Chain-length dependent behavior of per- and polyfluoroalkyl substances (PFASs): Environmental risks, migration patterns, remediation strategies and decontamination mechanisms

Per- and polyfluoroalkyl substances (PFASs), characterized by their persistent perfluoroalkyl backbone and functional terminal groups, have emerged as global contaminants of critical concern due to their detrimental impacts on human health and ecosystem integrity. While short-chain PFASs derivative have been increasingly adopted as alternatives to long-chain homologs, their heightened aqueous solubility and environmental mobility have facilitated widespread aquatic contamination. Despite extensive research on PFASs generally, systematic comparisons of environmental distribution patterns, transport mechanisms, and transformation pathways between long- and short-chain variants remain notably lacking. This comprehensive review analyzes global contamination profiles and environmental fate dynamics of PFASs compounds, with particular emphasis on human exposure pathways and toxicological consequences. We critically evaluate current remediation strategies, including: 1) Methodical examination of physical removal technologies with detailed analysis of material-specific adsorption characteristics and underlying molecular interaction mechanisms, 2) Comparative assessment of advanced oxidation/reduction processes (AO/RPs), particularly addressing chain-length dependent degradation efficiencies and mechanistic pathways, 3) Technological viability analysis for short-chain PFASs elimination, incorporating performance benchmarking across treatment modalities. Through systematic integration of contaminant behavior analysis and technological efficacy evaluation, this work advances predictive understanding of PFASs environmental dynamics while establishing a robust decision-making framework for selecting context-appropriate remediation solutions targeting both conventional and emerging PFASs contaminants.