Adsorption characteristics of methyl mercaptan, dimethyl disulfide, and trimethylamine on coconut-based activated carbons modified with acid and base

The influence of surface modification of activated carbon on the adsorption of methyl mercaptan (MM), dimethyl disulfide (DMDS), and trimethylamine (TMA) was investigated by treatments with 1N-HNO3 solution and 1N-NaOH solution. The surface modifications changed the concentrations of functional groups on the surface of activated carbon. Also, the surface modifications changed breakthrough time and equilibrium adsorption capacity of MM, DMDS, and TMA. The adsorption capacities of MM and DMDS were increased by acid treatment, but decreased by base treatment. On the other hand, the adsorption capacity of TMA was decreased by both acid and base treatments. But the difference ranges of equilibrium adsorption capacities according to acidity and basicity of the surface were relatively small.