Predicting the Kinetics of Resupply of Organic Pollutants from Sediments Using Diffusive Gradients in Thin Film Samplers and their Bioavailability to Aquatic Invertebrates.

This article focuses on using diffusive gradients in thin film (DGT) passive samplers combined with predictive modeling to estimate concentrations of seven selected antipsychotic compounds in water and their bioaccumulation in benthic crayfish (Faxonius virilis) at a wastewater-impacted site in Saskatchewan, Canada. The study developed a steady-state uptake model linking time-weighted mean dissolved concentrations measured by DGT to contaminant levels in crayfish tissues, showing generally good agreement except for venlafaxine. Additionally, the DGT-induced fluxes in sediments (DIFS) model and hydroxyl-β-cyclodextrin extraction were applied to characterize desorption kinetics and the labile contaminant pool at the sediment–water interface, indicating partial but limited resupply of antipsychotics from sediments to the aqueous phase. The findings suggest that DGT techniques can effectively predict bioavailable organic contaminants in benthic invertebrates and simulate sediment-to-water contaminant exchange, providing a useful tool for environmental monitoring without extensive organism sampling.