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

摘要

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 = 0.58 Fe 0.12 HP 0.10 ARS - 0.86. The degradation pathway was followed by UV-vis spectroscopy and GC-MS techniques. Based on the intermediates analyzed, a probable degradation mechanism has been proposed. © 2009 Elsevier B.V. All rights reserved.