safranin-O Dye Research Articles

Evaluation of the Physicochemical Characteristics and Adsorption Efficiency of Activated Carbons Derived from Banana Peels and Coconut Shell: A Comparative Study

The physicochemical characteristics and adsorption efficiencies of the activated carbons prepared from banana peels and coconut shell were evaluated using physical activation method. Phosphoric acid (H₃PO₄) was used as an activating agent. The physicochemical characteristics (IAN, pH, attrition, porosity, titratable surface functional groups, bulk density, moisture and ash content) were determined using standard analytical procedures and the adsorption efficiencies were evaluated through batch adsorption studies using aqueous solution of Safranin-O dye as adsorbate. The results revealed that the physicochemical parameters played a vital role in the adsorption performance of the two adsorbents and contributed majorly to their differences in the adsorption efficiency. The batch adsorption process was carried out by varying initial dye concentration, pH, adsorbent dosage and contact time. CSAC was found to be better adsorbent than BPAC as it recorded higher percentage of Safranin-O dye removal under all the experimental conditions.

Evaluation and characterization of Egyptian ferruginous kaolinite as adsorbent and heterogeneous catalyst for effective removal of safranin-O cationic dye from water

Raw ferruginous kaolinite was characterized as promising materials in the removal of safranin-O dye from water in comparison with fresh kaolinite. The studied samples were characterized utilizing different techniques including XRF, XRD, SEM, and optical polarized microscope. The sample appeared as highly crystalline kaolinite of structural iron impurities and 120-nm average crystallite size. This gives the sample large crystallite size, low basal spacing, and enhanced adsorption capacity and giving it catalytic properties in the advanced oxidation reactions (Fenton’s oxidation, photocatalytic degradation, and photo-Fenton’s oxidation). The kinetic modeling reflected strong agreement with the pseudo-first-order kinetic model of more physical nature and attending the equilibrium after 270 min. The equilibrium study revealed heterogeneous uptake of safranin-O dye by ferruginous kaolinite in multilayer form with experimental qmax of 59.3 mg/g. Moreover, the sample displayed promising catalytic properties and effective oxidation properties in photocatalytic, Fenton’s, and photo-Fenton’s oxidation processes for the removal of safranin-O dye. Ferruginous kaolinite achieved the best oxidation results by the photo-Fenton process in the presence of 6 mL of the H2O2 at pH 8.

Improving of Safranin-O Characteristics as a Photosynthesis Through Adjusting pH Value in Dye-sensitized Solar Cells

In this paper, Safranin-O as a viable photosensitizer in dye-sensitized solar cells (DSSCs) is introduced and its photosensitising properties respect to various concentrations and solvent is optimized. Moreover, the molecular structure of Safranin-O using density functional theory with the B3YLP method is computed in order to determine the Safranin-O energy bandgap in HOMO, LUMO and DOS. In the next level, the optimized Safranin-O dye is implemented as the photosensitizer within a DSSC and its functionalities investigated using the I-V curve as the figure of merit. In order to fully comprehend the absorption mechanisms within the solar cell structure, the full layer stack is simulated based on the finite element method (FEM) which shows that Safranin-O coated TiO2 nanoparticles are capable of sustaining whispering gallery modes which further improves the optical absorption of the proposed structure.

Equilibrium, Kinetics and Thermodynamic Studies on the Removal of Safranin-O from Waste Water Using Activated Carbons Derived from Coconut Shell and Pineapple Peel

This work is aimed at comparing the adsorption capacities of the activated carbons derived from coconut shell and pineapple peels using Safranin-O as adsorbate. Physical activation method was employed to generate the activated carbons using phosphoric acid (H3 PO4) as activating agent. Batch adsorption experiment was employed for the adsorption process. Effects of experimental factors such as adsorbent dosage, inititial Safranin-O dye concentration, pH and contact time on the adsorption process were examined. The results showed that the adsorption capacities were dependent on these factors. Langmuir and Freundlich Isotherms Models were applied and the results indicated that both models fitted well with the observed data but Freundlich Model fitted better. Pseudo first and second order kinetic models were also applied to describe the adsorption kinetic, only the second order model fitted well with the experimental data. Thermodynamic parameters such as enthalpy change (∆H), Gibb’s free energy change (∆G) and entropy change (∆S) were evaluated using Van’t Hoff equations, both the free energy and enthalpy change were found to be negative indicating the feasibility and exorthermic nature of the adsorption process respectively. While the entropy change was found to be positive indicating that the degree of dispersion in the adsorption process increased with increase in temperature, Based on the results obtained from this research work, the activated carbon derived from coconut shell (CSAC) showed better adsorbent when compared with the one derived from pineapple peel (PPAC) as CSAC recorded the highest percentage of Safranin-O dye removal from waste water under all the experimental conditions.

Simple Spectrophotometric Method for Estimation of Drugs and Pharmaceuticals by using Chloramine-T and Safranin-O Dye Couple

Simple Spectrophotometric Method for Estimation of Drugs and Pharmaceuticals by using Chloramine-T and Safranin-O Dye Couple

Adsorption of safranin-O dye by peanut shell-based polyurethane type foam

The adsorption of safranin-O dye was performed in batch and continuous column sysytems by polyurethane-type rigid foam produced from peanut shell. In batch system, effects of contact time, initial dye concentration, solution pH and temperature on the adsorption were investigated. In column system, solution flow rate and initial dye concentration effect were studied. Under conditions studied, the adsorption of safranin-O was 95-99% for batch system, and 93-99% for column system. Adsorption isotherm best followed the Langmuir model (R2 = 0.986). Adsorption kinetics was in consistent with best the pseudo-second order model (R2values ≥ 0.998). Adsorption was of sponteneous nature and in favor of increasing temperature (i.e. endothermic nature). For example, when the temperature was increased from 20 to 60°C, standard Gibbs free energy change (ΔG°) dereased regularitly from -5303 to -8170 J mol-1. The values of standard enthalpy (ΔH°) and standard entropy (ΔS°) were estimated as 13.35 kJ mol-1 and 0.64 kJ mol-1 K-1, respectively. Moreover, FTIR and SEM analyses were done, and the results were interpreated in detail.

Efficient photocatalytic removal of safarnin-O dye pollutants from water under sunlight using synthetic bentonite/polyaniline@Ni2O3 photocatalyst of enhanced properties.

This study involves a synthesis of bentonite/polyaniline composite (BE/PANI) of enhanced physicochemical properties as catalyst support for Ni2O3 photocatalyst. The change in the structural properties, morphological features, and optical behavior was addressed utilizing several analytic techniques. The characterization results reflected considerable enhancement in the specific surface area after the integration between bentonite and polyaniline (127m2/g) and after loading of the campsite by Ni2O3 forming bentonite/polyaniline@Ni2O3 composite (BE/PANI@Ni2O3) (231m2/g). Additionally, the band gap energy was reduced to 2.41eV and 1.61eV for BE/PANI and BE/PANI@Ni2O3, respectively, as compared to that of 3.4eV for pure Ni2O3. The photocatalytic removal of safranin-O dye under sunlight exposure using BE/PANI@Ni2O3 as catalyst revealed great enhancement in the removal percentages by 63%, 75%, and 72.35% higher than bentonite, polyaniline, and Ni2O3, respectively. Five milligrams per liter of safranin-O dye can be completely removed from 100ml water using 0.05g of the composite after 90min. The catalyst also was applied effectively in the removal of safranin-O dye from raw water samples as a realistic application of the synthetic composite. Synthetic BE/PANI@Ni2O3 as photocatalyst showed very high stability and can be used seven times as photocatalytic at amazing removal percentages.

Various methods for removal of dyes from industrial effluents - a review

Objectives: To explore most suitable and efficient method for the removal of dyes from textile effluent. Methods/ Statistical Analysis: In this paper, scattered information of research work carried out by many researchers related to various methods for the removal of cationic dyes especially Rhodamine-B, Methylene Blue, Crystal Violet, Malachite Green and Safranin-O dye present in textile effluent have been compiled and compared to find out cheap and effective method by calculating their percentage removal. Findings/Recommendations: It has been found that among all the methods reported so far, Adsorption process show promising results and overcomes almost all the demerits of otherwise efficient methods like advanced oxidation and electro coagulation etc. in terms of high cost and sludge problem. So ,the use of natural adsorbents and agricultural/industrial waste materials especially modified flyash, red mud ,activated rice husk , surfactant modified alumina, bentonite clay as adsorbents is recommended for the removal of cationic dyes since they are of less cost/ no cost, easily available and have great affinity for dyes. Moreover, agriculture/industrial waste often poses a disposal problem. So, their use (after chemical treatment) as adsorbent is environmental friendly. Applications/Improvements: This review paper would be helpful to find the most promising method for the removal of cationic dyes from the textile effluent considering the merits and demerits of each method. Much work has been done to explore the most effective and cheap method for the removal of dyes recently but not under the range of operating conditions. In future, more methods need to be explored to study and check removal of dyes from real textile effluent at the industrial level as the dye effluent also contains other harmful pollutants. Attention is to be paid to develop cheaper and more efficient adsorbents from the agriculture/ industrial waste with some modification which would be cost effective. Moreover, management of exhausted adsorbents is also to be taken care of. Keywords: Biodegradable, Biosorbent, Cationic Dyes, Carcinogenic, Solvent Extraction and Fenton’s Reagent

Synthesis of Mn2O3 nanoparticles using choline chloride-ethylene glycol deep eutectic solvent: A green solvent

ABSTRACTMn2O3 particles of nano scale were fabricated using deep eutectic solvent of choline chloride-ethylene glycol. Deep Eutectic Solvents (DES) is a new family of ionic fluids. Mn2O3 was fabricated by varying the amount of water in DES. With variation in amount of water, size and shape of particles also varied. Mn2O3 prepared in absence of water is of orthorhombic crystal system and those prepared in presence of water are of tetrahedral crystal system. Photocatalytic property of these Mn2O3 particles was also demonstrated using safranin-O dye. Rate constant calculated by plotting log A vs Time follow: k0.5 ml water > k0.0 ml water > k1 ml water.

Synthesis of Mesoporous Graphite Functionalized by Nitrogen for Efficient Removal of Safranin Dye Utilizing Rice Husk Ash; Equilibrium Studies and Response Surface Optimization

Mesoporous graphitic carbon (PG) was successfully synthesized from alkaline treated rice husk ash through chemical activation by phosphoric acid at 800 °C for 1 h and modified by nitric acid to produce porous graphite with nitrogen functional group (N.PG). The morphology and structure of N.PGC were characterized by XRD, SEM and Micromeritics ASAP2010 analyzer at 77 K. N.PG was applied as an adsorbent material for safranin-O dye from aqueous solution. The removal of safranin dye by the synthetic porous graphite with nitrogen functional groups shows higher capacity as compared to the pure phase of porous graphite. The adsorption process was investigated as a function of contact time, adsorbent mass, pH, initial dye concentration and ionic strength. The kinetic studies revealed that the adsorption equilibrium was reached after 480 min and the obtained data well fitted with the pseudo-second-order kinetic model and Elovich kinetic model. The equilibrium adsorption isotherm of safranin by the synthetic N.PG was described with Langmuir isotherm model, and the calculated qmax is 20.66 mg/g. The removal process is highly dependent on the pH value of the solution, and the optimum pH for maximum removal of safranin-O is pH 6. The response surface methodology in conjunction with the central composite rotatable design was used to optimize the sorption process. From the second order polynomial model, the predicted optimum conditions for maximum removal of safranin (100%) are 365 min contact time, 0.3 g dose, 5 g/l NaCl and pH 6 at initial concentration 127 mg/l.

Titania coated silica nanocomposite prepared via encapsulation method for the degradation of Safranin-O dye from aqueous solution: Optimization using statistical design

Titania coated silica nanoparticles, which were synthesized via nanoparticle encapsulation route, are employed to degrade safranin-O dye from aqueous solution under UV light irradiation and were characterized by FT-IR, XRD, FESEM, N2 adsorption-desorption method and Zeta potential measurement. The results showed that the nanoparticles have a core-shell structure composed of about 100nm of diameter of silica with several TiO2 fine particles in shell. After the degradation, this process is optimized through the response surface methodology (RSM). In this response study, photodegradation efficiency was evaluated by three main independent parameters such as catalyst dose, initial dye concentration and reaction time. Parameter sensitivity studies of the degradation efficiency of titania coated silica nanoparticles have shown 93.29% degraded under the optimal conditions of catalyst dose of 89.80mg/g, initial dye concentration of 17.61mg/L and reaction time of 12min. We cross-checked the predicted values of degradation efficiency with the experimental values and were found to be in good agreement (R2=0.9983 and adj-R2=0.9967).

Correction: Adsorption of safranin-O dye on CO2 neutralized activated red mud waste: process modelling, analysis and optimization using statistical design

Correction for ‘Adsorption of safranin-O dye on CO2 neutralized activated red mud waste: process modelling, analysis and optimization using statistical design’ by Manoj Kumar Sahu et al., RSC Adv., 2015, 5, 42294–42304.

Correction: Removal of safranin-O dye from aqueous solution using modified red mud: kinetics and equilibrium studies

Correction for ‘Removal of safranin-O dye from aqueous solution using modified red mud: kinetics and equilibrium studies’ by Manoj Kumar Sahu et al., RSC Adv., 2015, 5, 78491–78501.

Removal of safranin-O dye from aqueous solution using modified red mud: kinetics and equilibrium studies

Adsorption of safranin-O dye on SDS modified red mud at different pH.

Adsorption of safranin-O dye on CO2neutralized activated red mud waste: process modelling, analysis and optimization using statistical design

Neutralization of red mud using CO2and activated by calcined at 500 °C.

Predictive membrane transport models for Organic Solvent Nanofiltration: How complex do we need to be?

From feasibility tests at laboratory scale to large industrial scale processes, modelling can be applied to Organic Solvent Nanofiltration (OSN) for two purposes: (i) parameter estimation, when experimental data for standard solute + solvent systems are available, and it is desired to estimate relevant parameters for as yet uncharacterised systems, and (ii) prediction, when the model parameters for the solvent–solute are available, and modelling can be applied to describe the performance of a different solute + solvent system or operations at a different process scale. Both estimation and prediction require the choice of a transport model, to carry out regression and simulation, respectively. This paper reports a systematic comparison of a range of different transport models (irreversible thermodynamics, solution–diffusion, pore-flow and transient transport models, such as the solution–diffusion with imperfections model) using selected experimental data for various solutes and solvents through polymeric OSN membranes with different physico-chemical properties. Commercial integrally skinned asymmetric polyimide (PI, glassy) and thin film composite silicone-coated PI (rubbery) membranes from Evonik® MET were systematically tested in this study, with styrene oligomers and Safranin-O dye in different organic solvents under uniform operating conditions (temperature, pressure, cross-flow velocity and solute concentration). In addition, experimental data from the literature were taken for non-commercial thin film composite silicone-coated PI, glassy poly[1-(trimethylsilyl)-1-propyne] (PTMSP) and poly[4methyl2pentyne] (PMP) membranes, to include a broad spectrum of positive and negative rejection values. The different transport models were used to perform regression of experimental data and prediction at different pressure values, based on the regressed model parameters. The models were then compared in terms of regression performance and experimental/numerical effort required to use them for parameter estimation. Negative rejection data was used to further discriminate among the models. Solution–diffusion-based models gave a better description of permeation through flexible-chain glassy membranes than pore-flow models. On the other hand, pore-flow-based models gave a better description of permeation through glassy PTMSP and PMP membranes. For integrally skinned asymmetric PI membranes, the prediction of a concentration process using the best performing regression models (i.e. the Maxwell–Stefan and the classical solution–diffusion model) was also performed. Interestingly, no significant difference was observed between the two models for both a membrane with complete solute rejection (Duramem® 200) and a membrane with partial solute rejection (Duramem® 500). Process modelling by accounting for a classical solution–diffusion-type transport mechanism is therefore sufficient to obtain a reliable transport description for this membrane family.

Safranin-O dye in the ground state. A study by density functional theory, Raman, SERS and infrared spectroscopy

The analysis of ground state structural and vibrational properties of Safranin-O is presented. The experimental results, obtained by FTIR, Raman and SERS spectroscopy, are discussed in comparison to the results of DFT calculations carried out at the B3LYP/6-311+G(d,p) level of theory. The calculated spectra reproduce quite satisfactorily the experimental data. The calculated Safranin-O equilibrium structure and the assignment of the vibrational spectra are reported as well. From the changes between Raman and SERS spectra a model is presented for the interaction of Safranin-O with silver nanoparticles.

Nanostructured mesoporous Au/TiO2 for photocatalytic degradation of a textile dye: the effect of size similarity of the deposited Au with that of TiO2 pores

Mesoporous Au/TiO2 nanocomposites with different Au particle size (7.3–11.8 nm) were synthesized via deposition–precipitation method. The synthesized nanocomposites have been characterized by XRD, TEM, XPS, DLS, ICP-OES, N2 sorpometry, and UV–Vis spectroscopy. Au/TiO2 showed higher quantum yield and greater photocatalytic efficiency compared to pure TiO2 under both ultraviolet and sunlight illumination. The increase of the photocatalytic efficiency of TiO2 upon deposition with gold nanoparticles, Au NPs, is due to the interface electron transfer from Au nanoparticles to TiO2 under visible light illumination and from TiO2 to Au nanoparticles under UV illumination. For the first time, the effect of Au particle sizes when it is very similar to the interparticles pores of TiO2 has been investigated. The highest reaction rate (5.7 × 10−2 min−1) and degradation efficiency of Safranin-O (SO) dye (97 %) were observed when the deposited gold nanoparticles are the smallest among the studied samples (sAu/TiO2). In spite of blocking a high percentage of the TiO2 pores, the sAu/TiO2 sample demonstrated a complete degradation of SO dye in 50 min which is more efficient than any other reported catalysts in the literature.

Enhanced photocatalytic degradation of Safranin-O by heterogeneous nanoparticles for environmental applications

Abstract Nanostructure titanium dioxide (TiO2) has been synthesized by hydrolysis of titanium tetrachloride in aqueous solution and Ag–TiO2 nanoparticles were synthesized by photoreduction method. The resulting materials were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier-transform infrared (FT-IR) and UV–vis absorption spectroscopy. The experimental results showed that the sizes of the synthesized TiO2 and Ag–TiO2 particles are in the range of 1.9–3.2 nm and 2–10 nm, respectively. Moreover, Ag–TiO2 nanoparticles exhibit enhanced photocatalytic activity on photodegradation of Safranin-O (SO) dye as compared to pure TiO2. The positive effect of silver on the photocatalytic activity of TiO2 may be explained by its ability to trap electrons. This process reduces the recombination of light generated electron–hole pairs at TiO2 surface and therefore enhances the photocatalytic activity of the synthesized TiO2 nanoparticles. The effects of initial dye and nanoparticle concentrations on the photocatalytic activity have been studied and the results demonstrate that the dye photodegradation follows pseudo-first-order kinetics. The observed maximum degradation efficiency of SO is about 60% for TiO2 and 96% for Ag–TiO2.

Differential sectoriality in long-distance transport in temperate tree species: evidence from dye flow, 15N transport, and vessel element pitting

The capture of patchily distributed nutrients by tree roots has received extensive research, but the fate of those nutrients has not. We performed experiments to determine if nutrient transport within tree species is preferentially transported from specific roots to specific branches. Saplings of five species with contrasting growth requirements were examined: two Betula species (B. papyrifera and B. lenta), Populus tremuloides, and two Acer species (A. saccharum and A. rubrum). To quantify patterns of long-distance transport, we examined the accumulation of safranin-O dye and 15N in branches when these tracers were applied to isolated lateral roots (dye and 15N) and to the main root system (15N). Because transport of nutrients between sectors requires flow through intervessel pit pairs of adjacent xylem vessel elements, we quantified the area of intervessel pits, the number of pits per unit vessel wall area, and the % vessel wall area as pits in Acer and Betula. We found that the two Betula species were integrated (tracers applied to isolated roots were likely to accumulate in all branches), while P. tremuloides and the two Acer species were sectorial (tracer accumulation was more concentrated in particular branches). Betula had the largest number of intervessel pits per unit vessel wall area and the largest percentage of vessel wall area as pits. The high density of bordered pits may explain the ease of tracer movement throughout the two Betula species. Greater integration may allow certain trees (e.g., Betula) to exploit nutritionally patchy environments such as rocky soils, and may alter plant-herbivore interactions.