Functionalization and Application of Carboxylated Multi-Walled Carbon Nanotubes for Adsorptive Removal of Penicillin G from Aqueous Solution

Background: The presence of pharmaceutical contaminants such as Penicillin G in aquatic environments poses significant ecological and health risks. This study aimed to synthesize carboxyl-functionalized multi-walled carbon nanotubes (MWCNT-COOH) and evaluate their efficiency in removing Penicillin G from aqueous solutions through adsorption.Methods: This experimental study was conducted at the Toxicology and Pharmacology, Faculty of Pharmacy, Mazandaran University of Medical Sciences. MWCNT-COOH was synthesized via a diazonium-based surface modification and characterized using FTIR and SEM. Batch adsorption experiments were carried out to investigate the effects of pH, contact time, initial concentration, adsorbent dosage, and temperature. Adsorption data were fitted to Langmuir, Freundlich, and Temkin isotherms, and kinetics were assessed using pseudo-first-order and pseudo-second-order models.Results: The synthesized MWCNT-COOH showed efficient adsorption performance, with maximum removal observed at pH ۸ and equilibrium achieved within ۸۰ minutes. The Langmuir model best described the isotherm data, with a maximum monolayer adsorption capacity of ۱۱۸.۱۷ mg/g. Kinetic analysis revealed that the process followed a pseudo-second-order model, indicating chemisorption. Adsorption efficiency decreased with increasing temperature, suggesting an exothermic mechanism.Conclusion: MWCNT-COOH prepared via surface functionalization showed excellent potential as an adsorbent for Penicillin G removal. The findings support the use of functionalized carbon nanomaterials for the treatment of antibiotic-contaminated water.

کلیدواژه ها:

Penicillin G ، Multi-walled carbon nanotubes (MWCNTs) ، adsorption ، Isotherm models ، Kinetic modeling ، Thermodynamic analysis ، wastewater treatment