scholarly journals Electrochemically Induced Metal- vs. Ligand-Based Redox Changes in Mackinawite: Identification of a Fe3+- and Polysulfide-Containing Intermediate

2021 ◽  
Author(s):  
Sebastian Sanden ◽  
Robert Szilagyi ◽  
Yamei Li ◽  
Norio Kitadai ◽  
Samuel M Webb ◽  
...  
Keyword(s):  
Redox Potential ◽  
Ferrous Iron ◽  
Maturation Process ◽  
Anaerobic Conditions ◽  
Ph Dependent

Under anaerobic conditions, ferrous iron reacts with sulfide producing FeS, which can then undergo a temperature, redox potential, and pH dependent maturation process resulting in the formation of oxidized mineral...

The Reaction of Thiol Compounds with the Vitamin-K Dependent Clotting Factors

1969 ◽  
Vol 21 (03) ◽  
pp. 573-579 ◽  
Author(s):  
P Fantl
Keyword(s):  
Prothrombin Time ◽  
Vitamin K ◽  
Anaerobic Conditions ◽  
Clotting Factors ◽  
Thiol Compounds ◽  
Aerobic Conditions ◽  
One Stage ◽  
Factor Ii ◽  
Ph Dependent ◽  
The One

SummaryTreatment of human and dog oxalated plasma with 0.2 to 1.0 × 10−1 M 2.3-dithiopropanol (BAL) or dithiothreitol (DTT) at 2–4° C for 30 min results in the reduction of the vitamin-K dependent clotting factors II, VII, IX and X to the respective-SH derivatives. The reaction is pH dependent. Under aerobic conditions the delayed one stage prothrombin time can be partly reversed. Under anaerobic conditions a gradual prolongation of the one stage prothrombin time occurs without reversal.In very diluted plasma treated with the dithiols, prothrombin can be converted into thrombin if serum as source of active factors VII and X is added. In contrast SH factors VII, IX and X are inactive in the specific tests. Reoxidation to active factors II, VII, IX and X takes place during adsorption and elution of the SH derivatives. The experiments have indicated that not only factor II but also factors VII, IX and X have active-S-S-centres.

Microbial Metabolism of Benzene and the Oxidation of Ferrous Iron under Anaerobic Conditions: Implications for Bioremediation

Anaerobe ◽  
1999 ◽  
Vol 5 (6) ◽  
pp. 595-603 ◽  
Author(s):  
Matthew E Caldwell ◽  
Ralph S Tanner ◽  
Joseph M Suflita
Keyword(s):  
Ferrous Iron ◽  
Microbial Metabolism ◽  
Anaerobic Conditions

scholarly journals IRON DYNAMICS AND ITS RELATION TO SOIL REDOX POTENTIAL AND PLANT GROWTH IN ACID SULPHATE SOIL OF SOUTH KALIMANTAN, INDONESIA

2017 ◽  
Vol 17 (1) ◽  
pp. 1 ◽  
Author(s):  
Wahida Annisa ◽  
Dedy Nursyamsi
Keyword(s):  
Organic Matter ◽  
Plant Growth ◽  
Redox Potential ◽  
Rice Straw ◽  
Ferrous Iron ◽  
Block Design ◽  
Soil Redox Potential ◽  
Soil Redox ◽  
Acid Sulphate Soil ◽  
Acid Sulphate

<p>Organic matter has a function to maintain reductive conditions and to chelate toxic elements in acid sulphate soils. The study aimed to assess the dynamics of ferrous iron (Fe2+) in acid sulphate soil and its correlation with soil redox potential (Eh) and plant growth. The experiment was arranged in two factorial randomized block design with three replications. The first factor was two types of organic matter: (1) control (without organic matter), (2) rice straw and (3) rush weed (Eleocharis dulcis). The second factor was time of decomposition of organic matter: I1 = 2 weeks, I2 = 4 weeks, I3 = 8 weeks, and I4 = 12 weeks (farmer practice). The results showed that concentration of ferrous iron in the soil ranged from 782 to 1308 mg kg-1 during the rice growing season. The highest constant rate of iron reduction (k F2+) was observed on application of rice straw and rush weed with decomposition time of 8 weeks with the k Fe2+ value of 0.016 and 0.011 per day, respectively, while the ferrous iron formation without organic matter had the k Fe2+ value of 0.077 per day. The ferric iron (Fe3+) reduction served as a function of soil Eh as indicated by the negative correlation of ferrous iron and Eh (r = -0.856*). Organic matter decreased exchangeable iron due to chelating reaction. Iron concentration in roots was negatively correlated with soil soluble iron (r = -0.62*). Application of rice straw decomposed for 8 weeks increased the height of rice plant up to 105.67 cm. The score of Fe2+ toxicity at 8 weeks after planting ranged from 2 to 3, so rice crop did not show iron toxicity symptoms. </p>

Oxidation of Structural Ferrous Iron in Vermiculites: I. Oxidation by Fe3+

Clay Minerals ◽  
1988 ◽  
Vol 23 (3) ◽  
pp. 261-270 ◽  
Author(s):  
H. Graf ◽  
V. Reichenbach ◽  
B. Beyme
Keyword(s):  
Hydrogen Peroxide ◽  
Electron Transfer ◽  
Redox Potential ◽  
Cation Exchange ◽  
Ferrous Iron ◽  
Activity Ratio ◽  
Redox Potentials ◽  
Interlayer Cation ◽  
Pt Electrode ◽  
Coupled Reactions

AbstractVermiculite prepared from biotite by interlayer cation exchange was reacted with solutions exhibiting redox potentials between 625 and 765 mV. The redox potential was controlled by the Fe2+/Fe3+ activity ratio, measured with a Pt electrode, and kept constant by addition of hydrogen peroxide to balance electron transfer from structural Fe2+ to Fe3+ in solution. Oxidation of structural Fe2+ was followed by Eh-stat titration and the rate of oxidation was shown to depend on the amount of Fe3+ penetrating into interlayer positions. Consequently, it was affected not only by the redox potential, but also by the activity between Fe3+ and all other cations present in solution or in an exchangeable state. Oxidation and cation exchange are coupled reactions. In contrast to the redox potential in solution, the effective redox potential controlling the oxidation of structural Fe2+ was increased by preferential sorption of the Fe3+ ion.

EFFECTS OF TEMPERATURE ON NO3− AND NO2− REDUCTION, NITROGENOUS GAS PRODUCTION, AND REDOX POTENTIAL IN A SATURATED SOIL

1973 ◽  
Vol 53 (2) ◽  
pp. 213-218 ◽  
Author(s):  
L. D. BAILEY ◽  
E. G. BEAUCHAMP
Keyword(s):  
Redox Potential ◽  
Nitrogen Source ◽  
Low Temperatures ◽  
Slow Rate ◽  
Gas Production ◽  
Saturated Soil ◽  
Anaerobic Conditions ◽  
Ap Horizon ◽  
Effects Of Temperature ◽  
No2 Reduction

Samples of the Ap horizon of a Huron soil were used to investigate the effects of temperature on NO3− and NO2− reduction, nitrogenous gas production, and redox potential under anaerobic conditions in the laboratory. NO3− and NO2− reduction occurred at redox potential (Eh) values of 200 and 180 mV, respectively. The rate of NO3− and NO2− reduction decreased with decreasing temperatures (30–5 C). At 5 C, NO3− reduction was completely inhibited but NO2− reduction continued at a slow rate. Gas chromatographic analyses showed that the denitrification gas was composed of N2, N2O, and NO. Decreasing the temperature decreased the production of N2, increased the production of NO, and did not significantly affect the production of N2O. The increased production of NO at low temperatures when NO2− was the nitrogen source is attributed to chemodenitrification processes.

scholarly journals Evolving stability and pH-dependent activity of the high redox potential Botrytis aclada laccase for enzymatic fuel cells

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Stefan Scheiblbrandner ◽  
Erik Breslmayr ◽  
Florian Csarman ◽  
Regina Paukner ◽  
Johannes Führer ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Redox Potential ◽  
Dependent Activity ◽  
Ph Dependent ◽  
High Redox Potential
Sign in / Sign up

Export Citation Format

Share Document