Sound assisted photocatalytic degradation of formaldehyde in fluidized bed reactor

Abstract

The photocatalytic degradation of formaldehyde in an acoustic fluidized bed reactor (AFBR) was investigated using Degussa P25 and N-doped TiO 2 catalyst particles as the fluidized media. The effects of the illumination time, sound pressure level, and sound frequency on the degradation rate of formaldehyde were investigated. Experimental results showed that formaldehyde can be degraded effectively by N-doped TiO 2 catalyst. Sound parameter was an important parameter in determining the degradation efficiency of formaldehyde. The degradation efficiency of formaldehyde increased with increasing sound pressure level and has a maximum value over the sound frequency at 100 Hz. The photocatalytic degradation follows the pseudo-first-order reaction kinetics with respect to the concentration of formaldehyde. The apparent first-order rate constant increased with increasing sound pressure level, as well as increased with increasing sound frequency ranging from 50 to 100 Hz, then further decreased with increasing sound frequency from 100 to 150 Hz.