The collaboratively selective uranyl adsorption of marine fungal modification biosorbent linked by the open-chain polyether terminal with amidoxime

Abstract

To further improve the uranyl adsorption capacity and the selectivity adsorption ability of marine fungus ZZF51 from Zhanjiang sea area in China, its two new modification biosorbents (ZTBA/ZTDA) linked by the open-chain polyether terminal with two/one amidoxime unit(s) on mycelium were designed according to the synthesis process of etherification, sulfonylation, substitution, and amidoximation. By the reasonable characterization of Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TG), and scanning electron microscopy (SEM), it was confirmed that the above target materials were successfully prepared. The relevant experiments showed that both of ZTBA and ZTDA had not only the excellent uranium (VI) adsorption performance with the maximum adsorption capacity of 525.7 mg g−1 and 465.7 mg g−1, respectively, but also the better uranyl adsorption selectivity when in the simulated wastewater containing the various ions of UO2 2+, Th4+, Ba2+, Pb2+, Fe3+, Cu2+, and Ca2+. In addition, the selectivity analysis explored the longer polyether in the middle bridge and the more number of terminal amidoxime unit could synergistically improve their uranyl adsorption capacity and selectivity performance. Surely, the adsorption isotherm/kinetics models, the Gibbs free energy analysis, and the favourable reusability of the target materials were also discussed in this study in detail.