Phosphorus electron-acceptor

Bioremediation usually requires a procedure for stimulation of and maintaining the activity of microorganisms. For biodegradation to be successful, it is necessary to provide a continuous supply of a suitable electron acceptor (such as oxygen or nitrate), nutrients (nitrogen, phosphorus), and a carbon source for energy and cell material. The most commonly deficient components in the subsurface are eiectron acceptors and nutrients. 

Enhanced biorestoration is a means by which naturally occurring processes are deliberately manipulated to increase or enhance the rate of cleanup. Biological activity in the subsurface is controlled by the availability of one or more of the necessary metabolic requirements such as an electron acceptor or nutrient. Although electron acceptors are most often the limiting factor, inadequate availability of nitrogen, phosphorus, or micronutrients (such as potassium, copper, or even vitamins) can restrict optimum restoration. When the proper balance of these factors is established, the rate of chemical degradation is maximized. 

More vigorous conditions were required for the formylation of thienothiophene 3 with an electron acceptor group in the molecule. Thus, refluxing methyl thieno[3,4-6]thiophene-2-carboxylate, iV-methyl-formanilide and phosphorus oxychloride for 1 hour gave a mixture (1 1)... 

Low-oxidation state iron compounds are stabilized by electron acceptor ligands, especially carbon monoxide, isocyanide, and phosphorus donors. The most common coordination geometry encountered in iron compounds is octahedral, but tetrahedral, trigonal bipyramidal, and square pyramidal are also represented. There are only a few compounds with iron in the -II state, although reduction of [Fe(CO)s] with sodium amalgam in THF... 

Composites, in the usual sense, were proposed to improve the mechanical stability of the electrode. An example is 80 wt% coke powder in PVC [192]. Of greater interest are carbons with nanodispersed boron (via BCI3, 900 °C). The compound B0.17C0.83 has a reversible specific capacity of 437 Ah/kg [193]. An even stronger enhancement of ilTs, up to 500 Ah/kg could be achieved by silicon (via SiCLj/via Me2Cl2Si, 950 °C) for the composition Si0.nC0.g9 [194,195]. Structural aspects are compiled in Fig. 22. The improved stoichiometry is attributed to the electron-acceptor capability of boron or silicon. Doping of petroleum-fuel green coke by phosphorus elevates by 20% [191]. 

In contrast to the different sulfur and nitrogen species, phosphorus in marine environments occurs almost exclusively in the oxidation state -i-5. Thus, with few exceptions (Schink and Friedrich 2000), bacteria cannot gain energy by the oxidation of reduced phosphorus species and cannot use phosphate as an electron acceptor. Nevertheless, phosphorylation, the addition of a phosphate group to another compound, plays a major... 

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