Environmental remediation of novel Entities: Deep eutectic solvents as advanced water treatment technologies

In an era where water pollution threatens global health and environmental sustainability, conventional treatment methods continue to mostly rely on harsh chemicals that often create as many problems as they solve. This comprehensive review presents deep eutectic solvents (DES) as a revolutionary “green” solution that addresses novel entities—emerging synthetic chemicals and materials that represent one of the nine planetary boundaries that must not be transgressed— while transforming how we clean our water. These designer solvents function as selective molecular extractants, efficiently removing toxic metals, per- and polyfluoroalkyl substances (PFAS), pharmaceutical residues, and other hazardous pollutants from water while maintaining environmental compatibility. These designer solvents act like molecular tweezers, selectively pulling out toxic metals, ‘forever chemicals’ (PFAS), pharmaceutical residues, and other dangerous pollutants from water, while being environmentally friendly themselves. Our analysis reveals that DES can achieve removal efficiencies exceeding 90% for various pollutants, often surpassing traditional methods, while being biodegradable and cost-effective. By combining the latest advances in DES technology with real-world applications, we present how these innovative solvents could address multiple water treatment challenges simultaneously − from contamination with heavy metals to emerging pharmaceutical pollutants and industrial waste. In this review, our findings outline a clear pathway for scaling up DES technology from the laboratory scale to industrial implementation, potentially revolutionizing global water treatment practices. This work provides a critical roadmap for researchers, industry professionals, and policymakers seeking to ensure access to clean water while protecting environmental health for future generations.