Iron (III)-mediated photodegradation of orange green dye

The degradation of Orange Green (OG) by excitation of iron(III) in aqueous medium was investigated under UV, visible and solar irradiation. The degradation efficiency was influenced by the pH of the solution, initial concentration of OG and initial concentration of Fe(III). The progress of removal of OG from solution was monitored by recording the change of absorbance at ?max = 478 nm with time. The initial concentration of OG was varied from 1.00x10-4 molL-1 to 2.50x10-4 molL-1and pH was varied from 1.0 to 2.2. The range of initial concentration of Fe(III) was from 2.00x10-4 molL-1 to 2.00 x10-2 molL-1. As the concentration of Fe(III) was increased, percent degradation increased rapidly until the concentration of Fe(III) reached a value of 0.005M. Beyond this concentration, percent degradation becomes steady and independent of concentration of Fe(III). Percentage of degradation was increased with increasing pH and was found to be maximum when pH was 2.2 but percent degradation decreased with increasing concentration of dye. The percent degradation was found to be higher when irradiated under solar light than under the UV and visible light.