Improving cesium removal to clean-up the contaminated water using modified conjugate material

Abstract

Crown ether based conjugate material was enabling the high functionality for stable complexation mechanism with cesium (Cs) and attracted the scientific community for potential real radioactive contaminated water treatment. This study was focused on ligand anchored conjugate material for radioactive Cs disposal based on adsorption techniques from nuclear liquid waste in Fukushima with high selectivity. A macrocyclic ligand of acetyl dibenzo-20-crown-6-ethers (AcDB20C6) was synthesized and directly embedded onto mesoporous inorganic silica. The Cs adsorption behavior was carried out with batch equilibrium techniques. The affecting experimental parameters such as solution pH, contact time, initial Cs concentration and competitive adsorption of Na and K ion concentrations were measured and optimized systematically. The sensitive pH range for high Cs removal was with broad range of 5.5–9.0, and the maximum adsorption capacity was 65.06 mg/g by the material at pH 7.0. The results clarified that conjugate material was high selectivity towards Cs even in the presence of a high level of Na and K ions rather than inorganic adsorbent because of the possible Cs-π interaction of the benzene ring from the crown ether ligand. The material was successfully investigated for radioactive Cs disposal for the potential treatment in Fukushima in the connection of in nuclear contaminated water treatment. The adsorbed Cs was desorbed with the eluent of 0.20 M HCl and then simultaneously regenerated at the same into the initial form for the next disposal operation after washing with water. The conjugate material was kept high functionality even in several cycles during adsorption–elution–regeneration processes. Then the proposed material could be used as promising material for selective radioactive Cs disposal from contaminated water in Fukushima, Japan.