Grantee Research Project Results

Biodegradation of PFASs from Groundwater and Soil

EPA Grant Number: SU840169
Title: Biodegradation of PFASs from Groundwater and Soil
Investigators: Goel, Ramesh , Dentinger, Bryn , Diaz, Ruby , Podder, Aditi
Current Investigators: Goel, Ramesh , Dentinger, Bryn , Diaz, Ruby
Institution: University of Utah
EPA Project Officer: Spatz, Kyle
Phase: I
Project Period: December 1, 2020 through November 30, 2021 (Extended to November 30, 2023)
Project Amount: $24,978
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 - Safe and Sustainable Water Resources

Description:

Per-and poly-fluoroalkyl substances (PFASs) are man-made chemicals, also referred to as “forever chemicals” introduced to the environment in the 1940s. PFASs such as per-fluorinated octanoic acid (PFOA) and per-fluorinated octane sulfonate (PFOS) are the most common and most-occurring PFASs detected worldwide in environmental samples such as soil, water, wildlife and humans (Gallen et al., 2017). These chemicals have been proven to be very lasting in the human body and the environment and are known to affect the reproductive, developmental, and immunological systems of people exposed to the chemicals. Due to their hydrophobic nature, PFASs can move miles from the original point of release. (Ross et al., 2018). The chemical structure of PFASs (carbon backbone surrounded by fluorine atoms) makes them highly resistant to conventional treatment methods and degradation processes. The main objective of this project is to develop an energy-efficient, sustainable, and biodegradable method to transform PFASs found in groundwater and soils into safer byproducts such as carbon dioxide, calcium fluoride and water. Many of the PFASs contaminated sites have infiltrated soil and groundwater that feed water wells used for potable water use. The objective of this project is to demonstrate that the selected fungi and bacteria can generate enzymes to break down the bond between carbon and fluorine. After the microorganisms break the bonds, they can use the carbon found in the PFASs compounds as the primary food source. Injection of calcium carbonate CaCO3 and citric acid into contaminated soil and water at a ratio to be determined experimentally will enhance the development of bacteria and fungi and the freed fluorine can react with the available calcium in the soil and groundwater to form calcium fluoride CaF2.

Objective:

The project encompasses a novel approach of using a combination of microorganisms naturally found in soils. The bacteria Streptomyces cattleya and white-rot fungi strains have the potential to generate the enzymes needed to break down the C-F bond from PFASs. They also don’t pose a pathogenic threat to people, animals, or plants. The enzymes produced by the microorganisms will be identified, and enzyme engineering will be performed to amplify their capacity to break down the contaminants.
All the chemicals to be used during the development of the bioremediation technique include naturally occurring compounds such as calcium carbonate and citric acid. The citric acid will be used to help dissociate the calcium from the calcium carbonate and to maintain the optimal pH needed by the microorganisms.
PFASs are now threatening the US food supply as well as contaminated thousands of potable water sources and causing illnesses to animals and people exposed to the chemical. The proposed research using microorganisms and enzyme engineering will provide an energy-efficient and environmentally friendly alternative to biodegrade PFASs.

Approach:

The researchers will work with high school students from a local Indian reservation and provide them a 2-week hands-on experience working under the supervision of one of the researchers. Quarterly presentations will be scheduled at local high schools to educate and encourage high school students to pursue careers in research and engineering by showing an example of the career applications to real-world problems. The researchers will meet with three local communities located in the state that have been affected by PFAs and explain the impacts of PFASs in the environment, health, and people. The progress on the project will be presented in local and nationwide conferences and disseminated through publications and peer-reviewed journals.

Expected Results:

The successful completion of Phase I of this project aims to demonstrate that the selected microorganisms produced enzymes capable of breaking the carbon-fluorine bonds from PFASs. Compounds such as calcium fluoride, water, and carbon dioxide would replace the recalcitrant PFASs. The enzymes generated by the microorganisms will be fully identified, and the research data will be made available to other researchers. The project results will be presented in water, wastewater, agricultural, and environmental conferences. Local high school students will be part of the research team, and research techniques and critical thinking will be part of the educational experience.

Biodegradation of PFASs in soils and groundwater systems that feed potable water wells across the united states would have a positive impact on the health of all the people and animals currently exposed to the contaminants. Sustainability and energy-efficiency of the developed process will showcase the potential uses of co-cultivating bacteria and fungi to biodegrade other recalcitrant pollutants. Existing sites that are heavily contaminated would be able to be restored for future generations.

Relevant Websites:

Bioremediation, energy-efficient, sustainability, water quality, groundwater remediation, soil remediation.

Progress and Final Reports:

2021 Progress Report

2022 Progress Report

Final Report