Magnetically agitated photocatalytic reactor for photocatalytic oxidation of aqueous phase organic pollutants.

A magnetically agitated photocatalytic reactor (MAPR) has been developed and assessed for oxidation of phenol. The MAPR uses a titanium dioxide composite photocatalyst with a ferromagnetic barium ferrite core. The catalyst motion was controlled with a dual-component magnetic field. First, a permanent magnet above the reactor provided a static magnetic field to counteract the force of gravity, hence increasing catalyst exposure to UV. Second, an alternating magnetic field generated by a solenoid was used to agitate the catalyst, thus increasing mass transfer between pollutants and byproducts to the catalyst. Optimal performance of the MAPR was achieved with the permanent magnet present and 1 A of alternating current to the solenoid between 20 and 80 Hz. Operating with a 60-Hz signal at 1 A with the permanent magnet present and 100 mg of catalyst, the system reduced an 11 mg/L phenol concentration by97% and decreased nonpurgeable dissolved organic carbon by 93% in 7 h using three 8-W 365-nm peak UV lamps.