Mechanistic insight into cefuroxime sodium (CXM) by sepiolite-rich dolomite.

This study explored cefuroxime sodium (CXM) adsorption on sepiolite-rich dolomite, assessing the impact of various conditions like pH, contact time, temperature, and initial CXM concentration. The research utilized data mining, kinetic and isotherm models, and analytical techniques such as FTIR, SEM, and EDX to understand the adsorption mechanism and behavior. Findings indicated that pH significantly influenced CXM adsorption, with the highest efficiency at pH 5. Additionally, the adsorption kinetics were consistent with a pseudo-first-order model, showing that adsorption was rapid and cooperative and reached equilibrium within 60 minutes, while the Freundlich isotherm model best described the adsorption isotherm. The adsorption mechanism was mainly governed by the electrostatic attraction, ion exchange, and pore-filling processes, influenced by the adsorbent's surface heterogeneity and texture characteristics, the adsorbate functional groups, and the bulk solution. Thermodynamic parameters revealed the adsorption to be spontaneous, exothermic, and entropy-driven, suggesting a predominantly physical process. While the presence of negative ΔG values showed that adsorption preferred low temperatures, the presence of a positive ΔS value showed increased randomness at the solid-liquid interface during adsorption. SEM and FTIR results confirmed the changes in the sepiolite-rich dolomite's surface properties and functional groups after CXM adsorption. EDX analysis revealed that CXM's adsorption involved the replacement of Ca2+ ions by CXM's functional groups. The study proved that sepiolite-rich dolomite can be a very effective and environmentally friendly adsorbent to remove CXM and treat bacterial infections from domestic waste or wastewater. [ABSTRACT FROM AUTHOR]