Download or read book Photocatalytic Degradation of Acetic Acid in Gas Phase in the Presence and in the Absence of O2 Using Different TiO2 and M TiO2 written by Ha Son Ngo and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the thesis is to better understand the mechanisms of photocatalytic degradation occurring under air or under nitrogen by studying the disappearance, mineralization and intermediate products of a simple molecule acetic acid. The reactions are carried out under these two atmospheres in gas phase and dynamic mode in order to place themselves under conditions of depollution or of energy generation. Firstly, we studied the degradation of acetic acid using the reference photocatalyst, TiO2 P25. Regardless of the atmosphere, air or N2, we have shown that the decarboxylation reaction is the first step in the disappearance of acetic acid. However, the fate of the methyl group depends on the carrier gas and the molar flow rate (in other words, the concentration of the pollutant in the gas phase). The mechanism of degradation occurring on the surface of the photocatalyst is then represented to explain the importance of this mechanism compared to that involving the hydroxyl radicals. The schematization of the mechanism includes the regeneration of the photocatalyst and the possible formation of H2O2, which has been observed in the literature. The study of the degradation products of acetic acid labelled with carbon 13 on the carbonyl group (CH313COOH) suggests that acetone and acetaldehyde do not result from the reduction of the carboxylic group. In a second step, the impact of photonic flux and moisture in the presence of TiO2 P25 as well as the effect of different commercial TiO2 on the conversion and more particularly the distribution of the intermediate products have been studied. Comparison of the effectiveness of different commercial TiO2s was discussed by considering the presence of rutile phase, the nature of the active species, the specific surface area of TiO2, the number of OH groups on the surface of the catalysts, the presence of impurities and the porosity of the materials.
Download or read book Heterogeneous Photocatalysis written by M. Schiavello and published by . This book was released on 1997-10-09 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalysis is a reaction which is accelerated by light while a heterogeneous reaction consists of two phases ( a solid and a liquid for example). Heterogeneous Photocatalysis is a fast developing science which to date has not been fully detailed in a monograph. This title discusses the basic principles of heterogeneous photocatalysis and describes the bulk and surface properties of semiconductors. Applications of various types of photoreactions are described and the problems related to the modeling and design of photoreactors are covered.
Download or read book Gas Phase Photocatalytic Degradation on TiO2 Pellets of Volatile Chlorinated Organic Compounds from a Soil Vapor Extraction Well written by and published by . This book was released on 1993 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mineralization of trichloroethylene (TCE) and tetrachloroethylene (PCE) in gas stream from a soil vapor extraction (SVE) well was demonstrated with an annular photocatalytic reactor packed with porous TiO2 pellets in field trials at the Savannah River Site in Aiken, SC. The TiO2 pellets were prepared using a sol-gel method. The experiments were performed at 55 to 60°C using space times of 108 to 101° g s/mol for TCE and PCE. Chloroform (CHCl3) and carbon tetrachloride (CCl4) were detected as minor products from side reactions. On a molar basis, CCl4 and CHCl3 produced were about 2% and 0.2 % of the reactants.
Download or read book TiO2 Photocatalysis written by Akira Fujishima and published by . This book was released on 1999 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photochemical Purification of Water and Air written by Thomas Oppenländer and published by John Wiley & Sons. This book was released on 2007-06-27 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: While the treatment of water and exhaust gas using ultraviolet (UV) light offers both ecological and economic advantages, information on photo-initiated advanced oxidation technologies (AOTs) has been dispersed among various journals and proceedings until now. This authoritative and comprehensive handbook is the first to cover both the photochemical fundamentals and practical applications, including a description of advanced oxidation processes (AOPs) and process engineering of suitable photoreactors. The author presents various real-world examples, including economic aspects, while many references to current scientific literature facilitate access to current research topics relevant for water and air industries. Throughout, over 140 detailed figures visualize photochemical and photophysical phenomena, and help in interpreting important research results. From the foreword by James R. Bolton (President of Bolton Photosciences Inc., Executive Director of the International Ultraviolet Association (IUVA)): "Prof. Oppenländer is well qualified to write about the AOPs/AOTs, since he has contributed to this literature in a very significant manner. This book will be of considerable value to graduate students, science and engineering faculty, scientists, process engineers and sales engineers in industry, government regulators and health professionals."
Download or read book Heterogeneous Photocatalysis Using Inorganic Semiconductor Solids written by Umar Ibrahim Gaya and published by Springer Science & Business Media. This book was released on 2013-11-08 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book underscores the essential principles of photocatalysis and provides an update on its scientific foundations, research advances, and current opinions, and interpretations. It consists of an introduction to the concepts that form the backbone of photocatalysis, from the principles of solid-state chemistry and physics to the role of reactive oxidizing species. Having recognised the organic link with chemical kinetics, part of the book describes kinetic concepts as they apply to photocatalysis. The dependence of rate on the reaction conditions and parameters is detailed, the retrospective and prospective aspects of the mechanism of photocatalysis are highlighted, and the adsorption models, photocatalytic rate expressions, and kinetic disguises are examined. This book also discusses the structure, property, and activity relationship of prototypical semiconductor photocatalysts and reviews how to extend their spectral absorption to the visible region to enable the effective use of visible solar spectrum. Lastly, it presents strategies for deriving substantially improved photoactivity from semiconductor materials to support the latest applications and potential trends.
Download or read book Waste Gas Treatment for Resource Recovery written by Piet Lens and published by IWA Publishing. This book was released on 2006-07-31 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: The prevention of over-exploitation and the efficient use of natural resources are key goals of environmental managment in Industry. Waste Gas Treatment for Resource Recovery presents the reader with technical, ecological and economical aspects of gaseous effluent treatment and resource recovery. Practical experience from industry and agriculture is presented, the role of newly developed advanced technology in future recycling of gas streams discussed and attention given to criteria for sustainability in gas treatment. Detailed analysis of material flows, novel process applications and bioreactor designs, odour quantification and removal process techniques and European legislations for waste gas discharge and recovery are highlights of the extensive and comprehensive coverage of this book. Waste Gas Treatment for Resource Recovery will enable production, process and environmental engineers and managers to evaluate internal recycling possibilities, which contribute to an economically and environmentally friendly manufacturing processes with reduced pollution loads and waste gas volumes. Analysis of material flows, e.g. the development of methodologies and techniques to monitor the use and flow of materials on a life cycle basis Novel process applications and bioreactor designs for resource recovery from waste gases Odour quantification techniques and novel odour removal processes European dimension of polluted gas streams and the European legislation for waste gas discharges and recovery
Download or read book Photocatalytic Degradation of NOX VOCs and Chloramines by TiO2 Impregnated Surfaces written by Eva Miriam Land and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments were conducted to determine the photocatalytic degradation of three types of gas-phase compounds, NOX, VOCs, and chloramines, by TiO2 impregnated tiles. The oxides of nitrogen NO and NO2 (NOx) have a variety of negative impacts on human and environmental health ranging from serving as key precursors for the respiratory irritant ozone, to forming nitric acid, which is a primary component of acid rain. A flow tube reactor was designed for the experiments that allowed the UV illumination of the tiles under exposure to both NO and NO2 concentrations in simulated ambient air. The reactor was also used to assess NOx degradation for sampled ambient air. The PV values for NO and NO2 were 0.016 cm s-1 and 0.0015 cm s-1, respectively. For ambient experiments a decrease in ambient NOx of ~ 40% was observed over a period of roughly 5 days. The mean PV for NOx for ambient air was 0.016 cm s-1 and the maximum PV was .038 cm s-1. Overall, the results indicate that laboratory conditions generally simulate the efficiency of removing NOx by TiO2 impregnated tiles. Volatile organic compounds (VOC's) are formed in a variety of indoor environments, and can lead to respiratory problems (US EPA, 2010). The experiments determined the photocatalytic degradation of formaldehyde and methanol, two common VOCs, by TiO2 impregnated tiles. The same flow tube reactor used for the previous NOX experiments was used to test a standardized gas-phase concentration of formaldehyde and methanol. The extended UV illumination of the tiles resulted in a 50 % reduction in formaldehyde, and a 68% reduction in methanol. The deposition velocities (or the photocatalytic velocities, PV) were estimated for both VOC's. The PV for formaldehyde was 0.021 cm s-1, and the PV for methanol was 0.026 cm s-1. These PV values are slightly higher than the mean value determined for NO from the previous experiments which was 0.016 cm s-1. The results suggest that the TiO2 tiles could effectively reduce specific VOC levels in indoor environments. Chlorination is a widespread form of water disinfection. However, chlorine can produce unwanted disinfection byproducts when chlorine reacts with nitrogen containing compounds or other organics. The reaction of chlorine with ammonia produces one of three chloramines, (mono-, di-, and tri-chloramine). The production of chloramines compounds in indoor areas increases the likelihood of asthma in pool professionals, competitive swimmers, and children that frequently bath in indoor chlorinated swimming pools (Jacobs, 2007; Nemery, 2002; Zwiener, 2007). A modified flow tube reactor in conjunction with a standardized solution of monochloramine, NH2Cl, determined the photocatalytic reactions over the TiO2 tiles and seven concrete samples. The concrete samples included five different concrete types, and contained either 5 % or 15 % TiO2 by weight. The PV for the tiles was 0.045 cm s-1 for the tiles manufactured by TOTO Inc. The highest PV from the concrete samples was 0.054 cm s-1. Overall the commercial tiles were most efficient at reducing NH2Cl, compared to NOX and VOC compounds. However, the concrete samples had an even higher PV for NH2Cl than the tiles. The reason for this is unknown; however, distinct surface characteristics and a higher concentration of TiO2 in the concrete may have contributed to these findings.
Download or read book TiO2 Nanoparticles written by Aiguo Wu and published by John Wiley & Sons. This book was released on 2020-06-02 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unique book that summarizes the properties, toxicology, and biomedical applications of TiO2-based nanoparticles Nanotechnology is becoming increasingly important for products used in our daily lives. Nanometer-sized titanium dioxide (TiO2) are widely used in industry for different purposes, such as painting, sunscreen, printing, cosmetics, biomedicine, and so on. This book summarizes the advances of TiO2 based nanobiotechnology and nanomedicine, covering materials properties, toxicological research, and biomedical application, such as antibacter, biosensing, and cancer theranostics. It uniquely integrates the TiO2 applications from physical properties, toxicology to various biomedical applications, and includes black TiO2 based cancer theranostics. Beginning with a comprehensive introduction to the properties and applications of nanoparticles, TiO2 Nanoparticles: Applications in Nanobiotechnology, Theranostics and Nanomedicine offers chapters on: Toxicity of TiO2 Nanoparticles; Antibacterial Applications of TiO2 Nanoparticles; Surface Enhanced Raman Spectrum of TiO2 Nanoparticle for Biosensing (TiO2 Nanoparticle Served as SERS Sensing Substrate); TiO2 as Inorganic Photosensitizer for Photodynamic Therapy; Cancer Theranostics of Black TiO2 Nanoparticles; and Neurodegenerative Disease Diagnostics and Therapy of TiO2-Based Nanoparticles. This title: -Blends the physical properties, toxicology of TiO2 nanoparticles to the many biomedical applications -Includes black TiO2 based cancer theranostics in its coverage -Appeals to a broad audience of researchers in academia and industry working on nanomaterials-based biosensing, drug delivery, nanomedicine TiO2 Nanoparticles: Applications in Nanobiotechnology, Theranostics and Nanomedicine is an ideal book for medicinal chemists, analytical chemists, biochemists, materials scientists, toxicologists, and those in the pharmaceutical industry.
Download or read book Semiconductor Photocatalysis written by Wenbin Cao and published by BoD – Books on Demand. This book was released on 2016-08-24 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalysis is a hot topic because it is an environmentally friendly approach toward the conversion of light energy into chemical energy at mild reaction environments. Also, it is well applied in several major areas such as water splitting, bacterial inactivation, and pollutants elimination, which is a possible solution to energy shortage and environmental issues. The fundamental knowledge and the frontier research progress in typical photocatalytic materials, such as TiO2-based and non-TiO2-based photocatalysts, are included in this book. Methods to improve the photocatalytic efficiency and to provide a hint for the rational design of the new photocatalysts are covered.
Download or read book Heterogeneous Photocatalysis written by Mario J. Muñoz-Batista and published by Springer Nature. This book was released on 2020-07-01 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Current Chemistry Collections presents critical reviews from the journal Topics in Current Chemistry organized in topical volumes. The scope of coverage is all areas of chemical science including the interfaces with related disciplines such as biology, medicine and materials science. The goal of each thematic volume is to give the non-specialist reader, whether in academia or industry, a comprehensive insight into an area where new research is emerging which is of interest to a larger scientific audience. Each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5 to 10 years are presented using selected examples to illustrate the principles discussed. The coverage is not intended to be an exhaustive summary of the field or include large quantities of data, but should rather be conceptual, concentrating on the methodological thinking that will allow the non-specialist reader to understand the information presented. Contributions also offer an outlook on potential future developments in the field. The chapter "Mechanochemical Forces as a Synthetic Tool for Zero and One-Dimensional Titanium Oxide-Based Nano-photocatalysts" is available open access under a CC BY 4.0 License via link.springer.com.
Download or read book Titanium Dioxide written by Dongfang Yang and published by BoD – Books on Demand. This book was released on 2018-06-27 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium dioxide is currently being used in many industrial products. It provides unique photocatalytic properties for water splitting and purification, bacterial inactivation, and organics degradation. It has also been widely used as the photoanode for dye-sensitized solar cells and coatings for self-cleaning surfaces, biomedical implants, and nanomedicine. This book covers various aspects of titanium dioxide nanomaterials including their unique one-dimensional, two-dimensional, mesoporous, and hierarchical nanostructures and their synthetic methods such as sol-gel, hydrothermal, anodic oxidation, and electrophoretic deposition, as well as its key applications in environmental and energy sectors. Through these 24 chapters written by experts from the international scientific community, readers will have access to a comprehensive overview of the recent research and development findings on the titanium dioxide nanomaterials.
Download or read book Hierarchical Nanostructures for Energy Devices written by Seung H Ko and published by Royal Society of Chemistry. This book was released on 2014-10-29 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface area has a directly relationship with the efficiency of energy devices. Hierarchical nanostructuring has the potential to greatly increase surface area, and their electrical properties are favourable, not only to energy generation and storage, but also energy-consuming electronic circuits. This book provides systematic coverage of how nanostructured materials can be applied to energy devices, with an emphasis on the process of generation to storage and consumption. The fundamentals (including properties, characterisation and synthesis) are clearly presented across the first chapters of the book, providing readers new to the field with a clear overview of this expanding topic. The detailed discussion of applications will be an inspiration to those already well-versed in the field. The editors have more than a decade of experience in working on all aspects of energy generation and storage - in academia, national laboratories and industry. The book presents a balanced view from all sectors and is presented in a format accessible by postgraduate students and professional researchers alike.
Download or read book Photocatalytic Degradation of Dyes written by Sushma Dave and published by Elsevier. This book was released on 2021-08-09 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalytic Degradation of Dyes: Current Trends and Future Perspectives covers in detail current trends and future aspects on photocatalytic degradation of organic dyes using novel photocatalytic techniques such as metallic nanoparticles, heterogeneous and hybrid systems using visible light irradiation. It highlights the most recent scientific and technological achievements and importance of degradation of dyes in the textile effluent by simple environmental friendly approaches using eco-friendly catalysts. It is of assistance to everyone interested in bioremediation of effluents: professionals, consulting engineers, academicians, and research scholars as well. - Describes the basic photocatalytic techniques and their application in wastewater treatment - Covers the key reactive species accounting for the photodegradation of different dyes, providing helpful guidelines that could be applied to foster the development of efficient photodegradation systems - Includes Description of a wide variety of catalysts and their application in degradation of dyes in the effluent of variable matrices (such as textile effluent, pharmaceutical industry effluent, food industry effluent) - Presents the application of doped semiconductors in the degradation of dyes, hybrid systems and their importance in the dye degradation - Describes the biological synthesis of metallic nanostructures and their use in dye degradation using visible range of light irradiation - Discusses the mechanistic aspect of the dye degradation using photo catalysts
Download or read book Metal Oxides written by J.L.G. Fierro and published by CRC Press. This book was released on 2005-08-24 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt: The chemistry of metals has traditionally been more understood than that of its oxides. As catalytic applications continue to grow in a variety of disciplines, Metal Oxides: Chemistry and Applications offers a timely account of transition-metal oxides (TMO), one of the most important classes of metal oxides, in the context of catalysis. The
Download or read book Principles and Practice of Heterogeneous Catalysis written by John Meurig Thomas and published by John Wiley & Sons. This book was released on 2015-02-09 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt: This long-awaited second edition of the successful introduction to the fundamentals of heterogeneous catalysis is now completely revised and updated. Written by internationally acclaimed experts, this textbook includes fundamentals of adsorption, characterizing catalysts and their surfaces, the significance of pore structure and surface area, solid-state and surface chemistry, poisoning, promotion, deactivation and selectivity of catalysts, as well as catalytic process engineering. A final section provides a number of examples and case histories. With its color and numerous graphics plus references to help readers to easily find further reading, this is a pivotal work for an understanding of the principles involved.
Download or read book Assessing the Degradation and Transformation of Emerging Pollutants Submitted to TiO2 Photocatalysis by High resolution Mass Spectrometry Techniques written by Javier Jimenez Villarin and published by . This book was released on 2017 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past 50 years there has been increasing interest and concern over pharmaceutical drugs and their presence in the environment, since they and/or their metabolites could induce toxicological effects and bacterial resistance in living organisms. Conventional sewage treatment plants are not able to efficiently remove these chemicals, reason why these compounds are being introduced into the aquatic environment at concentration levels of parts per-billion (ppb) and parts per-trillion (ppt). Although these concentrations are much lower than those used in medical applications, the related potential toxic effects are still poorly known and cannot be discarded. Heterogeneous TiO2 photocatalysis is an advanced oxidation process that can achieve complete oxidation and mineralisation of such organic compounds. TiO2 nanoparticles and nanofibers have been extensively investigated as the suspended semiconductors in common heterogeneous photocatalysis set-ups. However, the complete recovery of the semiconductor is still a major industrial challenge. That is the reason why their fixation onto an inner support represents a great alternative to overcome this problem. The present PhD thesis has studied the degradation of four pharmaceutical drugs (ofloxacin, clofibric acid, diclofenac and ibuprofen) using two different set-ups (suspended and supported conditions) with three different TiO2 catalysts: synthesised TiO2 nanofibers and P25 nanoparticles and commercially available nanofibers, used as reference materials. Prior performing the photocatalytical process, all TiO2 samples were submitted to physical characterisation (BET surface area, X-Ray diffraction and SEM microscopy) showing significant differences between the synthesised and reference materials. Prepared TiO2 nanofibers, however, appeared to be the material with maximum adsorption capacity (derived from Langmuir's isotherm) and appeared to be slightly better at degrading the pharmaceuticals under study at a concentration of 10 μg L-1. Nevertheless, when the experiments were conducted under real conditions, none of all the studied catalysts could effectively degrade the studied compounds. Additionally, this work has studied how one of the selected pharmaceuticals (ofloxacin) was degraded along the photocatalytical process by mass spectrometry techniques: (tandem) high-resolution mass spectrometry and ion mobility mass spectrometry. Due to the vast amount of information generated by these cutting-edge instruments, different data treatment techniques were applied in order to achieve a fast identification of the generated transformation products (TPs). The degradation of ofloxacin led to the formation of 59 TPs. Chemical structures of these TPs were hypothesised on the basis of their accurate mass and product ion spectra. However, due to the lack of standards of these TPs, these hypothesised structures could not be confirmed until ion mobility, in combination with theoretical calculations, was used. This technique not only rendered additional separation in the gas phase for some of the identified TPs but also provided a tool to support the complete elucidation of the chemical structures hypothesised. Having detected and identified ofloxacin TPs, the investigation of this PhD thesis was centred on the study of their toxicological impact. Toxicity was assessed by two different end-points: luminescence, using the luminescent bacteria Vibrio-fischeri and cytotoxicity using three different human cell lines (HK-2, HepG2 and fibroblast cells). Both end-points clearly demonstrated that, even at low concentrations, the formation of these TPs led to a toxicity increase when compared to the parent drug ofloxacin. Even though this toxicity increase, complete detoxification was achieved by ensuring enough irradiation time and promoting the complete depletion of ofloxacin TPs. The individual toxicity of these TPs was then studied by fractionating the reaction crude with a semi- preparative HPLC column which restricted the number of toxic TPs. Due to the poor chromatographic resolution achieved, the chemical synthesis of the generated TPs seems to be the only option, to date, to study their individual toxicity.
