Adsorptive removal of amoxicillin from wastewater using wheat grains: equilibrium, kinetic, thermodynamic studies and mass transfer

AbstractWheat grains are natural products which grow in the north of Algeria. In this study, they were used as adsorbent to remove amoxicillin antibiotic from wastewater. Adsorption isotherm of amoxicillin on both crude and modified wheat grains with 20% tartaric acid was investigated in batch tests. A model was developed regarding both the kinetic partitioning and the mechanism governing the forward transfer of amoxicillin. Results were interpreted in terms of a two-film theory for flat interface. The percentage of maximum adsorption capacity of amoxicillin was found to be 84% for the following optimal conditions: amoxicillin concentration of 4 mg/L, 5 min contact time, pH 7, temperature 25°C, and 0.24 g/L initial amoxicillin concentration and 150 μg particle size. The pseudo-first-order, pseudo-second-order kinetic models and the intraparticle diffusion model were used to describe the kinetic data, and the rate constants were evaluated. It was found that the pseudo-second-order model provides the most a...