Towards the use of eco-friendly solvents as adjuvants in remediation processes

Abstract

Abstract The growing social concern regarding the use of more environmentally friendly processes is compelling the search of more biocompatible solvents able to overcome the drawbacks associated to the conventional ones. Thus, in this work, a Deep Eutectic Solvent (cholinium chloride:urea) was demonstrated to act as salting out agent in aqueous solutions of a model non-ionic surfactant (Triton X-100). Thus, the immiscibility region was thoroughly mapped in a range of temperatures, from T 293.15 to 323.15 K. The experimental data for each solubility curves were fitted to different empirical models based on exponential and polynomial equations. Furthermore, Othmer-Tobias and Bancroft equations have been used to correlate the tie-line data, and to provide a clearer picture of the role of these solvents as phase promoters in surfactants solutions. Finally, the extraction capacity of this system at 303.15 K was assessed for removing textiles dyes from aqueous streams, in order to demonstrate the suitability of DESs to be used as adjuvants in the remediation of industrial effluents.