Oxidation of Iron and Manganese

A Partial List of Microorganisms Involved in the Oxidation of Iron and Manganese Compounds 

Iron-oxidizing bacteria Neutrophilic Leptothrix, Gallionella, Ferroglobus, FeCOj, FeSj Oxygen 

Acidophilic Thiobacillus, Ferrobacillus, Sulfobacillus, Ferroglobus, Fe(II) FeS04, FeSj Oxygen, nitrate 

Ferroplasma, Sulfolobus Heterotrophs Naumanniella, Ochrobium, Siderocapsa, Siderococcus, Organic complexes of Fe Oxygen 

Sphaerotilus Manganese-oxidizing bacteria Arthrobacter, Bacillus, Leptothrix, Metallogenium, Mn(II) MnCOj Oxygen 

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Metals are sequestered by particulate oxides of iron and manganese. 

Little is known concerning the chemistry of nickel in the atmosphere. The probable species present in the atmosphere include soil minerals, nickel oxide, and nickel sulfate (Schmidt and Andren 1980). In aerobic waters at environmental pHs, the predominant form of nickel is the hexahydrate Ni(H20)g ion (Richter and Theis 1980). Complexes with naturally occurring anions, such as OH, SO/, and Cf, are formed to a small degree. Complexes with hydroxyl radicals are more stable than those with sulfate, which in turn are more stable than those with chloride. Ni(OH)2° becomes the dominant species above pH 9.5. In anaerobic systems, nickel sulfide forms if sulfur is present, and this limits the solubility of nickel. In soil, the most important sinks for nickel, other than soil minerals, are amorphous oxides of iron and manganese. The mobility of nickel in soil is site specific pH is the primary factor affecting leachability. Mobility increases at low pH. At one well-studied site, the sulfate concentration and the... 

Reckhow DA, Knocke WR, Kearney M, Parks CA. Oxidation of iron and manganese by ozone. Ozone Sci Eng 1991 13 675-695. 

The oxidation-reduction potentials and reaction constants of oxidation of iron and manganese differ and these reactions can occur in different amounts of oxygen. That is why the level of appearance of particulate manganese is situated higher than that of particulate iron [63]. Bacteria have been shown to oxidize manganese [64], whereas iron oxidation is possible without bacteria but can be carried out with bacteria [50]. Reduced iron can be oxidized by particulate manganese, forming complex compounds [65]. 

Some microorganisms can catalyze certain oxido-reduction reactions like the oxidation of iron and manganese in water, the oxidation of sulfur compounds, and oxidation-reduction of nitrogen compounds. Aerobic autotrophic bacteria of the type Thiobacillus can release soluble iron, copper, and sulfuric acid as sulphates into water. These organisms can be found everywhere in nature wherever an acidic environment is maintained in the presence of sulfide-containing minerals. 

The affect of physicochemical form on uptake from solids has been more carefully studied where sediments are the source of food to animals. When deposit-feeding clams -were fed various types of sedimentary substrates (oxides of iron and manganese organic detritus inorganic and biogenic carbonates) labelled with Cd, Co and Zn, uptake of the nuclides varied... 

There has been recent interest in a somewhat different aspect of adsorption and reaction on metal oxides photocatalysis. The interest stems partially from that role that some transition-metal oxides can play in photochemical reactions in the atmosphere. Atmospheric aerosol particles can act as substrates to catalyze heterogeneous photochemical reactions in the troposphere. Most tropospheric aerosols are silicates, aluminosilicates and salts whose bandgaps are larger than the cutoff of solar radiation in the troposphere (about 4.3 eV) they are thus unable to participate directly in photoexcited reactions. However, transition-metal oxides that have much smaller bandgaps also occur as aerosols — the most prevalent ones are the oxides of iron and manganese — and these materials may thus undergo charge-transfer excitations (discussed above) in the pres-... 

The MPF and TMGM prospecting methods are based on the use of metallo-organics (fulvates and humates of metals) and oxides of iron and manganese (metals bound in oxides and hydroxides of iron and manganese). These forms of metals are the result of the secondary fixation of the movable fomis in rocks and have features such as (1) increased concentration coefficient and (2) only a weak bond with their initial geological source (in comparison, for example, with the movable forms collected in CHIM and MDE). Samples for MPF are taken from the humus-enriched layer at a depth of 5-10 cm, and samples for TMGM are taken from the sand-clay layer at a depth of 15-20 cm. 

Brantner, H., 1970. Investigations on biological oxidation of iron and manganese. Zentralbl. Bakteriol. Parasitenkd., Infektionskr. Hyg., Abt. II, 124 412—426 (from Microbiology Abstracts, 1970, No. B7755). 

These serve, on the one hand, to increase the flection, and on the other to retard the explosion on igniting the match-head, so that the flame has time to act on the other materials, sulphur, paraffin, etc., which propagate the combustion. Brown umber is a variety of clay colour by the oxides of iron and manganese. Venetian red is ferric oxide, FctOa, and is obtained by the calcination of green vitriol. The use of chalk u 1 Riling material is now rare. Zinc oxide is employed chiefly In the compositions of matches containing phosphorus sesquisulphide, red phosphorus and the like. 

Table 1 summarizes various oxidants for chemical oxidation of iron and manganese. The following are chemical oxidation reactions assuming potassium permanganate is selected as an oxidant ... 

Industrial waste to the Saale River (Germany) resulted in zinc concentrations at Rubolstadt of several thousand milligrams per liter which decreased by a factor of 10 within 6 to 8 miles downstream. Surficial sediment in front of a dam 7.4 miles downstream had a zinc content of 0.86%, whereas similar sediment 21.8 miles further downstream had only 0.36% zinc (91), Since the hydrous oxides of iron and manganese are ubiquitous in surficial stream sediments, it is suggested that the zinc decontamination of the Saale River in this case may have been caused by the scavenging ability of the hydrous oxides. 

Syn. Wolfram—Occurs in nature, chiefly in the mineral wolfram, oxidised along with oxides of iron and manganese, and more sparingly in the mineral tungsten, a compound of tungstic acid with lime. The metal may he obtained as the preceding, but is little known. It is very infusible, and has the Sp. G. I7 4. When heated in air, it bums and forms tungstic acid. 

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