Hydrous Iron Oxide

The last is ion-chromatography of organophosphoms compounds (OPs) coupled with their adsoi ption concentration using hydrous iron oxide (HIO, Fe,03-nH,0). 

As a possible method of concentrating trace amounts of bioactive organic compounds occurring in the hydrosphere, adsorption properties of various compounds have been explored by employing hydrous metal oxides as the adsorbents. To date, a family of organophosphoms compounds and carbonic acids were adsorbed onto hydrous iron oxide, along with the adsoi ption of monosaccharides onto hydrous zirconium oxide. 

Fig. 15-17 The effect of chloride on adsorption of mercury by hydrous iron oxide at constant total mercury concentration of 3.4 x 10 M. The lines represent the predicted adsorption assuming that Hg-Cl complexes do not sorb at all. (Reprinted with permission from P. V. Avotins, Adsorption and coprecipitation studies of mercury on hydrous iron oxides," 1975, Ph.D. dissertation, Stanford University, Stanford, CA.)...

Bound in minerals such as uraninite, pitchblende, coffinite, etc. fixed as a replacement ion for Y, Ce, Zr, Th, Ca, and Ba in other, particularly accessory minerals and adsorbed as ion on clay minerals, hydrous iron oxides, etc. 

Sonoelectrochemistry has also been used for the efficient employment of porous electrodes, such as carbon nanofiber-ceramic composites electrodes in the reduction of colloidal hydrous iron oxide [59], In this kind of systems, the electrode reactions proceed with slow rate or require several collisions between reactant and electrode surface. Mass transport to and into the porous electrode is enhanced and extremely fast at only modest ultrasound intensity. This same approach was checked in the hydrogen peroxide sonoelectrosynthesis using RVC three-dimensional electrodes [58]. 

Ainsworth C.C., Pilon J.L., Gassman P.L., Van Der Sluys W.G. Cobalt, cadmium, and lead sorption to hydrous iron oxide Residence time effect. Soil Sci Soc Am J 1994 58 ... 

Hongshao Z, Stanforth R (2001) Competitive adsorption of phosphate and arsenate ongoethite. Environ Sci Technol 35 4753—4757 Hsia TH, Lo SL, Lin CF, Lee DY (1994) Characterization of arsenate adsorption on hydrous iron oxide using chemical and physical methods. Colloid Surface A 85 1-7... 

Dissolution of gelatinous hydrous iron oxide, which adsorbs and occludes metals... 

Ford, R.G., Bertsch, P.M., Farley, K.J. 1997. Changes in transition and heavy metal partitioning during hydrous iron oxide aging. Environmental Science and Technology, 31, 2028-2033. 

The hydrous iron oxide has been characterized to have a specific surface area of 600 m2 g 1 and 0.2 moles of active sites per mol of FeOOH. Then the concentration of the active sites is... 

Now the interaction of Zn(II) with the hydrous iron oxide surface can be readily computed because the surface charge is hardly affected by [=FeOZn+], because... 

Cadmium is found naturally deep in the subsurface in zinc, lead, and copper ores, in coal, shales, and other fossil fuels it also is released during volcanic activity. These deposits can serve as sources to ground and surface waters, especially when in contact with soft, acidic waters. Chloride, nitrate, and sulfate salts of cadmium are soluble, and sorption to soils is pH-dependent (increasing with alkalinity). Cadmium found in association with carbonate minerals, precipitated as stable solid compounds, or coprecipitated with hydrous iron oxides is less likely to be mobilized by resuspension of sediments or biological activity. Cadmium absorbed to mineral surfaces (e.g., clay) or organic materials is more easily bioaccumulated or released in a dissolved state when sediments are disturbed, such as during flooding. 

Hydrohetaerolite Zn2Mn ""408 HjO PBF 1 717 Limonite = hydrous iron oxides, mostly goethite PBF 1 685 Manganite MnO(OH) MW 95... 

Avnir, D. (1989) The fractal approach to heterogenous chemistry. J. Wiley, New York Avnir, D. Farin, D. Pfeifer, P. (1983) Chemistry in noninteger dimension between two and three. II. Fractal surfaces at adsorbens. J. Chem. Phys. 79 3566-3571 Avotins, P.V. (1975) Adsorption and coprecipitation studies of mercury on hydrous iron oxide. Ph.D. Thesis, Stanford University, California, 124 p. 

Childs, C.W Downes, C.J. Wells, N. (1982) Hydrous iron oxide minerals with short... 

R.E. Spitzer, C.R. (1977) The Viking magnetic properties experiment Primary mission results. J. Geophys. Res. 82 4547-4558 Harrison, J.B. Berkheiser,V.E. (1982) Anion interactions with freshly prepared hydrous iron oxides. Clays Clay Min. 30 97-102 Harrison, P.M. HoyT.G. (1973) Ferritin. In Eichhom, G.L. (ed.) Inorganic biochemistry. 

Lewis, D.G. Cardde, C.M. (1989) Hydrolysis of Fe(III) solution to hydrous iron oxides. Aust. J. Soil Res. 27 103-115 Lewis, D.G. Farmer,V.C. (1986) Infrared absorption of surface hydroxyl groups and lattice vibrations in lepidocrodte (y-FeOOH) and boehmite (y-Al-OOH). Clay Min. 21 93-100... 

Sorption of diromium(VI) on hydrous iron oxides. Z. Wasser-Abwasser-Forsdi. 19 186—... 

Perret, D. Gaillard, J.-F. Dominik, J. Atteia, O. (2000) The diversity of natural hydrous iron oxides. Environ. Sd. Tedm. 34 3540— 3546... 

Sylvester, P., Westerhoff, P., Moller, T. et al. (2007) A hybrid sorbent utilizing nanoparticles of hydrous iron oxide for arsenic removal from drinking water. Environmental Engineering Science, 24(1), 104-12. 

For the preparation of tris(ethylenediamine)nickel(II) chloride 2-hydrate, 28 g. of 70% aqueous ethylenediamine is added to a solution of 23.8 g. (0.1 mol) of NiCl2 6H20 in 100 to 150 ml. of water. The purple solution is filtered to remove the small amount of hydrous iron oxide which precipitates and is then evaporated to a volume of 60 to 70 ml. on a steam bath. Two drops of ethylenediamine are added, and the solution is cooled in an ice bath. The orchid-colored crystals that form are collected by suction, washed twice with 95 % ethanol, and air-dried. The yield is 28.6 g. (80%). Several more grams may be recovered from the mother liquor by adding ethanol and cooling. Anal. Calcd. for [Ni(C2H8N2)3]Cl2-2H20 Ni, 16.97% Cl, 20.50%. Found Ni, 16.87% Cl, 20.48%. 

Corrosion often begins at a location where the metal is stressed in some way or isolated from oxygen, such as between joints or under a paint film. The metal ions dissolve in the moisture film and the electrons migrate to another location where they are taken up by a depolarizer . Oxygen is the most common depolarizer the resulting hydroxide ions react with the Fe2+ to form the mixture of hydrous iron oxides known as rust . 

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