Oxidation of benzophenone-3 in aqueous solution by potassium permanganate: kinetics, degradation products, reaction pathways, and toxicity assessment

2021 ◽  
Author(s):  
Wanming Cao ◽  
Nannan Wu ◽  
Ruijuan Qu ◽  
Cheng Sun ◽  
Zongli Huo ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Potassium Permanganate ◽  
Degradation Products ◽  
Toxicity Assessment ◽  
Reaction Pathways

scholarly journals Relevance of Toxicity Assessment in Wastewater Treatments: Case Study—Four Fenton Processes Applied to the Mineralization of C.I. Acid Red 14

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Rajaa Idel-aouad ◽  
Manuel Valiente ◽  
Carmen Gutiérrez-Bouzán ◽  
Mercè Vilaseca ◽  
Abdlrani Yaacoubi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Oxidation Process ◽  
Dye Degradation ◽  
Degradation Products ◽  
Toxicity Assessment ◽  
Ph Adjustment ◽  
Low Toxicity ◽  
Fenton Oxidation Process ◽  
Short Time

Fenton and Fenton-like processes, both in homogeneous and heterogeneous phases, have been applied to an aqueous solution containing the dye AR 14 in order to study the mineralization and toxicity of the solutions generated after color elimination. The mineralization of AR 14 occurred slower than the decolorization. The Microtox analysis of the treated solutions showed low toxicity intrinsic to the chemicals used in the process rather than the degradation products obtained after the treatment of the dye solution. The dye degradation for the Fenton oxidation process was initially faster than for the Fenton-like process but after a short time, the four processes showed similar degradation yields. All processes have shown good results being the heterogeneous process the most convenient since the pH adjustment is not necessary, the catalyst is recovered and reused and the generation of contaminated sludge is avoided.

Über den Mechanismus der Bildung von Polyanionen in wäßriger Lösung. Zum Bildungsmechanismus eines Polytetramolybdations [Mo4O144-]n / On the Mechanism of Formation of Polyanions in Aqueous Solution. Concerning the Mechanism of Formation of a Polytetramolybdate Ion [Mo4O144-]n

1976 ◽  
Vol 31 (6) ◽  
pp. 737-748 ◽  
Author(s):  
Karl-Heinz Tytko
Keyword(s):  
Aqueous Solution ◽  
Coordination Sphere ◽  
Analytical Formula ◽  
Reaction Pathways ◽  
Mechanism Of Formation ◽  
X Ray ◽  
Theoretical Considerations

Possible structures and the pertinent reaction pathways for the polymetalate ion present in a slightly soluble polymetalate having the analytical formula A2O · 2 MOs have been derived on the basis of theoretical considerations. Structure and kind of combination of the tetrameric units of one of the possibilities are in agreement with the results of X-ray structure analyses. First the previously proposed planar tetrametalate ion [M4O12(OH)4]4--is formed by stepwise aggregation according to an addition mechanism. This species undergoes a rearrangement of the coordination sphere of two of the M atoms and is then subject to a polycondensation resulting in a polytetrametalate chain, [M4O144-]n.

scholarly journals Characterization and Study on Fragmentation Pathways of a Novel Nerve Agent, ‘Novichok (A234)’, in Aqueous Solution by Liquid Chromatography–Tandem Mass Spectrometry

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1059
Author(s):  
Jin Young Lee ◽  
Kyoung Chan Lim ◽  
Hyun Suk Kim
Keyword(s):  
Mass Spectrometry ◽  
Aqueous Solution ◽  
Liquid Chromatography ◽  
Degradation Products ◽  
Aqueous Sample ◽  
Tandem Mass ◽  
Aqueous Samples ◽  
Fragmentation Pathways ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

As a first step toward studying the properties of Novichok (ethyl (1-(diethylamino)ethylidene)phosphoramidofluoridate (A234)), we investigated its degradation products and fragmentation pathways in aqueous solution at different pH levels by liquid chromatography–tandem mass spectrometry. A234 was synthesized in our laboratory and characterized by nuclear magnetic resonance spectroscopy. Three sets of aqueous samples were prepared at different pH levels. A stock solution of A234 was prepared in acetonitrile at a concentration of 1 mg/mL and stored at −20 °C until use. Aqueous samples (0.1 mg/mL) were prepared by diluting the stock solution with deionized water. The acidic aqueous sample (pH = 3.5) and basic aqueous sample (pH = 9.4) were prepared using 0.01 M acetic acid and 0.01 M potassium carbonate, respectively. The analysis of the fragmentation patterns and degradation pathways of A234 showed that the same degradation products were formed at all pH levels. However, the hydrolysis rate of A234 was fastest under acidic conditions. In all three conditions, the fragmentation pattern and the major degradation product of A234 were determined. This information will be applicable to studies regarding the decontamination of Novichok and the trace analysis of its degradation products in various environmental matrices.

scholarly journals Photo-Induced Decomposition of 2-Chloroaniline in Aqueous Solution

2002 ◽  
Vol 57 (5-6) ◽  
pp. 512-515 ◽  
Author(s):  
Ermin Katrin Winarno ◽  
Nikola Getoff
Keyword(s):  
Aqueous Solution ◽  
Degradation Products ◽  
Chloride Ions ◽  
Pure Oxygen ◽  
Ammonium Ions ◽  
Probable Reaction Mechanism ◽  
Specific Analysis ◽  
Probable Reaction ◽  
Uv Dose ◽  
Induced Decomposition

A study was performed on the oxidizing degradation of 2-chloroaniline (used as a model pollutant in water) by photolysis (λ = 254 nm). The change of spectrum and substrate concentration of treated solutions was measured spectrophotometrically as well as by HPLC. The yields of the degradation products (chloride ions, ammonium ions, formaldehyde, etc.) were studied as a function of UV-dose. Their initial quantumyields (Qi) were determined by specific analysis. It was shown that the substrate photolysis in the presence of N2O is most efficient, followed by degradation in media saturated with pure oxygen and air. A probable reaction mechanism for the photo-induced degradation of 2-ClA is presented.

scholarly journals Ab Initio Study of CO2 Capture Mechanisms in Monoethanolamine Aqueous Solution: Reaction Pathways from Carbamate to Bicarbonate

2013 ◽  
Vol 37 ◽  
pp. 400-406 ◽  
Author(s):  
Yoichi Matsuzaki ◽  
Hidetaka Yamada ◽  
Firoz A. Chowdhury ◽  
Takayuki Higashii ◽  
Shingo Kazama ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ab Initio ◽  
Co2 Capture ◽  
Reaction Pathways ◽  
Ab Initio Study ◽  
Solution Reaction

scholarly journals Solution structures of nisin A and its two major degradation products determined by n.m.r

1992 ◽  
Vol 283 (2) ◽  
pp. 413-420 ◽  
Author(s):  
L Y Lian ◽  
W C Chan ◽  
S D Morley ◽  
G C Roberts ◽  
B W Bycroft ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ring Opening ◽  
Polypeptide Chain ◽  
Degradation Products ◽  
Correlation Spectroscopy ◽  
Solution Structures ◽  
Stimulated Annealing ◽  
Nuclear Overhauser Enhancement ◽  
Stereospecific Assignments ◽  
Nuclear Overhauser

The conformations of nisin and two major degradation products, nisin-(1-32)-peptide (nisin1-32) and des-delta Ala5-nisin1-32 (where delta Ala is alpha beta-didehydroalanine), in aqueous solution have been determined from n.m.r. data. Sequential assignments of the peptides using correlation spectroscopy (‘COSY‘), homonuclear Hartmann-Hahn spectroscopy (‘HOHAHA’), nuclear Overhauser enhancement spectroscopy (NOESY), relayed NOESY and rotating-frame nuclear Overhauser spectroscopy (ROESY) experiments are presented, including stereospecific assignments of beta-methylene protons of the lanthionine residues. ROESY experiments are also used to detect flexible regions in the polypeptide chain. A dynamic-stimulated-annealing approach is used for structural determination. It can be concluded that all these peptides are flexible in aqueous solution, with no experimental evidence of preferred overall conformations; the only defined conformational features are imposed by the presence of the lanthionine residues. Low-temperature studies also reveal that des-delta Ala5-nisin1-32 adopts conformations similar to those when the ring is intact, suggesting that the loss of activity of this degradation product is due to the absence of the delta Ala5 residue rather than to the conformational consequences of ring-opening.

Decolorization of azo dye C.I. Reactive Black 5 by ozonation in aqueous solution: influencing factors, degradation products, reaction pathway and toxicity assessment

2015 ◽  
Vol 73 (7) ◽  
pp. 1500-1510 ◽  
Author(s):  
Qing Zheng ◽  
Yong Dai ◽  
Xiangyun Han
Keyword(s):  
Aqueous Solution ◽  
Degradation Products ◽  
Reaction Pathway ◽  
Degradation Mechanism ◽  
Exchange Chromatography ◽  
Computational Method ◽  
Photobacterium Phosphoreum ◽  
Toxicity Tests ◽  
Reactive Black 5 ◽  
Oh Groups

In this study, ozonation treatment of C.I. Reactive Black 5 (RB5) was investigated at various operating parameters. The results showed that the aqueous solution initially containing 200 mg/L RB5 was quickly decolorized at pH 8.0 with an ozone dose of 3.2 g/h. Reaction intermediates with m/z 281, 546, 201, 350, 286 and 222 were elucidated using liquid chromatography-mass spectrometry, while sulfate ion, nitrate ion and three carboxylic acids (i.e., oxalic acid, formic acid, and acetic acid) were identified by ion exchange chromatography. Thus, the cleavage of the azo bond and the introduction of OH groups in the corresponding positions were proposed as the predominant reaction pathway. The detachment of sulfonic groups was also commonly observed during the ozonation treatment. The proposed degradation mechanism was confirmed by frontier electron density calculations, suggesting the feasibility of predicting the major events in the whole ozonation process with the computational method. Compared with RB5 degradation, the reduction of total organic carbon (TOC) proceeded much more slowly, and approximately 54% TOC was removed after 4 h of ozonation. Acute toxicity tests with Photobacterium phosphoreum showed that the toxicity of reaction solution was firstly increased and then decreased to a negligible level after 160 min.

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