Visible light photocatalytic water disinfection and its kinetics using Ag-doped titania nanoparticles

Environ Sci Pollut Res Int. 2014 Jan;21(1):740-52. doi: 10.1007/s11356-013-1980-7. Epub 2013 Jul 20.

Abstract

The UN estimated about five million deaths every year due to water-borne diseases, accounting from four billion patients. Keeping in view, the ever increasing health issues and to undermine this statistics, a reliable and sustainable water-treatment method has been developed using visible light for water treatment. titania nanoparticles (NPs) have been synthesized successfully by a more applicable method Viz: liquid impregnation (LI) method. The bacterial death rate by photocatalysis under visible light was studied by employing a typical fluorescent source and was found to follow pseudo first-order reaction kinetics. The nanoparticles were characterized using X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray spectroscopy to deduce their size range, surface morphology, and elemental compositions, respectively. Among all the prepared grades, 1% Ag-TiO2 was found to be a very effective photocatalytic agent against Escherichia coli. The resulted photoinactivated data were also evaluated by different empirical kinetic models for bacterial inactivation. Hom, Hom-power, Rational, and Selleck models were not able to explain the disinfection kinetics but modified-Hom model fitted best with the experimentally obtained data by producing a shoulder, log-linear, and a tail region.

MeSH terms

  • Catalysis
  • Coloring Agents / chemistry
  • Disinfection / methods*
  • Humans
  • Kinetics
  • Light
  • Nanoparticles / chemistry*
  • Photochemical Processes*
  • Silver / chemistry*
  • Titanium / chemistry*
  • Water Purification / methods*
  • X-Ray Diffraction

Substances

  • Coloring Agents
  • titanium dioxide
  • Silver
  • Titanium