Photocatalysis For Indoor Air Cleaning
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Photocatalysis For Indoor Air Cleaning
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Author :
language : en
Publisher:
Release Date : 2013
Photocatalysis For Indoor Air Cleaning written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2013 with categories.
Development Of Photocatalytic Oxidation Technology For Purification Of Air And Water
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Author : Chun-Wai Ringo Lam
language : en
Publisher: Open Dissertation Press
Release Date : 2017-01-27
Development Of Photocatalytic Oxidation Technology For Purification Of Air And Water written by Chun-Wai Ringo Lam and has been published by Open Dissertation Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017-01-27 with categories.
This dissertation, "Development of Photocatalytic Oxidation Technology for Purification of Air and Water" by Chun-wai, Ringo, Lam, 林俊偉, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled "Development of photocatalytic oxidation technology for purification of air and water" Submitted by Lam Chun Wai, Ringo for the degree of Master of Philosophy at the University of Hong Kong in January 2007 The adverse health effect of indoor air pollutants has aroused the attention of scientists and medical personnel since the outbreak of Legionnaires' disease in Philadelphia in 1976. Since then, numerous investigations of indoor air quality have demonstrated the positive correlation between the health risks and exposure to air pollutants such as oxides of nitrogen (NO ), sulphur dioxide (SO ), carbon monoxide x 2 (CO) and volatile organic compounds (VOC). Employees exposed to such pollutants complain of problems such as headaches and irritated eyes. These symptoms are related to elevated indoor air pollutant concentrations, which produce the condition known as sick building syndrome (SBS). There are various types of air purification systems available on the market to reduce the concentration of indoor air pollutants, such as particulate matters, VOC and micro-organisms. High-efficiency particulate air (HEPA) filters, ultraviolet germicidal irradiation (UVGI) lamps and ozone generators are commonly used. However, none of these systems offers a complete solution and some of them may even cause health hazards themselves. The photocatalytic oxidation technology employs a more robust air purification mechanism. When UVA light is incident on photocatalysts, hydroxyl and hydroperoxyl radicals will be generated. These strong oxidizing radicals can decompose VOCs into harmless simple compounds, eliminate odors and destroy microbial bioaerosols. Since the radicals generated stay on the surface of the photocatalyst and no reactive chemical is released into the air stream, the photocatalytic air purification device causes no harm to the building's occupants. This study aims to investigate the use of photocatalysis for indoor air purification. The TiO thin film was characterized with different characterization methods such as 2 Differential Scanning Calorimetry and Thermal Gravity (DSC/TG) analysis, X-ray diffraction (XRD), High Resolution Transmission Electron Microscopy (HRTEM), UV- Vis NIR absorption spectra, Scanning Electron microscope (SEM) and X-ray Photoelectron Spectroscopy (XPS). Common indoor air pollutants such as formaldehyde (HCHO), nitrogen monoxide (NO), nitrogen dioxide (NO ) and airborne bacteria were selected as target compounds. Parametric analyses were conducted with the aforementioned pollutants under different parameters in the presence of TiO . The photodegradation rate, in general, increased with decreasing initial pollutant concentration and increasing UVA light intensity. Airborne bacteria, staphylococcus aureus and mycobacterium tuberculosis (MTB), were successfully photo-degraded by UVA light with the presence of sol-gel TiO . Another objective of this study was to extend the useful spectral range of photocatalyst from UVA light to visible light. It could be done by implantation of chromium (Cr) ion into TiO photocatalyst. The experimental results revealed the effectiveness of the visible-light-assisted Cr/TiO photoreactors in degradation of gaseous formaldehyde. It implied that the photoreactors could be effectively applied to achieve solar photocatalysis.
Hydrothermal Solvothermal Synthesis Of Hierarchical Titanium Dioxide Photocatalysts For Indoor Air Purification
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Author : Alireza Haghighatmamaghani
language : en
Publisher:
Release Date : 2019
Hydrothermal Solvothermal Synthesis Of Hierarchical Titanium Dioxide Photocatalysts For Indoor Air Purification written by Alireza Haghighatmamaghani and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019 with categories.
Energy saving policies applied to modern buildings, tighter building envelopes, and decline in outdoor air quality promote the escalation in levels of indoor air pollutants. In recent years, concerns regarding the impact of indoor air quality (IAQ) on human health especially in well-insulated buildings in metropolitans have created a pressing need for reliable air remediation technologies. Heterogeneous ultraviolet photocatalytic oxidation (UV-PCO) has been put forward as an efficient method to ameliorate IAQ via catalytic degradation of harmful organic compounds to benign final products. In this context, developing highly photoactive and durable photocatalysts that can perform satisfactorily under realistic conditions is sought after to expedite UV-PCO systems commercialization. Photocatalyst's performance is a function of several interconnected features: crystallinity, crystal phase and size, surface area, porosity, surface chemistry, light-harvesting ability, exposed facet, and charge-separation efficiency. In this regard, thanks to their unique morphology and multimodal porosity, hierarchical photocatalysts can incorporate high molecular diffusion/transport, superior light harvesting, and large surface area. Template-free hydrothermal/solvothermal route is a green, versatile, and less costly strategy for fabricating hierarchical photocatalysts with controlled characteristics. Taking into account the above-mentioned merits of hierarchical photocatalysts and hydrothermal synthesis method, the core objectives of this research are: 1)Synthesize hierarchically porous titanium dioxide materials with enhanced photoactivity with respect to commercially available photocatalysts (e.g. P25) via hydrothermal method. 2)Explore the complex preparation-property-performance relationships for titanium dioxide photocatalysts utilized in photocatalytic air purification.3)Examine the role of photocatalyst's morphology in photocatalytic degradation by developing several potentially promising structures and assess their performance.4)Investigate the improvement in photocatalytic filter activity and stability with combining hierarchical titanium dioxide with carbonaceous support.. 5)Evaluate the activity of photocatalysts under realistic operating conditions to provide reliable information regarding the capability of UV-PCO air purifiers.To accomplish these goals, a large number of TiO2 photocatalysts are synthesized by systematically varying the hydrothermal preparation parameters (e.g. time, temperature, pressure, pH, solvent, titanium precursor, calcination temperature, etc.). Accordingly, by means of comprehensive characterization, the influence of synthetic methodology on textural, morphological, and crystallographic properties of photocatalysts is investigated. In the last stage, the performance of photocatalyst is evaluated by degradation of two prevalent indoor air pollutants (toluene and methyl ethyl ketone (MEK)) at wide ranges of operating conditions.
Photocatalytic Oxidation Of Volatile Organic Compounds For Indoor Air Applications
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Author :
language : en
Publisher:
Release Date : 2009
Photocatalytic Oxidation Of Volatile Organic Compounds For Indoor Air Applications written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009 with categories.
Photocatalytic oxidation (PCO) is a promising and emerging technique in controlling indoor air contaminants, including volatile organic compounds (VOCs). It has broad air cleaning and deodorization applications in indoor environments ranging from residential and office buildings to healthcare and nursing facilities as well as spacecrafts, aircraft cabins and clean rooms in the agricultural and food industry. Numerous studies have been conducted to improve the effectiveness and performance of this technology. These include development of new configurations, energy-efficient catalysts and other parameters to control the process. However, only limited research has been conducted under realistic indoor environmental conditions. One of the most recent developments in photocatalysis is the synthesis of 2% C- and V-doped TiO[subscript]2, which is active under both dark and visible light conditions. However, like most research conducted in photocatalysis, the study on the reactivity of this catalyst has been performed only under laboratory conditions. This study investigated the possible application of the novel C and V co-doped TiO[subscript]2 in cleaning indoor air. Mathematical modeling and simulation techniques were employed to assess the potential use of some of the promising systems that utilize the catalyst (i.e., packed bed and thin films) as well as the effect of mass transfer limitations in the degradation of acetaldehyde, one of the VOCs that can be found in offices, residential buildings and other facilities.
Experimental Evaluation Of Indoor Air Cleaning Technologies And Modeling Of Uv Pco Photocatalytic Oxidation Air Cleaners Under Multiple Vocs Conditions
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Author : Wenhao Chen
language : en
Publisher:
Release Date : 2007
Experimental Evaluation Of Indoor Air Cleaning Technologies And Modeling Of Uv Pco Photocatalytic Oxidation Air Cleaners Under Multiple Vocs Conditions written by Wenhao Chen and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2007 with Environmental engineering categories.
The objectives of this study were to: (1) develop much needed test methods and datasets for determining the performance of various air cleaning technologies, and (2) improve the understanding and develop a simulation model for the performance prediction of ultraviolet photocatalytic oxidation (UV-PCO) devices under multiple volatile organic compounds (VOCs) conditions.
Light Assisted Catalysis In Water And Indoor Air Cleaning
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Author : Ioan Balint
language : en
Publisher: Mdpi AG
Release Date : 2023-07-31
Light Assisted Catalysis In Water And Indoor Air Cleaning written by Ioan Balint and has been published by Mdpi AG this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023-07-31 with Science categories.
The detrimental effects of environmental pollution on human health, combined with global climate change, make it a critical contemporary problem. Despite the fact that water covers more than 71% of the Earth's surface, ensuring access to high-quality drinking water for everyone is a major concern that societies are encountering in the 21st century. Utilizing renewable solar light and a catalyst to mineralize various harmful chemicals present in indoor air and water sources into benign small molecules, such as H2O and CO2, is an attractive approach. In this context, photocatalytic processes have consistently offered smart, green, and eco-friendly scale-up methods for environmental remediation. Numerous photocatalysts have proven to be successful in achieving the mineralization of chlorinated pollutants, organic contaminants, dyes, or antibiotics. An analysis of the existing literature reveals the need for research studies to focus on developing efficient photocatalysts capable of mineralizing contaminants into non-toxic CO2. Only such photocatalytic materials should be envisaged for environmental remediation. This Special Issue, titled "Light-Assisted Catalysis in Water and Indoor Air Cleaning: Challenges and Perspectives", is a collection of ten papers, including three reviews and seven research articles. The aim of this Special Issue is to present recent advancements in the photocatalytic removal of pollutants, elucidating the main factors contributing to their mineralization and the implication of reactive oxygen species (ROS) through dedicated experiments.
Evaluation Of The Performance Of Photocatalytic Systems For The Treatment Of Indoor Air In Medical Environments
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Author : Henrietta Essie Whyte
language : en
Publisher:
Release Date : 2018
Evaluation Of The Performance Of Photocatalytic Systems For The Treatment Of Indoor Air In Medical Environments written by Henrietta Essie Whyte and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018 with categories.
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.
Indoor Environmental Quality
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Author : Arun Sharma
language : en
Publisher: Springer Nature
Release Date : 2020-01-02
Indoor Environmental Quality written by Arun Sharma and has been published by Springer Nature this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020-01-02 with Business & Economics categories.
This volume presents selected papers presented during the First Asian Conference on Indoor Environmental Quality (ACIEQ). The contents cover themes of indoor air quality monitoring and modeling; the influence of confounding factors like thermal comfort parameters, such as temperature and relative humidity with respect to different building types, e.g., residential, commercial, institutional; ventilation characteristics, lighting and acoustics. It also focuses on people's performance, productivity, and behavior with respect to their exposure to various indoor air pollutants and parameters influencing the overall indoor environmental quality. This volume is primarily aimed at researchers working in environmental science and engineering, building architecture and design, HVAC and ventilation, public health, and epidemiology. The contents of this volume will also be useful to policy makers working on occupational health and building codes.
Experimental Evaluation And Modeling Of Photocatalytic Oxidation Air Cleaners
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Author : Lexuan Zhong
language : en
Publisher:
Release Date : 2013
Experimental Evaluation And Modeling Of Photocatalytic Oxidation Air Cleaners written by Lexuan Zhong and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2013 with categories.
How To Make A Photocatalytic Air Purifier
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Author : J Richard Hollos
language : en
Publisher: Independently Published
Release Date : 2023-07-16
How To Make A Photocatalytic Air Purifier written by J Richard Hollos and has been published by Independently Published this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023-07-16 with categories.
We write books, so we spend a lot of time indoors. When we go outside the air seems so much fresher than inside. Is there any way to recreate that fresh air feeling indoors? That's a question we've been trying to answer for a few years now. We think we've found an answer. It's called photocatalytic air purification. What exactly this means is described in the first section. The final section of this guide describes in detail how to actually make an air purifier that uses photocatalysis to remove volatile organic chemicals (VOCs) from the air. The photocatalytic air purifier which we've created and describe here has made a positive difference to us. We set it on a table next to where we work and run it whenever we're working. When it's running, the air seems fresh, similar to having a nearby open window. It's not magic but it has reduced the incidence of itchy watery eyes, irritated throat, runny nose and general feeling of malaise that VOCs can produce.