Photocatalysis-Adsorption of Amoxicillin from Water Using MgO-Biosilica Nanostructure

The main objective of the present research study was the application of magnesium oxide (MgO) nanoparticles implanted in the matrix of biosilica for treating amoxicillin (AMX)-containing synthetic wastewater. Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) were used for the characterization. Although the efficiency of UV light alone was insignificant to degrade AMX (efficiency of 32%), the efficiency of the adsorption process was 42.6%, which implies the major role of the adsorption of AMX during its decomposition by photocatalysis. Regarding photocatalysis using MgO-implanted biosilica, increasing the initial pH from acidic to neutral conditions resulted in the enhanced removal of AMX (efficiency of 76%). At an optimum reaction time of 60 minutes and a photocatalyst dosage of 2 g/L, the removal efficiency (%) of AMX was found to be 94.9%. In the presence of 1 mM oxalic acid, the removal efficiency of AMX was 54.9%. The intermediate byproducts of AMX decomposition were also identified utilizing gas chromatography-mass spectroscopy (GC-MS) analysis. According to the results obtained, the treatment process of adsorption-photocatalysis using MgO-implanted biosilica can be recommended as an efficient technique for the degradation of pharmaceutical compounds such as AMX in aqueous environments.