Rapid Removal of Hazardous Rose Bengal Dye Using Fe(III)– Montmorillonite as an Effective Adsorbent in Aqueous Solution

Rose bengal (RB) is xanthene dye, that extensively used in dyeing, printing industries and also as an insecticide. It has severe toxic effects on the human health. Although there are many studies on adsorption/photodegradation of rose bengal using different reductants, it is of interest to explore the environmentally benign Fe(III)–montmorillonite (Fe(III)–Mt). Fe(III)–Mt was interacted with rose bengal (RB) solution at different pH (5-10), temperature (0-40°C) and solid-to-liquid ratio. The concentration of RB removal was estimated from its absorbance at λmax = 545 nm using UV-Vis spectrophotometer. In general, the dye removal was rapid in acidic pH and increases with temperature up to 50°C. A complete reduction through adsorption occurred within 3 min at pH 5 and 6. The time taken for complete adsorption at 0°C, 30°C and 40°C are 7 min, 5 min and 3 min respectively. The adsorption followed by immobilization of dye on the spent clay mineral was evident from FT-IR and FESEM/ EDX analysis. This adsorption process can be easily scaled-up for real system applications.