Effects of bioturbation and dissolved organic matter on PFAS bioaccumulation in the aquatic environment

Understanding the impact of bioturbation on the bioaccumulation of pollutants is crucial for assessing their ecological risks. However, the effects of bioturbation on per- and polyfluoroalkyl substances (PFAS) and other ionic pollutants remain unclear. This work investigated the effects of bioturbation and dissolved organic matter (DOM) on the bioavailability of seven PFAS via self-developed aquatic microcosms containing water, sediment, carp, and loach. Results revealed a significant positive log-log correlation between the membrane-water distribution coefficient (D_mw) and bioconcentration factor (BCF) of PFAS in carp, highlighting the role of D_mw in PFAS bioaccumulation. Conversely, an inverted U-shaped curve was observed between D_mw and biota-sediment accumulation factor (BSAF) of PFAS in loach, peaking at an estimated log D_mw of 5.46. Loach bioturbation slightly increases the BCF of longer-chain PFAS in carp by enhancing the uptake rate. The introduction of DOM reduces the PFAS uptake rate in carp, resulting in a decrease in BCF. Similarly, DOM negatively affects PFAS bioaccumulation in loach, leading to a reduction in BSAF. This study highlights the importance of considering bioturbation and DOM when investigating PFAS bioaccumulation in the aquatic environment.