Manganese colloids

Colloidal manganese. See Manganese Colloidal mercury. See Mercury Colloidal selenium. See Selenium Colloidal silica. See Silica, colloidal Silica, fumed... 

Removal of particulates, colloidal matter, iron and organics. Multimedia, manganese, greensand, diatomaceous earth, brim, or carbon filter. Caution carbon filters not recommended unless absolutely required for the removal of color and odor (as they provide a medium for microbial growth). 

Manganese ions enzyme activators, 6,578 probes, 6,563 RNA polymerases activation, 6, 585 transport microbes, 6, 569 plants, 6, 572 Manganese oxide colloidal... 

Davies, S. and Morgan, J. J. (1989). Manganese (II) oxidation kinetics on metal oxide surfaces, /. Colloid... 

Violence of reaction depends on concentration of acid and scale and proportion of reactants. The following observations were made with additions to 2-3 drops of ca. 90% acid. Nickel powder, becomes violent mercury, colloidal silver and thallium powder readily cause explosions zinc powder causes a violent explosion immediately. Iron powder is ineffective alone, but a trace of manganese dioxide promotes deflagration. Barium peroxide, copper(I) oxide, impure chromium trioxide, iridium dioxide, lead dioxide, manganese dioxide and vanadium pentoxide all cause violent decomposition, sometimes accelerating to explosion. Lead(II) oxide, lead(II),(IV) oxide and sodium peroxide all cause an immediate violent explosion. 

The 02(aq) reacted with the Mn11, forming a colloidal precipitate of oxidized manganese, likely composed of a mixture of Mnm and MnIv. We can write this reaction in a simple form as,... 

In the case of iron and manganese, most of these metals are removed from the hydrothermal fluids and converted to particulate form close to their point of entry. Some of these removals are in the form of sulfides, which fc>rm as the fluids emerge into the deep sea. The rest occurs as the fluids mix with cold, oxic, alkaline seawater, which promotes the oxidation of reduced metals. Thus, Fe (aq) and Mn (aq) are transformed into insoluble iron and manganese oxides, forming colloids and particles, the latter of which eventually settle onto the sediments. As described in the next chapter, at least some of these oxidation reactions are biologically mediated. Some of... 

Some metals are irreversibly adsorbed, probably via incorporation into the mineral phases, such as amorphous iron oxyhydroxides, as shown in Figure 11.6d. Some of these amorphous phases form by direct precipitation from seawater. As noted earlier, hydrothermal fluids are an important source of iron and manganese, both of which subsequently precipitate from seawater to form colloidal and particulate oxyhydroxides. Other metals tend to coprecipitate with the iron and manganese, creating a polymetallic oxyhydroxide. It is not clear the degree to which biological processes mediate the formation of such precipitates. Since the metals are incorporated into a mineral phase, this type of scavenging is better referred to as an absorption process. 

The Oxide Ores (e.g., ores of iron, chromium, manganese, tin).— The study of these ores involves high-temperature investigations similar to those on the silicates, and also studies of the hydrated and colloidal oxides. 

In Skirmer, H.G.W. Fitzpatrick, R.W. (eds.) Biomineralization processes of iron and manganese. Catena Verlag, Cremhngen-Destedt, Catena Suppl. 21 75—99 Ghoneimy, H.F. Morcos.T.N. Misak, N.Z. (1997) Adsorption of Co and Zn ions on hydrous Fe(lll), Sn(lV) and mixed Fe(lll)/ Sn(IV) oxides. Part 1. Characteristics of the hydrous oxides, apparent capacity and some equilibria measurements. Colloids Surfaces A. 122 13-26... 

Ghiorse.W.E. (2002) Effed of oxide formation mechanisms on lead adsorption by biogenic manganese hydroxides and their mixtures. Environ. Sci. Techn. 36 421-425 Nembrini, G. Buffle, J. Haerdi, W. (1976) Vol-tametric behavior of iron(III) hydrolyzed solutions and characterization of the reducible species. J. Colloid Interface Sci. 57 327-336 Nesson, M.H. Lowenstam, H.A. (1985) Biomineralization proceses of radula teeth of chitons. In Kirschvink, J.L. Stone, D.S. (eds.) Magnetite biomineralization and magneto reception in organisms. Plenum Press, New York, 333-363... 

Iron and aluminum precipitate out when treated with ammonia and are removed by filtration. Other metals, such as copper, zinc, lead and arsenic are precipitated and removed as sulfides upon passing hydrogen sufide through the solution. Colloidal particles of metaUic sulfides and sulfur are removed by treatment with iron(ll) sulfide. The purified solution of manganese(ll) sulfate is then electrolyzed in an electrolytic cell using lead anode and HasteUoy or Type 316 stainless steel cathode, both of which are resistant to acid. Manganese is deposited on the cathode as a thin film. 

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