Comprehensive Mapping of Ionic Liquid Degradation Pathways and Toxicity Risks in UV/NaClO Treatment via Integrated Molecular Networking and In Silico Toxicology

The widespread application of ionic liquids (ILs) as solvents and functional materials raises growing concerns about their environmental persistence and potential toxicity. This study demonstrates the efficient degradation (>96.2% in 20 min) of alkylimidazolium IL, 1-pentyl-3-methylimidazolium by the UV/NaClO process, which remains applicable across a broad pH range and in various real water matrices. By coupling feature-based molecular networking with in silico toxicological assessments, we identified transformation products (TPs) and uncovered potential toxicity risks correlated with structural evolution. Molecular docking showed that dealkylation and hydroxylation attenuate binding affinities with human serum albumin (HSA) and human acetylcholinesterase through diminished hydrophobic contacts. Subsequent molecular dynamics simulations explored the dynamic and thermodynamic behaviors of representative TPs, revealing potential impairment of HSA’s transport function and pseudoenzymatic activities triggered by ring-opening. Particular attention is warranted regarding structural risks associated with cleavage at the C(4)═ C(5) bond of the imidazole heterocycle. This work first establishes an analytical–computational framework for mapping degradation pathways and evaluating TP risks, providing both mechanistic insights and practical guidance for the sustainable treatment of IL-containing wastewater.