CHED 1117 |
| Metal modified TiO2 was investigated as a means of water disinfection using Escherichia coli as a model bacteria. Pd modified TiO2 was found to work many times faster than Pt, V, and Ag/AgBr modified TiO2. Pd/TiO2 was also active in the absence of light; therefore, an alternative mechanism was investigated. It was found that the catalyst does not work more than once, unless exposed to air for a period of time prior to its re-use. Also, sodium thiosulfate was used as a sacrificial electron donor to probe the presence of oxidizing species in the solution. The use of the electron donor drastically inhibited bactericidal activity, indicating the presence of strongly oxidizing species. It is proposed that the reduction of Pd2+ on the surface of the samples resulted in the formation of Cl2 in solution. The Cl 2 is postulated to be the source of the bactericidal properties of Pd/TiO2. |
|
Undergraduate Research Poster Session: Environmental Chemistry
2:00 PM-4:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster
Division of Chemical Education |