Rapid Decolorization of Acid Orange II in Aqueous Solution by Waste Iron Oxide Particles

Discharges of highly colored dye effluents in natural water constitute a significant burden on the environment. The solar driven photo-Fenton process based on Fe(III)-oxalate complexes, an important advanced oxidation processes (AOP) technology, has been attracting growing attention for the decomposition of organic dyes. Such processes are based on the light enhanced generation of the highly reactive hydroxyl radicals, which oxidize the organic matter in solution and convert it completely into water, CO2 and inorganic compounds. In the present study, the effectiveness of iron oxide wastes generated in steel re-rolling mills to decompose a synthesized textile dye named Acid Orange II under UV illuminations was investigated. The decomposition of dye by iron oxide suspension at neutral solution pH was investigated. The experiments were carried out by varying amount of Iron Oxide (IO) catalyst (0.05–1 g/100mL) in Oxalic Acid (OA) concentration of 1mmol/100 mL solution and with initial dye concentration of 0.1 mmol/100mL solution. The optimum catalyst dose was found to be 0.05 g/100mL solution. We also studied the effect of pH and initial dye concentration on the degradation behaviour. From this study it was found that iron oxide wastes could be useful in treating dye wastes thus can play an important role to minimize both iron oxide and dye wastes.