Uranium(VI) and zirconium(IV) sorption on magnetic chitosan derivatives – effect of different functional groups on separation properties

Abstract

BACKGROUND The recovery of metal ions from aqueous solutions for environmental preservation or resource saving requires the development of new sorbents with enhanced separation properties. A new process has been designed for the functionalization of magnetic chitosan microparticles with grafting of either amidoxime (AO‐AHC) or hydrazinyl amine (HZ‐AHC). Their sorption properties have been tested for the recovery of uranium(VI) and zirconium(IV) from aqueous solutions. RESULTS A wide range of analytical tools is used for characterizing not only the chemical modifications but also the interaction mode between the sorbent and target metal ions; including elemental analysis and titration, Fourier‐transform infrared (FTIR) spectroscopy and X‐ray photoelectron spectroscopy (XPS) characterizations, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) observations, energy‐dispersive X‐ray spectroscopy (EDX) analysis and textural characterization. The optimum pH values were found in the range 4–5. The maximum sorption capacities depend on the metal and the kind of functionalization: up to 1.38 mmol U g−1 for AO‐AHC and up to 1.96 mmol Zr g−1 for HZ‐AHC. The small size of magnetic particles limits the contribution of diffusion mechanisms in the overall control of uptake kinetics and the equilibrium is reached within 40–60 min. Metal desorption is highly effective (almost quantitative over five successive cycles of sorption and desorption) using 0.3 M hydrochloric acid solutions. CONCLUSION AO‐AHC sorbent is more selective than HZ‐AHC in terms of separation of uranium(VI) from zirconium(IV), especially at pH close to 4. The results obtained in the treatment of acidic ore leachates confirm these trends. © 2019 Society of Chemical Industry

Green Synthesis of Zinc Oxide Nanoparticles (ZnO-NPs) Using Arthrospira platensis (Class: Cyanophyceae) and Evaluation of their Biomedical Activities

“…C 1s ( Figure 6 B) was split into five peaks at 284.48, 285.75, 287.9, 287.05, and 288.9 eV for C(H, C), C–N, C–O, C=O, and C–O–C, respectively [ 52 , 53 ], verifying the hydrocarbon composition produced in the medium. N 1s was deconvoluting into two peaks with low intensities at 398.2 and 399.37 eV for N (C, H) and N tert , respectively [ 53 , 54 ].…”

“…O 1s ( Figure 6 C) has more peaks, verifying the structure of the materials; ZnO was overlapped with NaO at 529.4 eV, which confirms the presence of Zn as oxides. In addition, the excess amount of Na in the materials that appeared on the overall spectra is reflected in the O 1s that have other peaks for Na KL1 at 536.75 ( Figure 6 D) [ 55 ], while the hydrocarbons peaks have appeared at 531, 532.2, and 535.3 eV for O(C, H), O=C, and C–O–C, respectively [ 33 , 52 , 55 ]. These results were elucidated also by FT-IR with the broad bands of NH overlapped with OH, C=O, NH, and C–O (see the FT-IR analysis).…”

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].…”

“…It is thus necessary decreasing the size of the particles to enhance uptake kinetics, at the expense of difficulties in practically processing the sorption operations (more specifically proceeding the solid/liquid separation after sorbent saturation). This problem can be overcome by incorporation of magnetite nanoparticles for improving the ready separation of spent sorbent from treated solution [16,48,[55][56][57][58][59] using external magnetic field.…”

Binary Pectin-Chitosan Composites for the Uptake of Lanthanum and Yttrium Species in Aqueous Media

“…However, there are environmental concerns related to production of these resins from petroleum-based products [ 3 , 8 , 9 ]. By contrast, the utilization of sustainable adsorbents from natural materials [ 10 , 11 , 12 ] offer an alternative to conventional synthetic resins.…”