PMS activation via carbon-based-iron catalysts: Ion interactions and predictive modeling in fenton-like systems

Abstract

Fenton-like reactions are a promising method for degrading organic pollutants in wastewater. However, their efficiency is often hindered by the requirement for soluble metal catalysts and the scavenging of reactive species by common ions present in aqueous environments. To overcome these limitations, this study explored the use of a carbon-based material produced via hydrothermal carbonization (HTC) of garden waste to provide a solid matrix support for iron, enabling the heterogeneous activation of peroxymonosulfate (PMS). Reactive Orange 84 (RO84), an organic dye commonly found in industrial wastewater, was used as a representative contaminant to assess the degradation performance of the carbon-based iron catalyst. The system achieved over 80 % degradation efficiency, even in the presence of high concentrations of ions such as sodium carbonate, sodium chlorate, and sodium nitrate. These results demonstrate that a carbon-based iron catalyst not only activates PMS effectively but also mitigates the negative impact of ion scavenging, maintaining performance where traditional Fenton-like systems typically fail. To further understand and predict the system’s behavior, mathematical models were developed using principal component analysis (PCA) and correlation analysis. These models identified iron content, carbon-based material dosage, PMS concentration, and carbonate ion concentration as key variables influencing degradation efficiency. Overall, this work highlights the potential of carbon-based catalysts to enable more sustainable and robust Fenton-like processes, addressing the limitations of homogeneous systems in complex aquatic matrices.