Hamadan University of Medical Sciences Avicenna Journal of Environmental Health Engineering 2423-4583 12 2 2025 12 30 Photocatalysis-Adsorption of Amoxicillin from Water Using MgO-Biosilica Nanostructure 89 96 10.34172/ajehe.5548 EN Reza Darvishi Cheshmeh Soltani https://orcid.org/0000-0001-9621-0018 Mahdi Safari https://orcid.org/0000-0003-0347-9283 Reza Rezaee Afshin Maleki Behzad Shahmoradi Journal Article 10.34172/ajehe.5548 2024 09 09 2025 08 28 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.