Show simple item record dc.description.abstractExperiments 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. inov 8 air purifierThe same flow tube reactor used for the previous NOX experiments was used to test a standardized gas-phase concentration of formaldehyde and methanol. blueair blueair hepasilent eco10 air purifierThe extended UV illumination of the tiles resulted in a 50 % reduction in formaldehyde, and a 68% reduction in methanol. blueair 450e smokestop air purifier reviewThe 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; 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.en_US dc.publisherGeorgia Institute of Technologyen_US dc.subject.lcshIndoor air pollution Research dc.titlePhotocatalytic degradation of NOX, VOCs, and chloramines by TiO2 impregnated surfacesen_US dc.contributor.departmentCivil and Environmental Engineeringen_US dc.description.advisorCommittee Chair: Bergin, Mike; Committee Member: Huey, Greg; Committee Member: Mulholland, Jamesen_US

Files in this item This item appears in the following Collection(s) Georgia Tech Theses and Dissertations [19500]Theses and Dissertations School of Civil and Environmental Engineering Theses and Dissertations [1434]Original work by students in the School of Civil and Environmental Engineering Show simple item record The Green Zone Panel Mini White Pump Kit Job Link Clamp Meters TYTAN Coat & Seal Aerofin Division of Air & Liquid Systems Corporation Foshan Shunde Cold Magic Air-conditioning Equipment Co., Ltd Heat Transfer Products Group Heatcraft Worldwide Refrigeration LLC Johnson Controls, Inc., York Guangzhou Air-Conditioning and Refrigeration Co., Ltd Nortek Air Solutions, LLC Nortek Air Solutions Canada, Inc. Nortek Air Solutions Quebec, Inc. SGS Refrigeration dba LRC Coils Co. Smartech International Sdn Bhd. This standard applies to the enclosure which houses the fans, coils, filters, and other components of the Central Station Air-handling Unit (CSAHU).

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