Download or read book The Photocatalytic Degradation of Organic Contaminants in Water written by Jimmy Lea and published by . This book was released on 1998 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Photocatalytic Degradation of Organic Contaminants in Water written by Youn-Chul Oh and published by . This book was released on 2004 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation concerns the elucidation of degradation mechanisms of organic contaminants in aqueous suspension of TiO2, and extending understanding of photo catalysis condition to optimize degradation efficiency. The degradation mechanism of maleic acid, an important intermediate from the photocatalytic degradation of aromatic contaminants, was investigated via product distribution study and control experiments. The understanding of the mechanism of degradation of these compounds can assist us in ascertaining ideal conditions to perform the mineralization of recalcitrant organic compounds. The challenge to degrade a cyanyric acid, a recalcitrant species, by modifying TiO2 suspension was carried out. The addition of fluoride to aqueous suspensions of TiO2 has proved to be an important mechanistic tool in unraveling a long-standing conundrum in photocatalytic degradation. By using this method in parallel with other methods for producing homogeneous hydroxyl-type reagents, it is shown that cyanuric acid is susceptible to degradation under easily accessible conditions. There are isotope studies of photocatalysis of dimethyl phenyl phosphonate, a simple and safe form of organic phosphonate. Exposure of DMMP and related simple phosphonates to TiO2-mediated photocatalytic conditions results first in the loss of one of the methyl esters. An important unsettled mechanistic point is the mechanism by which the methyl is removed. Through the isotope studies of TiO2-mediated photocatalytic degradation of phosphonates, we can now understand removal of the alkyl ester portion of the compounds to produce phosphonic acid monoesters among the primary steps. The retention of 18O in the formation of MMPP clearly demonstrates that the dealkylation mechanism involves degradation of the methyl group exclusively, and neither attack at phosphorous by HO[Multiplied by][Subscript ads] or a related species, nor photoinduced hydrolysis. With an attempt to activate the modified TiO2 photo catalysts by the visible light and decrease the rapid recombination of excited electrons/holes during photoreaction, WO[Subscript x]-TiO2 powder was prepared by a sol-gel method. The WO[Subscript x]-TiO2 catalysts were characterized by XRD, XPS, and SEM-EDX. The degradation of 4-methoxyresorcinol by using WO[Subscript x]-TiO2 under visible light irradiation was observed.

Download or read book Photocatalysts for Organics Degradation written by Barbara Bonelli and published by MDPI. This book was released on 2020-06-23 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: The quality of water is not only a technological and scientific issue, but a social and economic problem, in both developed and developing countries. Besides local regulations, which differ between regions and need constant upgrades, significant scientific developments are required in both the detection and removal of water contaminants. This Issue focuses on some recent advancements in the photocatalytic removal of organic pollutants, which is one of the aspects of the problem that involves the need of advanced catalysts and implies significant advancements in the field of materials science and chemical engineering.

Download or read book Heterogeneous Photocatalytic Degradation of Organic Pollutants in Water Over Nanoscale Powdered Titanium Dioxide written by Khaled M. Mezughi and published by . This book was released on 2011 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic contaminants from industrial and/or domestic effluents may be harmful to humans directly or indirectly by degrading the quality of the aquatic environment. Consequently these contaminants must be reduced to levels that are not harmful to humans and the environment before disposal. Chemical, physical and biological methods exist for the removal of these pollutants from effluents. Among the available chemical methods, heterogeneous photocatalytic oxidation has been found particularly effective in removing a large number of persistent organics in water. In this study, photocatalytic degradation was explored for the removal of reactive azo-dye (textile dye), triclocarban (disinfectant), clopyralid (herbicide) and three endocrine disrupting compounds (EDCs) (estrone, 17?-estradiol and 17?-ethinylestradiol) from synthetic effluents. The major factors affecting the photocatalytic processes including the initial concentration of the target compounds, the amount of catalyst, the light intensity, the type of catalyst, the electron acceptor, the irradiation time and the pH were studied. Other oxidation techniques including (O3, H2O2, UV) were also studied. Generally UV light is used in combination with titanium dioxide, as photocatalyst, to generate photoinduced charge separation leading to the creation of electron-hole pairs. The holes act as electron acceptors hence the oxidation of organics occur at these sites. These holes can also lead to the formation of hydroxyl radicals which are also effective oxidants capable of degrading the organics. The results obtained in this study indicated that photolysis (i.e. UV only) was found to have no effect on the degradation of reactive azo-dye (RO16). However, complete photocatalytic degradation of 20 mg/L (3.24?10-2 mM) RO16 was achieved in 20 minutes in the presence of 1g/L TiO2 Degussa P25 at pH 5.5. Comparison between various types of catalysts (i.e. Degussa P25, VP Aeroperl, Hombifine N) gave varied results but Degussa P25 was the most effective photocatalyst hence it was selected for this study. For RO16 the optimum catalyst concentration was 0.5 g/L TiO2 with initial concentration of 20 mg/L RO16. It was found that the disappearance of RO16 satisfactorily followed the pseudo first-order kinetics according to Langmuir-Hinshelwood (L-H) model. The rate constant was k= 0.0928 mol/min. Photodegradation of TCC was studied in 70%v acetonitrile: 30%v water solutions. UV light degraded TCC effectively and the reaction rates increased with decreasing initial concentration of TCC. UV/TiO2 gave unsatisfactory degradation of triclocarban (TCC) since only 36% were removed in 60 minutes with initial concentration of TCC 20 mg/L. The degradation of clopyralid and the EDCs was studied using three oxidation systems UV/TiO2, UV/H2O2 and O3. Complete degradation of clopyralid (3,6-DCP) was achieved with UV/TiO2 in about 90 minutes at an optimum catalyst concentration of 1g/L. Zero-order kinetics was found to describe the first stage of the photocatalytic reaction in the concentration range 0.078-0.521 mM. At pH 5 the rate constant was 2.09?10-6? 4.32?10-7 M.s-1.Complete degradation of all the three EDCs was achieved with UV/H2O2 in 60 minutes at catalyst concentration of (2.94?10-2 M). On the other hand complete degradation of the EDCs was achieved in just 2 minutes with ozonation. For high concentration EDCs, TiO2/UV gave low efficiency of degradation as compared with ozone and H2O2/UV. First-order kinetics was found to describe the photocatalytic reaction of the EDCs.

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 Water Pollution and Remediation Photocatalysis written by Inamuddin and published by Springer Nature. This book was released on 2020-10-29 with total page 443 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the context of climate change and fossil fuel pollution, solar energy appears as a cheap and sustainable fuel for many environmental applications, yet the efficiency of techniques has to be improved. This book reviews recent methods and applications of photocatalysis for the treatment of wastewater containing bacteria, heavy metals, organic pollutants, dyes and tannery effluents. Basics of water pollution, polluted river ecosystems and membranes are also detailed.

Download or read book Photocatalytic Degradation of Organic Pollutants in Water written by Muhammad Umar and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalytic Degradation of Organic Pollutants in Water.

Download or read book Photodegradation of Water Pollutants written by Martin M. Halmann and published by CRC Press. This book was released on 1995-12-05 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photodegradation of Water Pollutants, the only complete survey available of current photocatalytic methods for treating water pollutants, covers all aspects of light-stimulated detoxification. Ideal for researchers and students, this new book explains methods for pollution treatment that have proven more effective than conventional biodegradation. Photodegradation of Water Pollutants examines advanced oxidation processes that have been successful in treating the chemical substances produced by industrial effluents and intensive agriculture. These oxidation processes include irradiation with ultraviolet or visible light, the use of homogenous sensitizers, such as dyes, and the use of heterogeneous photocatalysts, such as dispersed semiconductors. In addition, Photodegradation of Water Pollutants addresses the naturally occurring self-cleaning of some pollutants in sunlit surface waters, as well as several alternative non-photochemical approaches to water treatment. Available treatment options are discussed for the main groups of water pollutants, including toxic inorganic ions (cyanides, heavy metals), hydrocarbon derivatives (oil spills, surfactants, pulp and paper wastes), halocarbons, organo-N, organo-P, and organo-S compounds. The text also contains a unique section on the economics of advanced oxidation pollution treatments.

Download or read book Photocatalytic Reaction Engineering written by Hugo de Lasa and published by Springer Science & Business Media. This book was released on 2006-10-31 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heterogeneous photocatalysis is a novel technique for water purification. Publications on photocatalysis span a relatively recent period of not more than 25 years. This is a technique that, according to our extensive experience on the development of laboratory scale and pilot plant units, has great promise to eliminate water and air pollutants. Photocatalysis offers much more than competitive techniques where pollutants are transferred from phases; photocatalysis can achieve complete mineralization of pollutants leaving non-toxic species such as CO2 and H2O and can be exploited at close to room temperature and ambient pressure.

Download or read book Photocatalysts in Advanced Oxidation Processes for Wastewater Treatment written by Elvis Fosso-Kankeu and published by John Wiley & Sons. This book was released on 2020-04-28 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalysts in Advanced Oxidation Processes for Wastewater Treatment comprehensively covers a range of topics aiming to promote the implementation of photocatalysis at large scale through provision of facile and green methods for catalysts synthesis and elucidation of pollutants degradation mechanisms. This book is divided into two main parts namely “Synthesis of effective photocatalysts” (Part I) and “Mechanisms of the photocatalytic degradation of various pollutants” (Part II). The first part focuses on the exploration of various strategies to synthesize sustainable and effective photocatalysts. The second part of the book provides an insights into the photocatalytic degradation mechanisms and pathways under ultraviolet and visible light irradiation, as well as the challenges faced by this technology and its future prospects.

Download or read book Photocatalytic Degradation of Non biodegradable Organic Contaminants in Wastewaters written by and published by . This book was released on 2002 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Homogeneous and Heterogeneous Photocatalysis written by E. PELIZZETTI and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ever since the oil crisis of 1973, researchers in various fields of chemistry have proposed various schemes to conserve energy, as well to convert the sun's abundant and limitless supply of energy to produce chemical fuels (e. g. , hydrogen from water, . •. ). The enthusiasm had no previous parallel in the mid-1970's. Unfortunately, despite the several good proposals, the results have proven - in retrospect - somewhat disappointing from an economic viable point of view. The reasons for the meagre results are manyfold not the least of which are the experimental difficulties encountered in storage systems. Moreover, the lack of a concerted, well orchestrated interdisciplinary approach has been significant. By contrast, the chemical advances made in the understanding of the processes involved in such schemes have been phenomenal. A recent book on this issue ( M. Gratzel, Energy Resources through Photochemistry and Catalysis, 1983) is witness to the various efforts and approaches taken by researchers. In the recent years, many more groups have joined in these efforts, and the number of papers in the lit~rature is staggering ! One of the motives for organizing this NATO Advanced Research Workshop stemmed from our view that it was time to take stock of the accomplishments and rather than propose new schemes, it was time to consider seriously avenues that are most promising.

Download or read book Organic Pollutants in Wastewater I written by Inamuddin and published by Materials Research Forum LLC. This book was released on 2018-04-01 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wastewater represents an alternative to freshwater if it can be treated successfully for re-use applications. Promising techniques involve photocatalysis, adsorption, nanocomposites, and membranes. The book focusses on the following topics: Effluent detoxification and degradation kinetics of organic dyes using Fenton and photo-Fenton processes. Degradation of methylene blue using nanocomposites as a potential photocatalyst. Agricultural and agro-industries based wastes as low-cost biosorbents. Use of carbon quantum dots (CQDs) for photocatalytic degradation of organic pollutants. Detection, determination and removal of phenolic compounds from wastewater. Decomposition of organic dyes via photocatalysis. Oxide-semiconductor nanomaterials for photocatalytic wastewater purification. Photocatalytic efficiency of various ZnO composites for degradation of organic pollutants. TiO2 based nanocomposites. Membrane filtration processes for the removal of organics from industrial wastewater.

Download or read book New and Future Developments in Catalysis written by Steven L Suib and published by Newnes. This book was released on 2013-07-19 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: New and Future Developments in Catalysis is a package of seven books that compile the latest ideas concerning alternate and renewable energy sources and the role that catalysis plays in converting new renewable feedstock into biofuels and biochemicals. Both homogeneous and heterogeneous catalysts and catalytic processes will be discussed in a unified and comprehensive approach. There will be extensive cross-referencing within all volumes.The use of solar energy during various catalytic chemical processes for the production of an array of chemical products is the theme of this volume. Photocatalysis is a topic of increasing importance due to its essential role in many of today's environmental and energy source problems. The use of solar energy for catalytic reactions results in a carbon dioxide–neutral process. All photocatalytic processes and the future developments in this area are discussed, including an economic analysis of the various processes. - Offers in-depth coverage of all catalytic topics of current interest and outlines future challenges and research areas - A clear and visual description of all parameters and conditions, enabling the reader to draw conclusions for a particular case - Outlines the catalytic processes applicable to energy generation and design of green processes

Download or read book Photocatalysts in Advanced Oxidation Processes for Wastewater Treatment written by Elvis Fosso-Kankeu and published by John Wiley & Sons. This book was released on 2020-06-10 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalysts in Advanced Oxidation Processes for Wastewater Treatment comprehensively covers a range of topics aiming to promote the implementation of photocatalysis at large scale through provision of facile and green methods for catalysts synthesis and elucidation of pollutants degradation mechanisms. This book is divided into two main parts namely “Synthesis of effective photocatalysts” (Part I) and “Mechanisms of the photocatalytic degradation of various pollutants” (Part II). The first part focuses on the exploration of various strategies to synthesize sustainable and effective photocatalysts. The second part of the book provides an insights into the photocatalytic degradation mechanisms and pathways under ultraviolet and visible light irradiation, as well as the challenges faced by this technology and its future prospects.

Download or read book Surface Charging and Points of Zero Charge written by Marek Kosmulski and published by CRC Press. This book was released on 2009-05-14 with total page 1094 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Most Detailed Resource Available on Points of Zero ChargeWith their work growing in complexity, chemists involved with surface phenomena-related projects have outgrown the common resources available to them on points of zero charge (PZC) of oxides. Reporting on a limited number of materials in a limited number of scenarios, these resources ofte