Environmental concerns phosphates

The production of industrial-grade acid and phosphates has been influenced since the 1970s by environmental concerns and related legislation. ... 

Phosphate legislation. Environmental concern over the eutrophication of lakes prompted the advent of phosphate restrictions for laundry products. These restrictions were initially legislated in areas of high population density. They have since expanded to cover 40% of the U.S. population [2]. As more states and cities enacted phosphate restrictions, laundry formu-... 

The most critical decision to be made is the choice of the best solvent to facilitate extraction of the drug residue while minimizing interference. A review of available solubility, logP, and pK /pKb data for the marker residue can become an important first step in the selection of the best extraction solvents to try. A selected list of solvents from the literature methods include individual solvents (n-hexane, " dichloromethane, ethyl acetate, acetone, acetonitrile, methanol, and water ) mixtures of solvents (dichloromethane-methanol-acetic acid, isooctane-ethyl acetate, methanol-water, and acetonitrile-water ), and aqueous buffer solutions (phosphate and sodium sulfate ). Hexane is a very nonpolar solvent and could be chosen as an extraction solvent if the analyte is also very nonpolar. For example, Serrano et al used n-hexane to extract the very nonpolar polychlorinated biphenyls (PCBs) from fat, liver, and kidney of whale. One advantage of using n-hexane as an extraction solvent for fat tissue is that the fat itself will be completely dissolved, but this will necessitate an additional cleanup step to remove the substantial fat matrix. The choice of chlorinated hydrocarbons such as methylene chloride, chloroform, and carbon tetrachloride should be avoided owing to safety and environmental concerns with these solvents. Diethyl ether and ethyl acetate are other relatively nonpolar solvents that are appropriate for extraction of nonpolar analytes. Diethyl ether or ethyl acetate may also be combined with hexane (or other hydrocarbon solvent) to create an extraction solvent that has a polarity intermediate between the two solvents. For example, Gerhardt et a/. used a combination of isooctane and ethyl acetate for the extraction of several ionophores from various animal tissues. 

See also Borates Boric acid Sodium borates boron oxides, 4 246-249 boron oxides table,4 242t environmental concerns, 4 284—285 health and safety factors, 4 285-288 occurrence, 4 245—246 Boron perchlorates, 18 278 Boron phosphate, 4 242t, 283 Boron removal, from water, 14 418 Boron-stabilized carbanions, 13 660-661 Boron subhalides, 4 141 Boron suboxide, 4 242t Boron tribromide, 4 138 manufacture, 4 145—146 physical properties of, 4 139-140t, 325 reactions, 4 141 specifications, 4 147t uses of, 4 149 Boron trichloride, 4 138 manufacture, 4 145—146 physical properties of, 4 139-140t reactions, 4 141... 

Environmental inflows/outflows, in life cycle assessment, 74 809-810 Environmental interactions, test temperature and, 73 487-488 Environmental interventions, in life cycle assessment, 74 820 Environmental issues. See also Environmental concerns concerning phosphoric acids and phosphates, 73 861 electric furnaces, 72 314 emulsion-related, 70 128 ethylene glycol, 72 653-655 with fermentation, 77 49 in fine art examination/conservation, 77 407 108... 

Due to environmental concerns, research efforts have been directed toward the replacement of chromate-based post-treatments. This paper focuses on a new unique chromium free post-treatment based on "Mannich derivatives" of po1y-viny1pheno 1 which have demonstrated excellent performance on both zinc and iron phosphate treatments. 

Although chromate is the best aqueous corrosion inhibitor available, its use has been severely curtailed due to toxicity and environmental concerns ( ). One of the more successful non-chromate treatments involves the use of phosphate/phosphonate combinations. This treatment employs high levels of orthophosphate to promote passivation of the metal surfaces. Therefore, it is important to control calcium phosphate crystallization so that high levels of orthophosphate may be maintained in the system without fouling or impeding heat-transfer functions. 

Changes in the use of builders resulting from environmental concerns have been pushing surfactant production demand. Outright legal bans or consumer pressures on the use of inorganic phosphates and other materials as builders generally have led formulators to raise the contents of... 

Crannell, B. S., Eighmy, T. T., Butler, L., Emery, E. Cartledge, F. 2003a. Use of phosphate to stabilize heavy metals in contaminated sediments. In Pederson, J. Adams, E. (eds) Dredged Material Management Options and Environmental Concerns. MIT Sea Grant Publications, Cambridge, Massachusetts, 175-178. 

Disposal. These soaps and detergents may all be washed down the sink. Some of the older types contain phosphates and, due to environmental concerns, should be phased out, or used as little as possible. Additionally some concentrated liquid cleaners can be reused many times before they need to be disposed, so check the instructions before you discard a cleaner. 

Inhibitive Primers. The traditional primers are red lead and linseed oil, alkyd resins and zinc potassium chromate, proprietary epoxy, alkyd, urethane and latex systems with modified phosphate, borate and molybdate pigments. Chromate-based pigments, although in use in aircraft coatings, automotive primers and coil coating primers, are subject to environmental concern on the toxicity of hexavalent chromium which is likely to result in their replacement by innocuous products. 

Carbonate Complexes. Of the many ligands which are known to complex plutonium, only those of primary environmental concern, that is, carbonate, sulfate, fluoride, chloride, nitrate, phosphate, citrate, tributyl phosphate (TBP), and ethylenediaminetet-raacetic acid (EDTA), will be discussed. Of these, none is more important in natural systems than carbonate, but data on its reactions with plutonium are meager, primarily because of competitive hydrolysis at the low acidities that must be used. No stability constants have been published on the carbonate complexes of plutonium(III) and plutonyl(V), and the data for the plutoni-um(IV) species are not credible. Results from studies on the solubility of plutonium(IV) oxalate in K2CO3 solutions of various concentrations have been interpreted to indicate the existence of complexes as high as Pu(C03) , a species that is most unlikely from both electrostatic and steric considerations. From the influence of K2CO3 concentration on the solubility of PuCOH) at an ionic strength of 10 M, the stability constant of the complex Pu(C03) was calculated (10) to be 9.1 X 10 at 20°. This value... 

Heavy metals in wet-process phosphoric acid (WPA) and phosphate fluid fertilizers are an environmental concern in the United States and Europe. 

Environmental concerns are not just limited to the flame retardant molecules themselves or their decomposition products. The implementation of RCRA and the Clean Air Act have also taken their toll of the manufacturing processes for flame retardants. In the last year, one major flame retardant, tetrakis (2-chloroethoxy)ethylene bisphosphate (Figure 3) was withdrawn from the market because of environmental problems stemming from its manufacturing process. Similar manufacturing concerns may threaten other chloroalkyl phosphates if current government scrutiny of their chronic toxicity data doesn t do them in first. 

Much of the analytical chemistry of vanadium is concerned with its use in ferrous and nonferrous metallurgy. Vanadium also finds application in catalysis and in the paint and ceramic industries. Environmental concerns about vanadium arise primarily from air-pollution problems. Vanadium can be released from fly ash and oil-combustion products. There are only a few references on vanadium speciation. One reference reported the simultaneous determination of V(IV) and V(V) [25]. Postcolumn reaction with PAR resulted in detection limits of about 10 ppb, even in the presence of high concentration of phosphate. Unfortunately, the studies were not carried out in samples. Urasa et al. [2] used DCPAE detection to speciate V02 and another vanadium species thought to be VOCU ". 

Translocation in plant. The last step in elemental availability is translocation from roots to tops, a biological process that would seem outside the control of soil chemistry. A number of trace elements, especially those that take the form of cations in soils, do not readily translocate to plant tops. Therefore it is common for metals such as Cu, Pb, and Cd, after absorption from the soil, to accumulate in (or on) roots. Translocation behavior of plants is complex and not understood for many of the elements of environmental concern, but soil chemical factors (alkalinity, phosphate... 

Human cell response to environmental organic toxins. Holman et al. (2000) have investigated the changes in intracellular phosphate and lipid concentrations in human cells as a function of exposure to polychlorinated hydrocarbons and compared their findings to quantitative results from reverse transcription polymerase chain reaction (RT-PCR). The human cells were exposed to low doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent and well-studied man-made toxin. TCDD causes harmful effects at exposure levels of hundreds to thousands of times lower doses than most chemicals of environmental concern. This polychlorinated hydrocarbon causes an increase in the production of the cytochrome P4501A1 (CYP1A1) gene, which can be monitored with RT-PCR. 

Even from such a brief overview of its chemistry, it should be clear that phosphorus is an element still at the forefront of all areas of practical chemistry - from purely academic right to decidedly industrial. Though many of the latter uses are declining because of environmental concerns - witness the decrease in the use of phosphate detergents, ZDDP oil additives and organophosphorus pesticides - the fact remains that demand for the element is still enormous. Eventually, as the twenty-first century progresses, this demand will impact upon resources, and economics will dictate that phosphate recovery, - for example, from sewage - becomes vital. Much work to this end is already underway. ... 

Like many mining and refining operations there have been environmental concerns surrounding phosphate mining in Idaho. Until recently the most significant problems had been the air quality of calciner emissions, water quality surrounding waste piles, slight... 

Owing to environmental concerns over eutrophication, phosphate restrictions were implanented in 1970 in parts of the United States. Other areas with limitations now include Canada, Japan, and Western Europe. 

Because of environmental concerns regarding the use of halogenated FR derivatives [17], the demand for an alternative FR to replace the halogenated FR formulations has increased. One set of candidates is a group of aryl phosphates, whose chemical structures and applications for flame retardancy have been reviewed extensively in the literature [18, 19]. Some commonly used aryl phosphates and their properties are listed in Table 10.1. 

---