Preparation of tannin-immobilized gelatin/PVA nanofiber band for extraction of uranium (VI) from simulated seawater

A novel gelatin/PVA composite nanofiber band loaded with bayberry tannin (GPNB-BT) was prepared by electrostatic spinning and crosslinking for extraction of uranium (VI) from simulated seawater. The influential factors of tannin loaded on the nanofiber band were investigated in detail. Surface morphology and fiber diameter of GPNB-BT were studied by Scanning Electron Microscopy (SEM). Functional groups of GPNB-BT were investigated by Fourier Transform Infrared Spectrometer (FTIR). The adsorption process and mechanism of uranium on GPNB-BT was characterized by Energy Dispersive X-ray (EDX) and X-ray Photoelectron Spectroscopy (XPS). The results revealed that the BT had been stably solidified on the GPNB. Compared with other tannin-immobilized membranes, the nano-network structure of GPNB-BT with 200-400 nm diameter of fibers can promote solidification of tannins and improve adsorption capacity of GPNB-BT for uranium. The maximum adsorption capacity of the GPNB-BT for uranium is 170 mg/g at the optimal pH of 5.5 in 80 mg/L of initial uranium concentration and 1.4 μg/g even at extremely low initial concentration of 3 μg/L in the simulated seawater for 24 h. The GPNB-BT with good hydraulic properties, floatability and adsorption capacity for uranium is expected to be widely used in separation and enrichment of uranium in seawater and radioactive waste water.