Oxidative Treatment of Emerging Micropollutants and Viral Pathogens by Potassium Permanganate and Ferrate: Kinetics and Mechanisms PDF Download

Author: Lanhua Hu
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Providing clean drinking water is a primary challenge of this century. The ubiquitous occurrence of pharmaceutically active compounds (PhACs), including antibiotics, anticonvulsants, painkillers, estrogenic hormones, lipid regulators, beta-blockers, antihistamines, X-ray contrast media, etc., in drinking water sources has been reported in recent years. The presence of these contaminants, although at low concentrations, raises public concerns about potential adverse effects on aquatic ecology and human health. Another emerging concern in drinking water safety is the formation of toxic disinfection by-products (DBPs) when treating water with conventional disinfectants (i.e., free chlorine), and thus alternative disinfectants and disinfection processes are sought to control DBPs formation while still providing a sufficient barrier to pathogens. Chemical oxidation processes involving permanganate [MnO4-, Mn(VII)] and ferrate [FeO42-, Fe(VI)] salts are promising technologies for treatment of many PhACs. Permanganate is already widely used in water treatment facilities (e.g., for treatment of taste and odor compounds, soluble iron(II) and manganese(II)), while ferrate is an emerging water treatment oxidant that also has potential for use as an alternative disinfectant. This study investigates the oxidative transformation of PhACs using permanganate and ferrate and the use of ferrate for inactivation of a surrogate viral pathogen, MS2 bacteriophage. Survey tests show that permanganate and ferrate are both selective oxidants that target compounds with specific electron-rich moieties, including olefin, phenol, amine, cyclopropyl, thioether, and alkyne groups. Detailed kinetics studies were undertaken to characterize Mn(VII) oxidation of five representative PhACs that exhibit moderate to high reactivity (carbamazepine, CBZ; ciprofloxacin, CPR; lincomycin, LCM; trimethoprim, TMP; and 171̐Ł-ethinylestradiol, EE2), Fe(VI) oxidation of one representative PhAC (CBZ), and Fe(VI) inactivation of MS2 phage (Fe(VI) reactions with other PhACs were not conducted because recent literature reports addressed the topic). The Mn(VII) and Fe(VI) reactions examined with PhAC and MS2 phage were found to follow generalized second-order rate laws, first-order in oxidant concentration and first-order in target contaminant concentration. The temperature dependence of reaction rate constants was found to follow the Arrhenius equation. Changing of solution pH had varying effects on reaction rates, attributed to change in electron density on the target reactive groups upon protonation/deprotonation. The effects of pH on reaction rates were quantitatively described by kinetic models considering parallel reactions between different individual contaminant species and individual oxidant species. For Mn(VII) reactions, removal of PhACs in drinking water utility source waters was generally well predicted by kinetic models that include temperature, KMnO4 dosage, pH, and source water oxidant demand as input parameters. A large number of reaction products from Mn(VII) oxidation of CBZ, CPR, LCM, TMP, and EE2 and Fe(VI) oxidation of CBZ were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Structures of reaction products were proposed based on MS spectral data along with information collected from proton nuclear magnetic resonance (1H-NMR), chromatographic retention time, and reported literature on Mn(VII) reactions with specific organic functional groups. Mn(VII) and Fe(VI) rapidly oxidize CBZ by electrophilic attack at the olefinic group on the central heterocyclic ring. Mn(VII) oxidation of CPR was found to occur primary on the tertiary aromatic amine group on the piperazine ring, with minor reactions on the aliphatic amine and the cyclopropyl group. LCM was oxidized by Mn(VII) through the aliphatic amine group on the pyrrolidine ring and thioether group attached to the pyranose ring. TMP oxidation by Mn(VII) was proposed to occur at the C=C bonds on the pyrimidine ring and the bridging methylene group. EE2 oxidation by Mn(VII) resulted in several types of products, including dehydrogenated EE2, hydroxylated EE2, phenolic ring cleavage products, and products with structural modifications on the ethynyl group. Although little mineralization of PhAC solutions was observed after Mn(VII) treatment, results from bioassay tests of three antibiotics show that the antibacterial activity was effectively removed upon reaction with Mn(VII), demonstrating that incomplete oxidation of PhACs during Mn(VII) treatment will likely be sufficient to eliminate the pharmaceutical activity of impacted source waters. Overall, results show that reactions with Mn(VII) likely contribute to the fate of many PhACs in water treatment plants that currently use Mn(VII), and the kinetic model developed in this study can be used to predict the extent of PhAC removal by Mn(VII) treatment. For water contaminated with highly Mn(VII)-reactive PhACs (e.g., carbamazepine, estradiol), specific application of Mn(VII) may be warranted. Results suggest Fe(VI) may be a useful disinfecting agent, but more work is needed to characterize its activity and mode of inactivating with other pathogens of concern.

Author: Robert L. Siegrist
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 376

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Book Description
- 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.

Author: Shifa Zhong
Publisher:
ISBN:
Category : Chemical kinetics
Languages : en
Pages : 256

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Book Description
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.

Author: Ciro Bustillo-Lecompte
Publisher: BoD – Books on Demand
ISBN: 1789848903
Category : Technology & Engineering
Languages : en
Pages : 184

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Book Description
Advanced Oxidation Processes – Applications, Trends, and Prospects constitutes a comprehensive resource for civil, chemical, and environmental engineers researching in the field of water and wastewater treatment. The book covers the fundamentals, applications, and future work in Advanced Oxidation Processes (AOPs) as an attractive alternative and a complementary treatment option to conventional methods. This book also presents state-of-the-art research on AOPs and heterogeneous catalysis while covering recent progress and trends, including the application of AOPs at the laboratory, pilot, or industrial scale, the combination of AOPs with other technologies, hybrid processes, process intensification, reactor design, scale-up, and optimization. The book is divided into four sections: Introduction to Advanced Oxidation Processes, General Concepts of Heterogeneous Catalysis, Fenton and Ferrate in Wastewater Treatment, and Industrial Applications, Trends, and Prospects.

Author: Simon Parsons
Publisher: IWA Publishing
ISBN: 1843390175
Category : Science
Languages : en
Pages : 370

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Book Description
The suitability of Advanced Oxidation Processes (AOPs) for pollutant degradation was recognised in the early 1970s and much research and development work has been undertaken to commercialise some of these processes. AOPs have shown great potential in treating pollutants at both low and high concentrations and have found applications as diverse as ground water treatment, municipal wastewater sludge destruction and VOCs control. Advanced Oxidation Processes for Water and Wastewater Treatment is an overview of the advanced oxidation processes currently used or proposed for the remediation of water, wastewater, odours and sludge. The book contains two opening chapters which present introductions to advanced oxidation processes and a background to UV photolysis, seven chapters focusing on individual advanced oxidation processes and, finally, three chapters concentrating on selected applications of advanced oxidation processes. Advanced Oxidation Processes for Water and Wastewater Treatment will be invaluable to readers interested in water and wastewater treatment processes, including professionals and suppliers, as well as students and academics studying in this area. Dr Simon Parsons is a Senior Lecturer in Water Sciences at Cranfield University with ten years' experience of industrial and academic research and development.

Author: Jan Filip
Publisher: Springer Nature
ISBN: 303029840X
Category : Technology & Engineering
Languages : en
Pages : 656

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Book Description
We are proposing this comprehensive volume aimed at bridging and bonding of the theory and practical experiences for the elimination of a broad range of pollutants from various types of water and soil utilizing innovative nanotechnologies, biotechnologies and their possible combinations. Nowadays, a broad range of contaminants are emerging from the industry (and also representing old ecological burdens). Accidents and improper wastewater treatment requires a fast, efficient and cost-effective approach. Therefore, several innovative technologies of water and soil treatments have been invented and suggested in a number of published papers. Out of these, some nanotechnologies and biotechnologies (and possibly also their mutual combinations) turned out to be promising for practical utilization – i.e., based on both extensive laboratory testing and pilot-scale verification. With respect to the diverse character of targeted pollutants, the key technologies covered in this book will include oxidation, reduction, sorption and/or biological degradation. In relation to innovative technologies and new emerging pollutants mentioned in this proposed book, an important part will also cover the ecotoxicity of selected pollutants and novel nanomaterials used for remediation. Thus, this work will consist of 8 sections/chapters with a technical appendix as an important part of the book, where some technical details and standardized protocols will be clearly presented for their possible implementation at different contaminated sites. Although many previously published papers and books (or book chapters) are devoted to some aspects of nano-/biotechnologies, here we will bring a first complete and comprehensive treatise on the latest progress in innovative technologies with a clear demonstration of the applicability of particular methods based on results of the authors from pilot tests (i.e., based on the data collected within several applied projects, mainly national project “Environmentally friendly nanotechnologies and biotechnologies in water and soil treatment” of the Technology Agency of the Czech Republic, and 7FP project NANOREM: “Taking Nanotechnological Remediation Processes from Lab Scale to End User Applications for the Restoration of a Clean Environment”). This multidisciplinary book will be suitable for a broad audience including environmental scientists, practitioners, policymakers and toxicologists (and of course graduate students of diverse fields – material science, chemistry, biology, geology, hydrogeology, engineering etc.).

Author: Olcay Tunay
Publisher: IWA Publishing
ISBN: 1843393077
Category : Science
Languages : en
Pages : 361

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Book Description
This book covers the most recent scientific and technological developments (state-of-the-art) in the field of chemical oxidation processes applicable for the efficient treatment of biologically-difficult-to-degrade, toxic and/or recalcitrant effluents originating from different manufacturing processes. It is a comprehensive review of process and pollution profiles as well as conventional, advanced and emerging treatment processes & technologies developed for the most relevant and pollution (wet processing)-intensive industrial sectors. It addresses chemical/photochemical oxidative treatment processes, case-specific treatability problems of major industrial sectors, emerging (novel) as well as pilot/full-scale applications, process integration, treatment system design & sizing criteria (figure-of-merits), cost evaluation and success stories in the application of chemical oxidative treatment processes. Chemical Oxidation Applications for Industrial Wastewaters is an essential reference for lecturers, researchers, industrial and environmental engineers and practitioners working in the field of environmental science and engineering. Visit the IWA WaterWiki to read and share material related to this title: http://www.iwawaterwiki.org/xwiki/bin/view/Articles/CHEMICALOXIDATIONAPPLICATIONSFORINDUSTRIALWASTEWATERS Authors: Professor Olcay Tünay, Professor Isik Kabdasli, Associate Professor Idil Arslan-Alaton and Assistant Professor Tugba Ölmez-Hanci, Environmental Engineering Department, Istanbul Technical University, Turkey.

Author: Mihaela I. Stefan
Publisher: IWA Publishing
ISBN: 1780407181
Category : Science
Languages : en
Pages : 712

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Book Description
Advanced Oxidation Processes (AOPs) rely on the efficient generation of reactive radical species and are increasingly attractive options for water remediation from a wide variety of organic micropollutants of human health and/or environmental concern. Advanced Oxidation Processes for Water Treatment covers the key advanced oxidation processes developed for chemical contaminant destruction in polluted water sources, some of which have been implemented successfully at water treatment plants around the world. The book is structured in two sections; the first part is dedicated to the most relevant AOPs, whereas the topics covered in the second section include the photochemistry of chemical contaminants in the aquatic environment, advanced water treatment for water reuse, implementation of advanced treatment processes for drinking water production at a state-of-the art water treatment plant in Europe, advanced treatment of municipal and industrial wastewater, and green technologies for water remediation. The advanced oxidation processes discussed in the book cover the following aspects: - Process principles including the most recent scientific findings and interpretation. - Classes of compounds suitable to AOP treatment and examples of reaction mechanisms. - Chemical and photochemical degradation kinetics and modelling. - Water quality impact on process performance and practical considerations on process parameter selection criteria. - Process limitations and byproduct formation and strategies to mitigate any potential adverse effects on the treated water quality. - AOP equipment design and economics considerations. - Research studies and outcomes. - Case studies relevant to process implementation to water treatment. - Commercial applications. - Future research needs. Advanced Oxidation Processes for Water Treatment presents the most recent scientific and technological achievements in process understanding and implementation, and addresses to anyone interested in water remediation, including water industry professionals, consulting engineers, regulators, academics, students. Editor: Mihaela I. Stefan - Trojan Technologies - Canada

Author: John Bratby
Publisher: IWA Publishing
ISBN: 1843391066
Category : Science
Languages : en
Pages : 421

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Book Description
Coagulation and Flocculation in Water and Wastewater Treatment provides a comprehensive account of coagulation and flocculation techniques and technologies in a single volume covering theoretical principles to practical applications. Thoroughly revised and updated since the 1st Edition it has been progressively modified and increased in scope to cater for the requirements of practitioners involved with water and wastewater treatment. A thorough gamut of treatment scenarios is attempted, including turbidity, color and organics removal, including the technical aspects of enhanced coagulation. The effects of temperature and ionic content are described as well as the removal of specific substances such as arsenic and phosphorus. Chemical phosphorus removal is dealt with in detail, Rapid mixing for efficient coagulant utilization, and flocculation are dealt with in specific chapters. Water treatment plant waste sludge disposal is dealt with in considerable detail, in an Appendix devoted to this subject. Invaluble for water scientists, engineers and students of this field, Coagulation and Flocculation in Water and Wastewater Treatment is a convenient reference handbook in the form of numerous examples and appended information.

Author: Gabriel Bitton
Publisher: John Wiley & Sons
ISBN: 1118148150
Category : Science
Languages : en
Pages : 809

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Book Description
Wastewater Microbiology focuses on microbial contaminants found in wastewater, methods of detection for these contaminants, and methods of cleansing water of microbial contamination. This classic reference has now been updated to focus more exclusively on issues particular to wastewater, with new information on fecal contamination and new molecular methods. The book features new methods to determine cell viability/activity in environmental samples; a new section on bacterial spores as indicators; new information covering disinfection byproducts, UV disinfection, and photoreactivation; and much more. A PowerPoint of figures from the book is available at ftp://ftp.wiley.com/public/sci_tech_med/wastewater_microbiology.