Direct Sky Blue 5B Research Articles

Modification of coal fly ash and its use as low-cost adsorbent for the removal of directive, acid and reactive dyes

Directive, acid and reactive dyes are the carcinogenic dyes which have complex structures and difficult to remove from the industrial wastewater. In this study, coal fly ash (CFA) was modified with HCl and NaOH solution and used for the removal of direct fast scarlet 4BS, direct sky blue 5B, acid navy blue R, and reactive turquoise blue KN-G dyes. Laboratory experiments were carried out to analyze the performance of modified coal fly ash (MCFA) to check the removal efficiency and adsorption capacity of dyes. The maximum removal efficiency of direct fast scarlet 4BS and direct sky blue 5B were recorded 96.03% and 93.820%, respectively using 0.05 g adsorbent dosage at 100 mg/L initial concentration. The results of MCFA were compared with carbon black, chitosan, starch, zeolite and unmodified coal fly ash (UMCFA) at lower dosage 0.05 g and higher dosage 0.4 g. Adsorption isotherm were analyzed by Langmuir and Freundlich model by different dyes concentrations, the result stated that Freundlich and Langmuir model (±0.9918, ±0.9974) was fitted by chemisorption and physisorption methods for all four dyes. Adsorption kinetic were also determined by Pseudo-first-order and Pseudo-second-order at different contact times with dye molecules and adsorbent active sites, and the results showed that the adsorption behaviors of all four dyes were described better by pseudo-second-order kinetics than pseudo-first-order kinetics. Recommended dosage of modified fly ash is between 10 ‱ to 20 ‱ for simulated textile industrial waste water and regeneration temperature is 300 ℃.

Ultrafast and efficient removal of anionic dyes from wastewater by polyethyleneimine-modified silica nanoparticles

Trace anionic dyes in wastewater are difficult to be rapidly and efficiently removed because they are completely soluble and poorly biodegradable. Herein, a facile and environmentally friendly adsorbent was fabricated via the surface functioned SiO2 with abundant amine groups of polyethyleneimine (PEI). The structural characterization indicated that PEI was successfully immobilized on the SiO2 surface. The adsorption performance of SiO2-PEI was evaluated using acid orange II (AOII) as model pollutant. The adsorption of AOII on SiO2-PEI displayed high removal rates in the pH range of 2.0–9.0, and exhibited ultrafast removal (99.1% removal rate at 10 min). The adsorption behavior fitted well with the Langmuir isotherm and pseudo-second-order kinetic model, and the maximum uptake capability of AOII was higher than 705.3 mg/g. The excellent adsorption capacity of AOII on SiO2-PEI mainly relied on the electrostatic attraction between the sulfonic acid group of AOII and amine group of PEI in the adsorption process. Additionally, other anionic dyes like acid fuchsin and direct sky blue 5B could also be fast and efficiently removed by SiO2-PEI. This work is expected to open new possibilities for the ultrafast removal of anionic dye pollutants.

Adsorptive removal of Cu2+ and direct sky blue 5B from aqueous solutions by acid treated tea waste—application of response surface methodology

Adsorptive removal of Cu2+ and direct sky blue 5B from aqueous solutions by acid treated tea waste—application of response surface methodology

A new graphene bottom ash geopolymeric composite for photocatalytic H2 production and degradation of dyeing wastewater

A novel Mn2+-doped and CuO loaded graphene bottom ash-based geopolymeric (Mn2+-CuO/GBAG) composite was firstly synthesized by a four-step experiment of alkaline activated geopolymerization, ion exchange, co-impregnation and calcinations. The composite was employed as the photocatalyst for production of hydrogen by solar photo-reduction and degradation of dye by photo-oxidation. XRD, XPS and N2 adsorption-desorption equilibrium isotherms results revealed that Mn2+ ions implant into the lattice of CuO, and the CuO in the form of tenorite with average particle size of about 20 nm dispersed on the surface or inserted micro and mesoporous channels. The Mn2+-15CuO/GBAG composite exhibited the highest H2 yield of 2853.7 μmol g−1. It was found that the activity of photocatalytic reduction for hydrogen production was proportional to the contents of the Mn2+ doping and CuO loading, and inverse proportional to the intensity of photoluminescence due to the enhancement of separation efficiency of photogenerated electron–hole pairs. The Mn2+-15CuO/GBAG composite showed the highest photocatalytic degradation activity of 100% for direct sky blue 5B dye, and the degradation reaction fitted the first-order kinetics. A probable mechanism of photocatalytic reduction and oxidation was proposed in the paper.

Preparation and Adsorption Properties of Fe/Chitosan/Fly Ash Composite

Fly ash (FA), a kind of fine-powder solid waste, was utilized to prepare a novel Fe/chitosan/FA composite (Fe/CTS/FA) by the calcination and solution reaction with chitosan (CTS) and ferric iron. In combination with the adsorption for reactive turquoise blue KN-G (RTB KN-G) and direct sky blue 5B (DSB 5B) dyes, the main conditions of preparation and adsorption of Fe/CTS/FA were investigated. The composite was characterized with SEM, EDS, particle-size distribution and N2-gas adsorption-desorption technology. The results show that: (1) Fe/CTS/FA prepared by calcining FA at 500°C and further mixing reaction with CTS and FeCl3⋅6H2O solution according to the mass ratio of m(FA):m(CTS):m(Fe)=10:1:0.34 has excellent adsorption properties. The amount of adsorption is mainly affected by solution pH and reaches the equilibrium in 60 min for high-concentration RTB KN-G and DSB 5B dye wastewater with adsorption capacities of 892.95 mg/g and 615.65 mg/g, which are 16.28 and 32.56 times larger than those of FA, respectively. (2) The characterization results of Fe/CTS/FA indicate that CTS and iron hydroxides have been successfully loaded on FA. The surface morphology of Fe/CTS/FA is significantly changed, and the particle-size distribution is obviously smaller than that of FA.

Novel nano photocatalyst for the degradation of sky blue 5b textile dye

A new Nano photocatalyst, CuO-Al2O3-ZrO2-TiO2 was synthesized by co-precipitation for the removal of textile dye under ultra violet and direct sunlight. The synthesized catalyst was characterized by using X-rays diffraction, X-rays fluorescent, thermo gravimetric analysis, DRS, scanning electron microscopy and EDX. The dopants reduced the recombination of ecb- and hvb+ and decreased the band gap of TiO2 from 3.25eV to 1.38eV. Due to this change, light absorption increased under sun light. The photocatalytic activity of the degraded samples of direct sky blue5B was analyzed by UV/Visible spectrophotometer. The results showed an enhanced photocatalytic activity under sun light about 96.8% in time duration of 100 min. It was also found that the degraded samples followed the pseudo first order kinetic model. This technique is cheap, easy and novel for the treatment of textile industrial waste water. In present energy crises of the world it can replace old expensive technologies. Key words: Nano photocatalysis, direct sky blue5B, photocatalytic degradation, textile dyes, nano catalytic characterization.

Post-treatment effect on morphology and performance of polyurethane-based hollow fiber membranes through melt-spinning method

Polyurethane-based (PU-based) hollow fiber membranes were fabricated by melt-spinning method. The influence of hot-air treatment conditions including theoretical draw ratio, temperature and time on morphology and performance of membranes were investigated. The results showed that the maximum mean pore size and pure water flux were obtained as the theoretical draw ratio and treatment temperature reached to 2 and 70°C, respectively. The deformation-recovery was mainly governed by the treatment temperature in comparison with theoretical draw ratio when the membrane was treated in hot air. The least treatment time that obtained the best pure water flux was 30min. However, when the membrane treated in stress free conditions, the pore sizes on membrane outer surface were shrunk and the pure water flux decreased with the increment of heat treatment temperature. Moreover, a dense and smooth outer surface with thick skin layer formed as treatment temperature reached at 150°C. The PU-based hollow fiber membranes which treated at the optimum treatment conditions were used to the microfiltration test of the Direct Sky Blue 5B dye wastewater and the removal rate of Direct Sky Blue 5B particles was higher than 94.57%.

Photocatalytic degradation of an azo dye Direct Sky Blue 5B in water: a comparative study using nanostructured ITO, ZnO, and ZnO/ITO thin films

abstract Indium tin oxide (ITO), zinc oxide (ZnO), and ZnO/ITO interface composite thin films were deposited on glass substrates using electron-beam evaporation and the sol–gel method. The porous 2%PEG–ZnO/ITO thin films were also have been prepared using the polyethylene glycol (PEG) as an organic template. The samples were characterized by UV–Vis spectroscopy, X-ray diffraction, and scanning electron microscopy techniques. The photocatalytic degradation of Direct Sky Blue 5B in an aqueous solution, as a model compound, was investigated using different catalysts in an attempt to compare the decomposition reaction rates. The effects of various experimental parameters, such as an initial concentration of the Direct Sky Blue 5B (5–10 mg/l), pH of the solution (4–9), and catalystic nature and its microstructure, were systematically studied to achieve the maximum degradation efficiency. The results obtained were fitted with the Langmuir–Hinshelwood model to study the degradation kinetics and were discussed in...

ZnO/ITO interface nanostructure films for the photocatalytic degradation of a textile dye

We have produced zinc oxide (ZnO) photocatalyst nanostructure films by the deposition of ZnO onto indium tin oxide (ITO) glass substrates. A polyethylene glycol (PEG) aided sol–gel route using zinc acetate, 2-methoxyethanol and monoethanolamine, followed by spin coating and heat treatment, was utilized to form these photocatalyst films. The obtained interface nanostructure films were characterized with X-ray diffraction, scanning electron microscopy and UV–Vis spectroscopy. The photocatalytic activity of the films were also investigated using Direct Sky Blue 5B (C. I. Direct Blue 15) as a model organic compound under UV light irradiation. The influence of operating parameters, including the pH of the solution and the number of ZnO layers on Direct Sky Blue 5B degradation, were examined. An interesting decolorization performance was observed in the ZnO/ITO thin films produced using 2 % PEG.

A novel single-step synthesis of N-doped TiO 2 via a sonochemical method

A novel single-step synthetic method for the preparation of anatase N-doped TiO 2 nanocrystalline at low temperature has been devoleped. The N-doped anatase TiO 2 nanoparticles were synthesized by sonication of the solution of tetraisopropyl titanium and urea in water and isopropyl alcohol at 80 °C for 150 min. The as-prepared sample was characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and UV–vis absorption spectrum. The product structure depends on the reaction temperature and reaction time. The photocatalytic activity of the as-prepared photocatalyst was evaluated via the photodegradation of an azo dye direct sky blue 5B. The results show that the N-doped TiO 2 nanocrystalline prepared via sonication exhibit an excellent photocatalytic activity under UV light and simulated sunlight.

Degradation of azo dye direct sky blue 5B by sonication combined with zero-valent iron

The degradation of azo dye direct sky blue 5B by sonication combined with zero-valent iron (US-Fe 0)was investigated and an evident synergistic effect was observed. The synergetic effect is mainly due to the increase of OH radical concentration from Fenton’s reaction. The OH radical concentrations in sole sonication and US-Fe 0 process were detected by using terephthalic acid as a fluorescent probe and found that OH radicals were generated continuously during sonication and the production of OH radicals in US-Fe 0 process was much higher than that in sole sonication. The degradation of direct sky blue 5B followed a pseudo-first-order kinetics and the degradation rate constants were found to be 0.0206 and 0.169 min −1 with sole sonication and US-Fe 0 process respectively. It was also found that the degradation ratio of direct sky blue 5B increased with the increase of zero-valent iron dosage and decrease of pH value of the dye aqueous solution. The degradation mechanism of direct sky blue 5B with US-Fe 0 process was discussed by the changes of UV–Vis spectrogram of the dye during degradation. The dramatic changes of UV spectra showed a disappearance of both azo and aromatic groups during the degradation.

Decoloration of three azo dyes in water by photocatalysis of Fe (III)–oxalate complexes/H 2O 2 in the presence of inorganic salts

Coloration of textiles is improved by inorganic salts, which increase pollution load on dyehouse effluent in general. In this paper, four inorganic salts including sodium chloride, sodium sulphate, sodium nitrate and potassium chloride were used for investigating their effects on photocatalytic decoloration of three azo dyes, Mordant Black PV, Reactive Blue MS and Direct Sky Blue 5B in water based on Fe (III)–oxalate complexes/H 2O 2 system in a specially designed photoreactor. Also the photocatalytic degradation and mineralization of the dyes were examined by UV–vis spectrum and TOC measurements. The results indicate that photocatalytic decoloration of the dyes is significantly limited in the presence of salts. Increasing concentration of inorganic salts in water can give rise to reduced decoloration efficiency and kinetic reaction constants of the dyes. Sodium chloride and potassium chloride exhibit stronger inhabiting power on photocatalytic decoloration and degradation than sodium sulphate and sodium nitrate under the same reaction condition.

DYEING OF CELLULOSE BY BENZOPURPURINE 4B AND DIRECT SKY BLUE 5B IN AQUEOUS SODIUM ALGINATE SOLUTION

Dyeing of cotton and cellophane by Benzopurpurine 4B (C. I. Direct Red 2) and Direct Sky Blue 5B (C. I. Direct Blue 15) in aqueous sodium alginate solution has been studied. The effects of the carboxyl group contained in the cellulose and of the dye structure on the dye adsorption equilibrium to cellulose in aqueous sodium alginate solution have been reexamined based on the previously described multiple equilibrium model. The affinities of the dyes, which were calculated with an assumed ionization degree of the carboxyl group in the cellulose and valencies of the dyes were nearly constant under the present dyeing conditions. These results confirm the previous conclusion that the dyes are concentrated into the internal solution of cellulose due to the presence of sodium alginate in the bulk solution.

Studies on Pyrodextrinization of Corn Starch Part II. A Scanning Electron Microscopic Study

AbstractA scanning electron microscopic (SEM) study of dextrin prepared in the range of 120°C to 210°C revealed cracks on the surface of some granules and burst granules indicating a gush of hot inner gas and the heat expansion on the surface. And, fused granules appeared in the dextrin prepared at higher temperature (230°C). Furthermore, the damaged granules in the dextrin were determined by rapid differential‐staining method with Safranine OK 70: 100 and Direct Sky Blue 5B. The staining affinities of the granules have no relation to cracks, cavities, pin‐holes and other physical appearances observed by SEM.