Plant-Microbial Community-Perfluorinated Compound Response Relationships in River Sediments under Hydrodynamic Conditions

This study investigated the response mechanism between plant-microbial communities and perfluorinated compounds (PFCs) in river sediments under hydrodynamic conditions. Indoor simulation experiments were conducted using an overlying water-sediment-plant (WSP) system with or without plants and under three hydrodynamic perturbations (small, medium, large). Results showed that hydrodynamic strength was positively correlated with PFC release. Vallisneria natans inhibited PFC release through physical blocking and biochemical regulation, with inhibition rates ranging from 41.1% to 73.3%. Hydrodynamic disturbance significantly altered microbial community structure; Proteobacteria (34.3%–45.4%) and Chloroflexi (10.1%–19.0%) were dominant groups, and their abundance positively correlated with PFC concentrations. High PFC concentrations inhibited sensitive bacteria like Thiobacillus (decreased from 12.69% to 6.80%) and selected for resistant groups such as Verrucomicrobia. Hydrodynamic perturbation regulated microbial degradation pathways by changing environmental factors (e.g., pH, metal ions), while the plant system achieved dual effects of inhibiting PFC release and enhancing degradation through optimized microbial community function and reduced PFC levels. This work provides a theoretical basis for combining hydrodynamic regulation and phytoremediation to control PFC pollution in rivers.