Kinetic modeling based on the non-linear regression analysis for the degradation of Alizarin Red S by advanced photo Fenton process using zero valent metallic iron as the catalyst

The degradation of Alizarin Red S (ARS), an anthraquinone dye was investigated by advanced photo Fenton process using zero valent metallic iron (ZVMI) powder as the catalyst with symmetrical peroxides like hydrogen peroxide (HP)/ammonium persulfate (APS) as the oxidants. APS is proved to be a better oxidant compared to HP as it provides efficient acidic medium which is critical for Fenton process. A kinetic/mathematical model was developed based on the non-linear regression analysis and the validity of the model was tested by comparing the observed experimental values with the theoretically calculated data. The rate equation obtained was found to be a function of iron dosage, oxidant and dye concentration at pH 3.k=0.2456[Fe]0.21[APS]0.15[ARS]−0.76k=0.2456[Fe]0.21[APS]0.15[ARS]−0.76k=0.58[Fe]0.12[HP]0.10[ARS]−0.86k=0.58[Fe]0.12[HP]0.10[ARS]−0.86The degradation pathway was followed by UV–vis spectroscopy and GC–MS techniques. Based on the intermediates analyzed, a probable degradation mechanism has been proposed.

Graphical abstractAn approach to kinetic/mathematical model based on the non-linear regression analysis for the degradation of Alizarin Red S by advanced photo Fenton process.Figure optionsDownload full-size imageDownload as PowerPoint slide