Synergistic effect of PVP/chitosan/ZnFe₂O₄-polymer composite against amoxicillin: batch and fixed-bed adsorptive applications

Antibiotics in water are upcoming hazard that many are avoiding. Traditional adsorbents are incompetent in removing this class of contaminants. Thus, we aimed to eliminate most commonly used antibiotic, amoxicillin (AMX) from its solution using biodegradable polymer composite labelled as PCZF (polyvinylpyrrolidone/chitosan/ZnFe₂O₄). The material characterization was done by using FT–IR, SEM–EDX, Zeta-seizer, BET, XRD and VSM techniques. Batch and column studies were employed to test the economic utility of the prepared composite. Later, Langmuir, Freundlich and Temkin isotherm models were used to correlate the adsorption equilibrium data. The maximum adsorption capacity was attained up to 384.6 mg/g and 218.9 mg/g in batch and column studies, respectively. Kinetic and thermodynamic factors were also studied. As outcomes, Freundlich model was best fitted to the experimental data (R² = 0.999) and pseudo-second-order rate kinetics (R² = 0.999) were followed. In column studies, the flow rate was varied and with the increase in flow rate, breakthrough increased but the saturation time (C_t/C_o = 0.95) decreased. Fixed-bed kinetic model analysis using Thomas and Yoon–Nelson models was performed as well.