Surface modification of a granular activated carbon by dielectric barrier discharge plasma and its effects on pentachlorophenol adsorption

The surface properties of a granular activated carbon (GAC) were modified by dielectric barrier discharge (DBD) plasma to enhance its adsorption capacity to pentachlorophenol (PCP). Surface characteristics and adsorption capacity of GAC before and after DBD plasma modification were investigated. Results showed that the surface of GAC after plasma modification, especially N2 plasma, became smoother and the particulates on virgin GAC's surface were eliminated due to deposit effect of plasma. The N2 plasma modification reduced the specific surface area and surface oxygen-containing functional groups of GAC. In contrast, O2 plasma modification increased the specific surface area and introduced oxygen-containing groups.