Phosphate content

Detergents may be produced by the chemical reaction of fats and fatty acids with polar materials such as sulfuric or phosphoric acid or ethylene oxide. Detergents emulsify oil and grease because of their abiUty to reduce the surface tension and contact angle of water as well as the interfacial tension between water and oil. Recent trends in detergents have been to lower phosphate content to prevent eutrification of lakes when detergents are disposed of in municipal waste. 

Mona.Zlte, The commercial digestion process for m on a site uses caustic soda. The phosphate content of the ore is recovered as marketable trisodium phosphate and the rare earths as RE hydroxide (10). The usual industrial practice is to attack finely ground m on a site using a 50% sodium hydroxide solution at 150°C or a 70% sodium hydroxide solution at 180°C. The resultant mixed rare-earth and thorium hydroxide cake is dissolved in hydrochloric or nitric acid, then processed to remove thorium and other nonrare-earth elements, and processed to recover the individual rare earths (see... 

Some producers beneficiate the phosphate ore prior to agglomeration to increase the phosphate content and remove undesirable contaminants. One approach uses a water wash to remove fines which are lower in assay and higher in contamination. If too much clay is removed from the ore by the beneficiation, a binder such as bentonite clay must be added back to the ore to faciUtate agglomeration. 

Agriculture is the largest industry for sulfur consumption. Historically, the production of phosphate fertilizers has driven the sulfur market. Phosphate fertilizers account for approximately 60% of the sulfur consumed globally. Thus, although sulfur is an important plant nutrient in itself, its greatest use in the fertilizer industry is as sulfuric acid, which is needed to break down the chemical and physical stmcture of phosphate rock to make the phosphate content more available to plant life. Other mineral acids, as well as high temperatures, also have the abiUty to achieve this result. Because of market price and availabiUty, sulfuric acid is the most economic method. About 90% of sulfur used in the fertilizer industry is for the production of phosphate fertilizers. Based on this technology, the phosphate fertilizer industry is expected to continue to depend on sulfur and sulfuric acid as a raw material. 

Rock type Calcium phosphate content, % Work index, kw.-hr./ton... 

The relation between free phosphoric acid content and total phosphate content in a processing bath, whether based on iron, manganese or zinc, is very important this relation is generally referred to as the acid ratio. An excess of free acid will retard the dissociation of the primary and secondary phosphates and hinder the deposition of the tertiary phosphate coating sometimes excessive loss of metal takes place and the coating is loose and powdery. When the free acid content is too low, dissociation of phosphates (equations 15.2, 15.3 and 15.4) takes place in the solution as well as at the metal/solution interface and leads to precipitation of insoluble phosphates as sludge. The free acid content is usually determined by titrating with sodium... 

Determine the phosphate content of an unknown solution, containing say ca 0.005 mg P205 per mL use the calibration graph. 

Of the principal minerals of Ca listed in Table 1, the most important ores are the various deposits of CaCOj, especially limestones, which occur as immense sedimentary beds over extensive parts of the earth s surface. Extraction of Ca from CaCOj is a simple and relatively inexpensive process. Although the other Ca-bearing minerals are rarely considered as potential Ca sources, they are widely distributed and extensively mined fluorite and apatite for their fluoride and phosphate content, gypsum and anhydrite for their use in construction. 

Elderberries are considered excellent sources of vitamins A and C. The high potassium phosphate content in the flowers may be part of what helps elder calm the nerves. The potassium sulfate present in the flowers, leaves and bark may be a factor in why elder helps relieve excess mucus. 

Among other polyions Meyerhoff s group demonstrated successful detection of pentosan polysulfate (PPS) [45], an anti-osteoarthritis drug, in plasma and polyanions with high phosphate content, including polyphosphates and nucleic acids in saline solutions [46],... 

The phosphate content of each reservoir is the volume of that reservoir multiplied by the concentration of phosphate in that reservoir. Volumes are constant, so the rate of change of the content is the volume multiplied by the rate of change of the concentration. But for each reservoir, the rate of change of the content is the sum of all the fluxes of phosphorus in (the sources) minus the sum of all the fluxes of phosphorus out (the sinks). Thus, the content of the first reservoir, Atlantic surface, changes at the rate... 

In contrast, during the low flow season (June-October) important nutrient loads from both point and non-point sources are relevant. Summer irrigation drives nitrate inputs to stream waters [38], The lower dilution capacity of the river causes higher concentrations of nitrate and DOC, as well as an increase in phosphate content with... 

Typically, mammalian ferritins can store up to 4500 atoms of iron in a water-soluble, nontoxic, bioavailable form as a hydrated ferric oxide mineral core with variable amounts of phosphate. The iron cores of mammalian ferritins are ferrihydrite-like (5Fe203 -9H20) with varying degrees of crystallinity, whereas those from bacterioferritins are amorphous due to their high phosphate content. The Fe/phosphate ratio in bacterioferritins can range from 1 1 to 1 2, while the corresponding ratio in mammalian ferritins is approximately 1 0.1. 

Why mammalian ferritin cores contain ferrihydrite-like structures rather than some other mineral phase is less easy to understand, and presumably reflects the way in which the biomineral is built up within the interior of the protein shell together with the geometry of the presumed nucleation sites. The phosphate content in the intracellular milieu can readily be invoked to explain the amorphous nature of the iron core of bacterioferritins and plants. Indeed, when the iron cores of bacterioferritins are reconstituted in the absence of phosphate, they are found to be more highly ordered than their native counterparts, and give electron diffraction lines typical of the ferrihydrite structure. Recently it has been reported that the 12 subunit ferritin-like Dps protein (Figure 19.6), discussed in Chapter 8, forms a ferrihydrite-like mineral core, which would seem to imply that deposition of ferric oxyhydroxides within a hollow protein cavity (albeit smaller) leads to the production of this particular mineral form (Su et al., 2005 Kauko et al., 2006). 

Ord MG, Stocken LA (1968) Variations in the phosphate content and thioldisulphide ratio of histones during the cell cycle. Smdies with regenerating rat liver and sea urchins. Biochem J 107(3) 403 10... 

Known compositional variations of ferritin iron cores only Involve phosphate, which can range from as much as 80% (21) to as little as 5% of the iron (21) in normal mammalian liver or spleen, the amount of phosphate in the ferritin iron core is ca. 12% of the iron (24). When the phosphate content is high, the distribution of phosphate is clearly throughout the core rather than on the surface. However, interior locations for phosphate are also suggested when the phosphate content is lower, by data on an Fe(III)ATP model complex (P Fe 1 4) (25) or by phosphate accessibility studies in horse spleen ferritin (P Fe = 1 8) (24). Based on model studies, other possible variations in core composition could Include H2O or sulfate (26). 

Figure 6. Distribution coefficient K for cadmium in HH as function of sulfate concentration for various phosphate contents.

Salt content It affects the calcium activity in the serum and calcium phosphate content of the micelles. 

In these, As04 tetrahedra are built into the polyphosphate chains (309). Since the P—0—As bond has much the same sensitivity to hydrolysis as the As—0—As bond, they are rapidly hydrolyzed in aqueous solution to monoarsenate and mixtures of polyphosphates, the mean chain length of which depends on the As P ratio in the starting material (74)- Contrary to an idea based originally on gravimetric analysis (309), the As atoms are not distributed regularly in the chain, but statistically (308). The observation that, after careful hydrolysis, the phosphate content is exclusively in the form of polyphosphates provides chemical proof of catenation in the poly-arsenatophosphate anions. When arsenatophosphates with more than five P atoms per atom of As are hydrolyzed by hot water trimetaphosphates are formed, just as they are formed for all other high-molecular polyphosphates in solution (316). 

Provided only polyphosphates are present it is possible to determine titrimetrically (1) the end-group content of mixtures (2) the content of groups within the chain, after hydrolysis and by estimating the total phosphate content (3) the monophosphate content after precipitation with silver nitrate (347). These methods are likewise of no use in presence of meta- and cross-linked phosphates. 

The CO gas is easily removed, while the calcium phosphate and manganese oxide go into the molten slag, which has value in fertilizer manufacture because of the phosphate content (Section 9.6). Figure 17.9 shows that Mn, Si, and C will react preferentially with 02 before oxidation of the molten iron solvent begins, but S02 and P2Os have less negative AG°f... 

Although casein is a substrate for milk acid phosphatase, the major caseins, in the order as(asl + as2) > (3 > k, also act as competitive inhibitors of the enzyme when assayed on p-nitrophenylphosphate, probably due to binding of the enzyme to the casein phosphate groups (the effectiveness of the caseins as inhibitors is related to their phosphate content). 

As the cornea physiologically contains almost no phosphate, we have found evidence that for an osmolar conditioning of the cornea, an electrolyte conditioning is highly probable. We could prove this by means of Energy dispersive X-ray analysis (EDXA) [16], With this method, we have found elevated phosphate contents in the cornea after rinsing one or several times with phosphate buffer [17], This reflects a situation of... 

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