Revised Global Kinetic Measurements of Ammonia Oxidation in Supercritical Water

2006 ◽  
Vol 45 (20) ◽  
pp. 6842-6845 ◽  
Author(s):  
Jason M. Ploeger ◽  
Adam C. Madlinger ◽  
Jefferson W. Tester
Keyword(s):  
Supercritical Water ◽  
Ammonia Oxidation ◽  
Kinetic Measurements

Revised global kinetic measurements of methanol oxidation in supercritical water

1993 ◽  
Vol 32 (1) ◽  
pp. 236-239 ◽  
Author(s):  
Jefferson W. Tester ◽  
Paul A. Webley ◽  
H. Richard Holgate
Keyword(s):  
Methanol Oxidation ◽  
Supercritical Water ◽  
Kinetic Measurements

scholarly journals Ammonia-oxidizing archaea possess a wide range of cellular ammonia affinities

2021 ◽  
Author(s):  
Man-Young Jung ◽  
Christopher J. Sedlacek ◽  
K. Dimitri Kits ◽  
Anna J. Mueller ◽  
Sung-Keun Rhee ◽  
...  
Keyword(s):  
Ammonia Oxidation ◽  
Oxidation Kinetic ◽  
Ammonia Oxidizer ◽  
Substrate Affinity ◽  
Kinetic Properties ◽  
Ammonia Oxidizing Bacteria ◽  
Ammonia Oxidizers ◽  
Kinetic Measurements ◽  
Ammonia Oxidizing Archaea ◽  
Wide Range

AbstractNitrification, the oxidation of ammonia to nitrate, is an essential process in the biogeochemical nitrogen cycle. The first step of nitrification, ammonia oxidation, is performed by three, often co- occurring guilds of chemolithoautotrophs: ammonia-oxidizing bacteria (AOB), archaea (AOA), and complete ammonia oxidizers (comammox). Substrate kinetics are considered to be a major niche-differentiating factor between these guilds, but few AOA strains have been kinetically characterized. Here, the ammonia oxidation kinetic properties of 12 AOA representing all major phylogenetic lineages were determined using microrespirometry. Members of the genus Nitrosocosmicus have the lowest substrate affinity of any characterized AOA, which are similar to previously determined affinities of AOB. This contrasts previous assumptions that all AOA possess much higher substrate affinities than their comammox or AOB counterparts. The substrate affinity of ammonia oxidizers correlated with their cell surface area to volume ratios. In addition, kinetic measurements across a range of pH values strongly supports the hypothesis that – like for AOB – ammonia and not ammonium is the substrate for the ammonia monooxygenase enzyme of AOA and comammox. Together, these data will facilitate predictions and interpretation of ammonia oxidizer community structures and provide a robust basis for establishing testable hypotheses on competition between AOB, AOA, and comammox.

Determination of Ammonia Oxidation Rate in Sub- and Supercritical Water

2002 ◽  
Vol 41 (24) ◽  
pp. 6020-6027 ◽  
Author(s):  
Nathalie Segond ◽  
Yukihiko Matsumura ◽  
Kazuo Yamamoto
Keyword(s):  
Supercritical Water ◽  
Oxidation Rate ◽  
Ammonia Oxidation ◽  
Ammonia Oxidation Rate

scholarly journals Ammonia-oxidizing archaea possess a wide range of cellular ammonia affinities

2021 ◽  
Author(s):  
Man-Young Jung ◽  
Christopher J. Sedlacek ◽  
K. Dimitri Kits ◽  
Anna J. Mueller ◽  
Sung-Keun Rhee ◽  
...  
Keyword(s):  
Ammonia Oxidation ◽  
Oxidation Kinetic ◽  
Ammonia Oxidizer ◽  
Substrate Affinity ◽  
Kinetic Properties ◽  
Ammonia Oxidizing Bacteria ◽  
Ammonia Oxidizers ◽  
Kinetic Measurements ◽  
Wide Range ◽  
Total Ammonium

AbstractNitrification, the oxidation of ammonia to nitrate, is an essential process in the biogeochemical nitrogen cycle. The first step of nitrification, ammonia oxidation, is performed by three, often co-occurring guilds of chemolithoautotrophs: ammonia-oxidizing bacteria (AOB), archaea (AOA), and complete ammonia oxidizers (comammox). Substrate kinetics are considered to be a major niche-differentiating factor between these guilds, but few AOA strains have been kinetically characterized. Here, the ammonia oxidation kinetic properties of 12 AOA representing all major cultivated phylogenetic lineages were determined using microrespirometry. Members of the genus Nitrosocosmicus have the lowest affinity for both ammonia and total ammonium of any characterized AOA, and these values are similar to previously determined ammonia and total ammonium affinities of AOB. This contrasts previous assumptions that all AOA possess much higher substrate affinities than their comammox or AOB counterparts. The substrate affinity of ammonia oxidizers correlated with their cell surface area to volume ratios. In addition, kinetic measurements across a range of pH values supports the hypothesis that—like for AOB—ammonia and not ammonium is the substrate for the ammonia monooxygenase enzyme of AOA and comammox. Together, these data will facilitate predictions and interpretation of ammonia oxidizer community structures and provide a robust basis for establishing testable hypotheses on competition between AOB, AOA, and comammox.

PENGGUNAAN AIR SUPER KRITIS PADA DEPOLIMERISASI NYLON-12 (BATCH PROCESS)

2018 ◽  
Vol 5 (3) ◽  
Author(s):  
Mohamad Yusman
Keyword(s):  
Supercritical Water ◽  
Scale Up ◽  
Experimental Studies ◽  
Reaction System ◽  
Batch Process ◽  
Chemical Recycling ◽  
Water Decomposition ◽  
Product Distributions ◽  
New Process ◽  
Nylon 12

Water at the supercritical state is a new process for the chemical recycling. At this thermodynamic state i.e. Pc = 218 atmospheres and Tc = 374oC , water behaves very differently from its everyday temperament and it is a very good solvent for organic components. Experimental studies show that supercritical water can decompose hydrocarbons/polymers and produce useful products like 2-Azacyclotridecanone /lactam-1 from Nylon-12 (batch process). The decomposition process itself was carried out in batch reaction system in order to get more information about product distributions, time dependence, and scale-up possibilities.Keywords: supercritical water, decomposition, batch, polymer, hydrocarbon

Kinetics of Supercritical Water Oxidation. SERDP Compliance Technical Thrust Area

1996 ◽  
Author(s):  
Steven F. Rice ◽  
Richard R. Steeper ◽  
Russell G. Hanush ◽  
Jason D. Aiken ◽  
Eric Croiset
Keyword(s):  
Supercritical Water ◽  
Water Oxidation ◽  
Supercritical Water Oxidation ◽  
Kinetics Of
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