Date palm biochar application to remove binary mixtures of Atenolol, Ibuprofen and Sulfamethoxazole from aqueous solution: Experimental and statistical physics modeling

Date palm-derived biochar (DPF600) was utilized to remove and adsorb commonly occurring pharmaceuticals such as atenolol (ATE), sulfamethoxazole (SMX), and ibuprofen (IBP) as binary solutes. Factors such as pH, concentrations, dosage and contact time were varied and optimal conditions were determined. The binary mixtures ATE+IBP, ATE+SMX, and IBP + SMX best fit the Freundlich and pseudo-second-order models. From the competitive monolayer model, it was observed that SMX preferentially adsorbed onto DPF600 followed by IBP and ATE. Calculated adsorption energies for all binary mixtures were <20 kJ/mol, indicating that physisorption serves as one of the main mechanisms governing binary adsorption. Diverse characterization techniques validated the occurrence of adsorption mechanisms encompassing pore filling, hydrophobic interactions, hydrogen bonding, and pi-pi interactions through observed increases in carbon content, shifts in functional groups and reduction in peaks. DPF600 maintained stability over three successive cycles using thermal and chemical regeneration methods, thereby demonstrating the efficiency of the adsorbent.