Technical Paper
Comparison of Nano-Particles for the Photocatalytic Destruction of Organic Pollutants for Water Recovery
2003-07-07
2003-01-2334
Photocatalysis is used to mineralize water pollutants, providing water treatment without a waste stream. This water treatment method allows for a compact reactor design (i.e., reduced Equivalent Systems Mass (ESM)) that is applicable in future NASA missions that will require water recovery. The reactor would provide a post-processing unit to remove any organic contaminants (e.g., VOCs) not removed in prior water subsystems. Several approaches to the reactor design are being explored. Titanium dioxide (TiO2) is the chosen photocatalyst based on its proven performance and non-toxicity. Because of their propensity to adsorb pollutants, silica and activated carbon are being investigated as supporting materials for the titania. Three types of particles are being tested for their ability to destroy organic contaminants: silica gel doped with titania, activated carbon coated with titania, and silica gel doped with both activated carbon and titania. Each material has certain advantages.