Influence of Oxygen and Dissolved Inorganic Additives on the Removal of Gaseous Acetylaldehyde by Use of a Wetted‐Wall Corona Discharge Reactor

Abstract

A cylindrical wetted-wall corona discharge reactor was used for the removal of acetaldehyde in gas mixtures of N 2 and O 2 . Gaseous acetaldehyde was removed from the gas stream by simultaneous absorption and gaseous corona reaction. The acetaldehyde absorbed in water, was decomposed by the aqueous radical, OH, produced by contact of the gas corona with the water film. There is an optimized oxygen concentration for the effective removal. When oxygen coexists in the gas mixture at 5 %, acetaldehyde was effectively removed, resulting in overall sustainable removal of acetaldehyde. However, an increase in oxygen concentration resulted in a decrease in the extent of removal, when the corona current was excessively high. This is due to corona-induced turbulence broadening the residence time distribution of gas in the reaction zone. The decompositions of absorbed acetaldehyde and TOC in water were obviously affected by the varied oxygen concentrations. Acetaldehyde was not removed in the absence of oxygen. The dissolved inorganic additives, NaOH and HCl, strongly affected the acetaldehyde absorbability into water and subsequently, the decomposition rate of the absorbed acetaldehyde.

Modeling of Experimental Treatment of Acetaldehyde-Laden Air and Phenol-Containing Water Using Corona Discharge Technique

“…In these works, the corona was directly generated in water by submerged corona spot. However, according to our previous report (23), aqueous acetaldehyde could not be decomposed in the present reactor under corona discharge in the absence of oxygen. This indicated that production of OH by radiolysis in the present reactor was negligible.…”