Kinetics of adsorption of water-soluble dyes on activated carbons

We have investigated the kinetics of adsorption of anionic (methyl orange, acid orange, congo red) and cationic (methylene-blue, crystalline violet) dyes from aqueous solutions on activated carbons BAU-A, Filtrasorb 300, and Aquasorb 2000. It has been found that the kinetic curves of adsorption of the dyes may have a smooth or stepwise look depending on the nature of a dye or adsorbent. We have considered the possibility of using kinetic equations of the pseudofirst and pseudosecond order for describing the adsorption process.