Abstract ;

This study investigated whether MgO nanoparticles (NPs) produced via the sol–gel process can simultaneously remove the pharmaceutical diclofenac sodium (DCF) and cadmium ions (Cd2+) from water. The UV spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX) were used to confirm the composition, morphology and particle size of the MgO NPs. The adsorption performance of MgO NPs was compared to that of bentonite-nano zero valent iron (B-nZVI) and activated carbon (AC). The impact of contact time, adsorbate concentration, pH, and temperature on the removal efficacy of DCF and Cd2+ via MgO NPs in aqueous solutions were investigated, and the removal data was best described by the kinetic model of pseudo-second-order and the Langmuir isotherm model (R2 > 0.996). The maximum removal capacity of MgO for DCF and Cd2+ at pH 7 was 66.2 mg.g−1 (%R = 90) and 50.8 mg.g−1 (%R = 80), respectively. The average adsorption enthalpy for DCF and Cd2+ (ΔH° 50 kJ. mol−1) demonstrates the occurrence of physical adsorption process, while the negative value of ΔG° reveals the spontaneous nature of DCF and Cd2+ adsorption on the surface of MgO NPs. The DCF and Cd2+ adsorbed MgO surfaces were reused against various gram-positive bacteria. Finally, it was shown that MgO and sand column were more effective for removal of persistent substances and heavy metal residues than a column packed by a mixture of B-nZVI and sand.