Degradation pathway, toxicity and kinetics of 2,4,6-trichlorophenol with different co-substrate by aerobic granules in SBR

2011 ◽  
Vol 102 (13) ◽  
pp. 7016-7021 ◽  
Author(s):  
Mohammad Zain khan ◽  
Pijush Kanti Mondal ◽  
Suhail Sabir ◽  
Vinod Tare
Keyword(s):  
Degradation Pathway ◽  
Aerobic Granules ◽  
Kinetics Of

scholarly journals Photo degradation kinetics of insensitive munitions constituents nitroguanidine, nitrotriazolone, and dinitroanisole in natural waters

2021 ◽  
Author(s):  
Lee Moores ◽  
Stacy Jones ◽  
Garrett George ◽  
David Henderson ◽  
Timothy Schutt
Keyword(s):  
Laboratory Experiments ◽  
Natural Waters ◽  
Matrix Effects ◽  
Degradation Kinetics ◽  
Relative Rate ◽  
Ph Dependence ◽  
Degradation Pathway ◽  
Quantum Yields ◽  
The Individual ◽  
Kinetics Of

Herein the matrix effects on the kinetics of aqueous photolysis for the individual munitions constituents of IMX-101: nitroguanidine (NQ), dinitroanisole (DNAN), and nitrotriazolone (NTO) are reported along with the environmentally relevant kinetics and quantum yields. Photolysis potentially represents a major degradation pathway for these munitions in the environment and further understanding the complex matrices effects on photolytic kinetics was needed. Aqueous systems are of particular interest due to the high solubility of NQ (3,800 ppm) and NTO (16,642 ppm) compared to the traditional munitions trinitrotoluene (TNT, 100.5 ppm) and 1,3,5-trinitro-1,3,5-triazine (RDX, 59.9 ppm). Environmental half-lives (and quantum yields) were found to be 0.44 days, 0.83 days, and 4.4 days for NQ, DNAN, and NTO, respectively, under natural sunlight. In laboratory experiments using nominally 300 nm bulbs in a merry-go-round style reactor in DI water the relative rate of photolysis for the three munitions constituents followed the same order NQ > DNAN > NTO, where DNAN and NTO reacted 57 and 115 times more slowly, respectively, than NQ. In the various environmentally relevant matrices tested in the laboratory experiments NQ was not significantly affected, DNAN showed a faster degradation with increasing ionic strength, and NTO showed a modest salinity and pH dependence on its rate of photolysis.

Growth Kinetics of Aerobic Granules

2007 ◽  
pp. 111-130
Author(s):  
Qi-Shan Liu ◽  
Yu Liu
Keyword(s):  
Growth Kinetics ◽  
Aerobic Granules ◽  
Kinetics Of

scholarly journals Biochemical and structural characterization ofKlebsiella pneumoniaeoxamate amidohydrolase in the uric acid degradation pathway

2016 ◽  
Vol 72 (6) ◽  
pp. 808-816 ◽  
Author(s):  
Katherine A. Hicks ◽  
Steven E. Ealick
Keyword(s):  
Uric Acid ◽  
Active Site ◽  
Degradation Pathway ◽  
Α Subunit ◽  
Acid Degradation ◽  
Substrate Complex ◽  
Steady State Kinetics ◽  
Biochemical Studies ◽  
Kinetics Of ◽  
Insight Into

HpxW from the ubiquitous pathogenKlebsiella pneumoniaeis involved in a novel uric acid degradation pathway downstream from the formation of oxalurate. Specifically, HpxW is an oxamate amidohydrolase which catalyzes the conversion of oxamate to oxalate and is a member of the Ntn-hydrolase superfamily. HpxW is autoprocessed from an inactive precursor to form a heterodimer, resulting in a 35.5 kDa α subunit and a 20 kDa β subunit. Here, the structure of HpxW is presented and the substrate complex is modeled. In addition, the steady-state kinetics of this enzyme and two active-site variants were characterized. These structural and biochemical studies provide further insight into this class of enzymes and allow a mechanism for catalysis consistent with other members of the Ntn-hydrolase superfamily to be proposed.

Degradation Pathway and Kinetics of Vanillin with Gordonia sp.

2012 ◽  
Vol 550-553 ◽  
pp. 2824-2827 ◽  
Author(s):  
Liping Yao ◽  
Wenzhe Song ◽  
Yuan Cai Chen
Keyword(s):  
Rate Constant ◽  
Removal Rate ◽  
Degradation Pathway ◽  
Spectroscopic Technique ◽  
Product Structure ◽  
Reaction Pathways ◽  
Order Model ◽  
First Order ◽  
Kinetics Of

This study is to discuss the reaction pathways of vanillin (3-methoxy-4-hydroxy-benzaldehyde) degradation by Gordonia sp.The product structure was analyzed by spectroscopic technique. Vanillin removal kinetics could be best described by a simple recalcitrant first order model:-dS/dt=k s,1 X(S-S∞),k s,1 is the vanillin removal rate constant.

Anaerobic degradation pathway and kinetics of domestic wastewater at low temperatures

2009 ◽  
Vol 100 (24) ◽  
pp. 6155-6162 ◽  
Author(s):  
Beni Lew ◽  
Sheldon Tarre ◽  
Michael Beliavski ◽  
Michal Green
Keyword(s):  
Low Temperatures ◽  
Anaerobic Degradation ◽  
Domestic Wastewater ◽  
Degradation Pathway ◽  
Kinetics Of

Characterization of naphthalene degradation by Streptomyces sp. QWE-5 isolated from active sludge

2014 ◽  
Vol 70 (6) ◽  
pp. 1129-1134 ◽  
Author(s):  
Peng Xu ◽  
Wencheng Ma ◽  
Hongjun Han ◽  
Baolin Hou ◽  
Shengyong Jia
Keyword(s):  
Degradation Rate ◽  
Substrate Inhibition ◽  
Degradation Pathway ◽  
Active Sludge ◽  
Streptomyces Sp ◽  
Metabolic Intermediates ◽  
Naphthalene Degradation ◽  
Specific Degradation ◽  
Kinetics Of

A bacterial strain, QWE-5, which utilized naphthalene as its sole carbon and energy source, was isolated and identified as Streptomyces sp. It was a Gram-positive, spore-forming bacterium with a flagellum, with whole, smooth, convex and wet colonies. The optimal temperature and pH for QWE-5 were 35 °C and 7.0, respectively. The QWE-5 strain was capable of completely degrading naphthalene at a concentration as high as 100 mg/L. At initial naphthalene concentrations of 10, 20, 50, 80 and 100 mg/L, complete degradation was achieved within 32, 56, 96, 120 and 144 h, respectively. Kinetics of naphthalene degradation was described using the Andrews equation. The kinetic parameters were as follows: qmax (maximum specific degradation rate) = 1.56 h−1, Ks (half-rate constant) = 60.34 mg/L, and KI (substrate-inhibition constant) = 81.76 mg/L. Metabolic intermediates were identified by gas chromatography and mass spectrometry, allowing a new degradation pathway for naphthalene to be proposed. In this pathway, monooxygenation of naphthalene yielded naphthalen-1-ol. Further degradation by Streptomyces sp. QWE-5 produced acetophenone, followed by adipic acid, which was produced as a combination of decarboxylation and hydroxylation processes.

scholarly journals Morpholine Degradation Pathway of Mycobacterium aurumMO1: Direct Evidence of Intermediates by In Situ 1H Nuclear Magnetic Resonance

1998 ◽  
Vol 64 (1) ◽  
pp. 153-158 ◽  
Author(s):  
B. Combourieu ◽  
P. Besse ◽  
M. Sancelme ◽  
H. Veschambre ◽  
A. M. Delort ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Direct Detection ◽  
Quantitative Information ◽  
Degradation Pathway ◽  
H Nmr ◽  
Mycobacterium Aurum ◽  
Kinetics Of ◽  
Nuclear Magnetic

ABSTRACT Resting Mycobacterium aurum MO1 cells were incubated with morpholine, a waste from the chemical industry. The kinetics of biodegradation was monitored by using in situ nuclear magnetic resonance (NMR). The incubation medium was directly analyzed by1H NMR. This technique allowed the unambiguous identification of two intermediates of the metabolic pathway involved in the biodegradation process, glycolate and 2-(2-aminoethoxy)acetate. The latter compound, which was not commercially available, was synthesized, in three steps, from 2-(2-aminoethoxy)ethanol. Quantitative analysis of the kinetics of degradation of morpholine was performed by integrating the signals of the different metabolites in1H-NMR spectra. Morpholine was degraded within 10 h. The intermediates increased during the first 10 h and finally disappeared after 20 h incubation. Assays of degradation were also carried out with glycolate and ethanolamine, hypothetical intermediates of the morpholine degradation pathway. They were degraded within 4 and 8 h, respectively. Until now, no tool for direct detection of intermediates or even morpholine has been available, consequently, only hypothetical pathways have been proposed. The approach described here gives both qualitative and quantitative information about the metabolic routes used in morpholine degradation by M. aurum MO1. It could be used to investigate many biodegradative processes.

Removal of dissolved copper(II) and zinc(II) by aerobic granular sludge

2004 ◽  
Vol 50 (9) ◽  
pp. 155-160 ◽  
Author(s):  
H. Xu ◽  
J.-H. Tay ◽  
S.-K. Foo ◽  
S.-F. Yang ◽  
Y. Liu
Keyword(s):  
Experimental Data ◽  
High Efficiency ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Aerobic Granules ◽  
Batch Experiments ◽  
Order Model ◽  
Biosorption Capacity ◽  
Kinetics Of ◽  
Biosorption Kinetics

This study investigated the adsorption kinetics of dissolved copper(II) and zinc(II) by aerobic granular sludge. Two series of batch experiments were conducted at different initial copper(II), zinc(II) concentrations (Co) and initial granule concentrations (Xo). Results showed that the biosorption kinetics of individual copper(II) and zinc(II) by aerobic granules were closely related to Co and Xo. The maximum biosorption capacity of individual copper(II) and zinc(II) by aerobic granules was 246.1 mg g-1 and 180 mg g-1, respectively. In order to theoretically interpret the results obtained, two kinetic models previously developed for biosorption were employed and compared in this study. It was found that the model proposed by Liu et al. (2003) could fit the experimental data very well, but the second-order model failed to fit the data in some cases. It appears that aerobic granules would be potential biosorbent with high efficiency for the removal of dissolved copper(II) and zinc(II) from wastewater.

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