scholarly journals Effective Removal of Amido Black and Eosin B Dyes in Aqueous Solution by MWCNT/ZrO2/Pb Nanocomposites: Isotherm, Reusability and Kinetic Studies

2021 ◽  
Author(s):  
Marjan Sheibani ◽  
Mehrorang Ghaedi ◽  
Vahid Zare-Shahabadi ◽  
Arash Asfaram
Keyword(s):  
Aqueous Solution ◽  
High Efficiency ◽  
Average Particle Size ◽  
Theoretical Data ◽  
Kinetic Studies ◽  
Average Particle ◽  
Operational Conditions ◽  
Eosin B ◽  
Amido Black ◽  
Multi Walled Carbon Nanotubes

This research illustrates modification of multi-walled carbon nanotubes (MWCNT) by ZrO2/Pb to construct nanocomposites (MWCNT/ZrO2/Pb-NCs) by simple precipitation technique and subsequently examine its ability for adsorption of Amido black (AB) and Eosin B (EB) dyes in binary system. The present nanocomposites investigation by FESEM, XRD, FTIR, and EDX analysis, reveal its as-synthesized crystalline nature with cubic morphology and average particle size 30–50 nm. The present nano-adsorbent represent high efficiency for AB and EB adsorption from aqueous solution, while dependency of variables including pH, initial concentration of dyes, contact time and MWCNT/ZrO2/Pb-NCs mass were analyzed by central composite design (CCD). The predicted maximum removal percentage was 95% removal for both dyes is consequence of adjustment of operational conditions at pH of 6.0; 0.05 g MWCNT/ZrO2/Pb-NCs; 15 min stirring at 15 mg L-1 for both dyes. The Langmuir as applicable for representation and description of reveal data of adsorption with adsorption capacity of 15.46 and 16.92 mg g-1 for AB and EB, respectively. Pseudo-first order model owing to its high correlation coefficient and closeness of experimental and theoretical data well represented behavior of corresponding adsorption system. Mechanism examination strongly proof high contribution of external mass transference as the main rate-controlling step. The successful regeneration of MWCNT/ZrO2/Pb-NCs suggested their usefulness in wastewater treatment and its ability of environmental management.

Azithromycin nanosuspension preparation using evaporative precipitation into aqueous solution (EPAS) method and its comparative dissolution study

2020 ◽  
Vol 17 ◽  
Author(s):  
Mohammad Hossain Shariare ◽  
Tonmoy Kumar Mondal ◽  
Hani Alothaid ◽  
Md. Didaruzzaman Sohel ◽  
MD Wadud ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Dissolution Rate ◽  
Average Particle Size ◽  
Scale Up ◽  
Average Particle ◽  
Total Drug ◽  
Residual Solvent ◽  
Dissolution Study ◽  
Drug Content

Aim: EPAS (evaporative precipitation into aqueous solution) was used in the current studies to prepare azithromycin nanosuspensions and investigate the physicochemical characteristics for the nanosuspension batches with the aim of enhancing the dissolution rate of the nanopreparation to improve bioavailability. Methods: EPAS method used in this study for preparing azithromycin nanosuspension was achieved through developing an in-house instrumentation method. Particle size distribution was measured using Zetasizer Nano S without sample dilution. Dissolved azithromycin nanosuspensions were also compared with raw azithromycin powder and commercially available products. Total drug content of nanosuspension batches were measured using an Ultra-Performance Liquid Chromatography (UPLC) system with Photodiode Array (PDA) detector while residual solvent was measured using gas chromatography (GC). Results: The average particle size of azithromycin nanosuspension was 447.2 nm and total drug content was measured to be 97.81% upon recovery. Dissolution study data showed significant increase in dissolution rate for nanosuspension batch when compared to raw azithromycin and commercial version (microsuspension). The residual solvent found for azithromycin nanosuspension is 0.000098023 mg/ mL or 98.023 ppb. Conclusion: EPAS was successfully used to prepare azithromycin nanoparticles that exhibited significantly enhanced dissolution rate. Further studies are required to scale up the process and determine long term stability of the nanoparticles.

Ni/MWCNT-Supported Palladium Nanoparticles as Magnetic Catalysts for Selective Oxidation of Benzyl Alcohol

2013 ◽  
Vol 66 (5) ◽  
pp. 564 ◽  
Author(s):  
Mingmei Zhang ◽  
Qian Sun ◽  
Zaoxue Yan ◽  
Junjie Jing ◽  
Wei Wei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Benzyl Alcohol ◽  
Bimetallic Nanoparticles ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray ◽  
Oxidation Of Benzyl Alcohol ◽  
Uniform Dispersion ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Well dispersed Pd@Ni bimetallic nanoparticles on multi-walled carbon nanotubes (Pd@Ni/MWCNT) are prepared and used as catalysts for the oxidation of benzyl alcohol. Scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy analysis, and X-ray diffraction were performed to characterise the synthesised catalyst. The results show a uniform dispersion of Pd@Ni nanoparticles on MWCNT with an average particle size of 4.0 nm. The as synthesised catalyst was applied to the oxidation of benzyl alcohol. A 99 % conversion of benzyl alcohol and a 98 % selectivity of benzaldehyde were achieved by using the Pd@Ni/MWCNT (Pd: 0.2 mmol) catalyst with water as a solvent and H2O2 as oxidant at 80°C. The catalytic activity of Pd@Ni/MWCNT towards benzyl alcohol is higher than that of a Pd/MWCNT catalyst at the same Pd loadings. The catalyst can be easily separated due to its magnetic properties.

scholarly journals Preparation of ultrafine iron phosphate micro-powder from phosphate slag

2018 ◽  
Vol 238 ◽  
pp. 02002
Author(s):  
Fangjing Sun ◽  
Yi Zhang ◽  
Jiawei Zhang ◽  
Xixi Yan ◽  
Xiaoyu Liu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Electron Microscope ◽  
Average Particle Size ◽  
Iron Phosphate ◽  
Average Particle ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Phosphate Slag ◽  
Scanning Electron

In this experiment, ultrafine iron phosphate micro-powder was prepared by hydrothermal method which used phosphate slag as an iron source. The effects of reaction temperature, surfactants type and amount on its particle size were explored. The samples were characterized by using Malvern Laser Particle Size Analyzer (MS2000), X-Ray Diffractometer (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Spectroscopy (EDX).The results showed that at 160 °C, 1 wt%CTAB, monoclinic iron phosphate micro-powder was obtained with an average particle size about 0.4 μm which also has a good dispersion in aqueous solution.

Removal of diazo dye Direct Red 23 from aqueous solution using zero-valent iron nanoparticles immobilized on multi-walled carbon nanotubes

2015 ◽  
Vol 71 (9) ◽  
pp. 1367-1374 ◽  
Author(s):  
Mahmoud Reza Sohrabi ◽  
Nafiseh Mansouriieh ◽  
Morteza Khosravi ◽  
Mohsen Zolghadr
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Zero Valent Iron ◽  
Mass Ratio ◽  
Solution Ph ◽  
Operational Conditions ◽  
Multi Walled Carbon Nanotubes ◽  
Diazo Dye ◽  
Zero Valent Iron Nanoparticles ◽  
Walled Carbon Nanotubes

The present study immobilized nanoscale zero-valent iron (nZVI) on multi-walled carbon nanotubes (MWCNTs) to enhance the reactivity of nZVI and prevent its aggregation. This novel composite (nZVI/MWCNT) was characterized by scanning electron microscopy and X-ray diffraction. The results showed that nZVI particles dispersed on the surface of the MWCNTs. The composite was used to remove the diazo dye Direct Red 23 from aqueous solution. The effects of nZVI to MWCNT mass ratio, nanocomposite content, solution pH, initial dye concentration and temperature were studied. The optimum nZVI/MWCNT mass ratio was 1:3. Batch experiments suggest that degradation efficiency decreased as the initial dye concentration increased and increased as the nanocomposite content increased, decreasing the pH from 8 to 4. The reaction followed a pseudo-first-order model under the operational conditions investigated in this study.

PENGARUH LAJU PREKURSOR SERBUK ALUMINIUM TERHADAP BENTUK MORFOLOGI NANOPARTIKEL ALUMINA DENGAN METODE THERMAL PLASMA

ROTOR ◽  
2017 ◽  
Vol 10 (1) ◽  
pp. 17
Author(s):  
Havid Arifian Rochman ◽  
Arief Ginanjar Dirgantara ◽  
Salahudin Junus ◽  
Imam Sholahuddin ◽  
Aris Zainul Muttaqin
Keyword(s):  
Particle Size ◽  
Aluminum Powder ◽  
Thermal Plasma ◽  
High Efficiency ◽  
Average Particle Size ◽  
Alumina Nanoparticles ◽  
Rate Variation ◽  
Average Particle ◽  
Dc Plasma ◽  
Simple Method

The synthesis of nanoparticles using thermal DC plasma method is a simple method for ease of installation and high efficiency is due to the rate of precursor that can be controlled. Micro-sized aluminum powder is synthesized using thermal DC plasma undergoing a process of evaporation as it passes through high temperature plasma flame, where kemuadian oxidized aluminum particles which evaporates the particles are split and binds with oxygen to form aluminum oxide or also known as alumina (Al2O3). In this experiment, the flow rate of oxygen plasma parameters at 35 SCFH (Standard Cubic Feet per Hour) and 20 amperes flows with precursors rate variation of 1.16 g / min, 3.19 g / min, and 3.5 g / min. Precursors used is 88 micro sized aluminum powder. To determine the morphology of nanoparticles of alumina testing scanning electron microscopy (SEM), the morphology form of nanosphere. Results of the analysis showed that the rate of precursor low causing agglomeration level slightly while the higher rate of precursor agglomeration rate also increased. At the rate of precursor 1.16 g / min, nanoparikel undergo agglomeration with an average particle size of 36.55 nm, and then at a rate of 3.19 gr precursor / mnt an average particle size of 46.49 nm, and at a rate of 3.5 gr / mnt an average particle size of 46.49 nm. The powder nanoparticles were then characterized using X-ray defraksi (XRD) where all alumina nanoparticles were synthesized showed alumina phase that is formed is a phase δ-Al2O3. Keywords: Alumina nanoparticles, DC Thermal Plasma, morphology, precursor rate, nanoparticles size, SEM, XRD.

scholarly journals Surface Characterization and Thermodynamics of Adsorption of Pr, Nd and Er on Alumina from Aqueous Solution

1992 ◽  
Vol 9 (1) ◽  
pp. 17-29 ◽  
Author(s):  
M. Saleem ◽  
M. Afzal ◽  
F. Mahmood ◽  
A. Ali
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Free Energy ◽  
Adsorption Isotherms ◽  
Surface Characterization ◽  
Average Particle Size ◽  
Average Particle ◽  
Enthalpy Of Adsorption ◽  
Different Temperatures ◽  
Isotherm Equations

The porous nature of alumina has been investigated using various techniques. The values obtained for moisture content, surface area, pore volume, average particle size and porosity were 22%, 116 m2/g, 0.76 cm3/g, 17.0±0.5 μm and 68.0%, respectively. The adsorption isotherms of NdIII, PrIII and ErIII on alumina from aqueous solution have been obtained at different temperatures. All these adsorption isotherms obey the Langmuir, Freundlich and Dubinin-Radushkevich isotherm equations. Thermodynamic parameters such as the free energy, entropy and enthalpy of adsorption have been computed and interpreted. It is noteworthy that the adsorption of PrIII and NdIII increases with decreasing temperature while the reverse is observed for ErIII.

Synthesis of Ni@MWCNTs Magnetic Nanocatalysts and their Catalytic Activity towards 4-Nitrophenol Reduction

2012 ◽  
Vol 531 ◽  
pp. 358-361 ◽  
Author(s):  
Ming Mei Zhang ◽  
Qian Sun ◽  
Ji Min Xie
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Average Particle Size ◽  
Chemical Vapor ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Ni Nanoparticles ◽  
Nitrophenol Reduction ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

A well-dispersed Ni nanoparticles on multi-walled carbon nanotubes (Ni@MWCNTs) was prepared by chemical vapor deposition (CVD) method using a vacuum quartz tube furnace at the temperature of 600°C. The scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were performed to characterize the synthesized catalyst. It shows an unfirom dispersion of Ni nanoparticles on MWCNTs with the average particle size of 8.6 nm. The as synthesized catalyst was applied in a redox reaction of 4-nitrophenol, which showed very high catalytic activity, stability and well conversion. The catalyst can be easily separated due to the magnetical performance

Impacts of Acid Treatment on the Characteristics of Native Corn Starch Granules

2011 ◽  
Vol 221 ◽  
pp. 72-77 ◽  
Author(s):  
Xin Jin ◽  
Shuan Qing Hou ◽  
Xiao Xu Sha ◽  
Liang Yu
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Acid Treatment ◽  
Corn Starch ◽  
Average Particle Size ◽  
Peak Temperature ◽  
Average Particle ◽  
Starch Granules ◽  
Acid Modification ◽  
Before And After

Native corn starches were acid-treated at 53 °C for hours in HCl aqueous solution. The peak temperature (Tp) and heat of gelatinization (ΔHgel) before and after treatments were determined. The average particle size, TG and viscosity were measured. The results showed that the viscosity of corn starch decreased from 630mPa to 4.6mPa after acid treatment for 6h. The average particle size decreased and ΔHgel decreased obviously after acid modification.

Dodecane Decomposition in a Radio-Frequency (RF) Plasma Reactor

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Laura Merlo-Sosa ◽  
Gervais Soucy
Keyword(s):  
Carbon Black ◽  
Plasma Reactor ◽  
Average Particle Size ◽  
Plasma Temperature ◽  
Experimental Results ◽  
Rf Plasma ◽  
Average Particle ◽  
Statistical Experimental Design ◽  
Operational Conditions ◽  
Carbon Molecules

The research outlined here includes a study of the production of carbon black (CB) in an inductive plasma reactor, using dodecane (C12H26) as the starting material. Thermodynamic and kinetic studies were carried out to predict the species concentrations likely to be obtained in the pyrolysis process at plasma temperatures. A thorough statistical experimental design was undertaken to investigate the influence of the different operational conditions such as: the feed rates of dodecane, the reactor pressure, the plate power applied to the plasma torch and the composition of the plasma gas, on the production of carbon black and gaseous acetylene-like compounds. Thermodynamic and kinetic models were compared with experimental results, a kinetic reaction model best representing the experimental results. Morphological analysis of the solid product using Transmission Electron Microscopy (TEM) indicates that a high plasma temperature is the most important factor affecting the final morphology of the carbon black formed during the reaction. Carbon black with average particle size of 10-30 nm and specific surface of 130 m2/g was obtained. Morphological analyses also demonstrated the presence of new structures ranging from carbon black to fullerenes and including certain “graphitized” carbon molecules.

scholarly journals A New Collector for Effectively Increasing Recovery in Copper Oxide Ore-Staged Flotation

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 595
Author(s):  
Renfeng Zhu ◽  
Guohua Gu ◽  
Zhixiang Chen ◽  
Yanhong Wang ◽  
Siyu Song
Keyword(s):  
Particle Size ◽  
Copper Oxide ◽  
High Efficiency ◽  
Average Particle Size ◽  
Economic Feasibility ◽  
Processing Plant ◽  
Average Particle ◽  
Entrainment Rate ◽  
Flotation Process ◽  
New Type

A new method, staged flotation for effectively increasing the recovery of ultra-fine copper oxide ore with a new type of collector (ZH-1, C3-5 carbon chain xanthate) is proposed for the first time. The flotation process and mechanism were examined by flotation tests, entrainment rate analysis, laser particle size experiments and microscopic imagery as well as economic feasibility analysis. It was demonstrated that the collector isoamyl sodium xanthate (ISX) shows a good collection ability (recovery exceeded 95%) for azurite, but the recovery was relatively much lower for malachite (only near 80%) due to the different particle size distribution. The new type of xanthate ZH-1 has shown a high-efficiency collection performance for fine-grained malachite. The recovery achieved for −10 μm malachite was more than 95% when the ZH-1 dosage was 150 mg/L, while the average particle size of −10 μm malachite sharply increased from 4.641 μm to 9.631 μm. The batch flotation results indicated that the copper oxide flotation recovery increased from 79.67% to 83.38%, and the grade also raised from 18.08% to 18.14% after using the staged flotation technology with ZH-1 as collector during the flotation of −25 μm ore. It was confirmed that this technology was quite effective for the recovery of copper oxide at the Dishui Copper Processing Plant, which successfully increased its gross profit by 1.6 million US$ per year.

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