Adsorption of volatile organic compounds in nitrogen streams on oxidized activated carbon fibres

Viscose rayon-based activated carbon fibres (ACFs) with low and high specific surface areas were treated with conc. HNO3, 30 wt% H2O2 and air at different temperatures. The pore textures and surface chemistries of the samples were characterized by nitrogen adsorption at 77 K and X-ray photoelectron spectroscopic (XPS) methods. The adsorption of traces of volatile organic compounds (VOCs), i.e. benzene and methyl ethyl ketone (MEK), in nitrogen streams on the samples wwa measured by a gravimetric method. The results showed that the surface oxygen complexes and pore textures of all the oxidized ACFs were modified and differed depending on whether oxidation had been conducted under gaseous or solution conditions. ACFs with different specific surface areas possessed different adsorption characteristics towards VOC vapours after subjection to oxidation treatment.