Porous structure and adsorption properties of natural porous coal

From the analysis of the adsorption of hexane vapour, the volumes of micro- and mesopores, half widths, and specific surface areas of mesopores of natural porous coal were calculated. The quantities of acidic and basic groups existing at the surface of the coal were determined. It was shown that a high concentration of hydrophilic sites initiates the adsorption of water molecule associates in micro- and mesopores of the coal already at the initial part of the isotherm. The role of micro- and mesopores and the chemistry of the coal surface in the adsorption of phenol, p-nitroaniline, crystalline violet and the commercial non-ionic surfactant OP-10 from aqueous solutions were discussed. A comparative analysis of the adsorptive properties of natural coal and CAD-iodine active carbon showed that natural coal is a promising material for the removal of various organic compounds from water.