Oxidized inorganic nitrogen

Anaerobic conditions, i.e., the absence of DO and nitrate or other oxidized inorganic nitrogen compounds, are crucial for the formation of sulfide. Although sulfide requires strict anaerobic conditions for its formation, it is... 

The oxidized inorganic nitrogen species not included in NO is N2O. It is produced during nitrihcation and denitrification (Figure I). It has an atmospheric residence time of 100 yr and, because of this, emissions are globally distributed. Because of its stability, no significant chemical reactions take place in the troposphere but, once in the stratosphere, it is converted to NO by UV radiation ... 

Stable nitrogen isotope compositions are useful tracers of both the source of N to the biomass and the history of the organic nitrogen. The of dissolved N2 in surface waters (c.+ 0.6%o) is slightly enriched compared with atmospheric N2 (0%o) because the heavier gas molecules have a lower vapor pressure and are more soluble in water. In contrast, dissolved NO3 (by far the most abundant form of oxidized inorganic nitrogen in the sea) exhibits values that... 

Demonstrations (see below) of the acidic properties of the oxides of nitrogen and sulfur show students some of the inorganic reactions that will be background for class discussions and homework assignments. The students are also expected to know the natural and industrial sources of each gas. They must also be reminded of chemistry topics they have already studied, such as gas behavior and equilibrium, that will provide relevant background for understanding acid deposition. 

Patrick WH, Jugsujinda A. Sequential reduction and oxidation of inorganic nitrogen, manganese, and iron in flooded soil. Soil Sci. Soc. Am. J. 1992 56 1071-1073. 

Correction for inorganic nitrogen species present before oxidation. 

Of the methods in common use, the two wet oxidation methods offer the best possibilities for further development. The photo-oxidation method in particular is well suited to automatic analysis. In the version of the total organic carbon method published by Collins and Williams [30] the effluent from the quartz photolysis coil could as easily be diverted to the nitrate analysis unit if inorganic nitrogen were also measured, organic nitrogen could become a routine automatic method. 

A pH of 3 was optimal for the complete removal of inorganic carbon and the most efficient oxidation of nitrogen-free organic compounds, while a pH of 2.5 was optimal for nitrogenous compounds (Fig. 11.1). 

The chemistry of inorganic nitrogen compounds is very complicated, and therefore, it is difficult to prove which of these compounds is of a real importance in biological systems. In addition to NO and peroxynitrite, the formation of N02, N203, and NO- might be of importance in biological systems. Some reactions of nitrogen oxide species are cited below. 

Nitrites, inorganic Nitrogen oxides (NOx) Oxygen Peracetic acid Perchloric acid solutions Potassium bromate Potassium chlorate Potassium dichloro-s-triazinetrione (potassium dichloroisocyanurate) Potassium dichromate Potassium percarbonate Potassium perchlorate Potassium permanganate Potassium peroxide Potassium persulfate Potassium superoxide n-Propyl nitrate... 

Also included in Table 7.7 are the nitrogen fixation reactions. These are similar to the carbon fixation reactions in that they involve the conversion of an oxidized inorganic species (N2) 1° a reduced form, such as ammonium. The fixed forms of nitrogen can be taken up by plants. As with carbon fixation, this process requires an energy source in order to proceed. Some N2 fixers are photosynthetic and others use energy obtained from the oxidation of reduced inorganic compounds. 

Ragsdale, R. O. (1973). Reactions of nitrogen (II) oxide. Developments in Inorganic Nitrogen Chemistry. Elsevier, Amsterdam. 

The study of the biosynthesis of inorganic nitrogen oxides has a long and distinguished history, principally in the field of microbial and plant nitrogen metabolism (Zumft, 1993). Relatively recently, it has been found that NO, in addition to other species such as nitrite, nitrate, and NjO, is a true intermediate in the biological nitrogen cycle, as described in detail in Chapter 9. 

The products of hydrocarbon oxidation in SCWO are carbon dioxide and water. Heteroatoms are converted to inorganic compounds, usually acids, salts, or oxides in high oxidation states. Phosphorus is converted into phosphate, and sulphur to sulfate nitrogen-containing compounds are oxidized to nitrogen gas. Working at temperatures below 700 °C, no NOx is formed. 

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