A comparison. of phenol and 4-chlorophenol adsorption in aqueous solution on mineral activated carbon columns with different particle size. (1.3, 1.7, 2.3, 2.9, and 3.6 mm) was studied. The percentage saturation values of the columns at the break point were evaluated for carbon columns for the removal of phenol and 4-chlorophenol. It was concluded that phenol and 4-chlorophenol retention and the carbon saturation percentage in column systems depended on the pore volume and surface area of the mineral activated carbon.