Fabrication of a porous TiO2-coated silica glass tube and its application for a handy water purification unit

Abstract

A simple, handy, reusable, and inexpensive water purification unit including a one-end sealed porous amorphous-silica (a-silica) tube coated with 2 m of porous TiO2 photocatalyst layers has been developed. Both TiO2 and a-silica layers were formed through outside vapor deposition (OVD). Raman spectrum of the porous TiO2-coated a-silica glass tube indicated that the anatase content of the TiO2 layers of the tube was estimated to be approximately 60 wt%. Developed porous TiO2-coated a-silica glass tube has been assayed for the tube filtering feature against Escherichia coli (E. coli) solution used as one of the typical bacteria size species or Qβ phage also used as typical virus size species and compared with the feature of porous a-silica tubes alone. The tubes removed E. coli completely from the aqueous suspension which contained 106 CFU/mL of E. coli without UV irradiation. The porous TiO2-coated a-silica glass tube with UV-C lamps successfully reduced the Qβ phage amount in the suspension from 109 to 103 PFU/mL. © 2014 Tsuyoshi Ochiai et al.