The sediment was preincubated for 7 days. Afterwards, each of the reacted PEG solution timepoints was divided in three parts and pipetted into the triplicate sediment incubations with sediment from a sediment core collected in Lake Rotsee in Lucerne, Switzerland (sampling date: 27 th September, 2023). The top 5 cm of the sediment core was was mixed with an equal volume of lake water under stirring for 1 h. A volume of 40 mL of the suspension (with approx. 3 g of dry weight of sediment) was transferred into 100 mL Schott bottles used for the incubations (total number of 12). Each bottle was placed in an incubation chamber at 20 °C and continuously stirred over the course of the incubation.