Manganese oxides extraction

Reducible fraction of metals bound to iron and manganese oxides (extraction by hydroxylamine hydrochloride)... 

Armstrong AR, Robertson AD, Bruce PG (2005) Overcharging manganese oxides extracting lithium beyond Mn". J Power Sourc 146 275-280... 

CIS of potassium permanganate in 2000 c.c. of water is placed in a, and an emulsion of 100 grams of the hydrocarbon in 600 c.c. of water is gradually added in small portions. The mixture is kept cool by means of a current of cold water, and shaken continuously. The oxidation products are then treated as follows The liquid is filtered from manganese oxide, and evaporated to about 1000 c.c., saturated with carbon dioxide, and the neutral and unaltered compounds removed ly extract jn with ether in the usual manner. The crude pinonic acid is separated from its potassium salt by sulphuric acid and is then extracted with ether. If /S-pinene be present, nopinic acid will be present... 

Manganese oxides have been used to remediate contaminated soils as well. Hydrous manganese oxides decreased Cd and Pb in rye grass (Lolium spp.) and tobacco (Nicotiana tabacum L.) from soils with pH 7.4-7.8 (Mench et al., 1994). Cadmium concentrations decreased in water and in 0.1 M Ca(N03)2 and acetic acid extracts of treated soils (Mench et al., 1994). 

The scavenging ability toward O2 can also be measured by using electron spin resonance (ESR) spectrometry. The 02 anion is trapped with 5,5-dimethyl-1-pyrroline TV-oxidc (DMPO), and the resultant DMPO-OH adduct is detected by ESR using manganese oxide as internal standard. Noda and others (1997) used this technique to evaluate antioxidant activities of pomegranate fruit extract and its anthocyanidins (delphinidin, cyanidin, and pelargonidin). 

Terrestrial plants take up nickel from soil primarily via the roots (NRCC 1981 WHO 1991). The nickel uptake rate from soil is dependent on soil type, pH, humidity, organic content, and concentration of extractable nickel (NAS 1975 WHO 1991). For example, at soil pH less than 6.5 nickel uptake is enhanced due to breakdown of iron and manganese oxides that form stable complexes with nickel (Rencz and Shilts 1980). The exact chemical forms of nickel that are most readily accumulated from soil and water are unknown however, there is growing evidence that complexes of nickel with organic acids are the most favored (Kasprzak 1987). In addition to their uptake from the soils, plants consumed by humans may receive several milligrams of nickel per... 

The form of nickel in particles from different industries varies. The mineralogical composition, chemical content, and form of dusts from nine industries in Cracow, Poland, were examined (Rybicka 1989). The chemical form of a particle-associated heavy metal that was assessed by a five-step extraction scheme classified the metal as exchangeable, easily reducible (manganese oxides, partly amorphous iron oxyhydrates and carbonates), moderately reducible (amorphous and poorly crystallized iron oxyhydrates), organically bound or sulfidic, and residual. Dusts from power plants had a silicate characteristic with quartz and mullite predominant. Approximately 90% of the nickel from these... 

Shan and Chen [32] reported that various proportions of metals released from exchangeable, carbonate-bound iron, manganese oxide-bound and organic-bound fractions were readsorbed onto the other solid geochemical phases during sequential extractions. 

Some work on sediments is reported here in the belief that it may also be useful in the analysis of soil samples. Thus Asikainen and Nikolaides [33] have carried out a sequential extraction study of chromium from contaminated aquifer sediments and found that 65% of the chromium was extractable. Of this amount 25% was exchangeable, 11% was bound to organic matter and 30% was bound to iron and manganese oxide surfaces. Thomas et al. [34] also investigated the use of BCR sequential extraction procedures for river sediments, and found the method to work well. Real et al. [35] improved sequential extraction by optimising microwave heating. 

Some laboratories employ operationally defined procedures to extract total elements from soils, such as a one hour reflux with a mixture of boiling nitric and hydrochloric acids. Such an approach may be adequate, for example, to study the build up of elements such as zinc, cadmium, copper, lead, and nickel in sludge-treated soils. However, operationally defined procedures are much more often used to extract the portions of elements present in soils and sediments in a labile or plant-available form. For example, solutions of EDTA or CDTA may be used to extract copper, zinc, manganese, and iron from soils,17 or hydroxylamine hydrochloride may be used to extract easily reducible manganese or manganese oxide-bound trace elements.6... 

Douka, C.E., Kinetics of manganese oxidation by cell-free extracts of bacteria isolated from manganese concretions from soil, Appl. Environ, Microbiol., 39, 74, 1980. 

Step 1. Extraction of the acid soluble fraction (i.e., carbonates) with CH3COOH Step 2. Extraction of the reducible fraction (i.e., iron/manganese oxides) with hydroxyl amine hydrochloride... 

Metal contamination of soils is primarily due to the application of sewage sludge, manure, phosphate fertilizers, atmospheric deposition, and traffic emissions. The most common heavy metal ions found in soils are Zn, Cu, Ni, Pb, Cr, and Cd. As mentioned earlier (see Section 6.3.1.4), sequential extraction techniques can differentiate among the metal forms in a soil, typically the acid soluble fraction (e.g., carbonates), the reducible fraction (e.g., iron/manganese oxides), and the ox-idizable fraction (i.e., metals in low oxidation states). 

Phosphorus extracted from sediment by NaOH has been related to non-occluded, surface-exchangeable, bioavailable forms (22). Hydrochloric acid extraction yields occluded phosphorus incorporated in hydrous metal oxides, carbonate and phosphate minerals of sediment. Hydroxylamine reagent specifically removes hydrous manganese oxides, while amorphous hydrous oxides of iron and aluminijm are removed by the oxalate reagent. Total available sediment phosphorus analyses includes sediment organic phosphorus components in addition to the inorganic portion determined by the selective extraction procedures. 

Various chemical extraction techniques have been introduced in order to selectively remove metals from the different adsorption or complexation sites of natural sediments (e.g., Tessier et al, 1979 Erel et al, 1990 Leleyter et al., 1999). It is, for example, shown by Leleyter et al. (1999) that between 20% and 60% of REE in various suspended river sediments are removed by successive extractions by water, by Mg(N03)2 (exchangeable fraction), sodium actetate (acid-soluble fraction), NH2OH - - HCl (manganese oxide dissolution) ammonium oxalate (iron oxide dissolution) and a mixture of H2O2 + HNO3 (oxidizable fraction). The complexity of... 

Gummow, R.J., Liles, D.C., and Thackeray, M.M., Lithium extraction from orthorhombic lithium manganese oxide and the phase transformation to spinel. Mater. Res. Bull, 28, 1249, 1993. 

Ehrlich, H.L., 1968. Bacteriology of manganese nodules. II. Manganese oxidation by cell-free extract from a manganese nodule bacterium. Appl. Microbiol., 16 197—202. 

Effect of sucrose and yeast extract levels on manganese oxidation by Arthrobacter sp. and on the medium pH after 8 d incubation (Bromfield, 1974)... 

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