Phosphorus in water

Phosphorus and Silicon in Waters, Effluents and Sludges [e.g. Phosphorus in Waters, Effluents and Sludges by Spectrophotometry-phosphomolybdenum blue method. Phosphorus in Waters and Acidic Digests by Spectrophotometry-phosphovanadomolybdate method. Ion Chromatographic Methods for the Determination of Phosphorus Compound, Pretreatment Methods for Phosphorus Determinations, Determination of silicon by Spectrophotometric Determination of Molybdate Reactive Silicon-1 -amino-2-naphthol-4, sulphonic acid (ANSA) or Metol reduction methods or ascorbic acid reduction method. Pretreatment Methods to Convert Other Eorms of Silicon to Soluble Molybdate Reactive Silicon, Determination of Phosphorus and Silicon Emission Spectrophotometry], 1992... 

During preparation of hydrogen bromide by addition of bromine to a suspension of red phosphorus in water, the latter must be freshly prepared to avoid the possibility of explosion. This is due to formation of peroxides in the suspension on standing and subsequent thermal decomposition [1], In the earlier description of such an explosion, action of bromine on boiling tetralin was preferred to generate hydrogen bromide [2], which is now available in cylinders. 

A rapid method for determination of total phosphorus in water samples by digestion with persulphate was introduced by Koroleff [83], but this method has not been widely used for sediment samples. Preliminary measurements of phosphorus in lake sediments using the persulphate digestion method gave considerably lower values than the perchloric acid method [84],... 

Note In this experiment, the phosphorus in water samples is determined by visible spectrometry following a reaction of the phosphates in the sample with potassium antimonyl tartrate, ammonium molybdate, and ascorbic acid. All glassware should be washed in phosphate-free detergent prior to use to avoid phosphate contamination. 

Setting up and Preparing the Apparatus.—First pour into the washing tube (IF) 3 c.c. of a suspension of about 150 mg. of red phosphorus in water, the phosphorus having been thoroughly puri-... 

J. K. Robinson, M. J. Bollinger, and J. W. Birks, Luminol/H202 Chemiluminescence Detector for the Analysis of NO in Exhaled Breath, Anal. Chem. 1999, 71, 5131. Many substances can be analyzed by coupling their chemistry to luminol oxidation. See, for example, O. V. Zui and J. W. Birks, Trace Analysis of Phosphorus in Water by Sorption Preconcentration and Luminol Chemiluminescence, Anal. Chem. 2000, 72, 1699. 

The combustion of white phosphorus felt or red phosphorus butyl rubber will produce smoke. Smoke is an aerosol comprised of oxides of phosphorus (phosphorus pentoxide and phosphorus trioxide), some of their transformation products (see Section 3.2), and a small amount of unburnt phosphorus. The aerosol components in the smoke will undergo dispersion and chemical transformation in air to form acids or phosphorus, and will ultimately deposit from air to the hydrosphere and the lithosphere. The main components of the aerosol deposited over water and soil are acids of phosphorus. Under oxidizing conditions in soil and water, phosphorus acids will be transformed to phosphate or polyphosphates. Under reducing conditions, the disproportionation reaction of phosphorus acid can produce phosphine, and the gas may be released to the atmosphere. The fate of deposited unbumt phosphorus in water and soil has already been discussed in the preceding paragraph. 

White phosphorus can exist in water as dissolved phosphorus in amounts <3 mg/L, in the colloidal state, as large particles of elemental phosphorus at concentrations >3 mg/L, or in the particle-sorbed state (Bullock and Newlands 1969 EPA 1991). Elemental phosphorus can undergo oxidation and hydrolysis in water. The rate of reactions depends on the dissolved oxygen concentration, temperature, state of phosphorus in water (dissolved, sorbed, colloidal, or particle form), and possibly the pH of the solution. The rate of reaction grows faster as the temperature of the water increases (Lai and Rosenblatt 1977a). 

The disappearance half-life of elemental phosphorus in water also depends on the physical state of phosphorus. For example, the disappearance half-life of collodial phosphorus was 80 hours at 30°C and 240 hours at 0°C at concentrations between 10-50 mg/L (Bullock and Newlands 1969), compared to a half-life of 2 hours in solution form at 10 °C (Zitko et al. 1970). The half-life of white phosphorus in solution increased from 2 to 20 hours when the phosphorus was present in the sorbed state in sediment (Zitko et al. 1970). In anoxic water, the estimated half-life of a solid chunk of white phosphorus that was protectively coated due to oxidation/hydrolysis at the oxic zone was 2.43 years (Spanggord et al. 1985). 

The experiments discussed above determined the rate of disappearance and the half-life of elemental phosphorus in water in open systems. The phosphorus in these experiments disappeared due to hydrolysis/oxidation and evaporation. Spanggord et al. (1985) studied the loss of elemental phosphorus in sealed reaction flasks. In a closed reaction flask with argon-saturated water, the loss of white phosphorus can only be due to hydrolysis. The estimated half-life for hydrolysis at ambient temperatures was 84 hours (Spanggord et al. 1985). The estimated half-lives of white phosphorus at ambient temperatures due to a... 

White phosphorus reacts rapidly with chlorine to form phosphorus trichloride, which finally hydrolyzes and oxidizes to form phosphoric acids (EPA 1991). Chlorination of water, therefore, further shortens the half-life of phosphorus in water. 

No data on the biodegradation of white phosphorus in water under aerobic conditions were located. Considering the rapidity with which phosphorus disappears from aerated water as a result of a combination of evaporative and chemical processes, it is unlikely that aerobic biodegradation can compete with these loss processes. Anaerobic biodegradation studies concluded that biotransformation of elemental phosphorus is not rapid in water (Spanggord et al. 1985). 

Lai MG, Rosenblatt DH. 1977a. Identification of transformation products of white phosphorus in water. Naval Surface Weapons Center, Silver Spring, MD. Final Report No. 

Walsh ME. 1995. Analytical method for white phosphorus in water. Bulletin of Environmental Contamination and Toxicology 54(3) 432-439. 

Wang ZM. 1992. Oscillopolarographic determination of traces of yellow phosphorus in water. 

Lin, X. 2006. Determination of total phosphorus in water by flow injection analysis instrument. Fujian Fenxi Ceshi 15 42 14. 

Yang, C., X. Sun, B. Liu, and H. Lian. 2007. Determination of total phosphorus in water sample by digital imaging colorimetry. Fenxi Huaxue 35 850-853. 

Ai, S., B. Zhang, X. Qu, X. Zou, and L. Jin. 2006. Determination of total phosphorus in water based on nanometer titanium dioxide film photocatalytic oxidation with electrochemical method. Fenxi Fluaxue 34 1068-1072. 

The preparation of the acid by the combustion of phosphorus and solution of the flowers of phosphorus in water has an historical interest only. It is obviously too expensive for large-scale work, nor does it yield a pure product. 

This recommendation by the ACGIH (American Conference of Governmental Industrial Hygienists) and OSHA (Occupational Health and Safety Act) comes with an additional stipulation that exposures should not exceed 0.3mg/m, even for short periods. A primary environmental concern in the operation of a phosphorus furnace is with potential losses of dissolved and suspended elemental phosphorus in water, since even low concentrations are toxic to freshwater and marine animal life. Care is also taken to avoid losses of fluoride to air or freshwater, which are more likely to occur during process upsets, since fluorides may cause damage to adjacent plant life or freshwater organisms [20]. 

S. Hinkamp, G. Schwedt, Determination of total phosphorus in waters with amper-ometric detection by coupling of flow-injection analysis with continuous microwave oven digestion, Anal. Chim. Acta 236 (1990) 345. 

R.L. Benson, I.D. McKelvie, B.T. Hart, I.C. Hamilton, Determination of total phosphorus in waters and wastewaters by on-line microwave-induced digestion and flow-injection analysis, Anal. Chim. Acta 291 (1994) 233. 

The causes of the high productivity of coral-reef communities are still not clear. Concentrations of nitrogen and phosphorus in waters flowing over reefs are relatively low, but nevertheless there is a constant supply of nutrients. Lewis (1977) found some evidence to suggest that both these nutrients are recycled rapidly on the reef and that nitrogen is fixed by bacteria and primary producers. 

It is also important to remember that the expression of various constituents in terms of a common constituent is merely a convenience and has nothing to do with the nature of the constituent in a specific water. Often people speak of the amount of phosphorus in water or wastewater. There is no phosphorus in water or wastewater. If there were, we would be in trouble because the water would be unusable for most purposes. But there are various types of phosphates, which we analytically express as phosphorus. 

TABLE 6-4 Typical Concentrations of Total Phosphorus in Water... 

For many scientists involved in the analysis of phosphorus in water, sediment and soil, the only available techniques depend on the colorimetric determination of molybdate-reactive phosphorus, and that which can be made reactive during a digestion step. Molybdate-reactive phosphorus in filtered samples is generally equated to inor-... 

Non-specific Determination of Organic Phosphorus in Waters and Extracts... 

During the last decade, information on the organic phosphorus composition of soil solutions and water extracts has been obtained by phosphatase hydrolysis. This technique not only gives structural information on filterable organic phosphorus, but also indicates its potential biological availability. In solution from Scottish upland soils, up to 64% of the filterable organic phosphorus was hydrolysed by non-specific phosphatases (Shand and Smith, 1997), while hydrolysable unreactive phosphorus in water extracts of Australian pasture soils was dominated by phosphate diesters and myo-inositol hexakisphosphate (Turner et al., 2002a). Only small concentrations of labile monoesters were detected in the latter study, possibly due to the rapid hydrolysis of labile compounds by soil phosphatase enzymes. 

FIGURE 9.8 Schematic showing separation of dissolved reactive phosphorus and particulate phosphorus in water samples. 

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