Milos Emilia; Cocheci Laura; Popa Adriana; Filimon Anca; Lupa Lavinia: The use of hybrid materials (Mg3Al-LDH/ionic liquids/chitosan) in the recovery process of Pd ions from aqueous solutions.
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In this work, studies were carried out on the recovery of palladium ions from aqueous solutions by adsorption on hybrid materials, Mg 3 Al-LDH/ionic liquids/ chitosan. To synthesize the double layered hydroxide, Mg 3 Al, the coprecipitation method at low supersaturation was used , using as sources of metal ions Mg(NO 3 ) 2 ·6H 2 O and Al(NO ·9H 2 O) , the ratio between the cations being Mg 2+ /Al 3+ =3:1. Regarding obtaining the functionalized compound with 10% ionic liquid, the same method was used, specifying that the mixture of nitrates was added, dropwise, to the ionic liquid solution, dissolved in acetone, the ratio between them being ionic liquid:acetone =1g/50mL. To maintain the pH in the desired range, a NaOH solution was used , prepared from boiled and cooled water, and the mechanical strength of the obtained adsorbents (Mg 3 Al and Mg 3 Al-IL) was increased by dispersing them in chitosan solution dissolved in 1% acetic acid, obtaining the hybrid materials: Chitosan / Mg 3 Al, Chitosan / Mg 3 Al-IL, Chitosan / Mg 3 Al/IL. The hybrid materials were characterized by X-ray diffraction, Fourier transform IR spectroscopy (FTIR) and scanning electron microscopy (SEM) coupled with an energy dispersive X-ray detector (EDX). The X-ray spectrum of the Mg 3 Al sample, obtained by co -precipitation at low supersaturation, suggests a good compatibility of chitosan with LDH, which leads to the formation of porous networks. For all studied materials and for all initial palladium concentrations, the adsorption capacity of the studied materials increases with increasing contact time, up to 60 minutes, after which it remains practically constant. To clarify the palladium adsorption mechanism on the three studied materials, three kinetic models were used: the pseudo-first-order kinetic model, the pseudo-second-order kinetic model and the intraparticle diffusion model (Weber-Morris), the pseudo-order kinetic model second order being the one that confirmed, the best, the experimental data, value of the correlation coefficients R 2 , being approximately 1, regardless of the working temperature. In order to study the nature of the palladium adsorption process on the studied materials, the thermodynamic parameters were calculated: enthalpy, entropy, Gibbs free energy, activation energy, the results confirming that the reactions are spontaneous, endothermic, and the palladium adsorption process on the studied materials corresponds a chemosorption. In order to identify the mechanism of the process and evaluate, theoretically, the adsorption capacity at equilibrium, the Langmuir, Freundlich , Temkin and Redlich-Peterson isotherms were used , finding that the Langmuir isotherm best describes the palladium adsorption process on synthesized materials. It is recommended to add the ionic liquid in the synthesis process of the hybrid material, not in the synthesis process of the LDH.
| Mű típusa: | Konferencia vagy workshop anyag |
|---|---|
| Befoglaló folyóirat/kiadvány címe: | Proceedings of the International Symposium on Analytical and Environmental Problems |
| Dátum: | 2024 |
| Kötet: | 30 |
| ISBN: | 978-963-688-009-5 |
| Oldalak: | pp. 124-127 |
| Nyelv: | angol |
| Kiadó: | University of Szeged |
| Kiadás helye: | Szeged |
| Konferencia neve: | 30th International Symposium on Analytical and Environmental Problems |
| Konferencia típusa: | Konferencia |
| Helyszin: | Szeged |
| Befoglaló mű URL: | https://acta.bibl.u-szeged.hu/85607/ |
| Kulcsszavak: | Környezetkémia, Hibrid anyagok, Kitozán |
| Megjegyzések: | Bibliogr.: p. 126-127. ; összefoglalás angol nyelven |
| Szakterület: | 01. Természettudományok 01. Természettudományok > 01.04. Kémiai tudományok |
| Feltöltés dátuma: | 2024. nov. 21. 13:20 |
| Utolsó módosítás: | 2024. nov. 21. 13:20 |
| URI: | http://acta.bibl.u-szeged.hu/id/eprint/85687 |
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