Equilibrium, Thermodynamic, Reuse, and Selectivity Studies for the Bioadsorption of Lanthanum onto Sericin/Alginate/Poly(vinyl alcohol) Particles.
Polymers (Basel)
; 13(4)2021 Feb 19.
Article
em En
| MEDLINE
| ID: mdl-33669541
ABSTRACT
In a scenario of high demand, low availability, and high economic value, the recovery of rare-earth metals from wastewater is economically and environmentally attractive. Bioadsorption is a promising method as it offers simple design and operation. The aim of this study was to investigate lanthanum bioadsorption using a polymeric bioadsorbent of sericin/alginate/poly(vinyl alcohol)-based biocomposite. Batch system assays were performed to evaluate the equilibrium, thermodynamics, regeneration, and selectivity of bioadsorption. The maximum capture amount of lanthanum at equilibrium was 0.644 mmol/g at 328 K. The experimental equilibrium data were better fitted by Langmuir and Dubinin-Radushkevich isotherms. Ion exchange mechanism between calcium and lanthanum (23 ratio) was confirmed by bioadsorption isotherms. Thermodynamic quantities showed that the process of lanthanum bioadsorption was spontaneous (-17.586, -19.244, and -20.902 kJ/mol), endothermic (+15.372 kJ/mol), and governed by entropic changes (+110.543 J/mol·K). The reusability of particles was achieved using 0.1 mol/L HNO3/Ca(NO3)2 solution for up to five regeneration cycles. The bioadsorbent selectivity followed the order of lanthanum > cadmium > zinc > nickel. Additionally, characterization of the biocomposite prior to and post lanthanum bioadsorption showed low porosity (9.95 and 12.35%), low specific surface area (0.054 and 0.019 m2/g), amorphous character, and thermal stability at temperatures up to 473 K. This study shows that sericin/ alginate/poly(vinyl alcohol)-based biocomposites are effective in the removal and recovery of lanthanum from water.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Polymers (Basel)
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
CH
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SUIZA
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SUÍÇA
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SWITZERLAND