Rajni Lasyal; Shakunj Rajput
Abstract
In this study, the degradation of azo-dye acid orange 10 has been investigated using Polyvinylpyrrolidone and Brij-35 stabilized iridium oxide nanoclusters as catalysts. Simple chemical reduction method was used to synthesize the above-mentioned nanoclusters. The characteristics of the nanocatalysts ...
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In this study, the degradation of azo-dye acid orange 10 has been investigated using Polyvinylpyrrolidone and Brij-35 stabilized iridium oxide nanoclusters as catalysts. Simple chemical reduction method was used to synthesize the above-mentioned nanoclusters. The characteristics of the nanocatalysts were determined by UV-visible spectrophotometer, TEM and XRD. The kinetic study has been carried out at λmax of reaction mixture i.e. 479 nm spectrophotometrically. The degradation follows first order kinetics with respect to oxidant and catalyst concentration while order is one at lower substrate concentration tending towards zero at higher concentration. The degradation kinetics has been supported by the derived rate law. The results showed that Polyvinylpyrrolidone stabilized iridium oxide nanoclusters outperformed Brij-35 stabilized iridium oxide nanoclusters, exhibiting the fastest degradation rate. The progress of the degradation process was monitored by UV-vis spectroscopy. Using Polyvinylpyrrolidone stabilized iridium oxide nanoclusters as a catalyst is a very promising approach for the remediation of acid orange 10 due to the fast degradation rate and high degradation efficiency. In addition, Polyvinylpyrrolidone stabilized iridium oxide nanoclusters can be easily recovered and recycled for three consecutive cycles. It can be inferred from this study that catalytic oxidation methods are active and environment-friendly for the remediation of dyes.
Fatemeh Shahverdi; Aboulfazl Barati; Mansour Bayat
Abstract
This research work aims to investigate the sorption characteristic of synthesized Poly (vinyl alcohol)/Chitosan nanofiber mats modified with aluminum-cerium spinel oxide (CeAlO3) nanoparticles for methylene blue (MB) removal from aqueous solutions. The sorption is carried out by a batch technique. The ...
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This research work aims to investigate the sorption characteristic of synthesized Poly (vinyl alcohol)/Chitosan nanofiber mats modified with aluminum-cerium spinel oxide (CeAlO3) nanoparticles for methylene blue (MB) removal from aqueous solutions. The sorption is carried out by a batch technique. The structural characterization of this nanocomposite was performed by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD). Scanning electron microscopy (SEM) results showed uniform net and improved nanofibers with diameters ranging about 420 and 450 nm, respectively. The optimum conditions of MB removal onto modified PVA/CS nanofibers were found to be: pH 10, contact time 45 min, and 0.01 g of adsorbent in 400 ml in aqueous solution. Furthermore, the experimental adsorption data were in excellent agreement with the pseudo-second-order kinetics. The experimental results showed that there is a good correlation between the obtained data and the adsorption isotherm in the concentration range studied (400-600 mg/l). The results revealed that the maximum adsorption capacity of MB was 817.81 and 714.61 mg/g onto improved and net nanofibers, respectively.
Dhanraj S Shirsath
Abstract
Magnetic nano adsorbent is cost-effective and easily synthesized in the laboratory by chemical Co-precipitation method that provides not only high adsorption capacity but also rapid adsorption rate. The magnetic nano adsorbents were synthesized by Ferric and Ferrous ions precursor solution in the presence ...
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Magnetic nano adsorbent is cost-effective and easily synthesized in the laboratory by chemical Co-precipitation method that provides not only high adsorption capacity but also rapid adsorption rate. The magnetic nano adsorbents were synthesized by Ferric and Ferrous ions precursor solution in the presence of ammonium hydroxide. In the present investigation, a magnetic nano adsorbent has been employed for the removal of Pb (II) from an aqueous solution by batch adsorption technique along with photocatalysis. The different parametric study also carried out such as initial concentration of Pb (II), adsorbent dose, contact time, and Solution pH. The Pb (II) was fast adsorption and the equilibrium was achieved within 45 minutes. The amount Pb (II) adsorbed increases as the temperature increase. The optimal pH for Pb (II) was around 5.4 and for the removal of Pb (II) ions was up to 96.00%. The employed adsorbents were characterized by SEM, X-ray diffraction (XRD), Vibrating spinning magnetometer (VSM), and FTIR. The Kinetic of adsorption study was examined for the pseudo-first-order model and pseudo-second-order models. This Photocatalytic adsorption study obeys Pseudo second-order kinetic. The reusability and regeneration of magnetic nano adsorbents were studied and were recycled up to 87.00 %.
Subramanian Kanchana; Radhakrishnan Vijayalakshmi
Abstract
Photocatalysis mediated by metal nanoparticles is emerging as an effective method for removal of hazardous dye pollutants in natural aquatic bodies. Nanoparticles of Cu, Ni and Ag were synthesized by chemical method using PEG and PVP polymers as capping agents. Experimental photocatalyis was carried ...
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Photocatalysis mediated by metal nanoparticles is emerging as an effective method for removal of hazardous dye pollutants in natural aquatic bodies. Nanoparticles of Cu, Ni and Ag were synthesized by chemical method using PEG and PVP polymers as capping agents. Experimental photocatalyis was carried out in a one pot batch reactor using metal nanoparticle catalysts for degradation of crystal violet (CV), bromocresol green (BCG) and methylene blue (MB) in aqueous solution in the presence of NaBH4 reductant independently under solar and UV irradiations at 25oC. Metal nanoparticles caused the removal of BCG and CV in 90-120 min and MB in 30-60 min. Linear relationship between the irradiation time and the absorbance were recorded and the kinetic plots exhibited pseudo-first order kinetic. The trend of dye degradation among the nanoparticles based on the catalytic efficiency (c) and rate coefficient (k) values was Cu>Ag>Ni. Mineralization experiment indicated 94, 91 and 90% of TOC removal ratio (R) respectively for CV, MB and BCG dyes. Nanoparticles stabilized using PEG demonstrated better catalytic efficiency than those with PVP. Solar irradiation showed superior augmenting effect on the nanoparticle catalysts than the UV irradiation. The electron-hole pair mediated reduction mechanism was proposed as a basis for photocatalytic degradation of dyes.
Reza Jazini Zadeh; Mohammad Sayadi; Mohammad Reza Rezaei
Abstract
The present study was performed on the adsorption of 2,4-Dichlorophenoxyacetic acid from aqueous solutions by amine-modified magnetic nanoparticles. The adsorbent was synthesized by the co-precipitation method. The adsorbent properties of Fe3O4@SiO2-NH2 were investigated using XRD, FTIR, TGA, VSM and ...
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The present study was performed on the adsorption of 2,4-Dichlorophenoxyacetic acid from aqueous solutions by amine-modified magnetic nanoparticles. The adsorbent was synthesized by the co-precipitation method. The adsorbent properties of Fe3O4@SiO2-NH2 were investigated using XRD, FTIR, TGA, VSM and TEM. Adsorbent efficacy was studied by investigating the effect of pH, initial concentration of pollutants, and adsorbent dose, and times. Finally, kinetics equations and isotherms models were used to describe the data. The results showed that the highest removal percentage was observed at pH 6 and the initial concentration 20 mg/l of 2,4-Dichlorophenoxyacetic acid. Adsorption capacity was increased by 65.3% bypassing the time from the beginning of the process to 60 min. The results from the study of isotherms and adsorption kinetics presented that the sorption procedure follows the pseudo-second-order kinetics and the Langmuir isotherm with R2> 99. The maximum adsorption capacity of Fe3O4@SiO2-NH2 is 116.3 mg/g. Besides, thermodynamic studies have shown that the adsorption process in the present study is endothermic and spontaneous. The experiments showed that Fe3O4@SiO2-NH2 synthesized nanoparticles could be an excellent method to remove 2,4- Dichlorophenoxyacetic acid contaminants from the aqueous solutions due to the high efficiency, simplicity, and lack of secondary contamination in the solution.