Effect of OH Radicals on Formaldehyde Removal in Dielectric Barrier Discharge

Abstract

The removal of formaldehyde by dielectric barrier discharge in a coaxial cylindrical reactor has been studied at atmospheric pressure. The emission spectra of OH (A 2 Σ→X 2 Π, 0-0) emitted from the dielectric barrier discharge have been successfully recorded. The relationship between the removal efficiency of formaldehyde and the emission intensity of OH (A 2 Σ→X 2 Π, 0-0) has been investigated at different applied voltages, driving frequencies, concentrations of argon and oxygen. We find that the removal efficiency of HCHO increases when the emission intensity of OH (A 2 Σ→X 2 Π, 0-0) increases with rising applied voltage, driving frequency, and concentration of argon. However, the removal efficiency of HCHO decreases when the emission intensity of OH (A 2 Σ→X 2 Π, 0-0) decreases with an increase in the concentration of oxygen. The removal efficiency of HCHO is 93.8% in N2+HCHO mixed gas at 11.5 kV applied voltage and 9 kHz driving frequency.