Preparation and Characterization of Chitosan-Modified Bentonite Hydrogels and Application for Tetracycline Adsorption from Aqueous Solution

Autor: Xuebai Guo, Zhenjun Wu, Zheng Lu, Zelong Wang, Shunyi Li, Freeman Madhau, Ting Guo, Rongqican Huo
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Gels, Vol 10, Iss 8, p 503 (2024)
Druh dokumentu: article
ISSN: 10080503
2310-2861
DOI: 10.3390/gels10080503
Popis: The “sol–gel method” was used to prepare spherical chitosan-modified bentonite (SCB) hydrogels in this study. The SCB hydrogels were characterized and used as sorbents to remove tetracycline (TC) from aqueous solutions. The adsorbents were characterized by SEM, XRD, FTIR, TG, and BET techniques. Various characterization results showed that the SCB adsorbent had fewer surface pores and a specific surface area that was 96.6% lower than the powder, but the layered mesoporous structure of bentonite remained unchanged. The adsorption process fit to both the Freundlich model and the pseudo-second-order kinetic model showed that it was a non-monolayer chemical adsorption process affected by intra-particle diffusion. The maximum monolayer adsorption capacity determined by the Langmuir model was 39.49 mg/g. Thermodynamic parameters indicated that adsorption was a spontaneous, endothermic, and entropy-increasing process. In addition, solid–liquid separation was easy with the SCB adsorbent, providing important reference information for the synthesis of SCB as a novel and promising adsorbent for the removal of antibiotics from wastewater at the industrial level.
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