Aqueous Two-Phase Systems: A Versatile Approach to the Extraction, Separation, and Purification of Dyes

Dyes widely used in industrial sectors like pharmaceuticals and textiles cause a severe environmental threat due to the high stability and toxicity of synthetic dyes, which impair water quality and aquatic ecosystems. Normally, there are used traditional treatment methods, such as adsorption, and membrane filtration, but showed limitations including high costs, energy intensity, and low selectivity in complex matrices. Aqueous Two-Phase Systems (ATPSs) are an sustainable, economic, and versatile alternative for the extraction, separation, and purification of dyes. Therefore, this review examines the thermodynamic fundamentals, formation mechanisms, and the integration of innovative components like Ionic Liquids (ILs) and Deep Eutectic Solvents (DESs). Recent research highlights that ATPS can achieve extraction efficiencies exceeding 95% for dyes; however, the optimization of critical parameters such as pH, temperature, polymer molecular weight, and salt concentration is necessary. Furthermore, this review discusses the potential of these systems within circular economy schemes, emphasizing component recyclability and their alignment with green chemistry principles. Ultimately, ATPSs represent a scalable and eco-friendly platform for managing industrial effluents and recovering valuable compounds.