Background: The global discharge of industrial waste containing organic compounds such as phenol into water resources has sparked widespread concern due to its harmful effects on aquatic ecosystems, human health, and the environment. Magnetic Biochar/Ca-Al-Fe Layered double oxide (MBC/LDO) nanocomposite was synthesized as a novel adsorbent for phenol removal from wastewater. Methods: The adsorbent was synthesized via the co-precipitation method, and various analyses were carried out, including XRD, FTIR, FESEM, BET surface area and porosity analysis, VSM, and TEM. The RSM-BDD was used to model the phenol adsorption. Significant Findings: The analyses verified the successful synthesis of a magnetic nanocomposite with irregular aggregates, surface area of 264 m2/g and average pore diameter of 3.3 nm.Statistical analysis determined that optimal phenol removal efficiency (98.23%) was obtained under specific conditions: a pH of 2.0, initial phenol concentration of 25 mg/L, temperature of 43°C, and a contact duration of 45 min. The adsorption process showed a strong correlation with both the pseudo-second-order kinetic model and the Sips. isotherm model with a maximum phenol adsorption capacity of 32.95 mg/g. Thermodynamic investigations indicated the endothermic and spontaneous process. Even after four cycles of reuse, the removal efficiency remained above 89%, demonstrating its excellent reusability. The main mechanisms for phenol removal included complexation, hydrogen bonding, π–π interactions, and ion exchange.
