Modification of graphitic carbon nitride photocatalyst by Pb-contaminated water for efficient removal of cefixime from aqueous media

In this study, graphitic carbon nitride (g-C3N4) and its modified form with Pb wastewater were prepared with a thermal polymerization method at 520°C for 2 h with a 10°C/min heating rate. The prepared composites were used as active catalysts in visible light to remove cefixime from aqueous solutions. Various factors such as the initial concentration of the contaminant, catalyst loading, process time, and initial pH on cefixime removal were efficiently studied in this research. The results indicate that the modified catalyst has a better performance in cefixime removal than g-C3N4. Design-Expert software was performed to design experiments and find optimum conditions to achieve maximum cefixime removal efficiency by Pb doped g-C3N4. The maximum removal percentage was observed is 84%, which achieved at optimum conditions obtained by the design of experiments software (cefixime’s initial concentration of 47 mg/L, 1.7 g/L catalyst loading, 113 min process time, and initial pH of 6.2). Moreover, the removal process was done in continuous cycles at the optimum conditions to investigate the economic aspect and the results showed removal efficiency decreases from 84% to 37% in five cycles. One of the most notable novelties of this work is using lead as a water pollutant material, to make a new photocatalyst for cefixime removal.