Degradation of m-cresol over iron loaded carbon nanotube microfibrous composite: Kinetic optimization and deactivation study

Degradation of organic pollutant through catalytic wet peroxide oxidation (CWPO) is becoming more and more important in modern industry. As a commonly used organic synthetic material, excessive discharge of m-cresol may lead to severe damage of the environment and become a potential threat to human health. In this study, m-cresol was degraded over novel iron loaded carbon nanotube microfibrous composite (Fe-CNT-MF) catalyst packed fixed bed reactor. The kinetic parameters were first optimized, and then the deactivation mechanism of catalyst was also studied. The optimization model showed that total organic carbon (TOC) conversion of m-cresol degradation can reach about 70% under optimum conditions. Then the catalyst deactivation test was conducted with four consecutive runs (32 h in total). Fe-CNT-MF performed high m-cresol and TOC conversions (99% and 40%, respectively) as well as high H2O2 decomposition efficiency (100%) with no iron leaching. Besides, the effect of co-existing organic pollutants on m-cresol degradation was investigated with presence of 4-Ethylphenol and 2,5-dimethylphenol. Fe-CNT-MF exhibited good catalytic activity in multi-pollutant wastewater with 99% conversion for all pollutants. Finally, deactivation analysis results showed that the deactivation mechanism of Fe-CNT-MF included carbon deposition, surface property change and additional oxygen functionalities. A regeneration study was proceeded to further confirm the suggested mechanism, indicating that Fe-CNT-MF has a good regenerability.

Automated summary

Organic pollutant degradation through CWPO is crucial in modern industry. Fe-CNT-MF catalyst showed high stability and efficiency in m-cresol degradation, with TOC conversion reaching up to 70% under optimized conditions. Deactivation analysis revealed mechanisms including carbon deposition and surface property alteration.