Testing of activated carbon for water and non-volatile LNAPL quantitative determination in porous media under laboratory conditions

Activated carbon is a highly porous form of carbon, which has an exceptionally large surface area. Activated carbon material has been artificially processed as a set of plates, within which two different types of pores are present: micropores (< 2 nm) and transport pores (macropores > 50 nm and mesopores 2-50 nm). The transport pores bring molecules of different substances (organic compounds) into the micropores, which are basically the active centres where the adsorption takes place. Activated carbon, due to its high adsorption potential, is used in many applications such as air, water, wastewater or chemical purification. In this study, the pelletized activated carbon (Silcarbon SC40) was tested for water and non-volatile LNAPL (Light Non-Aqueous Phase Liquid; medicinal mineral oil used in this study) determination in a porous medium (silica sand). The experiments were carried out under controlled laboratory conditions. Three different sets of experiments were carried out: (i) the water or LNAPL adsorption from pure media (water or LNAPL liquids); (ii) the water or LNAPL adsorption from pure media (water or LNAPL vapours); (iii) water and/or LNAPL adsorption from the porous material at different sampling intervals. Furthermore, the water/LNAPL contents of the porous media were determined on the basis of the water/LNAPL contents of sampled Silcarbon SC40. The results confirmed the suitability of the Silcarbon SC40 for water/LNAPL sampling from the porous media under laboratory conditions. The method is suitable for detection of water and/or LNAPL in a liquid or gaseous phase and also for water and/or LNAPL quantitative determination. For the quantitative determination a calibration of this method would be required.