During wet seasons, waterlogged conditions favoured a lower redox potential
and the reduction of iron(III) to iron(II) releasing adsorbed ions such as sulfate.
Other reason for biological acceleration of galvanic interaction was the chelation of cysteine secreted by Tf with pyrite, which altered the redox potential
of Fe2+:Fe3 couple, thus accelerating the oxidation of pyrite sulfides as + indicated by Rojas and Tributsch, (2001).
Influence of soil redox potential
on nitrogen uptake and growth of wetland oak seedlings.
pH, redox potential
and oxygen concentration: The pH values showed no high variations in the whole samplings, neither in the bottom water (8.15 [+ or -] 0.11) nor in the interstitial water of sediments (8.6 [+ or -] 0.13).
For example, the redox potential
for the reduction of [Fe.sup.3+] to [Fe.sup.2+] is given as 770 mV and the redox potential
for the reduction of C[O.sub.2] to C[H.sub.4] is given as -230 mV If these reactions were coupled, Fel+ would be reduced because it has the higher redox potential
(it's a better electron acceptor).
TABLE 12-1 Typical Redox Potential
Values for Chemical Reactions in a Wetland Chemical Reaction Redox Potential
(mV) [O.sub.2] available 400 to 700 N[O.sup.-.sub.3] converted to [N.sub.2] 250 [Mn.sup.4+] converted to [Mn.sup.2+] 225 [Fe.sup.3+] converted to [Fe.sup.2+] 100 to -100 S[O.sup.2-.sub.4] converted to [H.sub.2]S -100 to -200 C[O.sub.2] converted to C[H.sub.4] < -200 TABLE 12-2 Typical Species Found in Wetlands Common Name Scientific Name Submerged Aquatic Species (0.1-3 m water depth) Water mosses Fontinalis spp.
data from 5 wk of waterlogging of 80 families derived from four soft winter wheat populations at LAES Central Station, Louisiana State University at Baton Rouge.
To determine the relationship between forest decline and reducing conditions in the top 10 cm of soil, where tree seedlings are most likely to be affected, soil redox potential
was measured on the nine islands with plots established in 1992.
- The redox potentials
below - 150 mV of the flooded seedlings indicate rhizosphere anoxia whereas the redox potentials
above + 250 of the unflooded rhizospheres indicate oxygenated soils (Mitsch and Gosselink, 1993).
Endari reduces oxidant damage to red blood cells by improving the redox potential
of nicotinamide adenine dinucleotide, a coenzyme that has been identified as the primary regulator of oxidation.
Fibroblasts isolated from the lungs of a young mouse conditioned the culture medium to achieve an extracellular [E.sub.h]CySS of about -95 mV within 24 hours, independent of the starting redox potential
of the medium (Figure 1(a)).
This observation indicates that pH has a larger effect on the redox potential
of hydroquinone (in the pH range of the present study) than it does on the stoichiometry and resulting reducibility of the Fe(III) kojic acid complex.