Simultaneous purification of contaminated gas and water by using a cylindrical wetted-wall corona discharge reactor was proposed in this work. Gaseous acetaldehyde and aqueous phenol were chosen as target compounds. The gaseous acetaldehyde was continuously removed from gas stream by absorption into the aqueous phenol solution used for making a wetted-wall. Aqueous phenol and the absorbed acetaldehyde in water were effectively degraded by aqueous radicals, OH, produced by direct contact of gaseous corona with the interfacial water. In addition, ozone partly contributed to decompositions of phenol and some byproducts. The experimental results show that gaseous acetaldehyde can be completely removed from gas mixture when its inlet concentration was in a range of 30 to 200 ppm since decomposition of aqueous acetaldehyde can sustain the absorption of acetaldehyde. This concentration range of acetaldehyde scarcely affected the decomposition of phenol. However, decomposition of total organic carbon (TOC) in water was strongly attenuated when the acetaldehyde concentration is higher than 100 ppm. The influence of the solution pH ranging from 2 to 13 was also investigated.