Stabilized sewage sludge from a Polish dairy wastewater treatment plant was used as a sorbent of (P-ClC6H4)(2)CHCCl3 and (p-ClC6H4)(2)C:CCl2 pesticides. Freundlich, Langmuir, BET and Dubinin-Raduszkiewicz adsorption isotherms were detd. under static conditions (pesticide equil. concn. up to 0.07 mg/L, adsorption up to 160 mg/g). A good fitting of all isotherms detd. was obsd. The studied sludge was recommended as barrier layer for Ci-contg. org. pesticides.