AWWA WQTC69251

Silver doped TiO₂ nanoparticles (Ag/TiO₂) were synthesized by the photochemicalreduction of silver nitrate with oxalic acid and ultraviolet (UV) radiation in the presence of TiO₂ (Degussa P-25). Inactivation of Bacteriophage MS-2 by the Ag/TiO₂ nanoparticles, the parent TiO₂ material,and silver nanoparticles (nAg) were assessed in small batch systems subjected to UV-Aradiation. The viral suspensions were assayed via the double agar layer method. The resultsobtained with silver doped TiO₂ were compared with those obtained with TiO₂ alone, nAg alone,and UV-A alone to determine if the presence of Ag enhances viral inactivation by TiO₂ and if asynergism exists between the antiviral activity of nAg and that of TiO₂. Chick's law was used tomodel the inactivation kinetics. Ag/TiO₂ initially inactivated MS-2 faster than bare TiO₂, with arate constant of 0.17 s^-1 vs. 0.12 s^-1, respectively. However, a tailing effect was observed withthe Ag/TiO₂, and the inactivation rate slowed after 20 s of irradiation, corresponding toapproximately 3.5 LOG removal. nAg alone and UV-A alone were not found to significantlyinactivate MS-2, supporting the hypothesis that a synergism occurs between nAg and TiO₂ whencombined. The understanding of the inactivation mechanisms will be used for the developmentof highly efficient Ag/TiO₂ materials for virus inactivation. Includes 22 references, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2008

Number of Pages:

11

File Size:

1 file , 790 KB