Ferric oxyhydroxide

Phosphate is also ubiquitous as a minor component within the crystal lattices of other minerals or adsorbed onto the surface of particles such as clays, calcium carbonate, or ferric oxyhydroxides (Ruttenberg, 1992). Therefore, in general, transport of these other particulate phases represents an important transport pathway of P as well. 

Ames LL, McGarrah JE, Walker BA, Salter PF (1983d) Uranium and radium sorption on amorphous ferric oxyhydroxide. Chem Geol 40 135-148... 

Hsi C, Langmuir D (1985) Adsorphon of uranyl onto ferric oxyhydroxides applications of the surface complexation site-binding model. Geochim Cosmochim Acta 49 1931-1941 Ingri J, Widerlund A, Land M, Gustafsson O, Anderson P, Ohlander B (2000) Temporal variation in the fractionation of the rare earth elements in a boreal river the role of colloidal particles. Chem Geol 166 23-45... 

The mammalian protein has an enzymatic activity and catalyzes the oxidation of Fe2+ at ferroxidase sites present only in H subunits [88], This reaction may proceed through a di-ferric-p-peroxo species, which rapidly decomposes, eventually forming a ferric oxyhydroxide mineral core via an inorganic hydrolysis polymerization [89]. 

Akg kaganeite, Apy=arsenopyrite, Ca-FA=amorphous C a ferric arsenate, Gt=goethite, HFA=hydrous ferric arsenate, HFO=hydrous ferric oxyhydroxide, Hm=hematite,... 

In situ Mossbauer parameters for small particles of a hydrated ferric oxyhydroxide, FeOOH(hydrated), dispersed on high area Vulcan XC-72 carbon ... 

As we pointed out earlier, the H subunit catalyses the ferroxidase reaction, which occurs at all levels of iron loading, but decreases with increasing amounts of iron added (48-800 Fe/ protein). Reaction (19.8) catalysed by both FI- and L-chain ferritins, occurs largely at intermediate iron loadings of 100-500 Fe/protein. Once nucleation has taken place, the role of the protein is to maintain the growing ferrihydrite core within the confines of the protein shell, thus maintaining the insoluble ferric oxyhydroxide in a water-soluble form. 

Why mammalian ferritin cores contain ferrihydrite-like structures rather than some other mineral phase is less easy to understand, and presumably reflects the way in which the biomineral is built up within the interior of the protein shell together with the geometry of the presumed nucleation sites. The phosphate content in the intracellular milieu can readily be invoked to explain the amorphous nature of the iron core of bacterioferritins and plants. Indeed, when the iron cores of bacterioferritins are reconstituted in the absence of phosphate, they are found to be more highly ordered than their native counterparts, and give electron diffraction lines typical of the ferrihydrite structure. Recently it has been reported that the 12 subunit ferritin-like Dps protein (Figure 19.6), discussed in Chapter 8, forms a ferrihydrite-like mineral core, which would seem to imply that deposition of ferric oxyhydroxides within a hollow protein cavity (albeit smaller) leads to the production of this particular mineral form (Su et al., 2005 Kauko et al., 2006). 

An end-member case would be precipitation of ferric oxyhydroxide by photosynthetic Fe(II)-oxidizing bacteria through simple Rayleigh fractionation, with no external Fe(II) flux or return of Fe(II) to the pool from Fe(III)-reducing bacterial activity, which will produce extreme Fe isotope compositions, but only in the latest fluids and precipitates (Fig. 17). In... 

Bauer, Ph. Genin, J.M. Rezel, D. (1986) Mossbauer effect evidence of chlorine environments in ferric oxyhydroxides from iron corrosion in chlorinated aqueous solution. Hyperfme Interactions 28 757-760... 

Harrison, P.M. Fischbach, F.A. Hoy, T.G. Haggis, G.H. (1967) Ferric oxyhydroxide core of ferritin. Nature 216 1188-1190 Harvey, D.T. Linton, R.W (1981) Chemical characterization of hydrous ferric oxides by X-ray photoelectron spectroscopy. Anal. 

Hotta,Y Ozeki, S. Suzuki,T. Imal, S. Ka-neko, S. (1991) Surface characterization of titanated a-Fe203. Langmuir 7 2649—2654 Howe, A.T. Gallagher, K.J. (1975) Mossbauer studies in the colloidal system P-FeOOH — P-Fe20j Structures and dehydration mechanism. J. Chem. Soc. Faraday Trans. I. 71 22-34 Hsi, C.D. Langmuir, D. (1985) Adsorption of uranyl onto ferric oxyhydroxides Application of the surface complexation site-binding model. Geochim. Cosmochim. Acta 49 1931-1941... 

Ishikawa, T. Inouye, K. (1972) The structural transformation of ferric oxyhydroxides and their activity to sulfur dioxide. Bull. Chem. Soc. Japan 45 2350-2354... 

Kandori, K. Tamura, S. Ishikawa.T. (1994) Inner structure and properties of diamondshaped and spherical a-Fe203 particles. Colloid Polym. Sci. 272 812-819 Kandori, K. Uchida, S. Kataoka, S. Ishikawa, T. (1992) Effects of silicate and phosphate on the formation of ferric oxide hydroxide particles. J. Mater Sci. 27 719-728 Kandori, K. Yasukawa, A. Ishikawa,T. (1996) Influence of amines on formation and texture of uniform hematite particles. J. Colloid Interface Sci. 180 446-452 Kaneko, K. Inouye, K. (1974) Electrical properties of ferric oxyhydroxides. Bull. Chem. 

Loeppert, R.H. Hossner, L.R. Amin, P.K. (1984) Formation of ferric oxyhydroxides from ferrous and ferric perchlorate in stirred calcareous systems. Soil Sd. Soc. Am. J. 48 ... 

Maeda, Y. Hachisu, S. (1983) Schiller layers in y-ferric oxyhydroxide sol as an order-disorder phase separating system. Colloids Surfaces 6 1-6... 

All physical evidence points to a compact structure for the pol5mier. Its shape is spherical and its density, 3.0, is fairly high. Nevertheless, the tetrahedral coordination of the iron significantly lowers the coordination requirements for the oxygen from what they are in the ferric oxyhydroxides, which are similar in composition. In these materials, each oxygen is surrounded by four iron atoms on the average 43). Given the stoichiometry of the polymer, and the assumption that the waters are at the surface occup)dng one iron coordination site, then a coordi-... 

In crystalline oxides and hydroxides of iron (III) octahedral coordination is much more common than tetrahedral 43). Only in y-FegOs is a substantial fraction of the iron (1/3) in tetrahedral sites. The polymer isolated from nitrate solution is the first example of a ferric oxyhydroxide in which apparently all of the irons are tetrahedrally coordinated. From the oxyhydroxide core of ferritin, Harrison et al. 44) have interpreted X-ray and electron diffraction results in terms of a crystalline model involving close packed oxygen layers with iron randomly distributed among the eight tetrahedral and four octahedral sites in the unit cell. In view of the close similarity in Mdssbauer parameters between ferritin and the synthetic poljmier it would appear unlikely that the local environment of the iron could be very different in the two materials, whatever the degree of crystallinity. Further study of this question is needed. 

Hsi, C.-K. D. Langmuir, D. 1985. Adsorption of uranyl onto ferric oxyhydroxides application of the surface complexation site-binding model. Geochimica et Cosmochimica A eta, 49,1931 -1941. 

Iron dextran is a stable complex of ferric oxyhydroxide and dextran polymers containing 50 mg of elemental iron per milliliter of solution. It can be given by deep intramuscular injection or by intravenous infusion, although the intravenous route is used most commonly. Intravenous administration eliminates the local pain and tissue staining that often occur... 

Inskeep, W.P., Macur, R.E., Harrison, G. et al. (2004) Biomineralization of As(V)-hydrous ferric oxyhydroxide in microbial mats of an acid-sulfate-chloride geothermal spring, Yellowstone National Park. Geochimica et Cos-mochimica Acta, 68(15), 3141-55. 

Macalady, D.L., D. Langmuir, T. Grundl, and A. Elzerman. 1990. Use of model-generated Fe3+ ion activities to compute Eh and ferric oxyhydroxide solubilities in anaerobic systems. In D.C. Melchior and R.L. Bassett, ed., Chemical Modeling of Aqueous Systems 11, Vol. 416 pp. 350-367. American Chemical Society, Washington, DC. 

Wetlands have the potential to remove metals from AD by metal adsorption on ferric oxyhydroxides, metal uptake by plant and algae, metal complexation by organic materials, and metal precipitation as oxides, oxyhydroxides, or sulfides. However, only metal precipitation as either oxides or sulfides has long-term metal-removal potential (Evangelou, 1995b). 

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