for the isolated molecules, that the low energy absorption hand of the E conformers involve at least two close electronic states. having the low-lying excited state a (1)(n,pi*) nature, and being the S-2 state attributed to a (1)(pi,pi*) transition. The data also suggest a small energy gap between the absorption peaks of A and B, related to the easy conversion between these forms. For the structures optimized in combination with the applied SCRF methodology, an states inversion is observed for the Substituted compounds, with a considerable diminish of the energy gap between A and B absorption peaks. The electronic spectra of these compounds are quite sensitive to changes in the solvent polarity. The positive solvatochromism is more evident in aprotic solvents, probably due to the polarization induced by the solute. These compounds do not fluoresce at 298 K, but present a small but perceptible fluorescence at 77 K, which seems to be favoured by the nature of the group in the 2 `-position of the phenyl ring. Moreover, such compounds present expressive values for first hyperpolarizability, which implies in good non-linear optics (NLO) responses and photoswitching capability. (C) 2008 Elsevier B.V. All rights reserved.

Fabrics of pre- and syntectonic granite plutons and chronology of shear zones in the Eastern Borborema Province, NE Brazil

We used the fabrics of two granite plutons and U/Pb (SHRIMP) zircon ages to constrain the tectonic evolution of the E-trending Patos shear zone (Borborema Province, NE Brazil). The pre-tectonic Teixeira batholith consists of an amphibole leucogranite locally with aegirine-augite. Zircons from a syenogranite yielded crystallization ages of 591 +/- 5 Ma. The batholith fabrics were determined by anisotropy of magnetic susceptibility (AMS) and mineral shape preferred orientation. The fabrics support pre-transcurrent batholith emplacement, as evidenced by: (i) magmatic/magnetic fabrics in low susceptibility (<0.35 mSI) leucogranites highly discordant to the regional host rock structure, and (ii) concordant magnetic fabrics restricted to high susceptibility (>1 mSI) corridors connected to shear zones branching off from Patos. One of these satellite shear zones controlled the syntectonic emplacement of the Serra Redonda pluton, which yields a crystallization age of 576 +/- 3 Ma. This late shearing event marks the peak regional deformation that, south of Patos, was coupled to crustal shortening nearly perpendicular to the shear belt. The chronology of the deformational events indicates that the major shear zones of the eastern Borborema are late structures active after the crustal blocks amalgamated. (C) 2007 Elsevier Ltd. All rights reserved.

Coating of Cotton Yarn with Poly(vinyl alcohol) and Poly(N-vinyl-2-pyrrolidone) Crosslinked via Ultraviolet Radiation

The coating of cotton fiber is used in the textile industry to increase the mechanical resistance of the yarn and their resistance to vibration, friction, impact, and elongation, which are some of the forces to which the yarn is subjected during the weaving process. The main objective of this study was to investigate the use of synthetic hydrophilic polymers, poly(vinyl alcohol) (PVA), and poly(N-vinyl-2-pyrrolidone) (PVP) to coat 100% cotton textile fiber, with the aim of giving the fiber temporary mechanical resistance. For the fixation of the polymer on the fiber, UV-C radiation was used as the crosslinking process. The influence of the crosslinking process was determined through tensile testing of the coated fibers. The results indicated that UV-C radiation increased the mechanical resistance of the yarn coated with PVP by up to 44% and the yarn coated with PVA by up to 67% compared with the pure cotton yarn, that is, without polymeric coating and crosslinking. This study is of great relevance, and it is important to consider that UV-C radiation dispenses with the use of chemical substances and prevents the generation of toxic waste at the end of the process. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 2560-2567, 2011

Decolourisation of real textile waste using electrochemical techniques: Effect of electrode composition

The present paper presents the study of the decolourisation of real textile effluent by constant current electrolysis in a flow-cell using a DSAO type material. The effect of using different anode materials (Ti/Ru0.3Ti0.7O2; Ti/Ir0.3Ti0.7O2; Ti/RuxSn1-xO2, where X = 0.1, 0.2 or 0.3) on the efficiency of colour removal is discussed. Attempts to perform galvanostatic oxidation (40 and 60 mA cm(-2)) on the as-received effluent demonstrate that colour removal and total organic carbon (TOC) removal are limited. In this case the greatest degree of colour removal is achieved when anode containing 90% SnO2 is used. If the conductivity of the effluent is increased by adding NaCl (0.1 mol L-1) appreciable colour/TOC removal is observed. The efficiencies of colour and TOC removal are discussed in terms of the energy per order (E-EO/kWhm(-3) order(-1)) and energy consumption (E-C/kW h kg(-1) TOC), respectively. Finally, the extent of colour removal is compared to consent levels presented in the literature. (C) 2008 Elsevier B.V. All rights reserved.