Effect of catechins and tannins on hydroxyl radical formation in depleted uranium-hydrogen peroxide systems

2009 ◽  
Vol 283 (1) ◽  
pp. 151-156 ◽  
Author(s):  
Akira Nakajima ◽  
Emiko Matsuda ◽  
Yuto Ueda
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Depleted Uranium ◽  
Radical Formation

Removal of Tributyltin in Shipyard Waters: Characterization and Treatment to Meet Low Parts per Trillion Levels

2003 ◽  
Vol 19 (03) ◽  
pp. 179-186
Author(s):  
Gary C. Schafran ◽  
R. Prasad ◽  
F. H. Thorn ◽  
R. Michael Ewing ◽  
J. Soles
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Hydroxyl Radical ◽  
Ultraviolet Irradiation ◽  
Treatment Plant ◽  
Full Scale ◽  
Radical Formation ◽  
Estuarine Waters ◽  
Treatment Conditions ◽  
Made In

Removal of tributyltin (TBT) from shipyard waters has been conducted in Virginia shipyards for over 2.5 years and has resulted in a 99% reduction of TBT discharged to coastal-estuarine waters. This has been achieved by conventional coagulation clarification for particulate TBT removal and removal of dissolved TBT using activated carbon. Although advances have been made in the understanding of TBT removal under various treatment conditions, TBT removal with the existing full-scale treatment plant to levels that would comply with a 50 parts per trillion (pptr) discharge limit are not possible. Results from study efforts that are currently ongoing suggest that the 50 pptr limit might be reached using ultraviolet irradiation or ozonation and that both processes would be substantially improved with the addition of hydrogen peroxide to promote hydroxyl radical formation.

Hydroxyl radical formation from bacteria-assisted Fenton chemistry at neutral pH under environmentally relevant conditions

2016 ◽  
Vol 13 (4) ◽  
pp. 757 ◽  
Author(s):  
Jarod N. Grossman ◽  
Tara F. Kahan
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Natural Waters ◽  
Shewanella Oneidensis ◽  
Radical Formation ◽  
Production Rates ◽  
Fenton Chemistry ◽  
Iron Reducing Bacteria ◽  
Neutral Ph ◽  
Reducing Bacteria

Environmental contextReactions in natural waters such as lakes and streams are thought to be extremely slow in the absence of sunlight (e.g. at night). We demonstrate that in the presence of iron, hydrogen peroxide and certain bacteria (all of which are common in natural waters), certain reactions may occur surprisingly quickly. These findings will help us predict the fate of many compounds, including pollutants, in natural waters at night. AbstractDark Fenton chemistry is an important source of hydroxyl radicals (OH•) in natural waters in the absence of sunlight. Hydroxyl radical production by this process is very slow in many bodies of water, owing to slow reduction and low solubility of FeIII at neutral and near-neutral pH. We have investigated the effects of the iron-reducing bacteria Shewanella oneidensis (SO) on OH• production rates from Fenton chemistry at environmentally relevant hydrogen peroxide (H2O2) and iron concentrations at neutral pH. In the presence of 2.0 × 10–4M H2O2, OH• production rates increased from 1.3 × 10–10 to 2.0 × 10–10Ms–1 in the presence of 7.0 × 106cellsmL–1 SO when iron (at a concentration of 100μM) was in the form of FeII, and from 3.6 × 10–11 to 2.2 × 10–10Ms–1 when iron was in the form of FeIII. This represents rate increases of factors of 1.5 and 6 respectively. We measured OH• production rates at a range of H2O2 concentrations and SO cell densities. Production rates depended linearly on both variables. We also demonstrate that bacteria-assisted Fenton chemistry can result in rapid degradation of aromatic pollutants such as anthracene. Our results suggest that iron-reducing bacteria such as SO may be important contributors to radical formation in dark natural waters.

Effect of amino acids on X-ray-induced hydrogen peroxide and hydroxyl radical formation in water and 8-oxoguanine in DNA

2008 ◽  
Vol 73 (4) ◽  
pp. 470-478 ◽  
Author(s):  
I. N. Shtarkman ◽  
S. V. Gudkov ◽  
A. V. Chernikov ◽  
V. I. Bruskov
Keyword(s):  
Amino Acids ◽  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Radical Formation ◽  
X Ray

scholarly journals Identifying the reactive sites of hydrogen peroxide decomposition and hydroxyl radical formation on chrysotile asbestos surfaces

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Martin Walter ◽  
Walter D. C. Schenkeveld ◽  
Gerald Geroldinger ◽  
Lars Gille ◽  
Michael Reissner ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Radical Formation ◽  
Chrysotile Asbestos ◽  
Hydrogen Peroxide Decomposition ◽  
Peroxide Decomposition

scholarly journals Superoxide dismutase enhances the formation of hydroxyl radicals in the reaction of 3-hydroxyanthranilic acid with molecular oxygen

1988 ◽  
Vol 251 (3) ◽  
pp. 893-899 ◽  
Author(s):  
H Iwahashi ◽  
T Ishii ◽  
R Sugata ◽  
R Kido
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Hydroxyl Radical ◽  
Molecular Oxygen ◽  
Hydroxyl Radicals ◽  
Fenton Reaction ◽  
Potassium Phosphate ◽  
Radical Formation ◽  
Superoxide Anions ◽  
Hydroxyanthranilic Acid

Superoxide dismutase (SOD) enhanced the formation of hydroxyl radicals, which were detected by using the e.s.r. spin-trapping technique, in a reaction mixture containing 3-hydroxyanthranilic acid (or p-aminophenol), Fe3+ ions, EDTA and potassium phosphate buffer, pH 7.4. The hydroxyl-radical formation enhanced by SOD was inhibited by catalase and desferrioxamine, and stimulated by EDTA and diethylenetriaminepenta-acetic acid, suggesting that both hydrogen peroxide and iron ions participate in the reaction. The hydroxyl-radical formation enhanced by SOD may be considered to proceed via the following steps. First, 3-hydroxyanthranilic acid is spontaneously auto-oxidized in a process that requires molecular oxygen and yields superoxide anions and anthranilyl radicals. This reaction seems to be reversible. Secondly, the superoxide anions formed in the first step are dismuted by SOD to generate hydrogen peroxide and molecular oxygen, and hence the equilibrium in the first step is displaced in favour of the formation of superoxide anions. Thirdly, hydroxyl radicals are generated from hydrogen peroxide through the Fenton reaction. In this Fenton reaction Fe2+ ions are available since Fe3+ ions are readily reduced by 3-hydroxyanthranilic acid. The superoxide anions do not seem to participate in the reduction of Fe3+ ions, since superoxide anions are rapidly dismuted by SOD present in the reaction mixture.

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