Fe-Rich Aragonite Concretion Applied to Industrial Dye Purification Using Fenton and Photo-Fenton Technologies

For a low cost and efficient oxidation process of industrial textile dye, this investigation described an economic process for the Indigo Carmine (IC) dye degradation from aqueous solution. Our study used a novel natural carbonated concretion catalyst, aragonite, which was collected from the thermal station waste located in El Hamma, Southwestern Tunisia, as an advanced oxidation process. This new studied ferrous sample Fe-rich aragonite (Fe–Ar) was characterized using various techniques, such as X-ray diffraction (XRD), Specific Surface Area (BET) and Infrared Spectroscopy (FTIR). The textural, structural and chemical characterizations confirmed the presence of Aragonite phases with a high amount of iron (almost 30%) on the surface material. The new catalyst activity was evaluated in the oxidation of IC dye in an aqueous solution by Fenton and photo-Fenton process. The test results show that the Fe-rich aragonite exhibited higher photocatalytic oxidation activity at pH 3. In addition, the IC dye could effectively be removed from the aqueous solution by photo-Fenton process in the existence of the used material as catalyst. Based on this work, the importance of this material in the purification of industrial effluents loaded with dyes is confirmed proving that this material can replace a very expensive commercial catalyst materials used in fenton and photo-Fenton technologies.