scholarly journals Three-Dimensional Electrochemical Oxidation of Recalcitrant Dye Using Green Iron Microparticles

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1925
Author(s):  
Manisha S. Kothari ◽  
Ashraf Aly Hassan ◽  
Kosha A. Shah
Keyword(s):  
Electrochemical Oxidation ◽  
Hydroxyl Radicals ◽  
Three Dimensional ◽  
Decolorization Efficiency ◽  
Initial Ph ◽  
Size Of Particles ◽  
Tea Extract ◽  
Average Size ◽  
Higher Doses ◽  
Reaction Works

This study evaluated the effect of the addition of green iron microparticles (Fe-MPs) as a three-dimensional electrode on efficiency of the electrochemical oxidation process. Polyphenols present in green tea extract act as a reducing and capping agent during green synthesis of the Fe-MPs. Scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis indicates that the average size of particles is 100 µm, with about ~47 wt % of Fe in oxide form. The addition of Fe-MPs as a third electrode in the conventional electro-oxidation (EO) process converts it into a three-dimensional (3D) catalytic EO process to enhance the decolorization efficiency. Green synthesized Fe-MPs function as several microelectrodes in the process. Adsorption study indicated that only 12% of decolorization is due to adsorption on the Fe-MPs surface. Moreover, improvement in generation of hydroxyl radicals was validated by applying dimethyl sulfoxide as scavenger, and it was observed that generation of hydroxyl radicals decreased with the addition of DMSO. Results showed that decolorization efficiency increased in the 3D EO process with Fe-MPs by about 24% compared to the conventional 2D process without the Fe-MPs dosing, and initial pH as well as the Fe-MPs dose has a significant effect on decolorization efficiency during the 3D process. It is observed that reaction works better at highly acidic pH (2-4), and decolorization efficiency improved with higher doses of Fe-MPs.

Hydroquinone Wastewater Treatment by Means of Electrochemical Oxidation in Three-Dimensional Bipolar Cell

2012 ◽  
Vol 518-523 ◽  
pp. 2539-2542 ◽  
Author(s):  
Jun Sheng Hu ◽  
Jia Li Dong ◽  
Ying Wang ◽  
Lei Guan ◽  
Ying Yong Duan
Keyword(s):  
Electrochemical Oxidation ◽  
Oxidation Process ◽  
Electrolyte Concentration ◽  
Ph Value ◽  
Removal Rate ◽  
Supporting Electrolyte ◽  
Three Dimensional ◽  
Initial Ph ◽  
Single Factor Analysis ◽  
Dimensional Cell

By the static experiment, we studied the electrochemical oxidation process of simulated hydroquinone wastewater (concentration for 300mg•L-1) in the three-dimensional cell. Experimental inspected how various factors of the packing quality ratio, electrolysis voltage, supporting electrolyte concentration, and the initial pH value influence the effect of the removal of hydroquinone and CODCr. The results of the experiment clearly indicated with the increase of voltage applied the removal rate of hydroquinone and CODCr increased first and then decreased, finally and increased again. In the weak alkali conditions (pH=8.5), the removal rate of hydroquinone and CODCr is the highest, Electrolyte concentration and packing quality ratio to the effect of hydroquinone by electrochemical degradation is the larger. The results of the single factor analysis show that the most suitable processing conditions of simulated hydroquinone wastewater by bipolar electrocatalysis oxidation are the Na2SO4 concentration of 0.03mol•L-1, the electrolytic voltage of 6V, the initial pH value of 8.5, the packing quality ratio of 1:2. With this condition processing 3h, the removal rate of hydroquinone and CODCr reached 83.96% and 39.9%, respectively.

Enhanced electrochemical oxidation of Acid Red 3R wastewater with iron phosphomolybdate supported catalyst

2015 ◽  
Vol 71 (6) ◽  
pp. 848-855 ◽  
Author(s):  
Li Wang ◽  
Lin Yue ◽  
Feng Shi ◽  
Jianbo Guo ◽  
Jingliang Yang ◽  
...  
Keyword(s):  
Electrochemical Oxidation ◽  
Molecular Sieves ◽  
Salt Effect ◽  
Supported Catalyst ◽  
X Ray Diffraction ◽  
X Ray ◽  
Decolorization Efficiency ◽  
Initial Ph ◽  
Negative Effect ◽  
The Fourier Transform

Electrochemical oxidation of Acid Red 3R (AR3R) was investigated with the new catalyst of iron phosphomolybdate (FePMo12) supported on modified molecular sieves type 4 Å (4A) as packing materials in the reactor. The results of the Fourier transform infrared spectroscopy and X-ray diffraction indicated that the heteropolyanion had a Keggin structure. The optimal conditions for decolorization of simulated AR3R wastewater were as follows: current density 35 mA/cm2, initial pH 4.0, airflow 0.08 m3/hour and inter-electrode distance 3.0 cm. With the addition of NaCl to the system, the decolorization efficiency increased. But Na2SO4 had a negative effect on the decolorization efficiency, which was attributed to the negative salt effect. The degradation mechanisms of AR3R were also discussed in detail.

scholarly journals Upconversion Luminescence of Silica–Calcia Nanoparticles Co-doped with Tm3+ and Yb3+ Ions

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 937
Author(s):  
Katarzyna Halubek-Gluchowska ◽  
Damian Szymański ◽  
Thi Ngoc Lam Tran ◽  
Maurizio Ferrari ◽  
Anna Lukowiak
Keyword(s):  
Energy Transfer ◽  
Near Infrared ◽  
Upconversion Luminescence ◽  
Sol Gel ◽  
Emission Spectra ◽  
Transmission Electron ◽  
Characteristic Emission ◽  
Diffraction Patterns ◽  
Size Of Particles ◽  
Average Size

Looking for upconverting biocompatible nanoparticles, we have prepared by the sol–gel method, silica–calcia glass nanopowders doped with different concentration of Tm3+ and Yb3+ ions (Tm3+ from 0.15 mol% up to 0.5 mol% and Yb3+ from 1 mol% up to 4 mol%) and characterized their structure, morphology, and optical properties. X-ray diffraction patterns indicated an amorphous phase of the silica-based glass with partial crystallization of samples with a higher content of lanthanides ions. Transmission electron microscopy images showed that the average size of particles decreased with increasing lanthanides content. The upconversion (UC) emission spectra and fluorescence lifetimes were registered under near infrared excitation (980 nm) at room temperature to study the energy transfer between Yb3+ and Tm3+ at various active ions concentrations. Characteristic emission bands of Tm3+ ions in the range of 350 nm to 850 nm were observed. To understand the mechanism of Yb3+–Tm3+ UC energy transfer in the SiO2–CaO powders, the kinetics of luminescence decays were studied.

scholarly journals Involvement of a local Fenton reaction in the reciprocal modulation by O2 of the glucagon-dependent activation of the phosphoenolpyruvate carboxykinase gene and the insulin-dependent activation of the glucokinase gene in rat hepatocytes

1998 ◽  
Vol 335 (2) ◽  
pp. 425-432 ◽  
Author(s):  
Thomas KIETZMANN ◽  
Torsten PORWOL ◽  
Karl ZIEROLD ◽  
Kurt JUNGERMANN ◽  
Helmut ACKER
Keyword(s):  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Fenton Reaction ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Gene Activation ◽  
Three Dimensional ◽  
Rat Hepatocytes ◽  
Confocal Laser ◽  
Radical Scavenger ◽  
Insulin Dependent

H2O2 mimicked the action of periportal pO2 in the modulation by O2 of the glucagon-dependent activation of the phosphoenolpyruvate carboxykinase (PCK) gene and the insulin-dependent activation of the glucokinase (GK) gene. H2O2 can be converted in the presence of Fe2+ in a Fenton reaction into hydroxyl anions and hydroxyl radicals (•OH). The hydroxyl radicals are highly reactive and might interfere locally with transcription factors. It was the aim of the present study to investigate the role of and to localize such a Fenton reaction. Hepatocytes cultured for 24 h were treated under conditions mimicking periportal or perivenous pO2 with glucagon or insulin plus the iron chelator desferrioxamine (DSF) or the hydroxyl radical scavenger dimethylthiourea (DMTU) to inhibit the Fenton reaction. PCK mRNA was induced by glucagon maximally under conditions of periportal pO2 and half-maximally under venous pO2. GK mRNA was induced by insulin with reciprocal modulation by O2. DSF and DMTU reduced the induction of PCK mRNA to about half-maximal and increased the induction of GK mRNA to maximal under both O2 tensions. Hydroxyl radical formation was maximal under arterial pO2. Perivenous pO2, DSF and DMTU each decreased the formation of •OH to about 70% of control. The Fenton reaction could be localized in a perinuclear space by confocal laser microscopy and three-dimensional reconstruction techniques. In the same compartment, iron could be detected by electron-probe X-ray microanalysis. Thus a local Fenton reaction is involved in the O2 signalling, which modulated the glucagon- and insulin-dependent PCK gene and GK gene activation.

Size Effect in Germanium Nanostructures Fabricated by Pulsed Laser Deposition

1999 ◽  
Vol 581 ◽  
Author(s):  
K.M. Hassan ◽  
A.K. Sharma ◽  
J. Narayan ◽  
J.F. Muth ◽  
C.W. Teng ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Band Gap ◽  
Quantum Confinement ◽  
Three Dimensional ◽  
Pulsed Laser ◽  
Wide Band ◽  
Laser Deposition ◽  
Island Growth ◽  
Wide Band Gap ◽  
Average Size

ABSTRACTWe have fabricated Ge nanostructures buried in AlN and Al2O3 matrices grown on Si(111) and sapphire substrates by pulsed laser deposition. Our approach involved three-dimensional island growth of low band-gap material followed by a layer of wide band-gap material. The nanodots were uniformly distributed in between alternating layers of AlN or Al2O3. It was observed that these nanodots exhibit crystalline structure when grown at 300-500 °C. The average size of Ge islands was determined to be ∼5-15 nm, which could be varied by controlling laser deposition and substrate parameters. The Raman spectrum showed a peak of the Ge-Ge vibrational mode downward shifted upto 295 cm− which is caused by quantum confinement of phonons in the Ge-dots. The photoluminescence of the Ge dots (size ∼15nm) was blue shifted by ∼0.266 eV from the bulk Ge value of 0.73 eV at 77 K, resulting in a distinct peak at ∼1.0 eV. The spectral positions of both E1 and E2 transitions in the absorption spectra at room temperature and 77K shift toward higher energy as the Ge dot size decreases. The interpretation of these behaviors in terms of quantum confinement is discussed in this work, and the importance of pulsed laser deposition in fabricating novel nanostructures is emphasized

scholarly journals Novel Antiviral Characteristics of Nanosized Copper(I) Iodide Particles Showing Inactivation Activity against 2009 Pandemic H1N1 Influenza Virus

2011 ◽  
Vol 78 (4) ◽  
pp. 951-955 ◽  
Author(s):  
Yoshie Fujimori ◽  
Tetsuya Sato ◽  
Taishi Hayata ◽  
Tomokazu Nagao ◽  
Mikio Nakayama ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Hydroxyl Radicals ◽  
Influenza A ◽  
Virus Titer ◽  
H1n1 Influenza ◽  
Radical Scavenger ◽  
Dependent Manner ◽  
Pandemic H1n1 ◽  
Titration Assay ◽  
Average Size

ABSTRACTWe investigated the antiviral activity of nanosized copper(I) iodide (CuI) particles having an average size of 160 nm. CuI particles showed aqueous stability and generated hydroxyl radicals, which were probably derived from monovalent copper (Cu+). We confirmed that CuI particles showed antiviral activity against an influenza A virus of swine origin (pandemic [H1N1] 2009) by plaque titration assay. The virus titer decreased in a dose-dependent manner upon incubation with CuI particles, with the 50% effective concentration being approximately 17 μg/ml after exposure for 60 min. SDS-PAGE analysis confirmed the inactivation of the virus due to the degradation of viral proteins such as hemagglutinin and neuraminidase by CuI. Electron spin resonance (ESR) spectroscopy revealed that CuI generates hydroxyl radicals in aqueous solution, and radical production was found to be blocked by the radical scavengerN-acetylcysteine. Taken together, these findings indicate that CuI particles exert antiviral activity by generating hydroxyl radicals. Thus, CuI may be a useful material for protecting against viral attacks and may be suitable for applications such as filters, face masks, protective clothing, and kitchen cloths.

Lead Free Paste with under 3um Solder Particles for Fine Pitch C4 bumping and pre-coating solder applications

2013 ◽  
Vol 2013 (DPC) ◽  
pp. 000862-000889
Author(s):  
Hironori Uno ◽  
Masayuki Ishikawa ◽  
Akihiro Masuda ◽  
Hiroki Muraoka ◽  
Kanji Kuba
Keyword(s):  
Chemical Reduction ◽  
Average Particle Size ◽  
Average Particle ◽  
Solder Paste ◽  
Chemical Reduction Method ◽  
Property Evaluation ◽  
Fine Pitch ◽  
Solder Bumps ◽  
Size Of Particles ◽  
Average Size

The work to be detailed in this paper is our development of 96.5mass%Sn-3.0mass%Ag-0.5mass%Cu fine solder particles with an average particle size of under 3um (D50), using a chemical reduction method. An evaluation was conducted on the properties of the particles. The average size of particles appeared to be under 3um with a higher yield compared to particles using the conventional gas atomization method. The melting temperature of fine solder particles using this method was its eutectic temperature, which is same as using the gas–atomized particles. 120um pitch solder bumps from the solder paste using the above mentioned fine solder particles were created on the substrate. As a result of property evaluation, it was turned out that the solder paste created a superior printing shape and coplanarity compared to the conventional paste with gas-atomized particles. In order to investigate the superior printing property generated by the paste with fine solder particles, the rheology of the paste was evaluated.It was verified that the anisotropic shape of particles has contributed to prevent the printed paste from slumping, which has resulted in the improvement of printed shape. It also shows that the filling characteristic of the paste was improved by the smaller particles and the better coplanarity was observed. The importance of finer solder particles for finer pitch assembly will be presented.

scholarly journals Three-Dimensional Nano-Morphology of Carbon Nanotube/Epoxy Filled Poly(methyl methacrylate) Microcapsules

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1387 ◽  
Author(s):  
M. Galip Icduygu ◽  
Meltem Asilturk ◽  
M. Akif Yalcinkaya ◽  
Youssef K. Hamidi ◽  
M. Cengiz Altan
Keyword(s):  
Confocal Microscopy ◽  
Methyl Methacrylate ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Confocal Microscopy ◽  
Poly Methyl Methacrylate ◽  
Scanning Confocal Microscopy ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Average Size

The three-dimensional nano-morphology of poly(methyl methacrylate; PMMA) microcapsules filled with carbon nanotubes (CNTs) and epoxy resin were investigated by various microscopy methods, including a novel, laser scanning confocal microscopy (LSCM) method. Initially, PMMA microcapsules containing various amounts of CNTs were synthesized by a solvent evaporation method. Scanning electron microscopy analysis showed that pore-free, smooth-surface microcapsules formed with various types of core-shell morphologies. The average size of CNT/epoxy/PMMA microcapsules was shown to decrease from ~52 μm to ~15 μm when mixing speed during synthesis increased from 300 rpm to 1000 rpm. In general, the presence of CNTs resulted in slightly larger microcapsules and higher variations in size. Moreover, three-dimensional scans obtained from confocal microscopy revealed that higher CNT content increased the occurrence and size of CNT aggregates inside the microcapsules. Entrapped submicron air bubbles were also observed inside most microcapsules, particularly within those with higher CNT content.

scholarly journals Electrochemical oxidation of m-cresol purple dye in aqueous media

2015 ◽  
Vol 50 (4) ◽  
pp. 305-313
Author(s):  
Sajjad Khezrianjoo ◽  
Hosakere Doddarevanna Revanasiddappa
Keyword(s):  
Electrochemical Oxidation ◽  
Applied Voltage ◽  
Supporting Electrolyte ◽  
Aqueous Media ◽  
Degradation Process ◽  
Cell System ◽  
Electrolysis Cell ◽  
System A ◽  
Initial Ph ◽  
Indicator Dye

The present investigation showed that the indicator dye m-cresol purple (mCP) was degraded in a laboratory scale, undivided electrolysis cell system. A platinum anode was used for generation of chlorine in the dye solution. The influence of supporting electrolyte, applied voltage, pH, initial dye concentration and temperature were studied. The ultraviolet-visible spectra of samples during the electrochemical oxidation showed rapid decolorization of the dye solution. During the electrochemical degradation process, dye concentration and current were measured to evaluate the energy consumption and current efficiency. After 10 minutes of electrolysis, a solution containing 20 mg/L mCP showed complete color removal at a supporting electrolyte concentration of 1 g/L NaCl, initial pH 6.7, temperature 25 °C and applied voltage 5 V; however, when pH was kept at 6.7, a higher rate constant was observed. There was good fit of the data to pseudo-first-order kinetics for dye removal in all experiments. Dependence of the decolorization rate on the initial mCP concentration can be described as roα[mCP]o−0.98. The apparent activation energy for the electrochemical decolorization of mCP was determined to be −6.29 kJ/mol.

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