Adsorption of Low-Concentration Uranyl Ion by Amidoxime Polyacrylonitrile Fibers

Abstract

Amidoxime polyacrylonitrile fibers (PAO fibers) were prepared with polyacrylonitrile fibers (PAN fibers) and hydroxylamine hydrochloride through a heterogeneous reaction, which were used for low-concentration uranyl ion adsorption (under 1 mg/L). The as-prepared PAO fibers were characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), thermalgravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) measurements. Batch adsorption experiments were conducted to explore the best adsorbent concentration, pH, contact time, and temperature. When the adsorbent concentration reaches 0.1 g/L to dispose of a uranium solution of 100 μg/L, the equilibrium concentration can be decreased under 10 μg/L. The optimum pH for this adsorption experiment is 5.0, and the adsorption can reach equilibrium in 8 h under 298 K. The adsorption process fit well with the intraparticle diffusion model and pseudo-second-order model. In addition, Langmuir, Freundlich, Temkin, and Dubinin−Radushkevich (D-R) models were used to explain the adsorption thermodynamic process. The adsorption process is spontaneous and endothermic.

Phosphorylation of Guar Gum/Magnetite/Chitosan Nanocomposites for Uranium (VI) Sorption and Antibacterial Applications

“…(a) Amidoxime groups immobilized on synthetic resins [12][13][14], metal-organic frameworks [15], or bio-based composites [16,17] (b) Sulfonic acid-bearing materials [18][19][20], (c) Quaternary ammonium-based sorbents [21][22][23], (d) Iminodiacetic acid-bearing groups [24].…”

Facile construction of Fe, N and P co-doped carbon spheres by carbothermal strategy for the adsorption and reduction of U(vi)

“…As shown in Fig. 1b, the typical absorption peaks appeared at 2243 cm À1 (C^N) and 1451 cm À1 [(CH 2 ) n ], 32 conrming the successful fabrication of PAN. However, the absorption peak of C^N disappeared from the Fe/P-CN precursors, and the stretching vibration of the -CH 2group was retained at 2923 and 2850 cm À1 , indicating that C^N participates in the hydrolysis and graing reactions.…”

Rational Synthesis of Polyamidoxime/Polydopamine-Decorated Graphene Oxide Composites for Efficient Uranium(VI) Removal from Mine Radioactive Wastewater

“…The ability to adsorb U(VI) decreased with the increase of percentage of PAO during the synthesis of GO/PDA/PAO, and the reason for this may be that more PAO crowded on the GO surface, resulting in the decease of active adsorption sites. 34 The maximum adsorption capacity of GO/PDA/PAO-0.2 is 240.9 mg/g at pH 6.0. In addition, we also studied the effect of ionic strength on the adsorption at pH 6.0.…”

“…In addition, the adsorption capacity of GO/PDA/PAO has the following sequence: GO/PDA/PAO-0.2 > GO/PDA/PAO-0.5 > GO/PDA/PAO-1. The ability to adsorb U­(VI) decreased with the increase of percentage of PAO during the synthesis of GO/PDA/PAO, and the reason for this may be that more PAO crowded on the GO surface, resulting in the decease of active adsorption sites . The maximum adsorption capacity of GO/PDA/PAO-0.2 is 240.9 mg/g at pH 6.0.…”