This article describes the results of a systematic study of rate and equilibrium phenomena associated with the adsorption of p-dichlorobenzene (PDB) individually and in the presence of background humic acids. A toxic compound, PDB has been detected in drinking waters and groundwaters and is included in the list of priority pollutants. The Michigan Adsorption Design and Applications Model (MADAM) is used for simulation and prediction of PDB adsorption under conditions approximating those encountered in water treatment practice. Results suggest that activated carbon adsorption may offer an attractive means for removal of PDB and similar compounds. Furthermore,the effectiveness of activated carbon for PDB removal appears not to be adversely affected by background organics such as humic acids. PDB adsorption by carbon appears readily reversible, suggesting that uptake from solution occurs primarily because of relatively weak van der Waals' attraction forces. In addition, the MADAM model was generally able to simulate and predict the performance of fixed-bed adsorbers for removal of PDB. Includes 9 references, figures.