The effect of carbonaceous adsorbents modification on their adsorption parameters for phenol removal is studied. The phenol adsorption on initial and modified adsorbents was investigated both under static and dynamic conditions. It is shown that the heat treatment of peat allows to prepare macroporous adsorbents, whereas the peat modification with the cationic polymeric flocculant KF-91 results in increasing the adsorption limit by 2.5-3 times. It is noted that the maximum adsorption capacity was demonstrated for the coal of SKT rank.