Adsorption of ofloxacin on carbon nanotubes: Solubility, pH and cosolvent effects

► Cationic and anionic OFL species have higher solubilities than zwitterionic OFL. ► Cationic OFL high sorption is from electrostatic interaction and cation exchange. ► Both OFL solubility and sorption decrease with increased methanol fraction. ► Methanol-CNTs interaction is much stronger than OFL-methanol interaction.