Degradation characteristics of toxic contaminant with modified activated carbons in aqueous pulsed discharge plasma process

Activated carbons (ACs) with different textural and surface chemistry properties obtained by HNO3 oxidation, N2-thermal treatment, and aqueous non-thermal plasma treatment were studied to analyze their behaviors in degradation of toxic organic pollutant parachlorophenol (4-CP) by the pulsed discharge plasma process in aqueous solution. N2-heated AC in the 50–110 μm diameter range with a dosage of 0.5 g l−1 under any solution pH had a remarkable promoting effect on 4-CP degradation, as well as an obvious enhancement in energy efficiency for 4-CP removal. Chemical and physical actions induced by pulsed discharge non-thermal plasma (PDP) pose little negative impact on catalytic ability of plasma-treated AC. From mathematical modeling on synergic degradation of 4-CP on AC surface, N2-heated AC had a strong adsorption ability of 4-CP, including high catalytic activities for H2O2 and O3 decompositions on AC surface, resulting in more amounts of highly reactive species formed, especially ·OH radical. This would enhance degradation rate and PDP energy efficiency for 4-CP removal, and simultaneously, the AC as catalyst in PDP process was regenerated.