Water Resources Research Act Program

Details for Project ID 2020OK195B

Passive samplers for monitoring perfluoroalkyl substances at contaminated sites

Institute: Oklahoma
Year Established: 2020 Start Date: 2020-03-01 End Date: 2021-02-28
Total Federal Funds: $5,000 Total Non-Federal Funds: $10,000

Principal Investigators: David Lampert

Abstract: Problem Statement: Per- and polyfluoroalkyl substances (PFAS) are a class of organic compounds possessing very strong and short carbon-fluorine bonds that make them persistent in the environment. PFAS impacts on humans in by affect the immune system, increase the risk of cancer, increase cholesterol levels, and affect growth, learning and behavior of infants and older children. Sediments and soils often act as a sink for the contaminants such as PFAS following their release that present risks to water quality after PFAS sources are controlled. The monitoring of soil and sediment quality and the success of remediation technologies for contaminated sites is contingent upon quantification of risks associated with contamination. Passive samplers provide a mechanism to infer the bioaccumulation risks associated with residual contamination in soils and sediments indirectly by mimicking biological uptake.Objectives: The long-term goal of this project is to apply passive sampling devices to measure interstitial water PFAS concentration in contaminated sites around the state and assess the implementation of the samplers on a large scale. The aims of this study are to determine the equilibrium partitioning relationships for PFAS between pore water, sediments and sampling material, including competitive sorption effects between the various phases on the sampling material, and sorption kinetics for the PFAS in the proposed sampler, and demonstrate the technology efficacy at PFAS-contaminated areas in Oklahoma. It is expected that equilibrium coefficients which are outcome by this study lead to solving PFAS issue in Oklahoma. This research is expected to develop and demonstrate a standard operating procedure (SOP) to assess PFAS concentrations in soils and sediments to protect water quality. Finally, the sampler will be used to assess PFAS at air force bases and other contaminated areas in Oklahoma to infer potential PFAS exposure routes such as drinking water or groundwater sources.Methods: The passive sampler makes use of an anionic sorbent resin within a stainless steel housing that accumulates PFAS via diffusion processes. The sampler is designed to be placed into a saturated soil bed, allowed to accumulate PFAS, then removed and analyzed. Analysis consists disassembly of the housing, recovery of the sorbent resin material, and elution of the PFAS with a series of solvents. The eluent is then re-constituted and analyzed for PFAS using liquid chromatography with tandem mass spectrometry (LC/MS). For this project, over 100 passive samplers have been manufactured that will be tested for efficacy in a series of experiments. For each experiment, PFAS will be spiked into a soil-water matrix and allowed to equilibrate. Samplers will then be placed into the soil-water matrix and tested periodically for PFAS accumulation over a one-month period to provide insight into the PFAS accumulation kinetics. The sampler will then be used to assess PFAS uptake from Oklahoma soils and sediments.Expected outcomes: This research is expected to develop and demonstrate a standard operating procedure (SOP) to assess PFAS concentrations in soils and sediments to protect water quality. Also, this study will compare different types of soils and sediments to gain insight into efficacy of the method for soils with different organic carbon content. Finally, the sampler will be used to assess PFAS at air force bases in Oklahoma (Tinker and Altus) and other potential PFAS exposure routes such as drinking water or groundwater sources in this state. The developed samplers are facile, compact, portable, and inexpensive, so they can be an affordable solution for monitoring PFAS problems.