Abstract
Gas-phase advanced oxidation (GPAO) is an emerging air cleaning technology based on the natural self-cleaning processes that occur in the Earth’s atmosphere. The technology uses ozone, UV-C lamps and water vapor to generate gas-phase hydroxyl radicals that initiate oxidation of a wide range of pollutants. In this study four types of GPAO systems are presented: a laboratory scale prototype, a shipping container prototype, a modular prototype, and commercial scale GPAO installations. The GPAO systems treat volatile organic compounds, reduced sulfur compounds, amines, ozone, nitrogen oxides, particles and odor. While the method covers a wide range of pollutants, effective treatment becomes difficult when temperature is outside the range of 0 to 80 °C, for anoxic gas streams and for pollution loads exceeding ca. 1000 ppm. Air residence time in the system and the rate of reaction of a given pollutant with hydroxyl radicals determine the removal efficiency of GPAO. For gas phase compounds and odors including VOCs (e.g. C6H6 and C3H8) and reduced sulfur compounds (e.g. H2S and CH3SH), removal efficiencies exceed 80%. The method is energy efficient relative to many established technologies and is applicable to pollutants emitted from diverse sources including food processing, foundries, water treatment, biofuel generation, and petrochemical industries.
Highlights
Anthropogenic emissions into the atmosphere have a wide range of negative effects including those on air quality, human health, agricultural output and climate [1,2,3,4]
Particle filters can remove particulate matter (PM), but they are not designed to treat gaseous pollutants and require ongoing maintenance and replacement, and the filters themselves can be a source of odor and volatile organic compounds (VOCs) [11,12]
This study describes applications of gas phase advanced oxidation, a new and emerging pollution control technique, to indoor air pollution and to industrial and agricultural emissions control
Summary
Anthropogenic (and natural) emissions into the atmosphere have a wide range of negative effects including those on air quality, human health, agricultural output and climate [1,2,3,4]. Price of catalyst Catalyst may contain rare and/or toxic elements Catalyst vulnerable to poisoning Generally not suited to complex or variable mixtures High energy input, high capital cost High pressure drop Potentially high temperature Susceptible to arcing Limited efficiency for nanoparticles (0–50 nm) Source of ozone Require cleaning. With time filters generate odor Cannot remove VOCs Release secondary pollutants when in contact with ozone Source of contamination for microorganisms Enable growth of microorganism Pressure drop Removal efficiency depends on residence time of polluted airstream No recovery of pollutants Not efficient to all pollutants Source of nanoparticles (0–50 nm) Possible formation of unwanted reaction products such as carbon monoxide and formaldehyde Requires investigation of oxidation products Produces ozone, NOx, CO and other by-products.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
