Download or read book Activation of Hydrogen Peroxide by Iron Containing Minerals and Catalysts in Circumneutral PH Solutions written by Anh Pham and published by . This book was released on 2012 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: The decomposition of hydrogen peroxide (H2O2) on iron minerals can generate hydroxyl radical (*OH), a strong oxidant capable of transforming a wide range of contaminants. This reaction is critical to ex situ advanced oxidation processes employed in waste treatment systems, as well as in situ chemical oxidation processes used for soil and groundwater remediation. Unfortunately, the process in the ex situ treatment systems is relatively inefficient at circumneutral pH values. In this research, the development of iron-containing catalysts with improved efficiency was investigated. In addition, little is known about the factors that control the performance of in situ treatment systems. Another aim of this dissertation was to elucidate those factors to provide a basis for improving the efficiency of the remediation method. Two types of silica- and alumina-containing iron (hydr)oxide catalysts were synthesized by sol-gel processing techniques (Chapter 2). Relative to iron oxides, such as hematite and goethite, these catalysts were 10 to 80 times more effective in catalyzing the production of *OH from H2O2 under circumneutral conditions. The higher efficiency makes these catalysts promising candidates for ex situ advanced oxidation processes. Moreover, because alumina and silica alter the reactivity of the iron oxides with H2O2, understanding the activity of iron associated with natural aluminosilicates and silica-containing minerals in the subsurface is crucial to explaining the variability of *OH production observed in in situ treatment systems. In addition to the sol-gel technique used in Chapter 2, silica-containing iron (hydr)oxide catalysts were synthesized by immobilizing iron oxide onto mesoporous silica supports, such as SBA-15 (Chapter 5). The iron-containing SBA-15 was 10 times more effective than iron oxides in catalyzing the production of *OH from H2O2. Moreover, this catalyst could be employed for selective oxidation of small organic contaminants based on size exclusion. However, a major drawback of the mesoporous silica-based catalysts is their instability under circumneutral conditions (Chapter 6). The dissolution of mesoporous silica materials raises questions about their use for water treatment, because silica dissolution might compromise the behavior of the material. To gain insight into factors that control H2O2 persistence and *OH yield in in situ processes, the decomposition of H2O2 and transformation of contaminants were investigated in the presence of iron-containing minerals and aquifer materials (Chapter 3). Consistent with the observation described in Chapter 2, iron-containing aluminosilicates were more effective than iron oxides in converting H2O2 into *OH. In both iron-containing mineral and aquifer material systems, the yield of *OH was inversely correlated with the rate of H2O2 decomposition. In the aquifer material systems, the yield also inversely correlated with the Mn content, consistent with the fact that the decomposition of H2O2 on manganese oxides does not produce *OH. The inverse correlation between Mn content and H2O2 loss rate and *OH yield suggests that the amount of Mn in aquifer materials could serve as a proxy for predicting H2O2 decomposition rates and contaminant oxidation efficiency. In addition to the surface and structure properties of iron solids, the presence of solutes, such as dissolved silica, also affected the decomposition of H2O2 (Chapter 4). The adsorption of dissolved silica onto mineral surfaces altered the catalytic sites, thereby decreasing the reactivity of iron- and manganese-containing minerals with H2O2. Therefore, the presence of dissolved SiO2 could lead to greater persistence of H2O2 in groundwater, which should be considered in the design of in situ H2O2-based treatment systems. In addition to in situ treatment, dissolved silica also can affect the reactivity of iron-containing catalysts used in ex situ processes. Therefore, its presence in contaminated industrial wastewater should be considered when ex situ treatment systems are designed.
Download or read book Applications of Hydrogen Peroxide and Derivatives written by C W Jones and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Simple, but beautifully versatile. Perhaps not a description many would choose for hydrogen peroxide, but an accurate one none the less, and this unique book explains the reasons behind the description. Beginning with an historical overview, and guidelines for the safe handling of peroxygens, Applications of Hydrogen Peroxide and Derivatives goes on to cover key activation mechanisms, organic functional group oxidations and the use of hydrogen peroxide with heterogeneous catalysts. The clean-up of environmental pollutants; chemical purification; and extraction of metals from their ores are also discussed in detail, using actual examples from industry. The versatility of this reagent may well prove to be a key to integrated pollution control in the future. This book should therefore be read by academics and industrialists at all levels, to encourage wider applications of the use of hydrogen peroxide in laboratories.
Download or read book Catalytic Oxidations with Hydrogen Peroxide as Oxidant written by G. Strukul and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogen peroxide is a chemical that is becoming increasingly fashionable as an oxidant, both in industry and in academia and whose production is expected to increase significantly in the next few years. This growth in interest is largely due to environmental considerations related to the clean nature of hydrogen peroxide as an oxidant, its by-product being only water. To date this chemical has largely been employed as a non-selective oxidant in operations like the bleaching of paper, cellulose and textiles, or in the formulation of detergents, and only to a minimal extent in the manufacture of organic chemicals. This book has been organized to cover the different aspects of the chemistry of hydrogen peroxide. The various chapters into which the book is divided have been written critically by the authors with the general aim of stimulating new ideas and emphasizing those aspects that are likely to lead to new developments in organic synthesis in the coming future.
Download or read book Advanced Oxidation Processes for Water Treatment written by Mihaela I. Stefan and published by IWA Publishing. This book was released on 2017-09-15 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book Oxidation Kinetics of Organics Using Hydrogen Peroxide Catalyzed by free and Complexed Iron written by Georgi Ivanov Tachiev and published by . This book was released on 1998 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Higher Oxidation State Organoselenides as Catalysts for the Activation of Hydrogen Peroxide written by and published by . This book was released on 2006 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organoselenides in higher oxidation states are effective catalysts for the activation of hydrogen peroxide. Arylseleninic acids were found to be catalysts for the oxidation of bromide with hydrogen peroxide in a two-phase mixture of ether and pH-6 phosphate buffer. Benzeneseleninic acid and 4-methoxyphenylseleninic acid were more efficient catalysts than 3,5-bis(trifluoromethyl)phenylseleninic acid, 4-nitrophenylseleninic acid, 4-dimethylaminophenylseleninic acid, and 2,4,6-trimethylphenylseleninic acid. Aryl benzyl selenoxides are also catalysts for the bromination of organic substrates in two-phase systems of CH 2 Cl 2 and pH-6 phosphate buffer containing 2 M NaBr and 2.6 M H202. The catalysts are effective at 2.5 mol % relative to the organic substrates. In the bromination of 4-pentenoic acid, catalysts with electron-donating groups (EDG) provide increased reactivity relative to electron-withdrawing group (EWG) substituted catalysts. Benzyl 2-(dimethylaminomethyl)phenyl selenoxide was the most effective catalyst and was used in the preparative bromination of 4-pentenoic acid, 2,2-diphenyl-4-pentenoic acid, 1,3,5-trimethoxybenzene, N, N -dimethylaniline, and N -phenylmorpholine. Initial studies have shown that aryl benzyl selenoxides are additionally effective catalysts for the epoxidation of organic substrates. In the epoxidation of cis-cyclooctene, electron-withdrawing substituents in the selenoxides demonstrate a faster rate of reaction compared to their electron-donating group counterparts. Benzyl 3,5-bistrifluoromethylphenyl selenoxide was the most effective catalyst studied. Aryl benzyl selenoxides are efficient catalysts for epoxidation of alkenes and for Baeyer-Villiger oxidation of various carbonyl-containing compounds using H 2 O 2 . Of the selenoxides examined here, selenoxide 63 is kinetically the most active catalyst. Rates of Baeyer-Villiger oxidation and epoxidation of the substrates studied with the selenoxide catalysts were similar. Attempts at asymmetric induction with C 2 symmetric selenoxides proved ineffective. Preliminary data indicates that chalcogen containing xerogels may be viable marine antifouling and fouling-release agents. The chalcogens catalyze formation of a hypo-halous barrier with the halide salts and hydrogen peroxide present in ocean water. This barrier aids in the prevention of settlement and removal of bioorganisms. It was determined that xerogels with some hydrophilic silanes are necessary for halide and hydrogen peroxide permeation. Catalysts with two active sites are more effective than catalysts with one active site. Further work is needed to determine the optimal xerogel composition and the most efficient chalcogen catalyst.
Download or read book The Catalytic Decomposition of Hydrogen Peroxide in the Presence of Iron Salts in Acid Solution written by Fred Harper Dempster and published by . This book was released on 1923 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In Situ Chemical Oxidation for Groundwater Remediation written by Robert L. Siegrist and published by Springer Science & Business Media. This book was released on 2011-02-25 with total page 715 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides comprehensive up-to-date descriptions of the principles and practices of in situ chemical oxidation (ISCO) for groundwater remediation based on a decade of intensive research, development, and demonstrations, and lessons learned from commercial field applications.
Download or read book Advanced Oxidation Processes for Water and Wastewater Treatment written by Simon Parsons and published by IWA Publishing. This book was released on 2004-03-01 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Principles and Applications of Aquatic Chemistry written by François M. M. Morel and published by John Wiley & Sons. This book was released on 1993-03-10 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents aquatic chemistry in a way that is truly useful to those with diverse backgrounds in the sciences. Major improvements to this edition include a complete rewrite of the first three background chapters making them user-friendly. There is less emphasis on mathematics and concepts are illustrated with actual examples to facilitate understanding.
Download or read book Chemical Oxidation Applications for Industrial Wastewaters written by Olcay Tunay and published by IWA Publishing. This book was released on 2010-10-12 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Chrysotile Asbestos written by Dr. Maria Neira and published by World Health Organization. This book was released on 2014 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Asbestos --- a group of minerals that includes chrysotile, crocidolite, amosite, anthophyllite, tremolite and actinolite --- is one of the most important occupational carcinogens. At least 107 000 people die each year from asbestos-related diseases, including lung cancer. Even though the use of asbestos has declined in many countries, chrysotile is still widely used, particularly in developing countries. This publication on chrysotile asbestos is divided into three parts. The first part reproduces a WHO short information document for decision-makers on the elimination of asbestos-related diseases. The second part addresses questions commonly raised in policy discussions, specifically to assist decision-makers. The third part is a technical summary of the health effects of chrysotile, which brings together and summarizes for the first time the most recent authoritative WHO evaluations performed by its International Agency for Research on Cancer and its International Programme on Chemical Safety. The technical summary also reviews results from key studies published after those evaluations and the conclusions drawn from WHO assessments of alternatives. The publication will be of interest to all government officials who need to make informed decisions about management of the health risks associated with exposure to chrysotile asbestos.""--Page 4 of cover.
Download or read book Applications of Advanced Oxidation Processes AOPs in Drinking Water Treatment written by Antonio Gil and published by Springer. This book was released on 2018-07-03 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reviews the drinking water treatments in which AOPs display a high application potential. Firstly it reveals the typical supply sources and limitations of conventional technologies and critically reviews natural organic matter characterization and removal techniques, focusing mainly on AOP treatments. It then explores using AOPs for simultaneous inactivation/disinfection of several types of microorganisms, including highly resistant Cryptosporidium protozoa. Lastly, it discusses relevant miscellaneous topics, like the most promising AOP solid catalysts, the regime change of Fenton-like processes toward continuous reactors, the application of chemometrics for process optimization, the impact on disinfection byproducts and the tracing of toxicity during AOP treatments. This work is a useful reference for researchers and students involved in water technologies, including analytical and environmental chemistry, chemical and environmental engineering, toxicology, biotechnology, and related fields. It is intended to encourage industrial and public-health scientists and decision-makers to accelerate the application of AOPs as technological alternatives for the improvement of drinking water treatment plants.
Download or read book Soil and Water Chemistry written by Michael E. Essington and published by CRC Press. This book was released on 2015-04-24 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition of a bestseller, Soil and Water Chemistry: An Integrative Approach maintains the balanced perspective that made the first edition a hugely popular textbook. The second edition includes new figures and tables, new chapters, and expanded exercises in each chapter. It covers topics including soil chemical environment, soil minerals,
Download or read book Chemistry of Advanced Environmental Purification Processes of Water written by Erik Sogaard and published by Newnes. This book was released on 2014-04-11 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemistry of Advanced Environmental Purification Processes of Water covers the fundamentals behind a broad spectrum of advanced purification processes for various types of water, showing numerous applications through worked examples. Purification processes for groundwater, soil water, reusable water, and raw water are examined where they are in use full-scale, as a pilot approach, or in the laboratory. This book also describes the production of ceramic particles (nanochemistry) and materials for the creation of filtration systems and catalysts that are involved. Uses chemistry fundamentals to explain the mechanisms behind the various purification processes Explains in detail process equipment and technical applications Describes the production of ceramic particles and other new materials applicable to filtration systems Includes worked examples
Download or read book Advanced Oxidation Technologies written by Marta I. Litter and published by CRC Press. This book was released on 2014-03-03 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Oxidation Technologies (AOTs) or Processes (AOPs) are relatively new and innovative technologies to remove harmful and toxic pollutants. The most important processes among them are those using light, such as UVC/H2O2, photo-Fenton and heterogeneous photocatalysis with TiO2. These technologies are also relatively low-cost and therefore usef
Download or read book Zeolite Chemistry and Catalysis written by L. Kubelková and published by Elsevier. This book was released on 1991-09-17 with total page 529 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings reflect recent developments in the field of zeolite chemistry and catalysis with an emphasis on the role of a modifying component on the properties of the molecular sieve material. The plenary lectures and contributed papers concentrate on the problem of isomorphous substitution in a zeolitic framework; on the occlusion and the structure of metal, metal oxide, and metal sulphide clusters and complexes in the intracrystalline void volume of molecular sieves and zeolites as well as in the interlaminar space of layered compounds. Catalytic applications are discussed, not only in regard to traditional hydrocarbon transformation, but also in such areas as: reduction of SO2, decomposition of NO, reactions of sulphur containing compounds and conversion of CO, CO2 to hydrocarbons or of alcohols to oxygenated products. Because the book provides valuable data and information on new achievements in the zeolite material science and application, it will be of considerable interest to all research groups involved in zeolite science.
