Titanium dioxide (TiO2) is an established photocatalyst utilized for the photo-oxidation of organics in wastewater. Aqueous suspensions of TiO2 require separation and re-suspension steps to be used on an industrial scale. A method of immobilizing TiO2 within the mesoporous structure of silica has been developed at the University of Alabama. The objective of this thesis was to design and evaluate a bench-scale, continuous, photocatalytic reactor utilizing these films. This was accomplished in two phases of work: (1) batch reactions and (2) continuous reactions. The batch reactor was a one-liter standard photochemical reactor from Ace Glass. The continuous photocatalytic reactor designed for this study consisted of nine 12-inch long, 6-mm ID quartz tubes aligned around the medium-pressure, ultra-violet lamp (UV) used in the batch reactor. The tubes were coated on the inside with a thin film of mesoporous silica impregnated with TiO2 and connected in series with 6-inch pieces of Masterflex tubing. Experimental conditions were as follows: 190 ppm solutions of 2,4-dichlorophenol (2,4-DCP), UV lamp, TiO2 in either 0.05 wt% suspensions (slurry) or thin films of mesoporous silica (film); and/or 750 ppm hydrogen peroxide (H2O2). In batch and continuous experiments the UV/H2O2 and the UV/TiO2 (slurry)/H2O2 systems were the most successful with respect to the oxidation of 2,4 ? DCP. The loss of 2,4 ? DCP in continuous UV/TiO2 (film) systems was not significantly different from continuous UV only systems. However, the continuous UV/TiO2 (film)/H2O2 system degraded more 2,4 ? DCP than the systems utilizing UV light alone. The continuous reactor developed in this study showed enhanced by-product degradation using UV/TiO2 (film)/H2O2 over the UV/H2O2 system.
| Identifer | oai:union.ndltd.org:MSSTATE/oai:scholarsjunction.msstate.edu:td-5305 |
| Date | 02 August 2003 |
| Creators | Macias, Transito Lynne |
| Publisher | Scholars Junction |
| Source Sets | Mississippi State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
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