Adsorption of phenol and reactive dyes from aqueous solution on carbon cryogel microspheres with controlled porous structure

The application of carbon cryogel microspheres (CC microspheres) with controlled porous structure as adsorbents of phenol and reactive dyes (Black 5 and Red E) from aqueous solutions was studied. Adsorption experiments using a commercial activated carbon were also conducted for the purpose of comparison. CC microspheres with varying mesoporosity could be produced by altering the amount of basic catalyst used in the inverse emulsion polymerization of resorcinol with formaldehyde. In the adsorption of phenol, the activated carbon showed much higher adsorption amount compared with the CC microspheres. The amount of adsorbed phenol on CC microspheres was almost same irrespective of the size of the mesopores. In contrast, the amounts of adsorbed Black 5 and Red E on CC microspheres were larger than those on activated carbon. The adsorption capacities of CC microspheres for Black 5 and Red E increased with an increase in the size of the mesopores of the adsorbents. This study confirmed that CC microspheres with a developed and controlled mesoporosity are useful adsorbents for the selective removal of large organic molecules from water.