Metronidazole adsorption by bio-synthesized silver-zinc ferrite nanoadsorbent in presence of chitosan from aqueous media: response surface methodology

Abstract

A novel magnetic biocomposite adsorbent, denoted as AgZnFe2O4@Ch, was utilized for the degradation of Metronidazole (MNZ) from water. Various analytical techniques, including vibrating sample magnetometer (VSM), X-ray diffraction (XRD), Brunauer–Emmett–Teller, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy (FESEM), were applied to investigate the characteristics of the magnetic biocomposite adsorbent. XRD examination confirmed the formation of spinel ferrites phases. FESEM assessment indicated a notable reduction in sample aggregation. The ferromagnetic character of the adsorbent was well demonstrated by VSM analysis. The saturation magnetization value for straightforward separating by the outside magnetic fields was 14.64 emu/g. An analytical modeling approach was used to evaluate and analyze the impacts of factors including MNZ initial concentration, temperature, contact time, adsorbent dosage, and pH. Optimized conditions involved an adsorbent dosage of 0.9 g/L, pH of 7, MNZ initial concentration of 10 mg/L, and a contact time of 50 min, resulting in a peak adsorption efficiency of 65.53% under favorable circumstances. A good degree of fit was achieved with the linear model. The experimental equilibrium data fitting to the Langmuir, Freundlich, and Temkin isotherm models demonstrates that the Langmuir model was an effective and appropriate model for evaluating adsorption. Intraparticle kinetic modeling was also shown to be better suitable for characterizing the MNZ adsorption onto the adsorbent. The thermodynamic analysis indicated that the process of MNZ adsorption by AgZnFe2O4@Ch was characterized by exothermicity and lacked spontaneity.