Removal of Sodium Dodecylbenzenesulfonate by Macroporous Adsorbent Resins

Among the surfactants used for removal of radioactive nuclides generated from nuclear decontamination, sodium dodecylbenzenesulfonate (SDBS) is frequently used. A potential environmental problem of incomplete elimination of SDBS from radioactive liquid wastes (RLWs), which contain a high concentration of SDBS and radioactive nuclides, still remains. Removal of SDBS was evaluated by adsorption using commercially available, macroporous polymer-based adsorbents, HP20 and HP2MGL, which are styrene (St)- and methyl methacrylate (MMA)-based crosslinked resin beads, respectively. The effect of the macroporosity and chemical structure of the macroporous adsorbent resins (MARs) on the adsorption behavior was investigated. HP20 did not have any functionality for adsorbing SDBS, but it showed effective adsorption toward SDBS (less than 20 min to reach 90% adsorption), because of the hydrophobic interaction between the phenyl groups in the St unit in HP20 and in the SDBS. The removal of SDBS from a mixed solution of SDBS and Cs ions was investigated to elucidate the adsorption process in an imitation of the sort of RLWs. This investigation suggests that MARs can potentially be used for the removal of SDBS not only from a SDBS solution but also from a mixed solution of SDBS and Cs ions.