Facile Fabrication of Silver Nanoparticles Grafted with Fe3O4-Chitosan for Efficient Removal of Amoxicillin from Aqueous Solution: Application of Central Composite Design

In this study, Fe3O4 nanoparticles and chitosan along with silver nanoparticles was synthesized to apply for the rapid and simple removal of amoxicillin (AMX) from aqueous environment. The characterization of fabricated adsorbent was carried out using scanning electron microscope, Energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction analysis. Four experimental variables, including pH, contact time, adsorbent dosage, and initial AMX concentration were optimized using response surface methodology based on the central composite design. The maximum removal efficiency was obtained 89.17% with pH of 4, contact time of 40 min, adsorbent dosage of 0.4 g L-1, and initial concentration of 20 mg L-1. The effect of parameters on the removal performance was assessed using analysis of variance via the second-order polynomial model. The adsorption of AMX onto the synthesized adsorbent was more consistent with the Langmuir model with a coefficient of determination (R-2) equal to 0.9991 than with the Freundlich model (R-2 = 0.9165). The maximum adsorption capacity of the adsorbent was obtained 43.10 mg g(-1). The pseudo-second-order kinetic model represents the most adequate correlation of empirical data compared to the pseudo-first-order (R-2 = 1). The proposed adsorbent could be considered as an effective and low-cost adsorbent for the AMX removal from aqueous media.