The effects of suspended activated carbon particles and oxygen flow through the high-voltage electrode in liquid-phase pulsed corona discharge reactors were evaluated for the degradation and removal of phenol. Experimental studies showed that phenol can be effectively degraded with a wide range of reactor conditions; however, the most efficient removal of phenol occurred when activated carbon and ferrous sulfate solutions were utilized in the liquid-phase corona reactor. The most efficient TOC removal occurred in the above conditions with the addition of oxygen flow. The oxygen gas flow leads to ozone formation, and the subsequent reactions of the dissolved ozone enhance reactions with the oxidation byproducts of phenol. The ferrous sulfate leads to Fenton's reactions from the hydrogen peroxide generated by the discharge. Through the combination of experimental measurements and a mathematical model accounting for adsorption, mass transfer, and surface reaction on the activated carbon, it was found that there is a strong possibility that the activated carbon participates in catalytic reactions with phenol and its primary byproducts.