Oxidation of adsorbed toluene was investigated in a dielectric barrier discharge reactor at atmospheric pressure coupled with Ag-Mn/gamma-Al2O3 catalysts. Gas flow-through and gas circulation systems were compared in the same reactor with the same operating conditions. After 90 min of plasma treatment, the mineralization of adsorbed toluene reached 68% in the O-2 flow-through system with some emission of desorbed toluene. For the O-2 circulation system, the mineralization of adsorbed toluene increased to 78% without any emission of desorbed toluene. Furthermore, compared to the gas flow-through system, the CO2 selectivity in the gas circulation system was improved in both air and oxygen plasma. Moreover, the circulation system was more efficient than the gas flow-through system for O-3 decomposition, resulting in better mineralization of adsorbed toluene and CO2 selectivity. (C) 2016 Elsevier B.V. All rights reserved.