Mineralization of Bacterial Cell Mass on a Photocatalytic Surface in Air

Abstract

Whole cells deposited on a titanium dioxide-coated surface have been oxidized in air to carbon dioxide via photocatalysis. This paper provides the first evidence that the organic matter in whole cells can be completely oxidized. Three experimental techniques were employed to monitor this reaction: scanning electron microscopy,14C radioisotope labeling, and batch reactor measurements. The scanning electron microscopy experiments illustrate the disappearance of Escherichia coli cell mass. The 14C radioisotope labeling experiments establish that the carbon content of E. coli is oxidized to form carbon dioxide with substantial closure of the mass balance. The batch reactor experiments corroborate the mass balance and provide a preliminary indication of the rate of the oxidation reaction. These results provide evidence that a photocatalytic surface used for disinfection can also be self-cleaning in an air−solid system.

Heat Treatment in Molecular Precursor Method for Fabricating Metal Oxide Thin Films

“…Many researchers study the fabrication and photoreactivity of Vis-responsive thin films by physical and/or chemical modification of anatase films because of the importance of Visphotoreactive materials [53][54][55][56][57][58][59][60][61]. However, there is little information on the enhancement of UV sensitivity of Vis-responsive anatase films.…”

Effect of the radiation flux on the photocatalytic inactivation of spores of Bacillus subtilis

“…Goswami et al [24] reported the total inactivation of Serratia marcescens in a photocatalytic reactor with recirculation. The photocatalytic inactivation of bioaerosols was also the subject of a handful of more recent publications [25][26][27][28][29][30][31][32][33][34][35][36][37][38]. The use of photocatalytic process to degrade spores immobilized on a TiO 2 -coated surface was first reported by Wolfrum et al [27].…”

Proposição de um reator fotocatalítico para destruição de microrganismos em ambientes interiores

“…O processo de imobilização consiste no preparo de uma suspensão contendo 12 g de TiO 2 , 4 mL de água destilada e 0,4 mL de acetilacetona (Aldrich) 14 . Esta suspensão foi homogeneizada por 10 min em banho de ultrasom e, em seguida, adicionou-se mais 25 mL de água e 0,2 mL de Triton  X-100.…”