Development, analysis, and effectiveness of an F-C-MgO/rGOP catalyst for the degradation of atrazine using ozonation process: Synergistic effect, mechanism, and toxicity assessment

Abstract

This study considered the effects of fluoride, MgO, sucrose, and rGO on the characteristics of the fluoride-carbon-MgO/rGO predicted (F-C-MgO/rGOP) catalyst and its effectiveness in the catalytic ozonation process (COP) for atrazine elimination from aqueous solutions. Using a mixture design, the catalyst composition was optimized to 13.6% sucrose, 50% Mg (OH)2, 25% NaF, and 11.4% rGO, which demonstrated the highest catalytic activity for atrazine degradation. Analysis of the synthesized F-C-MgO/rGO revealed a mesoporous structure with a BET surface area of 145 m²/g. The optimized COP parameters were a pH of 8.5, contact time of 11 min, catalyst dose of 1.38 g/L, and atrazine concentration of 10 mg/L. Atrazine mineralization reached 62.8% after 15 min of contact time. The COP exhibited a synergistic effect of 82.5%, a mineralization capacity of 17.75 mg/g, and a kinetic rate constant of 0.25 min⁻¹ for atrazine degradation. Intermediate analysis identified alkyl oxidation, dealkylation, and dechlorination-hydroxylation as the main pathways of degradation. Biodegradability index and toxicity assessments indicated a reduction in the toxicity of treated wastewater (both synthetic and real) after COP treatment. A BOD₅/COD ratio above 0.5 in both samples indicated the wastewater was suitably biodegradable.