Liquid-phase adsorption of organic materials with activated carbon derived from beer lees

Three activation methods, CO2 activation, steam activation and KOH activation, were used to activate beer lees charcoal manufactured from beer lees discharged by a brewery. Liquid-phase adsorption properties of phenol, methylene blue, 1,2-dichloroethane and 1,2-dichloropropane by the resulting activated charcoal were examined. The amounts of phenol and methylene blue adsorbed were found to increase in the order CO2 activated charcoal<steam activated charcoal<KOH activated charcoal. This order coincides with the order of their pore volume of the charcoals. Phenol was adsorbed in a larger amount than methylene blue on all charcoals, probably because of its smaller molecular size. The same order of performance was found for the adsorption of 1,2-dichloroethane and 1,2-dichloropropane: CO2 activated charcoal<steam activated charcoal<KOH activated charcoal. The amount of 1,2-dichloropropane adsorbed was twice that of 1,2-dichloroethane, even though they have similar molecular sizes. This is thought to be due to higher solubility of 1,2-dichloroethane in water, which would reflect its higher affinity for water molecules and make it more difficult to be captured by adsorbent.