Efficiency of levofloxacin removal from aqueous solutions using three-dimensional magnetic composite graphene oxide nanoparticle grafted onto melamine and chitosan dialdehyde

This study focuses on the synthesis of a novel graphene oxide (GO) based on the three-dimensional magnetic nanoparticles (3D/Fe/GO) grafted onto melamine (ME) and chitosan dialdehyde (DCS) and utilized for the efficient removal of levofloxacin (LEV) from aqueous solutions. The synthesized nanoadsorbent (3D/Fe/GO/ME/DCS) was characterized by vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), and thermal gravimetric analysis (TGA). The effects of various parameters such as pH, contact time, initial concentration, and the amount of adsorbent dosage on the removal efficiency were also investigated. The linear Langmuir model best described the isotherm results (R2 = 0.9947), while the linear pseudo-second-order model best described the kinetic results (R2 = 0.9996), showing monolayer LEV sorption and physisorption as the rate-determining stage, respectively. The maximum sorption capacity of the nanoadsorbent for LEV was 9.72 mg g−1 at pH = 7, a contact time of 30 min, initial concentration of 5 mg L−1, and adsorbent dosage of 1 g L−1. Using prepared nanoadsorbent, about 95% of the LEV was successfully recovered from real samples with relative standard deviation of 4.11% (RSD; n = 3). Moreover, under optimal conditions, excellent reusability was observed with (RSD = 2.61%) after three cycles. Based on the analytical data, the developed process can be a useful method for the removal of LEV from industrial wastewater and tap water samples.