Phosphorus colloidal

Tufenkji N, Elimelech M (2004) Correlation equation for predicting single-collector efficiency in physicochemical filtration in saturated porous media. Environ Sci Technol 38 529-536 Turner BL, Kay MA, Westermann DT (2004) Colloid phosphorus in surface runoff and water extracts from semiarid soils of the western United States. J Environ Qual 33 1464-1472 van Genuchten MT (1980) A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci Soc Am J 44 892-898... 

The coloring and bleaching phenomena are caused by changes in molecular configuration of colloidal phosphorus formed in the glasses. The P molecule (liquid or white phosphorus) is colorless. It polymerizes thermally or photochemically to the... 

Condensation of phosphorus vapor by direct contact with a water shower economically provides the efficient heat transfer necessary for condensation and provides the protective water covering to prevent the phosphorus from burning in air. It also places some dissolved (solubility ca. 3 mg/L [23]) and some colloidal phosphorus into the water layer. To prevent loss of this toxic form of phosphorus to surface waters, condensers are normally operated on a total water recycle basis from a lagoon or a holding pond reservoir. 

Since calcium fluoride is insoluble in water, loss of fluoride in this form is relatively benign. The fluoride present in the slag, however, may be mobilized into the water phase if the hot slag is contacted with water to fracture the material for use as fill. The fluoride not captured in the slag is converted to silicon tetrafluoride and hydrogen fluoride which leave the furnace with the phosphorus vapor and carbon monoxide. However, they are absorbed by the water stream of the phosphorus condensers (Eq. 10.11). Thus, the water from the phosphorus condenser contains dissolved and colloidal phosphorus and dissolved fluoride as the ion and as the complex fluosilicate anion. 

Fig. 191. Preparation of colloidal phosphorus Ai, i4 a) for water B) for phosphorus Q) collecting tube for the colloidal phosphorus B) cold finger.

Hens, M. and Merckx, R. (2001) Functional characterization of colloidal phosphorus species in the soil solution of sandy soils. Environmental Science and Technology 35, 493-500. 

Colloidal metals are usually prepared by reduction of a salt with a reducing agent, such as phosphorus, acetone, tannin, or carbon monoxide. Platinum metals can also be prepared as finely divided very active blacks by reducing the metal salt in an aqueous solution of sodium or potassium borohydride. 

Transport of contaminants by surface runoff is illustrated in the experimental results of Turner et al. (2004), which deal with the colloid-mediated transfer of phosphorus (P) from a calcareous agricultural land to watercourses. Colloidal molybdate-reactive phosphorus (MRP) was identified by ultrafiltration associated with particles between l am and Inm in diameter. Colloidal P compounds can constitute a substantial component of the filterable MRP in soil solution and include primary and secondary P minerals, P occluded or adsorbed on or within mineral or organic particles, and biocolloids (Kretzschmar et al. 1999). 

Table 12.4 Colloidal (1pm - Inm) and dissolved (

In the specific case of wastewater generated from the condenser water bleedoff in the production of elemental phosphorus from phosphate rock in an electric furnace, Yapijakis [33] reported that the flow varies from 10 to 100 gpm (2.3-23 m /hour), depending on the particular installation. The most important contaminants in this waste are elemental phosphoms, which is colloidally dispersed and may ignite if allowed to dry out, and fluorine, which is also present in the furnace gases. The general characteristics of this type of wastewater (if no soda ash or ammonia were added to the condenser water) are given in Table 9. 

Phossy water, a waste product in the production of elemental phosphorus by the electric furnace process, contains from 1000 to 5000 mg/L suspended solids that include 400-2500 mg/L of elemental phosphorus, distributed as liquid colloidal particles. These particles are usually positively charged, although this varies depending on the operation of the electrostatic precipitators. Furthermore, the chemical equilibrium between the fluoride and flurosilicate ions introduces an important source of variation in suspended solids that is a pH function. Commonly... 

A.J.G. Blesa, M.A. (1988) The dissolution of magnetite by nitrilotriacetatoferrate(II). J. Chem. Soc. Earaday Trans. I. 84 9-18 Delgado, A. Torrent, J. (2000) Phosphorus forms and desorption patterns in heavily fertilized calcareous and limed acid soils. Soil Sci. Soc. Am. J. 64 2031-2037 Delgado, A.V. Gonzalez-Caballero, F. (1998) Inorganic particles as colloidal models. Effects of size and shape on the electrokinetics of hematite (a-Fe203). Croatica Chemica Acta 71 1087-1104... 

Gardner, W.K. Parbery, D.G. Barber, D.A. (1982) The acquisition of phosphorus by Lu-pinus albus L. I. Some characteristics of the soil/root interface. Plant Soil 68 19-32 Garg, A. Matijevic, E. (1988) Preparation and properties of uniform coated colloidal particles. II. Chromium hydrous oxide on hematite. Langmuir 4 38-44 Garg, A. Matijevic, E. (1988) Preparation and properties of uniform coated colloidal parti-... 

Kuo, R.J. Matijevic, E. (1980) Particle adhesion and removal in model systems. III. Monodisperse ferric oxide on steel. J. Colloid Interface Sci. 78 407-421 Kuo, S. Jellum, E.J. (1994) The effect of soil phosphorus buffering capacity on phosphorus extraction by iron oxide-coated paper strips in some acid soils. Soil Sci. 158 124-131... 

Mayer, T.D. Jarrell, W.M. (1995) Assessing colloidal forms of phosphorus and iron in the Tualatin River Basin. J. Environ. Qual. 24 1117-1124... 

This relationship permits of experimental verification by direct observation of the diffusion coefficient and the measurement of the radius of the particle. Svedberg Zeit. Phys. Chem. LXVII. 105, 1907 Archiv f Kemi, etc., K. Svmska Vetensk. Akad. Stockholm, B, IV. 12,1911) employed colloidal gold prepared by reduction with phosphorus according to the directions of Faraday and Zsigmondy. 

USP 3314836(1967) CA 66, 10934(1967) (Military flame-producing compns consist of colloidal yellow phosphorus dispersed in a flammable medium. A typical compn ... 

Faraday prepared a colloidal dispersion of gold fine particles by reduction of gold(lll) ions with white phosphorus. Recently, Turkevich prepared the gold sol by reduction... 

Total phosphorus includes colloidal inorganic phosphate, casein (organic) phosphate, soluble inorganic phosphate, ester phosphate and phospholipids. 

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