Removal of sulfamethoxazole from aqueous solution onto bagasse-derived activated carbon: Response surface methodology, isotherm and kinetics studies

The highly-efficient and low-cost activated carbon (BAC-600) derived from the bagasse was prepared through one-step carbonization-activation method and used for the removal of sulfamethoxazole (SMZ) from water. The response surface methodology (RSM) with a Box-Behnken design (BBD) was used for optimizing the adsorption process conditions such as SMZ concentration (30–100 mg L−1), pH value (3.0–10.0) and temperature (5–35 °C). Based on the Langmuir model, BAC-600 exhibited excellent adsorption performance with maximum adsorption capacities of 270.2, 285.7 and 294.1 mg g−1 at 5, 20 and 35 °C, respectively. Adsorption process fitted well with the pseudo-second-order model and was found to be spontaneous and endothermic. The hydrogen bond, electrostatic interaction and π-π interaction played significant roles in the adsorption mechanism of SMZ on the BAC-600. BAC-600 was a highly-efficient and potential adsorbent for eliminating environmental pollution caused by antibiotics in water and provided possibility and approach for the reuse of agricultural waste.