PHOTOSPHERES® are hollow glass microspheres coated with photocatalytic titanium dioxide (TiO2).
In the presence of light in the near UV region, titanium dioxide generates reactive oxygen species and hydroxyl radicals capable of breaking down many organic and inorganic pollutants in wastewater, as well as destroying micro-organisms. However, TiO2 nanopowders used for this purpose are difficult to recover from treated wastewater by conventional, high throughput filtration techniques.
Our PHOTOSPHERES provide a buoyant, filterable and reusable alternative to solid TiO2 nanoparticles for photocatalytic water treatment. With a mean particle diameter of 45 microns, PHOTOSPHERES represent the optimised handling and activity solution between the high surface areas offered by TiO2 nanoparticles, and the low surface areas of TiO2-coated panels and piping.
PHOTOSPHERES can be used in enclosed, artifically illuminated reactor formats using UV light sources. Their buoyancy also enables application in open water systems, such as tanks, ponds and lakes, where solar UV wavelengths stimulate the photocatalytic activity.
PHOTOSPHERES show excellent photocatalytic activity against a range of water industry relevant organic pollutants and have also been demonstrated to be effective in reducing gaseous pollutants.
The titanium dioxide coating on PHOTOSPHERES is continuous, smooth and robust and does not shed into the treated water.
The benefits of PHOTOSPHERES
High photocatalytic activity
PHOTOSPHERES have also shown high photocatalytic activity against humic acids, NOx gases and other substrates.
Ease of Collection
Stage 1 - PHOTOSPHERES are added into polluted water.
Stage 2 - Agitation is achieved by air bubbling and UV provided by sunlight.
Stage 3 - Allowing the liquid to settle brings the PHOTOSPHERES to the surface.
Stage 4 - The clean water is drained leaving the PHOTOSPHERES ready to be reused.