The photo degradation of Amaranth (AR) dye by advanced photo Fenton process in the presence of symmetrical peroxides like hydrogen peroxide (H2O2) and ammonium persulfate (APS) are investigated. The influence of various reaction parameters like the effect of iron dosage, concentration of H2O2/APS, initial dye concentration, effect of pH and the influence of various aromatic derivatives were studied and optimum conditions are reported. The efficiency of the oxidant was strongly influenced by the nature of aromatic photoproducts formed during the course of the degradation reaction. To study their effect on the rate of degradation these aromatic derivatives were added in known concentration (10 ppm). The influence of various aromatic derivatives on the degradation kinetics shows the following order: hydroquinones> chlorophenol > dichlorobenzene> aromatic carboxylic acids> anilidine> nitrophenol. The addition of these derivatives did not influence the degradation pathway although it altered the reaction rate. The percentage COD and TOC removal were determined in presence of aromatic derivatives to evaluate the complete removal of the pollutant Based on the intermediates obtained in the UV-vis and GC-MS spectroscopic techniques probable degradation mechanism has been proposed. (C) 2010 Elsevier B.V. All rights reserved.