A novel chitosan/graphene oxide nanocomposite functionalized with zirconium to remove dexamethasone and ceftriaxone from aqueous solutions: Response surface methodology, isotherm, kinetic and thermodynamic

• Published in: Journal of water process engineering 2025-01, Vol.69, Article 106722
• Main Authors: Jafarzadeh, Narges, Jaafari, Jalil, Moslemzadeh, Mehrdad, Taghavi, Kamran
• Format: Article
• Language: English
• Subjects: Adsorption kinetics; Ceftriaxone; CS-GO/Zr; Dexamethasone; Thermodynamic study
• ISSN: 2214-7144; 2214-7144
• DOI: 10.1016/j.jwpe.2024.106722

The purpose of this research was to determine the effectiveness of chitosan-graphene oxide composite functionalized with zirconium (CS-GO/Zr) as a new adsorbent in removing dexamethasone (DXM) and ceftriaxone (CFX) from aqueous solutions. Operational parameters such as pH (4–10), adsorbent dose (0.1–2 g/L), drug concentration (20–80 mg/L), and solution temperature (25–45 °C) by response surface methodology (RSM) were performed based on the Box-Behnken (BBD) model. The maximum removal efficiency of DXM (96.2 %) and CFX (97.1 %) was obtained under optimum conditions near pH of 8.5 (DXM), 7.5 (CFX)and initial concentration of 45 mg/L (DXM), 20 mg/L (CFX) adsorbent dose of 1.5 g/L, and temperature of 25 °C. The absorption kinetic data of both drugs followed pseudo-second-order kinetic. The negative values of ΔG°, ΔH°, and ΔS° obtained from the thermodynamic study showed that the adsorption of pharmaceutical compounds on the composite is spontaneous, exothermic, and chemical. Regeneration tests showed that the adsorbent can be reused for 4 consecutive cycles with an efficiency of over 80 %. Based on the results, it can be concluded that CS-GO/Zr adsorbent can be used as a new adsorbent in the treatment of pharmaceutical compounds such as DXM and Ceftriaxone. [Display omitted] •Chitosan/graphene oxide nanocomposite functionalized with zirconium synthesized•The nanocomposite shows potential in the decontamination of DXM and CFX.•The removal efficiency of CS-GO/Zr to DXM and CFX reached up to 96 %.•The CS-GO/Zr nanocomposite is found to be stable and efficient for several cycles.•Excellent removal ability in presence of inorganic interfering substances