Grantee Research Project Results
Final Report: Sorbent-Amended Caps for PFAS-Contaminated Sediments
EPA Grant Number: SU840180Title: Sorbent-Amended Caps for PFAS-Contaminated Sediments
Investigators: Lampert, David , Sandhu, Amandeep , Atoufi, Hossein , Manwatkar, Prashik , Manoharan, Monika , Slominski, Anna , Tomasek, Anastasia , Snitovsky, Claire , Taher, Hibatullah , Khanolkar, Janhavi , Davis, Cornelius
Institution: Illinois Institute of Technology
EPA Project Officer: Spatz, Kyle
Phase: I
Project Period: December 28, 2020 through November 30, 2021
Project Amount: $25,000
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2020) RFA Text | Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Sustainable and Healthy Communities
Objective:
The widespread existence of per- and polyfluoroalkyl substances (PFAS) in the environment represents an emerging issue due to their stability, bioaccumulation potential, and risks to human and ecological well-being. Areas where PFAS have been released into the environment have contaminated soils and sediments that now pose bioaccumulation risks. One approach for risk reduction is to contain the contamination in-situ to prevent exposure. Previous research into assessment and remediation of contaminated sites has demonstrated that in-situ containment and stabilization for pollutants that are resistant to degradation is often the best strategy. Ex-situ approaches require pumping and treating large quantities of material, which is prohibitively expensive, and managing additional residuals requiring disposal and containment. Developing cost effective in-situ treatment methods for PFAS is a critical priority.
The hypothesis underlying this investigation is that sequestration of PFAS in contaminated sediments is a cost-effective approach to reduce environmental risks. The project seeks to provide new insight into the efficacy of PFAS remediation using sediment capping technologies. Capping is a proven approach for contaminated sediment management, but there have been limited efforts to assess capping in PFAS-contaminated areas. While there is existing literature on PFAS sorption to various materials, there have been few efforts to extend these data for capping and in-situ sequestration. This project is developing a framework for remediation of PFAS-contaminated sediments and providing insight into the costs and benefits of alternative materials for sediment caps. The results are expected to be of value to communities that are at risk of exposure to PFAS. The long-term goal of this project is to develop a sorbent-enhanced sand capping technology for PFAS-contaminated sediments to reduce mobilization and bioaccumulation. The specific objectives of the project are to:
1. Conduct laboratory-scale experiments to examine the effectiveness of sediment caps for PFAS containment
2. Develop analytical methods for PFAS using liquid chromatography with tandem mass spectrometry (LC/MS)
3. Characterize PFAS transport through caps made of different sorbent materials using fate and transport models
4. Assess the costs of various capping alternatives
Summary/Accomplishments (Outputs/Outcomes):
An interdisciplinary student team from engineering, food science, and business has been developed to work to address this critical sustainability challenge, which will provide important educational benefits to the students, communities affected by PFAS, and entities that manage PFAS contaminated sites. The project benefits people living in areas historically exposed to PFAS, many of whom are members of disadvantaged communities.
Objective #1. The team has constructed a series of lab-scale microcosms systems of riverine environments to test the efficacy of capping materials for containing PFAS-contaminated sediments. Soil was collected from a rural forested location free of PFAS that was then sieved, and spiked with PFAS for use in the experiments. Three PFAS are being used in the experiments: perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and perfluorobutane sulfonate (PFBS). Capping materials have been procured including sand, granular activated carbon, biochar, and the proprietary FluorosorbTM (CETCO Mineral Technologies, Inc.). The materials were placed above the spiked sediments and are being analyzed for effectiveness using the approach described in Objective #2.
Objective #2. An analytical method to determine PFAS concentrations in sediment pore water is being developed using LC/MS. Analytical standards for the three target compounds have been procured from Wellington Labs and are being used in the method development. The method has been developed based on EPA Method 533. Peak separation for the three target compounds has been demonstrated, and calibration curves have been developed. The detection limit and other quality assurance protocols are still in development and should be completed in the near future. Pore water sampling devices commonly called “peepers” have been designed to enable the collection of water at different depths within a cap have been constructed and tested to assess the migration of PFAS compounds through sediment capping systems. The peepers have been tested using migration of sodium chloride in a sediment column to verify the capability to assess chemical movement.
Objective #3. The assessment of PFAS movement within the sediment caps is being analyzed using the CapSim software platform. CapSim is designed specifically to analyze the fate and transport of pollutants in sediments and sediment caps by simulating the processes of pore water advection, diffusion, dispersion, bioturbation, and sorption of pollutants onto sediments and capping materials. Key properties of the sediments, PFAS compounds, and the capping materials have been compiled for use in simulations. Preliminary simulations have been performed to predict the migration of the three compounds in each experiment. After the completion of the experiment, the results will be interpreted with the model. The calibrated model could then be used along with site properties to design a cap in the field.
Objective #4. The project team has received the four capping materials (sand, activated carbon, biochar, and Fluorosorb) and been in close contact with the manufacturers. The model developed in Objective #3 will be used to assess the costs required for caps to meet design goals for a hypothetical cap design at a real contaminated area such as Milwaukee Harbor.
Conclusions:
The results to date have demonstrated that the sediment microcosm systems can be used to assess various capping alternatives. The analytical methods, including the LC/MS analysis and the peeper pore water samplers, can be used to monitor the performance of sediment caps for PFAS. The CapSim modeling platform can be used to interpret data from lab experiments and predict the effectiveness of various caps in the field. The most cost effective sorbent capping material remains unclear, although Fluorosorb appears to have good promise.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
Other project views: | All 1 publications | 1 publications in selected types | All 1 journal articles |
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Type | Citation | ||
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Atoufi H, Lampert D. Analysis of a Passive Sampling Device to Assess the Behavior of Per- and Polyfluoroalkyl Substances in Sediments. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2023; |
SU840180 (Final) 68HE0D18C0017 (Final) |
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Supplemental Keywords:
Sediments, soils, adsorption, chemical transport, bioavailability, remediation, cleanup, environmental chemistry, monitoringRelevant Websites:
EPA Press Release, YouTube Exit , YouTube P3 Exit
P3 Phase II:
Sorbent-Amended Caps for Per- and Polyfluoroalkyl Substances (PFAS) in SedimentThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.