Effective Removal of Acid Blue 113 Dye from Industrial Effluents Using Natural Coagulant and Fe3O4/MnO2 in Coagulation/Ozonation Combined Treatment System

In this study, the combined treatment method of coagulation with natural coagulant and catalytic ozonation was used to remove Acid Blue 113 dye from the dye solution. In the first stage, the mucilage extracted from the Balangu (Lallemantia royleana) plant seeds was used to pre-treat the dye-containing solution. In the second stage, catalytic ozonation with Fe3</sub>O4</sub>/MnO2</sub> nanocatalyst was used to completely remove the dye. Response surface methodology with Box-Benken design was used to analyze and optimize the parameters of both processes. Maximum dye removal by the coagulation-flocculation process was 56%, which was obtained in the optimal conditions of pH 5.2, 20 min, and a coagulant amount of 100 ppm. In the catalytic ozonation process at pH 3.5, 18 mg of the nanocomposite, 0.2 g.L-1</sup>.h-1</sup> of ozone, and 12 min, almost complete removal of dye was achieved. The results indicate that the combined treatment method performs excellent dye removal and can also be used to remove other organic pollutants from industrial effluents.