Download or read book Evaluation of the Performance of Photocatalytic Systems for the Treatment of Indoor Air in Medical Environments written by Henrietta Essie Whyte and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalytic oxidation (PCO) is an advanced air cleaning technology that is used asa means to improve air quality in indoor environments and could potentially be used inthe operating rooms (OR). In hospitals, operating rooms (ORs) are very demanding interms of the indoor air quality (IAQ) and require systems that minimize the concentrations of pollutants. In this work, the fate of two OR pollutants acrylonitrile (chemical found insurgical smoke) and isoflurane (anesthetic gas) when they go through a PCO device was investigated. Firstly, a parametric evaluation on the degradation of isoflurane and acrylonitrile by studying the influence of air velocity, light intensity, the change in media geometry, initial pollutant concentration, presence of chemical co-pollutants, presence of particles (bioaerosols) and relative humidity on their degradation efficiencies is performed. Secondly the safety of the use of PCO for the degradation of isoflurane and acrylonitrile through the identification of possible intermediates formed during their degradation is evaluated. The experiments were conducted in a closed loop reactor which has been designed to study low concentration air pollutants and has also been recently modeled. Finally, to better understand how the change in media geometry influenced the degradation efficiency, simulations with ANSYS 14.5 were performed and discussed.

Download or read book Performance Study of Photocatalytic Oxidation for the Abatement of Volatile Organic Compounds from Indoor Air Environments written by Daniel Vildozo and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many commercial systems based in the photocatalytic technology have reached the market recently in order to address the growing demand for improve poor indoor air qualities. The present work deals with the development of a new methodology in order to evaluate the efficiency of this process. For the study of photocatalytic oxidation for indoor air applications, an experimental set-up was designed and two analytical tools (ATD-GC-MS and GC-PDHID) were developed. The performance of the photocatalytic treatment of 2-propanol and toluene at indoor air concentrations levels (ppbv) were realised. The influence of several parameters and their interactions effects on the conversion, by-product formation and mineralization to CO2 were established.

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 Parametric Evaluation of an Innovative Ultra Violet PhotocatalyticOxidation UVPCO Air Cleaning Technology for Indoor Applications written by William J. Fisk and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An innovative Ultra-Violet Photocatalytic Oxidation (UVPCO) air cleaning technology employing a semitransparent catalyst coated on a semitransparent polymer substrate was evaluated to determine its effectiveness for treating mixtures of volatile organic compounds (VOCs) representative of indoor environments at low, indoor-relevant concentration levels. The experimental UVPCO contained four 30 by 30-cm honeycomb monoliths irradiated with nine UVA lamps arranged in three banks. A parametric evaluation of the effects of monolith thickness, air flow rate through the device, UV power, and reactant concentrations in inlet air was conducted for the purpose of suggesting design improvements. The UVPCO was challenged with three mixtures of VOCs. A synthetic office mixture contained 27 VOCs commonly measured in office buildings. A building product mixture was created by combining sources including painted wallboard, composite wood products, carpet systems, and vinyl flooring. The third mixture contained formaldehyde and acetaldehyde. Steady state concentrations were produced in a classroom laboratory or a 20-m{sup 3} chamber. Air was drawn through the UVPCO, and single-pass conversion efficiencies were measured from replicate samples collected upstream and downstream of the reactor. Thirteen experiments were conducted in total. In this UVPCO employing a semitransparent monolith design, an increase in monolith thickness is expected to result in general increases in both reaction efficiencies and absolute reaction rates for VOCs oxidized by photocatalysis. The thickness of individual monolith panels was varied between 1.2 and 5 cm (5 to 20 cm total thickness) in experiments with the office mixture. VOC reaction efficiencies and rates increased with monolith thickness. However, the analysis of the relationship was confounded by high reaction efficiencies in all configurations for a number of compounds. These reaction efficiencies approached or exceeded 90% for alcohols, glycol ethers, and other individual compounds including d-limonene, 1,2,4-trimethylbenzene, and decamethylcyclopentasiloxane. This result implies a reaction efficiency of about 30% per irradiated monolith face, which is in agreement with the maximum efficiency for the system predicted with a simulation model. In these and other experiments, the performance of the system for highly reactive VOCs appeared to be limited by mass transport of reactants to the catalyst surface rather than by photocatalytic activity. Increasing the air flow rate through the UVPCO device decreases the residence time of the air in the monoliths and improves mass transfer to the catalyst surface. The effect of gas velocity was examined in four pairs of experiments in which the air flow rate was varied from approximately 175 m{sup 3}/h to either 300 or 600 m{sup 3}/h. Increased gas velocity caused a decrease in reaction efficiency for nearly all reactive VOCs. For all of the more reactive VOCs, the decrease in performance was less, and often substantially less, than predicted based solely on residence time, again likely due to mass transfer limitations at the low flow rate. The results demonstrate that the UVPCO is capable of achieving high conversion efficiencies for reactive VOCs at air flow rates above the base experimental rate of 175 m{sup 3}/h. The effect of UV power was examined in a series of experiments with the building product mixture in which the number of lamps was varied between nine and three. For the most reactive VOCs in the mixture, the effects of UV power were surprisingly small. Thus, even with only one lamp in each section, there appears to be sufficient photocatalytic activity to decompose most of the mass of reactive VOCs that reach the catalyst surface. For some less reactive VOCs, the trend of decreasing efficiency with decreasing UV intensity was in general agreement with simulation model predictions.

Download or read book EPA Publications Bibliography written by United States. Environmental Protection Agency and published by . This book was released on 1998 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of International Conference of Aerospace and Mechanical Engineering 2019 written by Parvathy Rajendran and published by Springer Nature. This book was released on 2020-06-12 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents selected papers from the International Conference of Aerospace and Mechanical Engineering 2019 (AeroMech 2019), held at the Universiti Sains Malaysia's School of Aerospace Engineering. Sharing new innovations and discoveries concerning the Fourth Industrial Revolution (4IR), with a focus on 3D printing, big data analytics, Internet of Things, advanced human-machine interfaces, smart sensors and location detection technologies, it will appeal to mechanical and aerospace engineers.

Download or read book Photocatalytic Systems by Design written by Mohan Sakar and published by Elsevier. This book was released on 2021-08-14 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalytic Systems by Design: Materials, Mechanisms and Applications explores various aspects of photocatalysis, including the photocatalytic phenomenon and process, applications, and the design of photocatalysts via band gap engineering. The book also covers band edge position engineering for multiple photocatalytic applications, such as pollutant degradations, hydrogen production, CO2 reduction into hydrocarbon fuels, antimicrobial disinfections, organic synthesis, N2 fixation, and more. This book is designed to enable beginners to learn the concepts and applications of photocatalysis. Unlike conventional books on photocatalysis, the book provides a 360° perspective into the field of photocatalysis and serves as an informative handbook for all audiences. - Addresses all concepts and applications of photocatalysis - Covers the fundamentals, including mechanisms of photocatalytic materials - Describes the various material systems and engineering of photocatalysts - Offers insight into the schemes for photocatalysis of various materials - Discusses the application-specific design of photocatalysts

Download or read book Photocatalysis for Environmental Remediation and Energy Production written by Seema Garg and published by Springer Nature. This book was released on 2023-05-06 with total page 483 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores the modification of various synthesis processes to enhance the photocatalytic activity in varied applications in the fields of environmental remediation and energy production. It outlines the enhancement of photocatalytic activity via alloys synthesis, thin film coatings, electro-spun nanofibers and 3D printed photocatalysts. The book further states the diverse applications of materials for degrading organic pollutants and airborne pathogens, improving indoor air quality and as a potential antimicrobial agent. The application of photocatalysts in green organic synthesis, biomedical field and in hydrogen evolution are also presented in the book. It covers theoretical studies of photocatalytic material and conversion of CO2 to value added chemical feed stocks. The book is of relevance to researchers in academia and industry alike in the fields of material science, environmental science & technology, photocatalytic applications and in energy generation and conversion.

Download or read book Experimental Evaluation and Modeling of Photocatalytic Oxidation Air Cleaners written by Lexuan Zhong and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Visible Light Active Structured Photocatalysts for the Removal of Emerging Contaminants written by Olga Sacco and published by Elsevier. This book was released on 2019-09-11 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Visible Light Active Structured Photocatalysts for the Removal of Emerging Contaminants: Science and Engineering addresses the potential role of visible active photocatalytic processes for the removal of emerging contaminants. The book discusses the classification, sources and potential risks of emerging pollutants in water as well as the different synthesis methods of visible active structured photocatalysts with relation to their applications in photocatalytic processes for the removal of organic and inorganic emerging contaminants. Finally, the possible reaction pathways occurring during the visible or solar photocatalytic processes together with toxicity assessment are discussed. The book is a useful guide for academics, researchers and technicians in chemical engineering, chemistry and environmental sciences. - Defines emerging contaminants and what can be included in that group of contaminants commonly named "contaminants of emerging concern" - Presents different synthesis methods of visible active structured photocatalysts and their applications in solar or visible light photocatalytic systems for the removal of organic and inorganic emerging contaminants - Analyzes reaction pathways that occur during the visible or solar photocatalytic processes, also including toxicity assessments

Download or read book Photocatalytic Functional Materials for Environmental Remediation written by Alagarsamy Pandikumar and published by John Wiley & Sons. This book was released on 2019-06-10 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive volume on photocatalytic functional materials for environmental remediation As the need for removing large amounts of pollution and contamination in air, soil, and water grows, emerging technologies in the field of environmental remediation are of increasing importance. The use of photocatalysis—a green technology with enormous potential to resolve the issues related to environmental pollution—breaks down toxic organic compounds to mineralized products such as carbon dioxide and water. Due to their high performance, ease of fabrication, long-term stability, and low manufacturing costs, photofunctional materials constructed from nanocomposite materials hold great potential for environmental remediation. Photocatalytic Functional Materials for Environmental Remediation examines the development of high performance photofunctional materials for the treatment of environmental pollutants. This timely volume assembles and reviews a broad range of ideas from leading experts in fields of chemistry, physics, nanotechnology, materials science, and engineering. Precise, up-to-date chapters cover both the fundamentals and applications of photocatalytic functional materials. Semiconductor-metal nanocomposites, layered double hydroxides, metal-organic frameworks, polymer nanocomposites, and other photofunctional materials are examined in applications such as carbon dioxide reduction and organic pollutant degradation. Providing interdisciplinary focus to green technology materials for the treatment of environmental pollutants, this important work: Provides comprehensive coverage of various photocatalytic materials for environmental remediation useful for researchers and developers Encompasses both fundamental concepts and applied technology in the field Focuses on novel design and application of photocatalytic materials used for the removal of environmental contaminates and pollution Offers in-depth examination of highly topical green-technology solutions Presents an interdisciplinary approach to environmental remediation Photocatalytic Functional Materials for Environmental Remediation is a vital resource for researchers, engineers, and graduate students in the multi-disciplinary areas of chemistry, physics, nanotechnology, environmental science, materials science, and engineering related to photocatalytic environmental remediation.

Download or read book Photocatalytic Systems by Design written by Mohan Sakar and published by Elsevier. This book was released on 2021-08-20 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalytic Systems by Design: Materials, Mechanisms and Applications explores various aspects of photocatalysis, including the photocatalytic phenomenon and process, applications, and the design of photocatalysts via band gap engineering. The book also covers band edge position engineering for multiple photocatalytic applications, such as pollutant degradations, hydrogen production, CO2 reduction into hydrocarbon fuels, antimicrobial disinfections, organic synthesis, N2 fixation, and more. This book is designed to enable beginners to learn the concepts and applications of photocatalysis. Unlike conventional books on photocatalysis, the book provides a 360° perspective into the field of photocatalysis and serves as an informative handbook for all audiences. Addresses all concepts and applications of photocatalysis Covers the fundamentals, including mechanisms of photocatalytic materials Describes the various material systems and engineering of photocatalysts Offers insight into the schemes for photocatalysis of various materials Discusses the application-specific design of photocatalysts

Download or read book Smart Photocatalytic Building Materials for Autogenous Improvement of Indoor Environment written by Zhuoying Jiang and published by . This book was released on 2021 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: As people spend most of their time inside the buildings, the improvement of the indoor air quality has received considerable attention. The major contaminants inside the building is volatile organic compounds (VOCs) referred to the carbon-contained organic substances in the air. VOCs are usually not acutely toxic, but they cause an adverse health effect when human are exposed to a concentration of ppmv level of VOCs. Thus, it is critical to mitigate the VOCs level inside the building. To achieve the purpose of removing VOCs and improving the indoor environment, an innovative photocatalytic membrane we designed and fabricated. This new photocatalytic material can be applied to the indoor surface and used as a smart functional surface. Furthermore, the fundamentals related to its photocatalytic activities and practical applications were explored by integrating the experimental, physics-based and data-driven approaches. Nitrogen-doped TiO2 photocatalysts were synthesized using a sol-gel method and a post-annealing heat treatment. The annealing temperature and time affect their microstructures and surface chemical compositions. It was found that these characteristics are relevant to the adsorption and photocatalytic activities of the nitrogen-doped TiO2 photocatalysts. Therefore, a physics-based kinetic model was developed to distinguish the impact of three different mechanisms, including adsorption, photocatalysis, and direct light photolysis, on the removal of VOCs. The kinetic modeling and experimental results show that a higher annealing temperature leads to not only less adsorption, but also nitrogen loss. To predict the kinetics of contaminant degradation and facilitate the choice of the optimal photocatalyst, three data-driven machine-learning (ML) models were developed to predict the photocatalytic degradation performance. The ML model inputs include tens of organic contaminants and other experimental variables, including light level, photocatalyst dosage, concentration of contaminant, initial pH of the solution, and experimental temperature. It was found that the model predictions match reasonably well with the experimental results with the R2 of around 0.8. The functional surface, containing photocatalyst particles and nanofiber substrates, was fabricated. Three methods were used to fabricate the functional surface: direct-dispersing, post-dipping and post-electrospraying method. Post-electrospraying is a better approach since it is able to load TiO2 without reducing photocatalytic activity, and the amount of TiO2 on fiber can be tuned by electrospraying time. To evaluate the performance of the functional surface activated by visible light in removing indoor VOCs, a holistic model was developed. The kinetic simulations show that VOCs can be decomposed using nitrogen-doped TiO2 functional surface by 80% in an actual room size. As a whole, our work demonstrates the promise of photocatalyst driven by visible light to effectively remove VOCs and create a healthy indoor environment.

Download or read book Evaluation of Ultra Violet Photocatalytic Oxidation for Indoor AirApplications written by D. P. Sullivan and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Acceptable indoor air quality in office buildings may be achieved with less energy by combining effective air cleaning systems for volatile organic compounds (VOCs) with particle filtration then by relying solely on ventilation. For such applications, ultraviolet photocatalytic oxidation (UVPCO) systems are being developed for VOC destruction. An experimental evaluation of a UVPCO system is reported. The evaluation was unique in that it employed complex mixtures of VOCs commonly found in office buildings at realistically low concentrations. VOC conversion efficiencies varied over a broad range, usually exceeded 20%, and were as high as {approx}80%. Conversion efficiency generally diminished with increased air flow rate. Significant amounts of formaldehyde and acetaldehyde were produced due to incomplete mineralization. The results indicate that formaldehyde and acetaldehyde production rates may need to be reduced before such UVPCO systems can be deployed safely in occupied buildings.

Download or read book Photocatalysis for Environmental Applications written by Fan Dong and published by Frontiers Media SA. This book was released on 2019-07-19 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book From Biofiltration to Promising Options in Gaseous Fluxes Biotreatment written by Gabriela Soreanu and published by Elsevier. This book was released on 2020-04-03 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: From Biofiltration to Promising Options in Gaseous Fluxes Biotreatment: Recent Developments, New Trends, Advances, and Opportunities provides an overview on the biological tools used for the treatment of the gaseous fluxes, with emphasis on traditional and perspective options, opening new horizons for research and implementation in practice. It is known that air pollution is an emergent global issue and a priority within the international environmental programs. Moreover, technologies based on biological methods are significantly contributing to the sustainable development concept. Thus this book provides tools for solving air pollution issues in a sustainable manner. These issues can be solved at different levels (e.g., "end-of-pipe" gaseous streams, indoor/outdoor air, closed environments), which can be approached by the different biotechniques presented in the book, from classical biofiltration techniques (part 1) to phytotreatment and microalgae-based techniques (part 2). Although all options have their particularities that make them special for certain applications, a special attention is drawn to the potential of the last one, which offers multiple possibilities for biomass valorization. Scientists from worldwide with relevant experience in their field have been contributed to the development of this book. - Presents the main biotechnological aspects applied for gas purification, focusing on process understanding, limitations, and capability in different applications - Promotes a sustainable future of the biofiltration process by enhancing their performance together with the simultaneously economic and environmental impacts - Implements new aspects of scientific research and development in the field

Download or read book Evaluation of Ultra Violet Photocatalytic Oxidation UVPCO ForIndoor Air Applications written by William J. Fisk and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Efficient removal of indoor generated airborne particles and volatile organic compounds (VOCs) in office buildings and other large buildings may allow for a reduction in outdoor air supply rates with concomitant energy savings while still maintaining acceptable indoor air quality in these buildings. Ultra-Violet Photocatalytic Oxidation (UVPCO) air cleaners have the potential to achieve the necessary reductions in indoor VOC concentrations at relatively low cost. In this study, laboratory experiments were conducted with a scaled, prototype UVPCO device designed for use in a duct system. The experimental UVPCO contained two 30 by 30-cm honeycomb monoliths coated with titanium dioxide and 3% by weight tungsten oxide. The monoliths were irradiated with 12 UVC lamps arranged in four banks. The UVPCO was challenged with four mixtures of VOCs typical of mixtures encountered in indoor air. A synthetic office mixture contained 27 VOCs commonly measured in office buildings. A cleaning product mixture contained three cleaning products with high market shares. A building product mixture was created by combining sources including painted wallboard, composite wood products, carpet systems, and vinyl flooring. A fourth mixture contained formaldehyde and acetaldehyde. Steady-state concentrations were produced in a classroom laboratory or a 20-m{sup 3} environmental chamber. Air was drawn through the UVPCO, and single pass conversion efficiencies were measured from replicate air samples collected upstream and downstream of the reactor section. Concentrations of the mixtures were manipulated, with concentrations of individual VOCs mostly maintained below 10 ppb. Device flow rates were varied between 165 and 580 m{sup 3}/h. Production of formaldehyde, acetaldehyde, acetone, formic acid, and acetic acid as reaction products was investigated. Conversion efficiency data were generated for 48 individual VOCs or groups of closely related compounds. Alcohols and glycol ethers were the most reactive chemical classes with conversion efficiencies often near or above 70% at the low flow rate and near 40% at the high flow rate. Ketones and terpene hydrocarbons were somewhat less reactive. The relative VOC conversion rates are generally favorable for treatment of indoor air since many contemporary products used in buildings employ oxygenated solvents. A commercial UVPCO device likely would be installed in the supply air stream of a building and operated to treat both outdoor and recirculated air. Assuming a recirculation rate comparable to three times the normal outdoor air supply rate, simple mass-balance modeling suggests that a device with similar characteristics to the study unit has sufficient conversion efficiencies for most VOCs to compensate for a 50% reduction in outdoor air supply without substantially impacting indoor VOC concentrations. Formaldehyde, acetaldehyde, acetone, formic acid, and acetic acid were produced in these experiments as reaction byproducts. No other significant byproducts were observed. A coupled steady-state mass balance model is presented and applied to VOC data from a study of a single office building. For the operating assumptions described above, the model estimated a three-fold increase in indoor formaldehyde and acetaldehyde concentrations. The outcome of this limited assessment suggests that evaluation of the potential effects of the operation of a UVPCO device on indoor concentrations of these contaminants is warranted. Other suggested studies include determining VOC conversion efficiencies in actual buildings and evaluating changes in VOC conversion efficiency as monoliths age with long-term operation.