Application of modified Yoon-Nelson nonlinear equation for modeling antibiotics adsorption onto a composite adsorbent

This study focuses on the adsorptive removal of metronidazole (MET) antibiotics from wastewater using a cellulose-chitosan composite (Ce-C). The composite was synthesized through an in-situ adsorption mechanism, with glutaraldehyde as a crosslinking agent. The Ce-C composite exhibited a swelling capacity of 3.2 mL/g and a BET surface area of 110.53 m 2 /g. The batch adsorption isotherms revealed a maximum monolayer adsorption capacity of 14.32 mg/g, with the Langmuir model providing the best fit. Kinetic analysis indicated that the pseudo-first-order model best described the adsorption process. The Ce-C composite also demonstrated biodegradability, with a 79.31% mass loss over 25 days, an indication of the eco-friendliness of the composite. The findings suggest that the Ce-C composite is an effective and eco-friendly adsorbent for MET removal from wastewater. • The Ce-C composite removes metronidazole effectively from wastewater. • Batch studies show a maximum adsorption capacity of 14.32 mg/g. • Langmuir isotherm model fits MET adsorption, indicating monolayer behavior. • The composite is 79.31% biodegradable within 25 days, with a 3-day half-life. • Eco-friendly Ce-C adsorbent shows strong potential for wastewater remediation.