Iron reduced phosphorus

In all the experiments, the main decomposition products were phosphonates, which are also stable in concentrated solutions of Mg and Ca chlorides. In some experiments, pyrophosphate, and in smaller amounts triphosphate, could also be detected. The authors thus assume that the primeval ocean contained phosphonates as a source of phosphorus for reactions leading to biochemically relevant molecules. Iron meteorites could have delivered sufficient reduced phosphorus (Fe3P) to the primeval Earth, so the question of prebiotic phosphorus chemistry should be looked at in more detail in the future (Pasek and Lauretta, 2005). 

Brumm, M. C. (2000). Reducing phosphorus content of swine manure. Manure Matters 6,1-2. Brune, M., Rossander, L., and Hallberg, L. (1989). Iron absorption and phenolic compounds ... 

Analytical Chemical Data for Natural Waters. While elemental compositions of various natural waters usually can be determined with good reliability, analytical methods to distinguish between free and complex-bound species, oxidized and reduced forms, simple and polynuclear metal ion forms, and even between dissolved and colloidal or suspended phases are often lacking. Data on the nature and amounts of the individual substances which make up the total concentrations of organic material found in different natural waters are not yet extensive. These analytical deficiencies relate almost solely to the highly reactive, non-conservative elements—e.g., iron, manganese, phosphorus, carbon, nitrogen, aluminum, and other metal ions. 

When ferric phosphorus is reduced to ferrous phosphorus by iron-reducing bacteria, phosphorus is released. We know that phosphate is occluded in hydrated ferric hydroxide coating. This is released by reduction of ferric iron to ferrous iron. 

Direct reduced iron, produced from the reduction of iron oxide, can react with air and moisture to produce hydrogen gas and heat. Ferrophosphorus is an iron and phosphorus alloy (18 to 25% phosphorus) used to adjust phosphorus concentration in steel. 

In addition to the use of techniques to reduce nutrient run-off at source, entry of nutrients to lakes can be reduced by using pre-lake techniques. These include the use of artificial wetlands on inflow streams, the use of iron salt treatment in pre-lake lagoons or by installing treatment plants to remove phosphorus. 

Phosphorus is the eleventh element in order of abundance in crustal rocks of the earth and it occurs there to the extent of 1120 ppm (cf. H 1520 ppm, Mn 1060 ppm). All its known terrestrial minerals are orthophosphates though the reduced phosphide mineral schrieber-site (Fe,Ni)3P occurs in most iron meteorites. Some 200 crystalline phosphate minerals have been described, but by far the major amount of P occurs in a single mineral family, the apatites, and these are the only ones of industrial importance, the others being rare curiosities. Apatites (p. 523) have the idealized general formula 3Ca3(P04)2.CaX2, that is Caio(P04)6X2, and common members are fluorapatite Ca5(P04)3p, chloroapatite Ca5(P04)3Cl, and hydroxyapatite Ca5(P04)3(0H). In addition, there are vast deposits of amorphous phosphate rock, phosphorite, which approximates in composition to fluoroapatite. " These deposits are widely... 

The A -oxide reactions in quinazoline 3-oxide are, however, modified to a certain extent by the aforementioned properties. Thus, whereas it can be reduced to quinazoline with phosphorus trichloride or iron and ferrous sulfate in ethanol, reactions with alkali, acetic anhydride, and benzoyl chloride in the presence of cyanide result in ring fission (Scheme 4). 

The presence of active sulphate-reducing bacteria usually results in graphitic corrosion and this has led to a useful method of diagnosing this cause of corrosion. The leaching out of iron from the graphitic residue which is responsible for the characteristic appearance of this type of corrosion leads to an enriched carbon, silicon and phosphorus content in the residue as compared with the original content of these elements in the cast iron. Sulphur is usually lost to some extent but when active sulphate-reducing bacteria are present, this loss is offset by the accumulation of ferrous sulphide in the residue with a consequent increase in the sulphur content of the residue out... 

The iron formed in a blast furnace, called pig iron, contains impurities that make the metal brittle. These include phosphorus and silicon from silicate and phosphate minerals that contaminated the original ore, as well as carbon and sulfur from the coke. This iron is refined in a converter furnace. Here, a stream of O2 gas blows through molten impure iron. Oxygen reacts with the nonmetal impurities, converting them to oxides. As in the blast furnace, CaO is added to convert Si02 into liquid calcium silicate, in which the other oxides dissolve. The molten iron is analyzed at intervals until its impurities have been reduced to satisfactory levels. Then the liquid metal, now in the form called steel, is poured from the converter and allowed to solidify. 

Soil pH is easily tested for and determines the availability of nutrients and the success of white clover. Very acid soils (below pH 5.0) will cause a deficiency of the trace elements iron, boron, copper and molybdenum and conversely will cause injury to plant growth by increasing the availability of aluminium and manganese to toxic levels. Over-liming, on the other hand, which can raise the pH above 6.5, will reduce the availability of certain essential elements such as phosphorus, manganese and boron. 

The iron-based redox cycle depicted in Figure 18.9 provides an effective preconcentrating step for phosphorus by trapping remineralized phosphate in oxic sediments. The conversion of phosphorus from POM to Fe(lll)OOH to CFA is referred to as sink switching. Overall this process acts to convert phosphorus from unstable particulate phases (POM to Fe(lll)OOH) into a stable particulate phase (CFA) that acts to permanently remove bioavailable phosphorus from the ocean. This is pretty important because most of the particulate phosphate delivered to the seafloor is reminer-alized. Without a trapping mechanism, the remineralized phosphate would diffuse back into the bottom waters of the ocean, greatly reducing the burial efficiency of phosphorus. 

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