Extraction of Cr(VI) and Rose Bengal Dye Using Deep Eutectic Solvent: A Green Approach

This book focuses on the efficient and eco-friendly removal of hexavalent chromium (Cr(VI)) and Rose Bengal dye from aqueous solutions using hydrophobic deep eutectic solvents (DESs). Industrial effluents containing heavy metals and synthetic dyes pose serious environmental and health risks due to their toxicity, persistence, and bioaccumulation. To address these concerns, a green solvent system was developed using tetra methyl ammonium chloride (HBA) and octanoic acid (HBD), forming a stable hydrophobic DES.The prepared DES was characterized through density, pH, FTIR, UV–Visible spectroscopy, and DSC analysis to understand its physicochemical properties. Solvent extraction experiments were conducted under varying conditions of pH, temperature, contact time, and initial pollutant concentration. UV–Vis spectroscopy was used to construct calibration curves and quantify extraction efficiency. Overall, the study demonstrates that hydrophobic DESs are cost-effective, biodegradable, and highly efficient green solvents, offering a sustainable alternative to conventional organic solvents for wastewater treatment and pollutant removal.