Acid Violet Research Articles

Superior photocatalytic activity of bimetallic Cd-Ag-ZnO for the degradation of azo dyes under UV light

Development of bimetallic semiconductor oxides with synergistic functions makes a significant advancement in catalytic technologies. This study addresses the preparation of a codoped bimetallic Cd-Ag-ZnO photocatalyst by solvothermal process and its characterization by x-ray diffraction (XRD), high-resolution scanning electron microscopy (HR-SEM), UV-Vis diffuse reflectance spectroscopy (DRS), energy dispersive spectroscopy (EDS), and photoluminescence spectroscopy (PL). XRD and EDS reveal the presence of Cd and Ag in the catalyst. HR-SEM images show plate-like structure of ZnO and the clusters of Cd and Ag on the surface ZnO. Cd-Ag-ZnO has increased absorption in the UV region. This bimetalic photocatalyst shows higher photocatalytic activity for the degradation of Acid Black 1 (AB 1) and Acid Violet 7 (AV 7) under UV light (365 nm) than pure ZnO and commercial TiO2-P25. Cd-Ag-ZnO was found to be stable and reusable without appreciable loss of catalytic activity up to three runs.

Self assembled TiO2 with 5-sulfosalicylic acid for improvement its surface properties and photodegradation activity of dye

A new photocatalyst, 5-sulfosalicylic acid grafted TiO2 (5-SA-TiO2) was synthesized by a chemical adsorption-based self assembly technique, and its surface properties were characterized by means of XRD, BET, IR, and UV–vis spectra. After self assembly, a stable, yellow complex was formed quickly on TiO2 surface and then its UV–vis wavelength response range was expanded from 375 nm to 600 nm. The band gap of 5-SA-TiO2 was 2.95 ev, less than that of TiO2 (3.10 ev). The crystalline structure of TiO2 could be adjusted by self assembly, i.e., anatase was transformed into brookite and the proportion between brookite and anatase was increased. After self assembly, the adsorption ratio of acid violet 43 (AV 43) was enhanced from 13.56% to 52.36%, because the crystallite size of both anatase and brookite was smaller, the surface areas were larger, and the affinity of between AV 43 and the catalyst was enhanced for the interactions between phenyl groups. The visible light degradation ratio of TiO2 was increased by self assembly from 36.60% to 97.01% and 82.65% removal of total organic carbon was achieved.

Fabrication of Acid Violet 34/Nickel Hydroxide Ultrathin Film and Its Electrocatalytic Performance for Glucose

AbstractThis article reports the fabrication of Acid Violet 34 (AV34)/nickel hydroxide nanosheets ultrathin film on the glassy carbon electrode (GCE) via the electrostatic layer‐by‐layer (LBL) technique, and its electrocatalytic oxidation for glucose was demonstrated. UV‐vis absorption and electrochemical impedance spectra indicate the uniform deposition of the LBL film, with a continuous and smooth film surface observed by SEM and AFM. The electrochemical performance of the ultrathin film was studied by cyclic voltammetry and chronoamperometry. The (AV34/Ni(OH)2)5 ultrathin film modified electrode displays a fast direct electron transfer attributed to the Ni2+/Ni3+ redox couple as well as remarkable electrocatalytic activity towards the oxidation of glucose. The linear response was obtained in the range 0.5–13.5 mM (R=0.9994) with a low detection limit (14 µM), high sensitivity (25.9 µA mM−1 cm−2), rapid response (less than 1 s) and excellent anti‐interference properties to the species including ascorbic acid (AA), uric acid (UA), acetamidophenol (AP) and structurally related sugars. Therefore, the AV34/Ni(OH)2 ultrathin film can be potentially used as a feasible electrochemical sensor for the determination of glucose.

DEGRADATION OF ACID VIOLET 7 AND REACTIVE BLACK 5 IN WATER BY ELECTRO-FENTON AND PHOTO ELECTRO-FENTON BY

The mineralization of solutions containing azo dyes Acid Violet 7 (AV7) and Reactive Black 5 (RB5) in aqueous solutions using electro-Fenton (EF) and Photo electro-Fenton (PEF) methods were determined. The electrochemical system includes a glassy carbon mesh electrode (cathode) with a concentric outer steel mesh as anode. The optimized parameters were: 0.01 mM of Fe2+ ions, and 250 mA of applied current at pH 3. All experiments were made at 35oC. The degradation was evaluated by color removal and total organic carbon (TOC) decay for solutions of 250 mg L-1 of both cases. The results indicate that the system achieves a degradation efficiency for both dyes proposed, being observed a quickly decolorization of the solutions and the complete transformation of organic compounds to carbon dioxide. The efficiency process and decoloration kinetic constant were evaluated. Generated carboxylic acids such oxalic, oxamic, citric and maleic were

Solar active fire clay based hetero-Fenton catalyst over a wide pH range for degradation of Acid Violet 7

Fe(III) immobilized fire clay (Fe-FC) was prepared using ferric nitrate by solid state dispersion method and this hetero-Fenton catalyst was applied for the degradation of Acid Violet 7 (AV 7) under natural sunlight. The 26% ferric nitrate loaded fire clay was found to be most efficient. The experimental conditions such as solution pH, H2O2 concentration for efficient degradation of AV 7 have been determined. Unlike Fenton catalyst, Fe-FC is photoactive over a wide pH range of 3–7. This catalyst was found to be stable and reusable. The GC-MS analysis of experimental solutions during irradiation revealed the formation of 2,8-diaminonaphthalene-1,3,6-triol, 8-aminonaphthalene-1,2,3,6-tetrol, 2-aminonaphthalene-1,3,6,8-tetrol and 2-aminobenzene-1,3-diol/5-aminonbenzene-1,3-diol/2-aminobenzene-1,4-diol as intermediates. The 26% ferric nitrate loaded fire clay was characterized by XRD, ICP-AES, BET surface area, FT-IR, SEM-EDS and UV-DRS studies.

Wastewater treatment by multi-stage batch adsorption and electrochemical regeneration

The removal and destruction of a tri-phenyl methane dye, Acid Violet 17 (AV17), from aqueous solution by adsorption and electrochemical regeneration was studied using a graphite intercalation compound (GIC) adsorbent. It was demonstrated that the adsor­bent could be regenerated by anodic oxidation of the adsorbed dye in a simple electro­chemical cell. The GIC adsorbent recovered its initial adsorption capacity after 40 to 60 min of treatment at a current density of 10 mA cm - 2 , corresponding to a charge of 12 to 18 C g - 1 of adsorbent. The charge passed is consistent with that expected for mine­rali­sation of the dye, suggesting that the dye was removed and destroyed with high charge efficiency. The energy cost of the regeneration was found to be around 120 J per g of adsorbent regenerated or 115 J per mg of the AV17 dye removed and destroyed. A model describing the process of wastewater treatment by multiple cycles of adsorption and electrochemical regeneration, based on adsorption isotherm data, has been deve­loped and validated. It was found that relatively modest improvements in the adsorption capacity of the adsorbent material could significantly improve the process performance.

Paraneuronal pseudobranchial neurosecretory cells in scorpion catfish Heteropneustes fossilis: an environment scanning electron microscope and transmission electron microscope study

AbstractYadav, L., Sengar, M., Zaccone, D. and Gopesh, A. 2011. Paraneuronal pseudobranchial neurosecretory cells in scorpion catfish Heteropneustes fossilis: an environment scanning electron microscope and transmission electron microscope study. —Acta Zoologica (Stockholm) 00: 1–8.Pseudobranchial neurosecretory system (PNS), found in the gill region of certain groups of teleosts, falls under the category of the ‘diffuse neuroendocrine system’ (DNES). The cells belonging to the system share morpho‐functional features with the paraneuronal cells observed in respiratory tract and airway surfaces of higher vertebrates. On the basis of the experimental observations, a role in condition of hypoxia has been recorded for this system. In an attempt to elucidate the ultrastructure of pseudobranchial neurosecretory cells, present investigation was undertaken using environment scanning electron microscope (ESEM) and TEM in an air‐breathing catfish, Heteropneustes fossilis. The external morphology of PNS under ESEM appeared as a mass of cells supplied with nerves and blood capillaries. Each cell mass is made up of numerous pear‐shaped neurosecretory cells, confirmed by neurosecretion‐specific acid violet stain. The TEM investigation of the cells revealed the presence of different sizes of dense‐cored vesicles in the cytoplasm, which was observed as granular cytoplasm under light microscope. Presence of large number of mitochondria in the cytoplasm confirmed active involvement of these cells in the physiology of fishes. Although lacuna prevails regarding the exact function of this system of fish, its probable role in hypoxic condition and surfacing behavior are speculated.

Application of Polyaniline Nano Composite for the Adsorption of Acid Dye from Aqueous Solutions

In this research, Polyaniline coated sawdust (Polyaniline nano composite) was synthesized via direct chemical polymerization and used as an adsorbent for the removal of acid dye (Acid Violet 49) from aqueous solutions. The effect of some important parameters such as pH, initial concentration of dye, contact time and temperature on the removal efficiency was investigated in batch adsorption system. The adsorption capacity of PAC was high (96.84 %) at a pH of 3‐4. The experimental data fitted well for pseudo second order model. Langmuir model is more appropriate to explain the nature of adsorption with high correlation coefficient. The Energy of activation from arrehenius plot suggested that the adsorption of AV49 onto PAC involves physisorption mechanism.

Analysis of Acid Alizarin Violet N Dye Removal Using Sugarcane Bagasse as Adsorbent

With the development of the textile industry, there has been a demand for dye removal from contaminated effluents. In recent years, attention has been directed toward various natural solid materials that are capable of removing pollutants from contaminated water at low cost. One such material is sugarcane bagasse. The aim of the present study was to evaluate adsorption of the dye Acid Violet Alizarin N with different concentrations of sugarcane bagasse and granulometry in agitated systems at different pH. The most promising data (achieved with pH 2.5) was analyzed with both Freundlich and Langmuir isotherms equations. The model that better fits dye adsorption interaction into sugarcane bagasse is Freundlich equation, and thus the multilayer model. Moreover, a smaller bagasse granulometry led to greater dye adsorption. The best treatment was achieved with a granulometry value lower than 0.21 mm at pH 2.50, in which the total removal was estimated at a concentration of 16.25 mg mL−1. Hence, sugarcane bagasse proves to be very attractive for dye removal from textile effluents.

Influence of operational parameters on photocatalytic degradation of a genotoxic azo dye Acid Violet 7 in aqueous ZnO suspensions

The photocatalytic degradation of a genotoxic azo dye Acid Violet 7 (AV 7) using ZnO as a photocatalyst in aqueous solution has been investigated under UV irradiation. The degradation is higher with UV/ZnO process than with UV/TiO 2-P25 process at pH 9. The effects of different parameters such as pH of the solution, amount of catalyst, initial dye concentration and the influence of cations, anions and oxidants on photodegradation of AV 7 were analyzed. Addition of oxidants except H 2O 2 has no significant effect on degradation. The degradation of AV 7 follows pseudo-first order kinetics according to the Langmuir–Hinshelwood model. The degradation of AV 7 has also been confirmed by COD and CV measurements.

Imaging of sialidase activity in rat brain sections by a highly sensitive fluorescent histochemical method

Sialidase (EC 3.2.1.18) removes sialic acid from sialoglycoconjugates. Since sialidase extracellularly applied to the rat hippocampus influences many neural functions, including synaptic plasticity and innervations of glutamatergic neurons, endogenous sialidase activities on the extracellular membrane surface could also affect neural functions. However, the distribution of sialidase activity in the brain remains unknown. To visualize extracellular sialidase activity on the membrane surface in the rat brain, acute brain slices were incubated with 5-bromo-4-chloroindol-3-yl-α-d-N-acetylneuraminic acid (X-Neu5Ac) and Fast Red Violet LB (FRV LB) at pH 7.3. After 1h, myelin-abundant regions showed intense fluorescence in the rat brain. Although the hippocampus showed weak fluorescence in the brain, mossy fiber terminals in the hippocampus showed relatively intense fluorescence. These fluorescence intensities were attenuated with a sialidase-specific inhibitor, 2,3-dehydro-2-deoxy-N-acetylneuraminic acid (DANA, 1mM). Additionally, the fluorescence intensities caused by X-Neu5Ac and FRV LB were correlated with the sialidase activity measured with 4-methylumbelliferyl-α-d-N-acetylneuraminic acid (4MU-Neu5Ac), a classical substrate for quantitative measurement of sialidase activity, in each brain region. Therefore, staining with X-Neu5Ac and FRV LB is specific for sialidase and useful for quantitative analysis of sialidase activities. The results suggest that white matter of the rat brain has intense sialidase activity.

Green chemistry approach for the synthesis of PbSnO3

We report synthesis of light-induced heterogeneous photocatalyst PbSnO3 by green chemistry approach, using mechanochemical method. The synthesized catalyst was characterized physically by various analytical investigative techniques like UV-DRS, FTIR, XRD, SEM, EDAX, TEM, and TG. The product corresponded to average particle size of 100 nm by TEM images. Photocatalytic activity of PbSnO3 was studied by photodegradation of Methyl blue, Indigo carmine, and Acid violet dyes under sunlight. The results indicate that the sunlight stimulates a photochemical reaction and successfully complete mineralization of Methyl blue, Indigo carmine, and Acid violet dyes. Antimicrobial activity shows that PbSnO3 photocatalyst was found non-toxic to the environment.

Simultaneous decolorization of binary mixture of Reactive Yellow and Acid Violet from wastewaters by electrocoagulation

Dyes are common pollutants in a large variety of industrial wastewaters, and the treatment of these wastes has been extensively studied by coagulation. For the removal of pollutants from the wastewaters, different techniques have been used and electrocougulation is one of the widely used methods. This process is very effective in removing organic pollutants including dyestuff wastewater. The purposes of this study were to investigate the effects of the operating parameters, such as current density, electrolyte concentration, dyestuff concentration, and pH of solution on decolorization and chemical oxygen demand (COD) removal of wastewater containing two different dyes in same solution by direct current electrocoagulation. The amount of dye removed was found by application of first derivative spectrophotometric method to the synthetic dye mixtures. In this work synthetic dye mixture which include C.I. Reactive Yellow 145 (RY145) and C.I. Acid Violet 90 (AV 90) were used for electrocougulation (EC) process with iron electrodes. In the presence of both dye molecules, the optimum pH was found to be 4, optimum NaCI concentration was 3000 mg/L and optimum current density was 5.56 mA/cm2. Under these conditions in the case of 100 mg/L-1 each dye concentration at 20 degrees C and 3 cm interelectro distance the color removal efficiency was reached 97.7% for AV 90 and 97.1% for RY145 in 10 minutes time duration. Dye concentration dependent highest COD removal efficiency was measured as 82% around at 100 mg/L dye concentration.

Continuous water treatment by adsorption and electrochemical regeneration

This study describes a process for water treatment by continuous adsorption and electrochemical regeneration using an air-lift reactor. The process is based on the adsorption of dissolved organic pollutants onto an adsorbent material (a graphite intercalation compound, Nyex ®1000) and subsequent electrochemical regeneration of the adsorbent leading to oxidation of the adsorbed pollutant. Batch experiments were carried out to determine the adsorption kinetics and equilibrium isotherm for adsorption of a sample contaminant, the organic dye Acid Violet 17. The adsorbent circulation rate, the residence time distribution (RTD) of the reactor, and treatment by continuous adsorption and electrochemical regeneration were studied to investigate the process performance. The RTD behaviour could be approximated as a continuously stirred tank. It was found that greater than 98% removal could be achieved for continuous treatment by adsorption and electrochemical regeneration for feed concentrations of up to 300 mg L −1. A steady state model has been developed for the process performance, assuming full regeneration of the adsorbent in the electrochemical cell. Experimental data and modelled predictions (using parameters for the adsorbent circulation rate, adsorption kinetics and isotherm obtained experimentally) of the dye removal achieved were found to be in good agreement.

Electrodeposited Crack-Free CdS Thin Films Using Organic Solvents

Crack-free CdS thin films have been electrodeposited on conductive glass substrate by CdCl2 and S powder in dimethylformamide (DMF) and mixed organic solvents with appropriate volume ratio at temperatures lower than 100°C. The effects of solvents on the cracks and the photovoltaic property and catalytic property of CdS thin film are investigated. The results show that the crack-free CdS thin films have higher photoluminescence (PL) emission intensity and better photoelectrichemistry and photocatalytic activities for degradation organic dyes of Fuchsin acid, phenol red and crystal violet than thin films with cracks.

Removal of Acid Violet 17 from Aqueous Solutions by Adsorption onto Activated Carbon Prepared from Pistachio Nut Shell

Adsorbents prepared from pistachio nut shell, an agricultural waste biomass, were successfully used to remove Acid Violet 17 from an aqueous solution. The activated carbons PNS1, PNS2, and PNS3 were characterized by scanning electron microscope (SEM), Fourier Transform – Infra Red spectroscopy (FTIR) and (BET). The effect of pH, adsorbent dosage, and temperature on dye removal was studied. Maximum color removal was observed at pH 2. The adsorption increased with the increase in adsorbent dosage. As the adsorption capacity increased with the increase in temperature, the process was concluded to be endothermic. The experimental data were analyzed by the Langmuir and Freundlich isotherm models of adsorption. Equilibrium data fitted well with the Langmuir model. The rates of adsorption confirmed the pseudo-second order kinetics with good correlation values. The results indicated that the activated carbon prepared from pistachio nut shell can be effectively used for the removal of Acid Violet 17 from aqueous solution.

Acid violet 6B as a novel corrosion inhibitor for cold rolled steel in hydrochloric acid solution

The inhibition effect of acid violet 6B (AV6B) on the corrosion of cold rolled steel (CRS) in 1.0–5.0 M HCl solution was studied for the first time by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) methods. The results show that AV6B is a very good inhibitor in 1.0 M HCl, and the adsorption of AV6B on CRS surface obeys Langmuir adsorption isotherm. Polarization curves reveal that AV6B behaves as a mixed-type inhibitor. EIS spectra exhibit one capacitive loop and confirm the inhibitive ability. Effects of immersion time and acid concentration on inhibition performance were also discussed.

Encapsulation of hydrophilic dyes with polystyrene using double miniemulsion technique

AbstractHydrophilic dyes, reactive brilliant red K‐2BP (C.I. Reactive red 24), acid fuchsin (C.I. Acid violet 19), and cationic brilliant red 5GN (C.I. Basic red 14), have been encapsulated into hydrophobic polystyrene (PS) latex particles using double miniemulsion technique. In this method, the water droplets containing dyes were first suspended in octane/styrene phase using lipophilic emulsifiers to form a primary miniemulsion. This miniemulsion was further dispersed in water and miniemulsified, followed by polymerization at high temperature to form dye/PS core‐shell colorants. Experimental results show that this technique can cause as high as 80% of encapsulation efficiency for all three dyes, and obviously improve the water‐proofing property and photostability of organic dyes. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Removal of acid dye (violet 54) and adsorption kinetics model of using musa spp. waste: A low-cost natural sorbent material

Experimental studies and biosorption kinetics of an intraparticle diffusion model for acid dye removal using a musa spp. waste sorbent were carried out to find the removal effects and dynamics of various operating parameters, such as initial dye concentration, sorbent dosage, pH and temperature. Experimental data were modeled with kinetic models and two biosorption isotherms of intraparticle diffusion models as well as the physiochemical data of sorbents characterized by SEM and FT-IR. Kinetic studies showed that the sorption process follows second-order rate kinetics with an average rate constant of 0.0018675 (g/mg·min). Thermodynamic parameters such as entropy of biosorption (ΔS0), enthalpy of biosorption (ΔH0) and Gibbs free energy of biosorption (ΔG0) were obtained and analyzed. Sorbent, musa spp. waste (banana peel) was characterized by FTIR and SEM. The results showed that musa spp. waste can be considered as potential sorbent for the sorption of acid violet 54 from dilute aqueous solution.

Acid dyeing of linen fabrics using gemini cationic surfactants

Three novel gemini cationic surfactants were synthesized and their structures confirmed by 1H-NMR analysis. The interaction of C.I. Acid Violet 1 dye with gemini cationic surfactants in aqueous solution was investigated by UV-Vis spectroscopy at the λmax of the acid dye–cationic surfactants. The dyeing behavior of the acid dye–cationic surfactants and their fastness properties were investigated. It was observed that the aggregation of surfactant and dye takes place at low concentrations far below 1 g/l. The further addition of surfactant resulted in an absorption spectrum characteristic of fully saturated acid dye in the cases of the 16–2-16 and 16–3-16 surfactants at 1 g/l, and in the case of the 10–3-10 surfactant 1.2 g/l. The results also showed bathochromic shifts for the acid dye followed by significant increase in the λmax at the optimum concentrations of these surfactants. The dyeability of linen fabric with acid dye–gemini cationic surfactants increased as the electrostatic interactions between the surfactant head groups and the anionic nature of the acid dye increased, but the hydrophobic interactions decreased at higher temperature. The fastness to washing and rubbing improved by increasing the alkyl length of the gemini surfactants from 10–3-10 to 16–2-16 and 16–3-16, although the spacer length had no effect.