Nitrogen nitrification

It is remarkable that the nitrogen cycle employs extreme oxidation-reduction states of nitrogen. Nitrification carries N from 3 to 5, whereas denitrification reduces N from 5+ to 0. A more direct cycle using only redox states of N between... 

As mentioned, three types of kinetics are involved in the removal of nitrogen nitrification kinetics, denitrification kinetics, and carbon kinetics. Carbon kinetics refer to the kinetics of the heterotrophic aerobic reactions. By analogy with the nitrification or denitrification kinetics,... 

Upon decay of organic matter the nitrogen is released first as ammonium (the process of ammonifi-cation) and then is either recycled by organisms or tends to become oxidized to various oxides of nitrogen. Nitrification, the conversion of ammonium to nitrate via nitrite, is carried out by the combined action of two groups of aerobic chemosynthesizers. In soils the first step (NH4+ to N02 ) is primarily performed by Nitrosomonas and the second step (N02 to N03 ) by Nitrobacter. Some fungi can also carry out nitrification at low pH. 

Denitrification is a process in which facultative organisms will reduce nitrate to nitrogen gas in the absence of molecular oxygen. This consequendy results in the removal of BOD. The denitrification process also generates one hydroxyl ion so that alkalinity requirements are reduced to half when both nitrification and denitrification are practiced. 

The interest in gaseous losses of nitrogen from soil is now extensive and includes the well established community of soil scientists concerned with losses of fertilizer-applied nitrogen by nitrification and denitrification. More recently, interest in ammonia losses from plants and soil has been stimulated by the very large emissions from intensive cattle production in the Netherlands and their... 

Salpeter-schwefels ure, /. nitrosulfuric acid (a mixture) nitrosylsulfuric acid, -siederei, /. saltpeter works, -stkrkemehl, n. nitrated starch, -stoff, m. nitrogen, -strauch, m. niter bush Nitraria). -ung,/. nitrification, -verbindung, /. nitrate. -waC4)ge, /. nitrometer. 

Nitrification. Nitrification refers to biologically mediated oxidation of reduced nitrogen to higher oxidation states ... 

Delwiche, C. C. (1981). The nitrogen cycle and nitrous oxide. In "Denitrification, Nitrification, and Atmospheric Nitrous Oxide" (C. C. Delwiche, ed.). Wiley, New York. 

Davidson, E., Hart, S.C., Shanks, C.A. and Firestone, M.K. 1991 Measuring gross nitrogen mineralization, immobilization, and nitrification by isotopic pool dilution in intact soil cores. Journal of Soil Science 42 335—349. 

Mariotti, A., Germon, J.C., Hubert, P., Kaiser, R, Letolle, R., Tardieux, A. and Tardieux, P. 1981 Experimental determination of nitrogen kinetic isotope fractionation some principles illustration for the denitrification and nitrification processes. Plant and Soil 62 413-430. 

L. Landi, L. Badalucco, F. Pomare, and P. Nannipieri, Effectiveness of antibiotics to distinguish the contributions of fungi and bacteria to net nitrogen mineralization, nitrification and re.spiration. Soil Biol. Biocheiii. 25 1771 (1993). 

D. M. Crawford and P. M. Chalk, Mineralization and immobilization of soil and fertilizer nitrogen with nitrification inhibitors and solvents. Soil Biol. Biochem. 24 559 (1992). 

The methane content of the first UASB reactor was ca. 60%. The NH4-N removal efficiency of the total system was 99.6%. Ammonium nitrogen was converted to nitrate in the aerobic system via nitrification. The BOD5/COD value obtained at the final stage was in the range 0.12 to 0.15. 

To maintain high recycling ratios between the nitrification and denitrification units. This recommendation is also useful to increase the efficiency of nitrogen removal. 

Nitrification reactions can occur, in which organic nitrogen and ammonia are converted to nitrate ... 

Bioprocesses for the removal of nitrogen oxides from polluted air are an interesting alternative [58], but current reaction rates are still too low for large-scale applications. Advanced biological processes for the removal of NO from flue gases are based on the catalytic activity of either eukaryotes or prokaryotes, e.g. nitrification, denitrification, the use of microalgae and a combined physicochemical and biological process (BioDeNO ). 

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