Adsorption and Recovery of Ionic Surfactants by beta-Cyclodextrin Polymer

The adsorption and recovery of ionic surfactants, such as dodecylbenzenesulfonic acid (DBS) and benzalkonium chloride (BKC), from an aqueous solution were studied using the beta-cyclodextrin polymer (beta-CDP). BKC always demonstrated a higher adsorption efficiency than DBS in batch tests, isotherms, and column tests. The adsorption characteristics of the surfactants seemed to be caused by inclusion into beta-CD, and they were easily determined using the Langmuir adsorption isotherm. Furthermore, the surfactants adsorbed by beta-CDP were easily released by shaking it with a mixture of water and methanol. Recovery efficiency was dependent on the mixture ratio of the solvent, and regenerated beta-CDP was reusable as an adsorbent.