Comprehensive technoeconomic-environmental assessment of deep eutectic solvents for PFAS water treatment: Economics, circularity, and scale-up pathways

The global challenge of per - and polyfluoroalkyl substance (PFAS) contamination demands economically viable and environmentally sustainable remediation technologies. While deep eutectic solvents (DES) have demonstrated exceptional PFAS extraction performance, comprehensive economic and environmental assessments remain absent. This study provides the first integrated technoeconomic analysis (TEA) and life cycle assessment (LCA) of a trioctylphosphine oxide-lauric acid (TOPO:LauA) DES system for PFAS remediation. Based on experimental data showing 99.74% perfluorooctanoic acid removal across pH 3–9 and concentrations of 0.1–1000 mg/L, we developed a comprehensive process design for continuous liquid-liquid extraction. For a 1000 m 3 /day municipal facility, capital investment totals $9.29 million with levelized treatment costs of $9.61/m 3 —substantially higher than conventional technologies ($0.60–1.50/m 3 ) but justified by superior removal efficiency (>99% vs 60–95%). Monte Carlo analysis (10,000 iterations) revealed robust cost estimates (CV 5.6%, 90% CI: $8.89–10.74/m 3 ), with operational parameters rather than material costs dominating economic uncertainty due to exceptional reusability (7 cycles, 98% recovery). Life cycle assessment following ISO 14040/14044 standards quantified environmental impacts at 2.47 kg CO₂-eq/m 3 —higher than alternatives but offset by an exceptional material circularity index of 86.8% and 75% green chemistry compliance. Economy of scale analysis demonstrated 94.6% cost reduction from 100 to 10,000 m 3 /day capacity. This work establishes a reproducible framework for evaluating emerging water treatment technologies, positioning TOPO:LauA DES as viable for high-priority contamination sites where superior performance justifies environmental trade-offs.