Kinetics ferrous iron oxidation

Halfmeier, H, Schafer-Treffenfeldt, W., andReuss, M., Potential ofThiobacillus ferrooxidans for Waste Gas Purification. Part 2. Increase in Continuous Ferrous Iron Oxidation Kinetics Using Immobilized Cells, / / / /. Microbiol. 

Breed A. W. and Hansford G. S. (1999) Effects of pH on ferrous-iron oxidation kinetics of Leptospirillium ferro-oxidans in continuous culture. Biochem. Eng. J. 3, 193-201. 

A number of investigators have attempted to construct kinetic models of the light-mediated transformations of iron in natural waters. For example, Miller et al. [98] used a relatively simple scheme incorporating LMCT, reduction of inorganic Fe(III) by superoxide, ferrous iron oxidation and superoxide disproportionation to model the generation and decay of ferrous iron and... 

Osaki, S., Kinetic Studies of Ferrous Iron Oxidation with Crystalline... 

The purpose of this section is to expand the discussion on the chemistry of iron and to use it as an example of redox reactions in natural waters. The reaction kinetics of redox reactions will be discussed using ferrous iron oxidation as an example. 

Table 28.1. Surface complexation reactions considered by Liger et al. (1999) in describing the kinetics of the catalytic oxidation ofuranyl by ferrous iron...

Ahmad AR, Nye PH. 1990. Coupled diffusion and oxidation of ferrous iron in soils. I. Kinetics of oxygenation of ferrous iron in soil suspension. Journal of Soil Science 41 395-409. 

Core and valence level photoemission studies of iron oxide surfaces and the oxidation of iron. Surface Sd. 68 459—468 Bruno, J. Sturam, J.A. Wersin, P. Brand-berg, E. (1992) On the influence of carbonate on mineral dissolutions I. The thermodynamics and kinetics of hematite dissolution in bicarbonate solutions at T = 25°C. Geo-chim. Cosmochim. Acta 56 1139—1147 Brusic.V. (1979) Ferrous passivation. In Corrosion Chemistry, 153—184 Bruun Hansen, H.C. Raben-Lange, R. Rau-lund-Rasmussen, K. Borggaard, O.K. 

Davidson, W. Seed, G. (1983) The kinetics of the oxidation of ferrous iron in synthetic and natural waters. Geochim. Cosmochim. Acta 47 67-79... 

Recently we presented (23) the results of an experimental study on the kinetics and mechanisms of the reaction of lepidocrocite (y-FeOOH) with H2S. With respect to the interaction between iron and sulfur, lepidocrocite merits special attention. It forms by reoxidation of ferrous iron under cir-cumneutral pH conditions (24), and it can therefore be classified as a reactive iron oxide (19). The concept of reactive iron was established by Canfield (19), who differentiated between a residual iron fraction and a reactive iron fraction (operationally defined as soluble in ammonium oxalate). The reactive iron fraction is rapidly reduced by sulfide or by microorganisms. 

The relationship of the stirring rate in these experiments to the rates of hydrolysis reactions of basalt phases is indicative of surface-reaction controlled dissolution (21). First order kinetics are not inconsistent with certain rate-determining surface processes (22). Approximate first order kinetics with respect to dissolved oxygen concentration have been reported for the oxidation of aqueous ferrous iron (23) and sulfide (24), and in oxygen consumption studies with roll-type uranium deposits(25). 

Example 9. Kinetic oxidation of dissolved ferrous iron with oxygen Example 10.—Aragonite-strontianite solid solution Example 11.-Transport and cation exchange Example 12—Advective and diffusive flux of heat and solutes Example 13.-ID transport in a dual porosity column with cation exchange Example 14.-Advective transport, cation exchange, surface complexation, and mineral equilibria... 

Singer P. C. and Stumm W. (1968) Kinetics of the oxidation of ferrous iron. In 2nd Symp. Coal Mine Drainage Research. National Coal Association/Bituminous Coal Research, pp. 12-34. 

This mechanism of oxidative attack has two facets, namely the regeneration of ferric ions by the organism and the chemical interaction of ferric ions with the sulfide mineral. Singer and Stumm (1970) have shown that the rate of oxidation of ferrous iron by oxygen in abiotic systems is a function of pH. At pH values greater than 4.5, the kinetic relationship is described by eqn. (13) ... 

Abiotic oxidation kinetics of sulfur and Fe(ll). The abiotic oxidation rates of pyrite and ferrous iron have been studied extensively for more than 30 years (cf. Garrels and Thompson 1960 McKibben and Barnes 1986 Nicholson et al. 1988 Moses and Herman 1991). The work on pyrite-oxidation kinetics has been updated and critiqued by Williamson and Rimstidt (1994), while Wehrli (1990) has synthesized the published data on Fe oxidation. (See also King et al, 1995.)... 

Davison, W. and G. Seed (1983), The Kinetics of the Oxidation of Ferrous Iron in Synthetic and Natural Waters, Geochim. Cosmochim. Acta. 47, 67-79. 

The kinetics of aqueous dispersion polymerization differ very little from acrylonitrile bulk or emulsion polymerization. Redox initiation is normally used in commercial production of polymers for acrylic fibers. This type of initiator can generate free radicals in an aqueous medium efficiently at relatively low temperatures. The most common redox system consists of ammonium or potassium persulfate (oxidizer), sodium bisulfite (reducing agent), and ferric or ferrous iron (catalyst). This system gives the added benefit of supplying dye sites for the fiber. 

Figure 7. Uptake kinetics of dissolved Fe(II) by different iron oxides in anoxic aqueous supensions (pH 7.2, 25 m L" , 1=20 mM, T=25 C, Fe(II)soi= dissolved concentration of ferrous iron). The difference between Fe(II)tot and Fe(II)sol gives surface-bound ferrous iron. Adapted from (7).

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