Amoxicillin adsorption from aqueous solution by magnetite iron nanoparticles: molecular modelling and simulation

ABSTRACTMolecular modelling and simulation were used to examine the efficacy of iron nanoparticles (Fe3O4–NPs) in removing amoxicillin (AMX) from aqueous media and determine the optimal conditions. Fe3O4–NPs were initially ascertained using scanning electron microscopy, and Fourier transform infrared spectroscopy. The molecular optimisation modelling via DFT confirmed AMX molecule has chemical potential (–3.59), and electrophilicity index (2.14). The results established that a small chemical hardness = 3.0 eV and molecular energy gap of 6.01 eV, which makes it reactive. The molecule of the antibiotics could interact and be absorbed by the lactase enzyme. The parameters: pH (3–7), time (15–80 min), Fe3O4–NPs dosage (0.1–1.0 g/L), and antibiotic concentration (10–100 mg/L) were studied. The impact of optimum variables pH3, and dosage (0.5 g/L) for adsorption of AMX molecules onto coated Fe3O4–NPs translated to 98% efficiency at 60 mg/l of AMX and 60 min. The adsorption data fitted the Langmuir (R2: 0.9245) with minimal error metrics RMSE ≤ 1.2 when compared to the Freundlich isotherm R2 (0.88) and intraparticle diffusion model R2 (0.58). The maximum adsorption capacity of AMX to Fe3O4–NPs corresponds to 6.47 mg/g with a corresponding adsorption constant of 2.8. Furthermore, AMX adsorption onto Fe3O4–NPs followed pseudo-second-order at R2 (0.9999), with an adsorption constant (k = 3.6 × 10−2g/mg.min).KEYWORDS: Molecular modellingamoxicillinadsorptionnanoparticleskinetics Data availability statementNo data were used to support this study. All data generated or analyzed during this study are included in this article.Disclosure statementNo potential conflict of interest was reported by the author(s).