scholarly journals Removal of refractory organosulfur compounds via oxidation with hydrogen peroxide on amorphous Ti/SiO2 catalysts

2010 ◽  
Vol 3 (3) ◽  
pp. 328 ◽  
Author(s):  
M. Carmen Capel-Sanchez ◽  
Jose M. Campos-Martin ◽  
Jose L. G. Fierro
Keyword(s):  
Hydrogen Peroxide ◽  
Organosulfur Compounds

scholarly journals A Mn(iii) polyoxotungstate in the oxidation of organosulfur compounds by H2O2 at room temperature: an environmentally safe catalytic approach

2016 ◽  
Vol 6 (9) ◽  
pp. 3271-3278 ◽  
Author(s):  
Tiago A. G. Duarte ◽  
Sónia M. G. Pires ◽  
Isabel C. M. S. Santos ◽  
Mário M. Q. Simões ◽  
M. Graça P. M. S. Neves ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Room Temperature ◽  
Organosulfur Compounds ◽  
Keggin Type ◽  
Environmentally Safe

A manganese monosubstituted Keggin-type polyoxometalate was used as a catalyst in the oxidation of recalcitrant organosulfur compounds by hydrogen peroxide at room temperature.

Treatment of VX Hydrolysate with Ultraviolet Light and Hydrogen Peroxide

1997 ◽  
Vol 2 (3) ◽  
Author(s):  
Michael G. MacNaughton ◽  
James R. Scott
Keyword(s):  
Hydrogen Peroxide ◽  
Ultraviolet Light ◽  
Pilot Scale ◽  
Methylphosphonic Acid ◽  
Chemical Agent ◽  
Organosulfur Compounds ◽  
Two Phase ◽  
First Order ◽  
Engineering Study ◽  
Inorganic Sulfate

AbstractAn engineering study was performed to evaluate the use of ultraviolet light and hydrogen peroxide to destroy caustic-neutralized VX nerve agent in the U.S. chemical agent stockpile as an alternative to incineration. Whereas caustic neutralization completely destroys VX, (3-ethyl-S-2-(diisopropylamino)ethyl methylphosphonothiolate, the reaction leaves a complex two-phase mixture containing organic phosphates and organosulfur compounds which require treatment prior to ultimate disposal. Studies performed in laboratory-scale (320-mL), bench-scale (10-L) and pilot-scale (20-L) reactors demonstrated that the principal products of the caustic neutralization-ethyl methylphosphonic acid (EMPA), methylphosphonic acid (MPA), 2-(diisopropylamino)ethyl sulfide (RSR), disulfide (RSSR) and the other mixed sulfides-could be oxidized to inorganic sulfate, phosphate, ammonia and carbon dioxide. The reaction was zero order above 1000 mg/L and pseudo first order below. To mineralize 10,000 lb of VX per day to less than 10 mg/L organic carbon would require more than 1100 lamps of 30 kW each.

Biomimetic oxidation of organosulfur compounds with hydrogen peroxide catalyzed by manganese porphyrins

2012 ◽  
Vol 439-440 ◽  
pp. 51-56 ◽  
Author(s):  
S.M.G. Pires ◽  
M.M.Q. Simões ◽  
I.C.M.S. Santos ◽  
S.L.H. Rebelo ◽  
M.M. Pereira ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Organosulfur Compounds ◽  
Manganese Porphyrins ◽  
Biomimetic Oxidation

Oxidation of organosulfur compounds by hydrogen peroxide in the presence of niobium and vanadium peroxo complexes

2008 ◽  
Vol 42 (5) ◽  
pp. 636-642 ◽  
Author(s):  
Tkhai Fam Vin’ ◽  
A. V. Tarakanova ◽  
O. V. Kostyuchenko ◽  
B. N. Tarasevich ◽  
N. S. Kulikov ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Organosulfur Compounds ◽  
Peroxo Complexes

In situ diesel desulfurization in divided-cell trickle bed electrochemical reactor

2017 ◽  
Author(s):  
◽  
Ghassan Hamad Abdulla
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfur Content ◽  
Diesel Fuel ◽  
Electrochemical Reactor ◽  
Organosulfur Compounds ◽  
Hydrogen Peroxide Production ◽  
In Situ Oxidation ◽  
Divided Cell ◽  
Trickle Bed

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Crude oil contains natural organic components such as organosulfur compounds, and these compounds largely remain in refined petroleum products such as gasoline, diesel and jet fuel products. During fuel combustion, sulfur was emitted as sulfur dioxide or sulfate, which is one of the main causes of air pollution and acid rain. The oil price is inversely proportional to the sulfur content because upgrade of heavy, high-sulfur-containing oil is much more difficult than the light feeds. Many regulations have been established by different countries to control sulfur level in fuels; in the U.S. the maximum required concentration is 15 ppm (parts per million) sulfur in diesel. The most commonly used technology to remove sulfur from diesel fuel is hydrodesulfurization (HDS). The major drawback of HDS is the harsh operating conditions that require high temperatures and pressures with consumption of a large amount of hydrogen. The HDS process is only able to reduce sulfur content to about 500 ppm in diesel. Further reduction requires more intense processing with a significant increase in hydrogen usage, particularly in removing the refractory sulfur compounds, such as benzothiophene (BT), dibenzothiophene (DBT), and their alkyl derivatives. In this dissertation, an efficient and cost-effective process for oxidation of organosulfur compounds (OSCs) in diesel has been developed and investigated. A divided-cell trickle bed electrochemical reactor (TBER) was first developed to produce hydrogen peroxide. The divided-cell trickle bed electrochemical reactor (TBER) has a porous cathode composed of carbon black and polytetrafluoroethylene. It was designed and fabricated to have hydrophobic and hydrophilic components for liquid and gas flows. Hydrogen peroxide generation was successfully demonstrated from reducing oxygen in concentrated alkaline electrolyte solutions. An important feature of the reactor was a cathode made with stainless steel meshes that divide it into four packed-bed cells. This division into sectional cathode resulted in a concentration of hydrogen peroxide that more than doubles that produced in an undivided cathode. The much-improved performance was attributed to the even distribution of the electrolyte and oxygen in the cathode bed, as well as an effective mass transport of oxygen from the gas phase to the electrolyte-cathode interface. After the successful production of hydrogen peroxide, the TBER was employed for in situ oxidation desulfurization of diesel fuel. The possibility of diesel desulfurization with in situ generated hydrogen peroxide in the presence of DBT was systematically investigated. The maximum concentration of hydrogen peroxide after two-hour electrolysis was 31.79 mM without diesel, whereas in the presence of 10% diesel (by volume) in the electrolyte was 18.0 mM. DBT was successfully oxidized in situ in the TBER, with conversion efficiency of 97.75% in six hours. To further improve the efficiency of the hydrogen peroxide production, cathode was modified with MnO2, a potentially more active catalyst for hydrogen peroxide production in alkaline electrolytes. It was found that incorporation of MnO2 indeed promoted in situ oxidation of DBT which was attributed to more hydrogen peroxide produced. The results showed the in situ oxidation process in the divided-cell TBER is a promising and environmentally friendly approach for desulfurization of diesel.

Peroxidase Localization in Hartmanella Trophozoites

1971 ◽  
Vol 29 ◽  
pp. 346-347 ◽  
Author(s):  
George E. Childs ◽  
Joseph H. Miller
Keyword(s):  
Hydrogen Peroxide ◽  
Ultrastructural Localization ◽  
Pathogenic Strain ◽  
Oxidative Enzymes ◽  
Differential Centrifugation ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
The Subject ◽  
Axenic Cultures

Biochemical and differential centrifugation studies have demonstrated that the oxidative enzymes of Acanthamoeba sp. are localized in mitochondria and peroxisomes (microbodies). Although hartmanellid amoebae have been the subject of several electron microscopic studies, peroxisomes have not been described from these organisms or other protozoa. Cytochemical tests employing diaminobenzidine-tetra HCl (DAB) and hydrogen peroxide were used for the ultrastructural localization of peroxidases of trophozoites of Hartmanella sp. (A-l, Culbertson), a pathogenic strain grown in axenic cultures of trypticase soy broth.

Fluorescent proteins for in vivo imaging, where's the biliverdin?

2020 ◽  
Vol 48 (6) ◽  
pp. 2657-2667
Author(s):  
Felipe Montecinos-Franjola ◽  
John Y. Lin ◽  
Erik A. Rodriguez
Keyword(s):  
Hydrogen Peroxide ◽  
In Vivo Imaging ◽  
Near Infrared ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Fluorescent Imaging ◽  
Infrared Light ◽  
Red Fluorescent Protein ◽  
Color Palette

Noninvasive fluorescent imaging requires far-red and near-infrared fluorescent proteins for deeper imaging. Near-infrared light penetrates biological tissue with blood vessels due to low absorbance, scattering, and reflection of light and has a greater signal-to-noise due to less autofluorescence. Far-red and near-infrared fluorescent proteins absorb light >600 nm to expand the color palette for imaging multiple biosensors and noninvasive in vivo imaging. The ideal fluorescent proteins are bright, photobleach minimally, express well in the desired cells, do not oligomerize, and generate or incorporate exogenous fluorophores efficiently. Coral-derived red fluorescent proteins require oxygen for fluorophore formation and release two hydrogen peroxide molecules. New fluorescent proteins based on phytochrome and phycobiliproteins use biliverdin IXα as fluorophores, do not require oxygen for maturation to image anaerobic organisms and tumor core, and do not generate hydrogen peroxide. The small Ultra-Red Fluorescent Protein (smURFP) was evolved from a cyanobacterial phycobiliprotein to covalently attach biliverdin as an exogenous fluorophore. The small Ultra-Red Fluorescent Protein is biophysically as bright as the enhanced green fluorescent protein, is exceptionally photostable, used for biosensor development, and visible in living mice. Novel applications of smURFP include in vitro protein diagnostics with attomolar (10−18 M) sensitivity, encapsulation in viral particles, and fluorescent protein nanoparticles. However, the availability of biliverdin limits the fluorescence of biliverdin-attaching fluorescent proteins; hence, extra biliverdin is needed to enhance brightness. New methods for improved biliverdin bioavailability are necessary to develop improved bright far-red and near-infrared fluorescent proteins for noninvasive imaging in vivo.

Protective effect of chitooligosaccharides on hydrogen peroxide-induced PC-12 cells death by inhibition of oxidative damage

2010 ◽  
Vol 34 (8) ◽  
pp. S27-S27
Author(s):  
Xueling Dai ◽  
Ping Chang ◽  
Ke Xu ◽  
Changjun Lin ◽  
Hanchang Huang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidative Damage ◽  
Protective Effect ◽  
Pc 12 Cells ◽  
Cells Death
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