Reza Darvishi Cheshmeh Soltani
1 
, Mahdi Safari
2,3* , Reza Rezaee
2, Afshin Maleki
2, Behzad Shahmoradi
21 Department of Environmental Health, School of Health, Arak University of Medical Sciences, Arak, Iran
2 Environmental Health Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
3 Department of Environmental Health Engineering, Faculty of Health, Kurdistan University of Medical Sciences, Sanandaj, Iran
Abstract
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.