Manganese in water

Aqueous potassium permanganate solutions are not perfectiy thermodynamically stable at 25°C, because Mn02, not MnO is the thermodynamically stable form of manganese in water. Thus permanganate tends to oxidize water with the evolution of oxygen and the deposition of manganese dioxide, which acts to further catalyze the reaction. 

Mandal LN (1961) Transformation of iron and manganese in water-logged rice soils. Soil Sci 121-126... 

In order to prevent the reduction between iron(II) and formaldoxime occurring, another iron complexing agent (potassium cyanide) was used in the presence of a reductant (ascorbic acid) that reduces iron(III) to iron(II). Aluminium, titanium, uranium, molybdenum and chromium also form light-coloured complexes that normally do not interfere in the determination of manganese in water or plant material by this method. If the aluminium or titanium concentrations are higher than 40 ppm an additional masking flow of tartrate is recommended [31]. 

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. 

Wolfe, R.S., 1960. Microbial concentration of iron and manganese in water with low concentrations of these elements. J. Am. Water Works Assoc., 52 1335—1337. 

The transport and partitioning of manganese in water is controlled by the solubility of the specific chemical form present, which in turn is determined... 

Manganese in water may be significantly bioconcentrated at lower trophic levels. 

Formaldoxime has been applied in the determination of manganese in water [69,70], plants [69,71], silicate and carbonate minerals [72], uranium oxide [9], tin [73], and alkalies [74]. The formaldoxime method has been automated in the determination of manganese in water [75] and in silicate minerals [76]. The FIA technique has been applied in the analysis of natural waters [77] and silicates [78]. 

Identification of Manganese in Water Solutions by Electron Spin Resonance... 

The transport and partitioning of manganese in water is controlled by the solubility of the specific chemical form present, which in turn is determined by pH, Eh (oxidation-reduction potential), and the characteristics of the available anions. The metal may exist in water in any of four oxidation states. Manganese(II) predominates in most waters (pH 4—7) but may become oxidized at a pH >8 or 9 (EPA 1984a). The... 

Manganese in water may be significantly bioconcentrated at lower trophic levels. A bioconcentration factor (BCF) relates the concentration of a chemical in plant and animal tissues to the concentration of the chemical in the water in which they live. Folsom et al. (1963) estimated that the BCF of manganese was... 

Manganese in water may undergo oxidation at high pH or Eh (see Section 5.3.1.2) and is also subject to microbial activity. For example, Mn(II) in a lake was oxidized during the summer months, but this was inhibited by a microbial poison, indicating that the oxidation was mediated by bacteria (Johnston and Kipphut 1988). The microbial metabolism of manganese is presumed to be a function of pH, temperature, and other factors, but no data were located on this. 

Goto, K., Komatsu, T., and Furukawa, T, (1962). Rapid colorimetric determination of manganese in waters containing iron. Anal. Chim. Acta 27, 331-334. 

Henriksen, A. (1966). An automated modified formaldoxime method for determining low concentrations of manganese in water containing iron. Analyst 91, 647-651. 

To Color a Maple Stock Brown —Dissolve a few grains of sulphate of manganese in water wet the stock and hold over the flame of an alcohol lamp so as to eooich it. By beating some parts moro than others the color can be variegated. Oil with raw linseed oil. and polish with a piece of hard wood. The oil and polishing will develop the color, which may be dull at first... 

Here oxidizing iron and manganese plays the role not of a source of energy but of detoxifier of a harmful released product. Thereby iron-depositing bacteria prevent the accumulation of iron and manganese in water. 

In the middle of 1980s, the United States Environmental Protection Agency (US EPA) approved ion chromatography for the analysis of alkali and alkaline earth cations and ammonium in rain water and wet precipitation. In 1998, International Standard Organization (ISO) published Method 14911 ° for the simultaneous determination of dissolved alkali and alkaline earth cations, ammonia and manganese in water and wastewater using suppressed ion chromatography. 

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