Properties of diclofenac sodium sorption onto natural zeolite modified with cetylpyridinium chloride

▶ The modification of clinoptilolite with cetylpyridinium chloride is performed. ▶ The sorbed surfactant forms an organic layer without changing the zeolite structure. ▶ The surfactant molecules associate to produce aggregates of different shape. ▶ Modified zeolites are effective in sorption of diclofenac sodium as a model drug. ▶ Adsorption and partitioning of diclofenac sodium take place simultaneously.