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Book Kinetics of the Periodate Oxidation of Manganese to Permanganate

Download or read book Kinetics of the Periodate Oxidation of Manganese to Permanganate written by Glenn R. Waterbury and published by . This book was released on 1951 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Permanganate Reaction Kinetics and Mechanisms and Machine Learning Application in Oxidative Water Treatment

Download or read book Permanganate Reaction Kinetics and Mechanisms and Machine Learning Application in Oxidative Water Treatment written by Shifa Zhong and published by . This book was released on 2021 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Permanganate (MnO4-) plays an important role in water treatment as a strong oxidant. Two additives, i.e., bisulfite (HSO3-) and ligands, have been found to significantly accelerate its oxidation rates toward organic contaminants, but the specific mechanisms remain largely unknown or controversial. Reaction rate constants of contaminants toward various oxidants or reductants are an important parameter for optimizing water/wastewater treatment; however, experimentally measuring rate constants for thousands of contaminants is time-consuming and labor-intensive. In comparison, developing quantitative structure activity relationship (QSAR) models for estimating their rate constants is an efficient approach with satisfactory accuracy. The presence of bisulfite can make the oxidation of organic compounds by MnO4- complete in milliseconds. Previous studies concluded that uncomplexed Mn(III) was responsible for this millisecond reactivity. However, we revealed that this ultrafast reactivity was only observed in the presence of O2. We also found that HSO3- and O2 were rapidly consumed when mixing HSO3- with MnO4- in the presence of O2. This was because reactive Mn intermediates, mainly Mn(III) species, were generated in situ from the reaction of HSO3- and MnO4-, which then acted as a catalyst for the reaction of HSO3- and O2. In the presence of organic compounds, this catalytic effect was weakened because the reactive Mn intermediates were consumed by reacting with the organic compounds. However, without O2 these reactive Mn intermediates cannot oxidize the organic compounds. Hence, we concluded that only the Mn(III) with this catalytic role can oxidize organic compounds in milliseconds. This work unveiled the important role of O2 in the HSO3-/MnO4- system, which is important for its real applications. Ligands, such as pyrophosphate (PP), nitrilotriacetate (NTA), and ethylenediaminetetraacetic acid (EDTA), are known to increase the oxidation reactivity of phenolic compounds by MnO4- by several times. The traditional explanation for this acceleration effect is that ligands can complex with the Mn(III) intermediates being generated from the reaction of MnO4- and phenolic compounds to form Mn(III)-ligand complexes, and these complexes then oxidize phenolic compounds much faster than MnO4- can. Here, we observed that Mn(III)-ligand complexes formed during the reaction but were not further consumed. We then used pentachlorophenol (PCP) as a probe because it can be oxidized by MnO4- but not by Mn(III)-ligand complexes. In the presence of these complexes, the oxidation rate of PCP by MnO4- was accelerated. Hence, we proposed a new reaction mechanism in which Mn(III)-ligand complexes also act as a catalyst for the reaction of MnO4- and phenolic compounds. This work gave another explanation to the effect of ligands on MnO4-, which will substantially benefit the application of MnO4-/ligand systems in water/wastewater treatment. Not only for MnO4- but also for other common oxidants, e.g., O3, HO• and SO4•- radicals, the reaction rate constant is an important parameter for optimizing the treatment process, such as determining the dosage of an oxidant or the treatment time. However, it is time-consuming and labor-intensive to experimentally measure the rate constants of thousands of organic compounds. Toward this end, quantitative structure−activity relationships (QSARs) have been widely employed to correlate chemical structures of compounds with their reactivity. Well-calibrated QSARs can help predict the rate constants of a large number of organic contaminants based on their chemical structures and have played important roles in many environmental applications, such as estimating the rate constants or chemical toxicity. We here introduced molecular fingerprints (MF) to represent various organic contaminants and combined them with machine learning algorithms to develop QSAR models. We compared the predictive performance of MF-based QSAR models with that of MD-based ones, and found that their predictive performance was comparable, thus demonstrating the effectiveness of MF-based QSAR models. Due to the "black box" nature of machine learning algorithms in general, we then interpreted the MF-based machine learning QSAR models by the Shapley Additive Explanation (SHAP) method. Results showed that MF-based machine learning QSAR models made prediction on the rate constants based on the correct understanding of how the atom groups affect the rate constants, such as the effect of electron-donating and electron-withdrawing groups, thus demonstrating that the MF-base machine learning models were trustful. Apart from the molecular fingerprints, we also employed 2D molecular images to represent organic compounds and combined them with a convolutional neural network (CNN) to develop QSAR models. When developing CNN-based QSARs, we applied transfer learning and data augmentation to further enhance the predictive performance and robustness of the model. We also interpreted the obtained molecular image-CNN model by the Gradient-weighted Class Activation Mapping (Grad-CAM) technique, and the results showed that our model makes predictions by choosing correct features in the molecular images. Overall, this work introduced two new representations for organic contaminants, which have not been reported in the environmental field before, and the interpretations for the QSAR models offered some much-needed theoretical support for trusting these models. Overall, the new findings on HSO3-/MnO4- further elucidate why HSO3-/MnO4- is so reactive, especially regarding the key role of O2. In real applications, supplying enough O2, such as bubbling with air, is necessary for this system to achieve high efficiency. The new findings on MnO4-/ligand illustrate how ligands accelerate the oxidation of phenolic compounds by MnO4- and imply that Mn(III)-ligand complexes may be released into water and continue to facilitate the oxidation of compounds that cannot be oxidized by Mn(III)-ligand alone. In real applications, we should pay more attention to compounds that can be oxidized by MnO4- rather than by Mn(III)-ligand, because Mn(III)-ligand mainly acts as a catalyst. For QSAR model development, we introduced two new representations for contaminants, namely, molecular fingerprints and molecular images, to combine with machine learning to develop QSAR models for predicting the rate constants of contaminants toward HO• radicals. Reactivity of contaminants in AOPs can be more easily estimated with these QSAR models. Transfer learning, data augmentation and model interpretation are three important concepts that can be applied to other QSAR models, such as predicting plant uptake or toxicity. Any QSAR models that involve chemicals can benefit from our study, that is, representing the chemicals by molecular fingerprints or molecular images, applying transfer learning and data augmentation, and interpreting the QSAR models.

Book Organic Reaction Mechanisms 1998

Download or read book Organic Reaction Mechanisms 1998 written by A. C. Knipe and published by John Wiley & Sons. This book was released on 2003-09-12 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt: 34th volume in this highly successful series, Organic Reaction Mechanisms Provides the most recent developments in organic chemistry Compiled by well-respected editors with many years of relevant experience

Book The Nonlinear Kinetics and the Mechanism of the Reduction of Permanganate Ion by Iodide Ion in Alkaline Solution

Download or read book The Nonlinear Kinetics and the Mechanism of the Reduction of Permanganate Ion by Iodide Ion in Alkaline Solution written by Jack Douglas Rickly and published by . This book was released on 1980 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Principles and Practices of in Situ Chemical Oxidation Using Permanganate

Download or read book Principles and Practices of in Situ Chemical Oxidation Using Permanganate written by Robert L. Siegrist and published by . This book was released on 2001 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: - Chapter 1: An overview of chemical oxidation including its development and application for in situ treatment of contaminated sites. The oxidation chemistry of Fenton's reagent, permanganate, and ozone are highlighted along with optional methods of oxidant delivery for in situ application. The results of lab-and field-scale applications are summarized.- Chapter 2: A description of the principles and processes of chemical oxidation using potassium or sodium permanganate for organic chemical degradation, including reaction stoichiometry, equilibria, and kinetics, as well as the effects of environmental factors.- Chapter 3: Information provided on the effects of permanganate on the behavior of metals.- Chapter 4: A discussion of the potential for permeability loss and other secondary effects during in situ oxidation using permanganate.- Chapter 5: A description of optional methods of oxidant delivery for in situ remediation.- Chapter 6: A description of a process for evaluation, design, and implementation of permanganate systems.- Chapter 7: A detailed description of five different applications of an in situ chemical oxidation using potassium or sodium permanganate.- Chapter 8: Highlights of the current status and future directions of this remediation technology.

Book The Oxidation of Organic Compounds by Permanganate Ion and Hexavalent Chromium

Download or read book The Oxidation of Organic Compounds by Permanganate Ion and Hexavalent Chromium written by Donald G. Lee and published by . This book was released on 1980 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Journal of the Indian Chemical Society

Download or read book Journal of the Indian Chemical Society written by Indian Chemical Society and published by . This book was released on 1997 with total page 1146 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Oxidation of Amino Acids Peptides and Proteins

Download or read book Oxidation of Amino Acids Peptides and Proteins written by Virender K. Sharma and published by John Wiley & Sons. This book was released on 2012-11-06 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explains the role of reactive intermediates in biological systems as well as in environmental remediation With its clear and systematic approach, this book examined the broad range of reactive intermediate that can be generated in biological environments, detailing the fundamental properties of each reactive intermediate. Readers gain a contemporary understanding of how these intermediates react with different compounds, with an emphasis on amino acids, peptides, and proteins. The author not only sets forth the basic chemistry and nature of reactive intermediates, he also demonstrates how the properties of the intermediates presented in the book compare with each other. Oxidation of Amino Acids, Peptides, and Proteins begins with a discussion of radical and non-radical reactive species as well as an exploration of the significance of reactive species in the atmosphere, disinfection processes, and environmental remediation. Next, the book covers such topics as: Thermodynamics of amino acids and reactive species and the effect of metal-ligand binding in oxidation chemistry Kinetics and mechanisms of reactive halogen, oxygen, nitrogen, carbon, sulfur and phosphate species as well as reactive high-valent Cr, Mn, and Fe species Reactivity of the species with molecules of biological and environmental importance Generation of reactive species in the laboratory for kinetics studies Oxidation of amino acids, peptides, and proteins by permanganate, ferryl, and ferrate species Application of reactive species in purifying water and treating wastewater With this book as their guide, readers will be able to assess the overall effects of reactive intermediates in biological environments. Moreover, they’ll learn how to apply this knowledge for successful water purification and wastewater treatment.

Book The Kinetics of the Oxidation of Malonic Acid by Potassium Permanganate

Download or read book The Kinetics of the Oxidation of Malonic Acid by Potassium Permanganate written by D. A. Temple and published by . This book was released on 1946 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Journal of the Indian Chemical Society

Download or read book Journal of the Indian Chemical Society written by Indian Chemical Society, Calcutta and published by . This book was released on 1981 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Indian Journal of Chemistry

Download or read book Indian Journal of Chemistry written by and published by . This book was released on 1975 with total page 874 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Inorganic Reaction Mechanisms

Download or read book Inorganic Reaction Mechanisms written by A McAuley and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: Specialist Periodical Reports provide systematic and detailed review coverage of progress in the major areas of chemical research. Written by experts in their specialist fields the series creates a unique service for the active research chemist, supplying regular critical in-depth accounts of progress in particular areas of chemistry. For over 80 years the Royal Society of Chemistry and its predecessor, the Chemical Society, have been publishing reports charting developments in chemistry, which originally took the form of Annual Reports. However, by 1967 the whole spectrum of chemistry could no longer be contained within one volume and the series Specialist Periodical Reports was born. The Annual Reports themselves still existed but were divided into two, and subsequently three, volumes covering Inorganic, Organic and Physical Chemistry. For more general coverage of the highlights in chemistry they remain a 'must'. Since that time the SPR series has altered according to the fluctuating degree of activity in various fields of chemistry. Some titles have remained unchanged, while others have altered their emphasis along with their titles; some have been combined under a new name whereas others have had to be discontinued. The current list of Specialist Periodical Reports can be seen on the inside flap of this volume.