Regeneration of activated carbon saturated with odors by non-thermal plasma

• It is a novel, efficient alternative process for odor-saturated AC regeneration.
• Sustainable high regeneration efficiency was obtained in successive regeneration cycles.
• DBD improved structural properties and surface chemistry of AC surface.

The dielectric barrier discharge (DBD) regeneration process of an activated carbon (AC) saturated with dimethyl sulfide was studied on a laboratory scale. The results showed sustainable high regeneration efficiency (RE) (>90%) in successive regeneration cycles (10 cycles). Energy density, humidity and oxygen content were key factors for DBD system, with optimum conditions of 761 J L−1, 0–1 vol% and 5%, respectively. The high efficiency was likely attributed to the improvement of structure and surface properties of AC by DBD. After the first regeneration, surface area, micropore volume and total pore volume of AC increased by 8%, 23% and 15% respectively, while average pore size decreased by 9.5%. The number of carboxylic groups doubled (from 0.22 to 0.48 mmol g−1) while that of phenolic groups remarkably decreased (from 0.48 to 0.26 mmol g−1) after successive regeneration cycles, which helped to maintain high RE. The results suggested DBD as a novel, efficient alternative process for odor-saturated AC regeneration.