Efficient and rapid capture of uranium(VI) in wastewater via multi-amine modified β-cyclodextrin porous polymer

It is a quite important to ensure the safety and sustainable development of nuclear energy for the treatment of radioactive wastewater. To treat radioactive wastewater efficiently and rapidly, two multi-amine β-cyclodextrin polymers (diethylenetriamine β-cyclodextrin polymer (DETA-TFCDP) and triethylenetetramine β-cyclodextrin polymer (TETA-TFCDP)) were prepared and applied to capture uranium. Results exhibited that DETA-TFCDP and TETA-TFCDP displayed the advantages of high adsorption amounts (612.2 and 628.2 mg·g–1, respectively) and rapid adsorption rate, which can reach (88±1)% of their equilibrium adsorption amount in 10 min. Moreover, the adsorbent processes of DETA-TFCDP and TETA-TFCDP on uranium(VI) followed the Langmuir model and pseudo-second-order model, stating they were mainly chemisorption and self-endothermic. Besides, TETA-TFCDP also showed excellent selectivity in the presence of seven competing cations and could be effectively reused 5 times via Na2CO3 as the desorption reagent. Meanwhile, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy illustrated that the enriched multi-amine groups and oxygen-containing functional groups on the surface of TETA-TFCDP were the main active sites for capturing uranium(VI). Hence, multi-amine β-cyclodextrin polymers are a highly efficient, rapid, and promising adsorbent for capturing uranium(VI) from radioactive wastewater.