Comparing the efficiency of N-doped TiO and commercial TiO as photo catalysts for amoxicillin and ciprofloxacin photo-degradation under solar irradiation.

Advanced oxidation processes (AOPs) have gained traction as alternative solutions for eliminating pollutants from pharmaceutical wastewater for reuse. In this research, the performance of two photo-catalysts (Commercial TiO and synthesis N-doped TiO) were compared in terms of the degradation of amoxicillin and ciprofloxacin from an aqueous solution using a photo-catalytic batch system under solar irradiation. The influence of five operating factors is: pH (5-11), HO concentrations (200-600) mg/L, catalyst concentrations (25-100 mg/L), Antibiotic concentration (25-100) mg/L and reaction time (30-120 min), on the oxidation of the listed above pollutants were investigated using the central composite design (CCD) of response surface methodology (RSM). The catalyst of N-doping TiO was synthesized by sol-gel method, using the urea (CHNO) as a nitrogen source. The resulting material was analyzed using Scanning Electron Microscopy (SEM), X-Ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Additionally, it can be observed from the analysis of the characteristics of N-doped TiO the homogenous dispersion of nitrogen molecules, small particle sizes, and energy-gap reduction, prompting a 6% increase in antibiotic degradation compared with Com. TiO. In the RSM analysis, the ideal conditions were found to be a pH of 5, HO conc. of 400 mg/L, catalyst conc. of 50 mg, and antibiotics conc. of 25 mg/L for an antibiotics reduction rate of 89.31% (AMOX/Com. TiO/Solar), 90.2 (CFX/Com. TiO/Solar), 95.8% (AMOX/N-TiO/Solar) and 97.3% (CFX/N-TiO/Solar). Experimental results were in good agreement with predictions because the predicted R matched well with the adjusted R.