Highly Effective Removal of Moxifloxacin from Aqueous Solutions Using Graphene Oxide Functionalized with Sodium Dodecyl Sulfate

Abstract

In this study, sodium dodecyl sulfate modified graphene oxide (GO-SDS) was prepared as an adsorbent to remove moxifloxacin (MFX) from aqueous solution. Transmission electron microscopic (TEM) and scanning electron microscopic (SEM) images showed that SDS decreases the aggregation of the GO surface, which significantly increased the surface area and the interlayer distance between successive layers of GO-SDS. Adsorption studies demonstrated that 98% of MFX was removed by GO-SDS within 15 min at pH 5.8, while the adsorbent dosage was 37.5 mg L^–1. The adsorption kinetics followed the pseudo-second order linear model, while the linear Langmuir adsorption isotherm model fitted the data better than the Freundlich model. The values of ΔH and ΔS obtained from the thermodynamic studies were +5.603 kJ mol^–1 and +2.114 kJ mol^–1 K^–1, respectively, indicating that the adsorption process between GO-SDS and MFX is endothermic and spontaneous. Furthermore, the satisfactory reusability of GO-SDS revealed that it could be an effective adsorbent for MFX removal from the aqueous solution.