Amoxicillin removal from water by adsorption on activated carbon of mineral sources: discussion of experimental data, mechanisms and modeling.

The use of antibiotics has increased considerably in the last decades in human medicine, as well as agriculture and animal production. Consequently, high loads of these emerging contaminants in the environment can increase antibiotic-resistant genes and the development of multi-resistant pathogenic microorganisms. This work aims to evaluate the removal of amoxicillin trihydrate in aqueous medium using mineral-activated carbon of bituminous origin as an adsorbent. The adsorbent was classified as microporous with associated mesopores, showing phenolic groups on its surface, which indicates the versatility of the adsorbent. The adsorption kinetics and isotherms were predominantly chemical. Pseudo-second-order model, as well as LDF model adjusted to the kinetic data. Sips and Langmuir isotherms adjusted to the adsorption equilibrium data. The maximum adsorptive capacity obtained experimentally was 313.30 mg g-1 at 50°C. The thermodynamic properties suggested spontaneous, monolayer, and endothermic adsorption. Overall, compared to previous works, the adsorbent proved to be a viable and promising alternative for the removal of antibiotics from water, with high adsorption capacity of amoxicillin, without being necessary to perform any prior changes to the material.