Removal of Cephalexin From Aqueous Solutions Using Magnesium Oxide/Granular Activated Carbon Hybrid Photocatalytic Process

In the present study, magnesium oxide/granular activated carbon (mgo/gac) composite as a catalyst was synthesized using the sol-gel method and its catalytic potential was investigated in the presence of ultraviolet (uv) irradiation for the removal of cephalexin (clx) in a batch mode reactor. then, the characterization of the mgo/gac composite was determined by x-ray diffraction (xrd) and scanning electron microscopy (sem). next, the effect of operational parameters was evaluated, including the ph of the solution (3-11), the dosage of composite (1-6 g/l), initial clx concentration (20-100 mg/l), and contact time (10-60 minutes). the maximum clx degradation with an initial concentration of 20 mg/l was as high as 98% at ph=3, 4 g/l of mgo/gac composite with uv irradiation within 60-minute contact time. in addition, the removal process of clx could be described by the pseudo-first-order kinetic. further, the chemical oxygen demand (cod) and total organic carbon (toc) removal rate were 78% and, 62.3% in optimum conditions, respectively. the results indicated that the uv/mgo/gac hybrid photocatalytic process can be considered as an efficient alternative for treating the wastewater containing clx.