The global accumulation of per- and polyfluoroalkyl substances (PFAS) in soils raises concerns about soil quality. While PFAS sorption may depend on the quality of soil organic matter (SOM), their unique properties may also affect SOM dynamics in complex and poorly understood ways, impacting long-term soil quality. Literature provides vague conclusions about how SOM, particularly its quality, influences PFAS–soil interactions and whether PFAS can modify SOM characteristics. The present study aims to enhance both the qualitative and quantitative understanding of the reciprocal impact that PFAS and SOM have on each other’s environmental fate. Sorption of three PFAS molecules and simultaneous mobilization of dissolved organic matter (DOM) in three distinct soils were studied. PFOS had the highest sorption by ranging 61–98% followed by PFOA and PFBA. 13C NMR analysis indicated that PFAS sorption is driven by hydrophobic components of SOM. The highest PFAS sorption was observed in soils containing polycyclic aromatic hydrocarbons (PAHs), while the lowest was recorded in soils with less hydrophobic SOM. Conversely, the presence of PFAS increased the release of DOM in soils with less hydrophobic SOM. The changes in DOM release induced by PFAS were directly influenced by the chemical properties of the soil components. Additionally, 1H NMR revealed notable structural changes in the chemical composition of DOM caused by PFAS, characterized by an increase in hydrophobic constituents and a decrease in hydrophilic components. The results indicated that PFAS can affect both the quantity and quality of SOM, potentially compromising long-term SOM stability and carbon sequestration in contaminated soils.

Effective removal of per- and polyfluoroalkyl substances (PFAS) form contaminated waters remains a significant treatment challenge in remediation facilities due to their structural heterogenicity, high aqueous mobility, and frequent occurrence as complex multi-component mixtures. Although granular activated carbon (GAC) and ion exchange resins (IER) are widely used for PFAS treatment, their performance is strongly influenced by water-matrix composition and competitive adsorption among PFAS, which can accelerate breakthrough and reduce adsorption capacity. Consequently, treatment performance assessments and capacity estimates may remain uncertain under multi-component conditions. Accordingly, this study evaluates how structurally diverse PFAS compete during adsorption and displacement in single- and multi-solute systems. This unified comparison clarifies how GAC and IER chemistry influence PFAS competitive behavior. Coexisting organic and inorganic constituents, dissolved organic matter (DOM) and phosphate, were incorporated to simulate realistic water matrices and to quantify their influence on PFAS competition and displacement. Results revealed that PFAS chain length and functional group chemistry governed the competitive hierarchy, with sulfonates generally exhibiting greater surface stability and removal efficiency than carboxylates. In addition, the results demonstrated distinct surface-dependent competitive behavior across the studied sorbents. GAC exhibited pronounced inhibition and displacement of PFAS in the presence of dissolved organic matter, whereas IER maintained relatively higher selectivity toward PFAS but was more susceptible to phosphate-induced displacement, highlighting the distinct matrix sensitivities of the two sorbents. These findings provide critical insight into PFAS treatment in multi-component systems and emphasize the importance of water-matrix specific design considerations to improve treatment efficiency, particularly for short-chain PFAS.

Despite advances in reactor-based process intensification, the influence of hydrodynamic conditions on PFAS removal remains poorly understood. In particular, rotating bed reactors (RBRs), which are designed to enhance mass transfer, have not been systematically evaluated for PFAS removal or compared with conventional batch and fixed-bed column systems. This lack of comparative understanding limits the ability to assess their practical relevance for PFAS remediation. In this study, PFAS removal was investigated under intensified hydrodynamic conditions using an RBR and compared with batch and small-scale column systems with special focus on short-chain PFAS compounds. The RBR significantly enhanced adsorption kinetics, with pseudo-first-order rate constants increasing by 3 to 16-fold across PFAS, particularly for short-chain PFAS. For instance, PFBA exhibited near-complete removal within 12 h in the RBR, whereas only ~50% removal was achieved in batch conditions. However, faster kinetics did not translate into superior long-term breakthrough performance compared to the column treatment system. After 50 treatment cycles using ion exchange resin, PFBA reached approximately 40% C/C0 in the RBR, while the column system maintained C/C0 below 5%; similar trends were observed for PFPeA (15% vs. ~0.5%) and PFHxA (6.2% vs. ~0.2%). These findings reveal a fundamental trade-off between kinetic intensification and long-term treatment performance. The results highlight distinct design roles, with RBR systems enabling rapid and intensified treatment (e.g., staged or parallel configurations), while conventional column systems perform better for continuous operation and compliance control in PFAS remediation.