Methanol-modified ultra-fine magnetic orange peel powder biochar as an effective adsorbent for removal of ibuprofen and sulfamethoxazole from water

Abstract

The efficient capture of drug metabolites from aquatic environments has been recognized as an essential task for environmental protection. A methanol-modified ultra-fine magnetic biochar (CH3OH-OP-char/Fe3O4) was prepared from orange peel powder using ball milling, and its adsorption behaviors for ibuprofen and sulfamethoxazole were evaluated. The obtained materials were characterized by laser particle size analyzer, EA, ICP-OES, VSM, BET, TG-DTG, and FTIR. Furthermore, the experiments were conducted to study the vital operating parameters such as solution pH (2.0–11.0), contact time (0.5–240 min), initial drug concentration (0.5–100 mg/L), and temperatures (15–40°C) on the removal process. The results showed that the adsorption of IBP and sulfamethoxazole on CH3OH-OP-char/Fe3O4 was highly pH-dependent. Kinetic studies indicated that physisorption was the dominant adsorption mechanism, and film diffusion played a vital role in adsorption onto CH3OH-OP-char/Fe3O4. Equilibrium data were fitted well with the Langmuir isotherm model, implying monolayer adsorption. The adsorption process was spontaneous and endothermic due to the thermodynamic calculation, and high temperatures were favorable to the adsorption process.