Sodium triphosphate (STP), also sodium tripolyphosphate (STPP), or tripolyphosphate (TPP),) is an inorganic compound with the formula Na 5 P 3 O 10 . This is the sodium salt of penta polyphosphate anion, which is a triphosphoric acid conjugate base. It is produced on a large scale as a component of many domestic and industrial products, especially detergents. Environmental problems associated with eutrophication are associated with their widespread use.
Video Sodium triphosphate
Preparation and properties
Sodium tripolyphosphate is produced by heating the stoichiometric mixture of sodium phosphate, Na 2 HPO 4 , and monosodium phosphate, NaH 2 PO 4 , under carefully controlled conditions.
- 2 Na 2 NaO 2 PO 4 -> Na 5 P 3 O 10 2 H 2 O
In this way, about 2 million tonnes are produced each year.
STPP is a colorless salt, which exists in both anhydrous form and as a hexahydrate. Anions can be described as a pentanionic chain [O 3 POP (O) 2 OPO 3 ] 5 - . Many of the di-, tri, and associated polyphosphates are known to include cyclic triphosphate P 3 O 9 3 - . It binds strongly to good metal cations as bidentate chelating agents and trident.
Maps Sodium triphosphate
Usage
In detergent
The majority of STPP is consumed as a commercial detergent component. It serves as a "builder," the industry jargon for water softeners. In hard water (water containing high concentrations of Mg 2 and Ca 2 ), detergent is disabled. Being a high-loaded chelating agent, TPP 5 - tightly binds the thorn and prevents it from interfering with sulfonate detergents.
Food apps
STPP is a preservative for seafood, meat, poultry, and animal feed. This is common in food production as the number E E451 . In food, STPP is used as emulsifier and to maintain moisture. Many governments regulate the amount allowed in food, because it can substantially increase the weight of seafood sales in particular. The Food and Drug Administration of the United States listed STPP as "commonly known as safe."
Other uses
Other uses (hundreds of thousands of tons/year) include ceramics (reducing glaze viscosity to some extent), tannery (as a masking agent and synthetic tannery agent - SYNTAN), anticaking, retarder settings, flame retardants, paper, anticorrosion pigments, textiles, rubber, fermentation, antifreeze. "TPP is used as polianion crosslinker in drug delivery based on polysaccharide, toothpaste/toothpaste Saxton C, Van der Ouderra FGJ J Periodontal Res.1989; 24: 75. 2. Lobene RR Clin Prev Dent, 1986, 8 (1) : 3. 3. Lobene RR, et al, Clin Prev Dent 1982, 4: 5-8, 4.Mankodi S. et al, J Peruval Clin 2005: 32; 75-80 5. Mankodi S. et al. Comp Contin Educ Dent 1997: 18 (Spec No.), 10-15 6. Mallatt M. et al J Clin Periodontol 2007; 34: 762-767 Lang Lang Oral Arch Bial 1990; 35 (Suppl): 95-145.
Health effects
Polyphosphates are hydrolysed into simpler phosphates, which are in moderate amounts of nutrients. For example, ATP, a related derivative of triphosphate, is essential for life. Thus, the low polyphosphate toxicity, as the lowest LD 50 after oral administration is & gt; 1,000 mg/kg body weight. Similarly, no mutagenic, carcinogenic, or reproductive effects have been noted. Anion polyphosphate salts are quite disturbing to the skin and mucous membranes because they are slightly alkaline.
Environmental effects
In 2000, STPP consumption worldwide was estimated at 2,000,000 tons. Because it is very soluble in water, it is not significantly transferred to the sewage sludge, and therefore to the soil with the spread of mud. No environmental risk associated with the use of STPP in detergents is indicated in soil or air. As a household cleaning product, STPP in domestic wastewater is primarily discharged into water compartments, directly, via wastewater treatment plants, through septic tanks, infiltration or other autonomous wastewater systems.
Because STPP is an inorganic substance, biodegradation studies can not be applied. However, STPP can be hydrolyzed, eventually becoming an orthophosphate, which can be assimilated by algae and/or by micro-organisms. STPP is eventually assimilated into the natural phosphorus cycle. Reliable published studies confirm biochemical understandings, suggesting that STPP is progressively hydrolyzed by biochemical activity in contact with wastewater (in sewerage pipes and in waste work) as well as in natural aquatic environments. This information allows "worst case" calculations to predict environmental concentrations using EUSES models and HERA detergent scenarios. A regional standard release of 10% is applied in lieu of the 7% regional release shown in the HERA detergent scenario. Reliable acute ecotoxicity ecotoxicity studies are available which show that STPP is non-toxic to aquatic organisms: all EC/LC50 values ​​above 100 mg/l ( Daphnia , fish, algae). Because of this, and because of the only temporary presence of STPP in the aquatic environment (due to hydrolysis), no studies have been done to date regarding the chronic effects of STPP in this aquatic organism. Concentration estimates without effect were calculated for aqueous and sedimentary environments based on acute aquatic ecotoxicity results.
Effects of wastewater containing phosphorus
Detergents containing phosphorus contribute, along with other phosphorus sources, to the eutrophication of many freshwater. Eutrophication is the improvement of chemical nutrients - usually compounds containing nitrogen or phosphorus - in an ecosystem. It can happen on land or in water. This term, however, is often used to mean the increase produced in the major ecosystem productivity (excessive plant growth and decay), and further effects include lack of oxygen and severe reductions in water and fish quality and other animal populations.
Phosphorus can in theory produce about 500 times in algae. While the main production in marine waters especially nitrogen is limited, fresh water is considered as limited phosphorus. Most waste discharges in many countries are released to freshwater recipients, and here the use of phosphorus as a complex agent remains an environmental problem.
See also
- Daily intakes received
References
Source of the article : Wikipedia
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