Please use this identifier to cite or link to this item: http://hdl.handle.net/10553/49820
Title: Competition between O2 and H2O2 in the oxidation of Fe(II) in natural waters
Authors: González-Dávila, Melchor 
Santana-Casiano, J. Magdalena 
Millero, Frank J.
UNESCO Clasification: 251002 Oceanografía química
Keywords: Kinetics
Oxidation
Iron
Oxygen
Hydrogen peroxide
Issue Date: 2006
Project: Efecto de Los Compuestos Catecolatos, Hidroxamatos y Porfirinas en El Comportamiento Qwuimico de Fe(Ii) en El Medio Marino. 
Journal: Journal of Solution Chemistry 
Abstract: The oxidation rates of nanomolar levels of Fe(II) in seawater (salinity S = 36.2) by mixtures of O2 and H2O2 has been measured as a function of pH (5.8–8.4) and temperature (3–35∘C). A competition exists for the oxidation of Fe(II) in the presence of both O2 (μ mol⋅L−1 levels) and H2O2 (nmol⋅L−1 levels). A kinetic model has been applied to explain the experimental results that considers the interactions of Fe(II) with the major ions in seawater. In the presence of both oxidants, the hydrolyzed Fe(II) species dominate the Fe(II) oxidation process between pH 6 and 8.5. Over pH range 6.2–7.9, the FeOH+ species are the most active, whereas above pH 7.9, the Fe(OH)02 species are the most active at the levels of CO2−3 concentration present in seawater. The predicted Fe(II) oxidation rate at [Fe(II)]0 = 30nmol⋅L−1 and pH = 8.17 in the oxygen-saturated seawater with [H2O2]0 = 50nmol⋅L−1 (log 10 k = −2.24s−1) is in excellent agreement with the experimental value of log 10 k = −2.29s−1 ([H2O2]0 = 55nmol⋅L−1, pH = 8).
URI: http://hdl.handle.net/10553/49820
ISSN: 0095-9782
DOI: 10.1007/s10953-006-8942-3
Source: Journal of Solution Chemistry [ISSN 0095-9782], v. 35 (1), p. 95-111
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