Kinetics, thermodynamic and chromatographic behaviour of the uranyl ions sorption from aqueous thiocyanate media onto polyurethane foams

The Performance of Different AgTiO2 Loading into Poly(3-Nitrothiophene) for Efficient Adsorption of Hazardous Brilliant Green and Crystal Violet Dyes

The in-situ polymerization technology was used to successfully produce nanostructured binary nanocomposites (NCs) made from a poly (3-nitrothiophen) matrix (P3NT) that were loaded effectively with nanoparticles (NPs) of silver titanium dioxide (AgTiO2), of varying percentages (10%, 20%, and 30%). A uniform coating of P3NT covers the AgTiO2 NPs. Various methods were performed to confirm the fabrication of the binary P3NT/AgTiO2 NCs adsorbents, such as FTIR, XRD, SEM, and EDX. Both dyes (brilliant green (B.G.) and crystal violet (C.V.)) were removed from liquid media by using the binary P3NT/AgTiO2 NCs. A range of batch adsorption studies was used to optimize various factors that impact the elimination of B.G. or C.V. dyes, including the pH, weight of the binary P3NT/AgTiO2 NC, proportion of AgTiO2 NP, time, and temperature. The pseudo-second-order kinetics ( $R^2=0.999$ ) was better adapted for the adsorption procedure’s empirical data whereby the maximum adsorption capacity of the C.V. dye was 43.10 mg/g and ( $R^2=0.996$ ) the maximum adsorption potential was 40.16 mg/g for B.G. dye, succeeded by the pseudo-second-order kinetics. Moreover, the adhesion of B.G. and C.V. pigments on the layers of NCs involves an endothermic reaction. In addition, the concocted adsorbent not only exhibited strong adsorption characteristics during four consecutive cycles but also possessed a higher potential for its reuse. According to the findings, the NCs might possibly be used as a robust and reusable adsorbent to remove B.G. and C.V. pigments from an aqueous medium.

XPS, EXAFS, and FTIR as tools to probe the unexpected adsorption-coupled reduction of U(VI) to U(V) and U(IV) on Borassus flabellifer-based adsorbents

Palm shell-based adsorbents prepared under five different thermochemical conditions and palm shell powder have been shown to be quite effective for removal of uranium from aqueous solutions. X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine structure (EXAFS), and Fourier transform infrared spectroscopy (FTIR) have been used to determine information about the speciation and binding of uranium on the adsorbents under study. Studies indicate that the uranium which is present as uranyl ion in aqueous solution is present in mixed valence states (U(IV), U(V), and U(VI)) when it is bound to the adsorbents. The mechanism of adsorption is likely to be adsorption-coupled reduction as well as complexation. Adsorption of uranium, cesium, and iron was found to be quantitative in binary as well as ternary mixtures.

The removal of some rare earth elements from their aqueous solutions on by-pass cement dust (BCD)

The sorption behavior of yttrium (Y(3+)), neodymium (Nd(3+)), gadolinium (Gd(3+)), samarium (Sm(3+)) and lutetium (Lu(3+)) from their aqueous solutions by by-pass cement dust (BCD) has been investigated using a batch technique. The sorption on BCD was studied as a function of pH, shaking time, initial concentration, mass of BCD and temperature. It was found that the sorption capacity of BCD had the order of Lu(3+) > Sm(3+) > Y(3+) > Gd(3+) ≈ Nd(3+) following Freundlich isotherm at the determined optimum conditions. The results also demonstrated that the sorption data fit well the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔH°, ΔS° and ΔG° indicated that the sorption of the investigated REEs on BCD was endothermic, favored at high temperature and spontaneous in nature.