Denitrification kinetics

The first run with ICR 106 catalyst (Run 81-4) was a 2000-hr test made in a relatively small pilot plant containing 130 mL of catalyst to determine denitrification kinetics and hydrogen consumption. Activity data are plotted in Figure 1 for 0.2, 0.3, and 0.6 LHSV. A simple first-... 

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,... 

Starr, J.L., and J.Y. Parlange. 1975. Nonlinear denitrification kinetics with continuous flow in soil columns. Soil Sci. Soc. Am. Proc. 39 875-880. 

In 1973 we began an experimental measurement of denitrification kinetics using (16). Again the 0(p, ) N reaction was used,... 

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. 

Poth M, DD Focht (1985) N kinetic analysis of N2O production by Nitrosomonas europaea an examination of nitrifier denitrification. Appl Environ Microbiol 49 1134-1141. 

Green, M., Schnitzer, M., and Tarre, S., Kinetics of a Fluidized-Bed Reactor for Ground-Water Denitrification, / / / /. Microbiol. Biotechnol., 43 188 (1995)... 

Microbial reduction of nitrate to N2, known as denitrification, is similar. It is kinetically inhibited in the absence of bacteria and is known to induce a kinetic isotope effect (Blackmer and Bremner 1977 Kohl and Shearer 1978 Mariotti et al. 1981 Bryan et al. 1983 Htibner 1986 Mariotti et al. 1988). W N shifts ranging from 6.5%o to 20%o have been observed experimentally. As with sulfate, microbial fractionations appear to depend on the metabolic states of the microbes. 

Transport of NO3 formed from NH4+ towards the root and its consumption in denitrification and uptake by the root. Denitrification is described with Michaelis-Menten kinetics with an inhibition function related to [O2]. 

In short, the overall features of the chemistry involved with the massive destruction of ozone and formation of the ozone hole are now reasonably well understood and include as a key component heterogeneous reactions on the surfaces of polar stratospheric clouds and aerosols. However, there remain a number of questions relating to the details of the chemistry, including the microphysics of dehydration and denitrification, the kinetics and photochemistry of some of the C10x and BrOx species, and the nature of PSCs under various conditions. PSCs and aerosols, and their role in halogen and NOx chemistry, are discussed in more detail in the following section. 

The first product of nitrosyl transfer to nitrite in Eq. (2), E N203, contains N-N bonded N2O3 which is itself a well-known and powerful nitrosyl donor. It is reasonable to suppose therefore that nitrosyl transfer reactions with N- and O-nucleophiles could involve both E NO (or E HONO) and E N205. In addition, the involvement of a second molecule of nitrite for denitrification would require that the substrate saturation curve should be sigmoidal to reflect a term second-order in nitrite concentration. No such effect has been reported to our knowledge. The use of bimolecular substrate kinetics in dilute solutions to generate an intermediate subject to solvolysis seems metabolically unwise hut not impossible. 

Betlach, M. R., and Tiedje, J. M. (1981). Kinetic explanation for accumulation of nitrite, nitric oxide, and nitrous oxide during bacterial denitrification. Appl. Environ. Microbiol. 

Goretski, J., and Hollocher, T. C. (1990). Tire kinetic and isotopic competence of nitric oxide as an intermediate in denitrification. J. Biol. Chem. 265, 889-895. 

The reaction and separation synthesis approach of Section 5 has been adopted to the problem of activated sludge process design (83). The conventional designs as well as all novel schemes for combined oxidation/denitrification of wastewater are explored. The process is optimized using a novel methodology for optimal reaction/separation network synthesis, supplied with a comprehensive kinetic model (84). The activated sludge process is synthesized using the systematic... 

This model assumes irreversible first-order kinetics for nitrification, denitrification, mineralization, immobilization, and plant uptake. It takes the following form, in which sinks and sources are aggregated ... 

Frissel and van Veen (1981) Revised version of Beek and Frissel (1983) growth of Nitrosomonas and Nitrobacter by Michaelis-Menten kinetics, including considerations of oxygen levels denitrification by a physical-biological model involving oxygen diffusion ... 

Mariotti A. Germon J. C. Leclerc A. Catroux G. Letolle R. Experimental determination of kinetic isotope fractionation of nitrogen isotopes during denitrification. Anal. Chem. Symp. Ser. 1982, 11, 459 464. 

The technical and economic aspects of wet flue gas simultaneous desulfurization and denitrification systems are presented so that their practicality for utilization by utility industry can be assessed. The emphasis is on the kinetics of the systems based on the employment of ferrous chelates to promote the solubility of NO and the reactivity of NO with SO2 in scrubbing liquors. Analytical techniques are developed for characterizing reaction intermediates and products. Alternative approaches and novel ideas that could develop into a more efficient and cost-effective scrubber system employing metal chelate additives are discussed. 

Choe S, Chang YY, Hwang KY, Khim J. Kinetics of reductive denitrification by nanoscale zero-valent iron. Chemosphere 2000 41 1307-1311. 

In denitrification, the parameters that can limit the kinetics are the concentrations of the carbon source [5J and the nitrate nitrogen [Sno,]- The Monod equation may be written as... 

A domestic wastewater with a flow of 20,000 m /d is to be denitrified. The effluent from the nitrification tank contains 30 mg/L of NO3-N, 2.0 mg/L of dissolved oxygen, and 0.5 mg/L of NO2-N. The concentration of total nitrogen in the effluent is 2.53 mg/L. Assuming all kinetic parameters are known, calculate the fraction of nitrate nitrogen destroyed in the denitrification process. 

After cutting off the aeration to a nitrification plant, the dissolved oxygen concentration is 2.0 mg/L. The BOD5 sewage needed for the carbonaceous reaction in this last stage of aerobic reaction before denitrification sets in is 1.34 mg/L. Assuming all kinetic parameters are known except calculate F. ... 

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