Removal of streptomycin from aqueous solution by 3-aminopropyltriethosilane-functionalized graphene oxide nanoparticle

This study explores the removal of streptomycin (STM) from aqueous solutions using graphene oxide (GO) nanoparticles functionalized with 3-aminopropyltriethoxysilane (APTES). The structural characterization of GO-APTES was confirmed through X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). The adsorption process was analyzed using 519 nm UV–Vis spectroscopy, revealing a maximum adsorption capacity of 28.818 mg/g, consistent with the Langmuir isotherm model. Optimal conditions for STM adsorption were determined to be an adsorbent dosage of 2000 mg/L, a contact time of 15 min, and a pH of 8. The pseudo-second-order kinetic model was found to best describe the adsorption kinetics, while thermodynamic analysis suggested that the process is non-spontaneous and endothermic. SEM and TEM provided detailed insights into the structural morphology of GO-APTES, both pre- and post-adsorption. The adsorption mechanism involves π-π interactions, hydrogen bonding, and electrostatic interactions, demonstrating the efficacy of GO-APTES in removing antibiotics like STM from water.