Synthesis and selective Au(III) adsorption properties of poly(2-aminothiophenol) chelating polymer: equilibrium, kinetics and thermodynamics

ERİM Ü. C., Gülfen M., AYDIN A.

International Journal of Environmental Science and Technology, 2024 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1007/s13762-024-05942-9
  • Dergi Adı: International Journal of Environmental Science and Technology
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Agricultural & Environmental Science Database, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), Biotechnology Research Abstracts, CAB Abstracts, Compendex, Environment Index, Geobase, INSPEC, Pollution Abstracts, Veterinary Science Database
  • Anahtar Kelimeler: Adsorption, Au(III), Chelating polymer, Poly(2-aminothiophenol)
  • İstanbul Medipol Üniversitesi Adresli: Evet

Özet

This study focuses on evaluating the selective adsorption of Au(III) ions utilizing a chelating polymer called poly(2-aminothiophenol) (p-ATP). The p-ATP polymer was synthesized by oxidation of 2-aminothiophenol with ammonium peroxydisulfate (APS). The synthesized polymer was analyzed by FT-IR, thermal analysis, and SEM/EDS analyses. The adsorption characteristics of the material were evaluated by assessing the effects of acidity, initial Au(III) ion concentration, and adsorption temperature employing a one-factor-at-a-time (OFAT) approach to determine the ideal adsorption environment. Our findings revealed that the optimized acidity of the solution for Au(III) adsorption was 3 M HCl and the adsorption capacity of Au(III) on the p-ATP polymer was 41.67 mg/g. The adsorption data accommodated to the Langmuir isotherm more efficiently and the adsorption kinetics fitted to kinetic model of pseudo-second-order. The ΔG° values were − 1809.5, − 3203.6, − 4549.8 and − 5648.2 kJ/mol at 25, 35, 45 and 55 °C, respectively, where negative values represent that the Au(III) adsorption on the p-ATP was feasible and spontaneous. The enthalpy, the entropy and the activation energy for the Au(III) adsorption were 36.548 kJ/mol, 128.85 J/mol and 43.576 kJ/mol, respectively. The adsorption of Au(III) on the p-ATP was an endothermic process governed by ionic interactions and chelating mechanisms. In the Au(III) adsorption, ionic interactions are more effective. Finally, the selective adsorption of Au(III) ions with Fe(III), Ni(II) and Cu(II) ions was investigated. This study explains that p-ATP polymer can be used efficiently as an adsorbent to separate and recover the Au(III) ions from these ions in aqueous media.