Development of bamboo biochar–iron nano bio- composite for efficient removal of ceftaroline from pharmaceutical wastewater through adsorption and Fenton-like oxidation

This paper aimed to design a biochar-based nanobiocomposite from bamboo to remove fifth-generation cephalosporin antibiotics, such as Ceftaroline, from pharmaceutical wastewater. Porous biochar was prepared by pyrolysis of bamboo biomass at 500 °C (BBC-A500) and 700 °C with KOH activation (BBC-Fe10), whereas iron nanoparticles were produced via a chemical reduction pathway and later linked to the biochar network. This was systematically characterized by a series of analyses, i.e., SEM, TEM, XRD, FTIR, BET, and XPS, which verified the presence of stable iron loading, a high specific surface area, and numerous surface functional groups. XPS analysis confirmed mixed Fe²⁺/Fe³⁺ surface states (Fe²⁺/Fe³⁺ ratio = 0.92), which are catalytically active for Fenton-like reactions. The degradation experiment was also conducted in batch mode to evaluate degradation performance as a function of contact time, pH, catalyst load, and oxidant concentration. This elimination was carried out in a two-step mechanism, in which preliminary adsorption concentrated Ceftaroline molecules on the biochar surface, and catalytic oxidation was conducted via Fenton-like oxidation by encapsulated iron nanoparticles. The resulting reactive species are generated to enable rapid and extensive degradation of antibiotics, and mechanistic probing indicated that hydroxyl radicals — both free and surface-bound — were the predominant oxidizing species, with minor contributions from superoxide and singlet oxygen. The composite achieved 98% removal within 60 min (k_app = 0.092 min⁻¹) and retained 82% activity after five cycles, with cumulative Fe leaching below 1.5%. Overall, the adsorption-oxidation synergy makes the bamboo biochar-iron nanocomposite a promising solution for treating pharmaceutical effluents.