Extraction of Erichrome Black-T Dye by Liquid-Liquid-Micro-Extraction Using Deep Eutectic Mixtures

Abstract

Water is one of the greatest necessary natural source, unluckily misused the most by humanoid. The reasons behind this are, human population, increased living standards, rapid industrialization, and urbanization. Due to the color effluent (dye) large amount of wastewater is generated, now numerous forms of dyes are existing that are used in many productions for coloring the products most commonly synthetic dyes. These dyes are non-biodegradable and affect the human and aquatic life. For treatment of this wastewater various methods have been applied but they are also associated with many drawbacks. Ionic liquids (ILs) have been used as novel extracting agent for dye removal from textile waste water. Although their clear benefits, maximum ILs are overpriced to prepare than organic solvents and are also non-bio degradable. Deep eutectic solvents (DESs), which is known as green solvent, presents physicochemical properties which resembles those of ILs. Other than this, they can be produced from low-priced, non-toxic, completely eco-friendly materials and their preparation is very humble. Present study investigates the use of deep eutectic solvents (DESs) for the first time as extraction media for dye removal. Anionic dye Eriochrome black-T (EBT) was selected for this study by using Liquid-Liquid Micro-extraction technique. Glycolic acid & choline chloride (G:C), based DESs prepared in different molar ratios were used in this work. Extraction efficiency achieved in this study was quite comparable to ionic liquids for the same dye under similar operating conditions. While comparing the performance of different DESs, G:C (1:1,2:1,3:1) achieved the higher efficiency. Effect of different relevant parameters (solution pH, volume of DES and initial dye concentration) on extraction efficiency was also studied. From this study it can be concluded that, DESs can be used for extraction of dyes from textile effluent. There is need to explore other DESs also other than used in this study for this purpose. The prepared DES was characterized by FTIR and NMR spectroscopy.