Antibiotic adsorption from real pharmaceutical factory wastewater using a hole-punched flat ceramic membrane based on clay and hydroxyapatite in a fixed bed module

• Synthesis of ceramic nanocomposite adsorbent using clay, hydroxyapatite, and human hair. • Removal of over 90% of antibiotics in a fixed bed column. • High mechanical strength (withstands 3.6 bar) and chemical resistance. • Adsorbent regenerable up to 142 cycles, suitable for environmental applications. This study introduces a novel ceramic nanostructured adsorbent made from clay, bovine bone nanoparticles, and human hair waste for antibiotic removal from aqueous solutions. The adsorbent was optimized by high-temperature sintering, converting bone nanoparticles into hydroxyapatite, and utilizing human hair as a pore-forming agent, resulting in a highly porous structure with a surface area of 172.46 m² g⁻¹ and pore volume of 913.73 cm³ g⁻¹. Characterization using FTIR, XRD, SEM, and BET confirmed the successful integration of hydroxyapatite, enhancing adsorption capacity. Optimal conditions for antibiotic removal were pH 7, 25 g adsorbent dose, 25°C, and 40 minutes contact time. The maximum adsorption capacities for ofloxacin, tetracycline, and sulfadiazine were 26.59, 23.04, and 23.64 mg g⁻¹, respectively. Kinetic studies indicated surface diffusion control, while thermodynamic analysis showed a spontaneous, exothermic, and entropy-driven process. The adsorption isotherms fit the Langmuir model (R² > 0.99). After 142 regeneration cycles with 37% HCl, the adsorbent retained over 90% of its initial efficiency, highlighting its sustainability, cost-effectiveness, and high regeneration capacity for antibiotic removal.