A representative reactor for treatment of air by use of photocatalytic/magnetic composite particles (see Figure 2) includes a fluidized bed loaded with the particles. An ultraviolet lamp provides the excitatory photons needed for photocatalysis. An electromagnet coil generates a magnetic field to control the movement of the composite particles.

Figure 2. A Fluidized Bed containing photocatalytic/magnetic composite particles is illuminated byultraviolet light. The bed is agitated by the flow of polluted air to be treated and by an alternatingmagnetic field.
In operation, polluted air or water enters at the bottom and flows upward through the fluidized bed. The polluted fluid agitates, and mixes with, the composite particles in the bed. Additional agitation is provided by an alternating magnetic field generated by supplying alternating current to the electromagnet coil. The agitation enhances the fluidization, and is almost entirely responsible for fluidization when the flow is not rapid enough to fluidize the particles sufficiently. The agitation promotes the exposure of the photocatalyst particles to ultraviolet light from the lamp and increases the rate of generation of hydroxyl radicals, which react with the pollutants. The exhaust flowing from the top of the reactor consists of purified fluid.

This work was done by Chang-Yu Wu, Yogi Goswami, Charles Garretson, Jean Andino, and David Mazyck of the University of Florida for Johnson Space Center. For further information, contact the Johnson Commercial Technology Office at (281) 483-3809. In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to: University of Florida, Environmental Engineering Black Hall Gainesville, FL 32611 Refer to MSC-23829, volume and number of this NASA Tech Briefs issue, and the page number.