Performance and mechanism of a novel bamboo-based magnetic biochar composite for efficient removal of norfloxacin

Quinolone antibiotics have become prominent organic contaminants in aquatic ecosystems, significantly threatening the environment and human health. Efficient removal of these pollutants in an eco-friendly manner still remains a challenge. In this study, a simple and environmentally friendly bamboo-based magnetic biochar was prepared by KOH-activated magnetized hydrothermal method to remove the antibiotics norfloxacin (NOR) from water. The characterization results demonstrated that the KOH activation significantly increased the specific surface area of bamboo biochar, with KMDBC reaching 1253.66 m²·g⁻¹. The adsorption process of NOR by KMDBC followed the Pseudo-second order kinetic model and Langmuir isothermal model, with a maximum adsorption capacity of 458.43 mg·L⁻¹. Based on the thermodynamic results, the adsorption process was exothermic, spontaneous, and involved chemisorption, likely through π-π interactions, hydrogen bonding, and electrostatic repulsion. This study demonstrates that KMDBC is an effective and recyclable material for NOR removal, offering valuable insights into utilizing forest resources for environmental remediation.