Cd2+ ions were adsorbed onto walnut shells with an efficiency 41.9-70.4%. The effect concn. of natural sorbent, mixing time, pH, and temp. was studied. The process of Cd2+ ions sorption on the natural sorbent studied was described by the Langmuir and Freundlich models. The max. adsorption capacity of walnut shells for Cd2+ ions was 17.5 mg/g.