Influence of surface chemistry and structure of activated carbon on adsorption of fulvic acids from water solution

摘要

The adsorption of fulvic acids (FA) from aqueous solutions on activated carbon (AC) with differentncharacteristics of surface chemical state has been investigated. To characterize the adsorbabilitynof FA with complex fractional composition, a method of estimation of modified Freundlichnequation constants was employed, and “conventional component” was used to evaluate thenchange in Gibbs free adsorption energy. It has been shown that change in activated carbonnsurface energy in-homogeneity due to oxidation leads mainly to a decrease in the adsorptionnenergy of fulvic acids and to an increase of the concentration range of the conventional portionnof the low adsorbable fraction. Decrease in the adsorption energy of organic substrate may resultnin higher degree of spontaneous bioregeneration of activated carbon and hence in its longer lifenin the processes of FA solutions filtration.