Location: Water Quality and Ecology Research
Project Number: 6060-13660-009-018-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2022
End Date: Aug 31, 2025
Objective:
1. Evaluate the occurrence, identity, sources, and concentrations of emergent contaminants such as per- and polyfluroralkyl substances (PFAS) in various agricultural ecosystems.
2. Design and conduct a biomonitoring study for PFAS in environmental media (water, sediments, plant materials).
3. Evaluate different native aquatic plants for effectiveness as a bioaccumulator for PFAS and recommendations for biomass disposal if necessary.
Approach:
Water quality will be assessed on-site using portable field meters and samples requiring laboratory analysis will be iced and immediately transported back to the Cooperator. Samples transported to the laboratory will be used to measure variables by procedures according to APHA standard methods. PFASs (perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA)) concentration for surface waters, sediments, and plant tissues will be shipped to and analyzed by The Center for PFAS Research at Michigan State University using US EPA Method 533 solid-phase extraction (SPE) liquid chromatography/tandem mass spectrometry (LC/MS/MS). Biomonitoring with laboratory toxicity tests will follow the US EPA (2002) and APHA (1998) procedures for acute 48-h static non-renewal (EPA method EPA-821-R-02-012) and chronic 7-d static-renewal (EPA method EPA-821-R-02-013) effluent exposures. Mesocosms (1.25×0.6×0.8 m) will be constructed outdoors in Rubbermaid tubs (1.25×0.6×0.8 m). The base of each tub will be fill with 50 cm of sand, on top of which 20 cm of sediment will be layered. Mesocosms will be populated with monocultures of various native aquatic plants. Three replicate mesocosms and unvegetated sediment controls will be arranged randomly. Mesocosms will be dosed with known concentration of PFOS and PFOA. A target concentration will be selected based on current literature. Spiked water will be pumped into individual mesocosms using Fluid Metering Inc. (FMI™) piston pumps, models QD-1 and QD-2. Water will flow through each mesocosm and exit at the surface through a discharge hose on the opposite end of the mesocosm. Pump flow rates will be adjusted so that all mesocosms had a 6-h hydraulic retention time. Mesocosms will be exposed to a constant flow of spiked water for 6 h, after which they will be allowed to sit undisturbed for 42 h. Forty-eight hours after initiation spiked waters, mesocosms will be flushed with clean water for an additional 6 h in order to simulate flushing effects of a second storm event. Water and plant (root, stem, and leaves) samples will be collected in 250 mL polyethylene bottles before exposure and at 2, 2.5, 3, 3.5, 4, 5, 6, 8, 10, 12, 24, 48, 49, 51, 54, 72, and 168 h after initiation of spiked water. All water and plant samples will be analyzed to determine concentrations PFOS and PFOA.
