Treatment and Fate Assessment

PFAS in North Carolina: Identification and Remediation

Dr. Pingping Meng

This project aims to increase understanding of PFAS removal technologies and quantify the concentration of both unknown and traditionally studied PFAS using targeted methods.

This project will

1. assess PFAS adsorption on granular activated carbon (GAC) and alternative adsorbents adsorption using rapid small-scale column tests (RSSCTs)
2. investigate the adsorption mechanism of PFAS and (3) evaluate the scalability of bench-scale data.

Additionally, this project will develop a quantification method for total organofluorine in different environmental matrices using a triple-quadrupole inductively coupled plasma–mass spectrometry (ICP-MS/MS).

Benefit to North Carolina

The findings of this study will contribute to our understanding of methods to remove PFAS from water and ways to reduce North Carolina residents exposure from drinking water. Additionally, the new PFAS testing method developed in this proposal will allow researchers and water utilities to quantify PFAS outside of the traditionally studied compounds, increasing awareness of potential risks from the unknown.

Photo-Catalyst and Soil Microbiome Synergy: Targeting GenX Degradation Using Soil from Nearby PFAS-Affected Sites

Dr. Dongyang Deng

This project introduces an innovative approach to tackling the persistent issue of GenX contamination by leveraging environmental remediation. Dr. Deng’s team is not only targeting GenX but also investigating the diverse functional microbial groups thriving in various PFAS-contaminated sites across North Carolina.

From industrial regions like Greensboro’s Piedmont Triad International Airport and the Fayetteville area to the urban areas near Charlotte Douglas Airport, the researchers are collecting soil samples to uncover the unique microbial dynamics at each site. Their goal is to compare how various microbial communities, adapt and respond to different levels and types of PFAS contamination.

The project employs a two-pronged strategy: first, the initial breakdown of GenX through photocatalysis; second, the subsequent biodegradation using the most effective local microbial consortia. This method aims not only to degrade GenX more efficiently but also to understand and harness the inherent resilience and diversity of microbial communities in contaminated environments.

Benefit to North Carolina

The findings of this project can provide environmental agencies with more effective and sustainable methods to mitigate PFAS compounds. This will directly benefit communities living near PFAS-contaminated sites by reducing associated health risks.

The Fate and Geochronology of PFAS in Sediments

Dr. Brent McKee

This project assesses the relationship between PFAS compounds and sediments in North Carolina. In a previous project, high concentrations of PFAS compounds were found to be associated with lake bottom sediments collected close to the input from the Haw River. Using naturally occurring radioisotopes to determine sedimentation rates for lake bottom sediments, we were also able to create a sediment history of PFAS inputs to the reservoir over the 40 years since it was formed.

In this project we will make the same measurements in other environments to see how they compare with the Jordan Lake results. We will also perform experiments to understand the environmental conditions (variability in oxygen concentrations, pH and resuspension activity) under which PFAS compounds are released from sediments. The results of this project will provide valuable insights regarding the prevalence of sediment bound PFAS and the permanence of that association.

Benefits to North Carolina

This project will produce insights into the prevalence of sediment-bound PFAS compounds in various bodies of water throughout North Carolina, as well as the environmental conditions under which PFAS compounds are released from these sediments. This knowledge can be used by environmental managers and water treatment engineers to develop new strategies for processing inland waters to avoid additional PFAS inputs from sediments.

Data-Driven Machine Learning Approaches for Estimation of PFAS Fate and Transport

Dr. Renzun Zhao

Dr. Zhao will use machine learning and data mining approaches to estimate the fate and transport behaviors of PFAS compounds in natural and built environments. The development of this technology will allow data science tools to be used to partially replace wet chemistry experiments to estimate the fate and transport behavior and remediation efficiency of various PFAS compounds.

Benefit to the people of North Carolina

The use of data science tools for PFAS fate and transport studies will yield not only a greater understanding of how PFAS move through the environment and where they end up but also make this information easier and more efficient to obtain. Using this technology, mitigation and management strategies for PFAS in natural and built environments can be greatly improved.

Rapid Detection of Trace Short-Chain PFAS in Water using Nanoengineered Surface Enhanced Raman Scattering

Dr. Renzun Zhao

The objective of this project is to study the detection and measurement of short-chain PFAS, particularly GenX, in water using nanoengineered Surface Enhanced Raman Scattering (SERS) substrate. SERS is a sensitive and fast technique for trace amount or even single molecule detection that has not previously been used for short-chain PFAS. Upon success, this project will have enabled an alternative technique for short-chain PFAS detection and measurement with higher sensitivity (below ng/L), easier use (convenience), and faster speed (less than a couple of minutes) as compared to the traditional PFAS analysis using LCMS.

Benefit to North Carolina

The testing method developed in this proposal will allow for rapid detection of trace quantities of GenX and other short-chained PFAS compounds, providing a new more efficient way to get North Carolina residents urgently needed testing results.

PFAS in Groundwater: New Insights on Inputs and Outputs

Dr. David Genereux

This project uses a variety of data and analyses to provide new insights on PFAS inputs to and outputs from groundwater near a fluorochemical manufacturing facility in North Carolina, with the goal of improving understanding and models of future PFAS persistence in groundwater. Data to be collected and analyzed include hydrologic measurements of water flow, groundwater age, and PFAS concentration in groundwater, stream water, and atmospheric deposition.

Benefit to North Carolina

Findings from this study will improve understanding of PFAS persistence in surface water and groundwater. This is vital for determining future removal and mitigation strategies of PFAS.

Sorptive treatment of PFAS and geochronology of PFAS in sediments

Dr. Detlef Knappe

• Sorptive Treatment of PFAS: Novel PFAS sorbents are materials that remove PFAS from water, and the processes by which the sorbents work have not been well studied. This proposal aims to understand mechanisms of PFAS removal by novel sorbents with the goal of developing predictive models.
• Geochronology of PFAS in sediments: The goal of this research is to understand the presence of PFAS and PFAS precursors, such as fluorinated side-chain polymers, in sediment of important drinking water sources, including Jordan Lake, Falls Lake, and Lock and Dam #1 on the Cape Fear River.

Benefit to North Carolina

The data generated in this project will benefit public utilities, consulting engineers, and the North Carolina Department of Environmental Quality (DEQ) by developing process models that can predict the performance of novel sorbents at conditions relevant to drinking water treatment. Additionally, the sediment portion of this research will provide information about the presence of PFAS and PFAS precursors in sediments of important drinking water sources that can support source water protection decisions.

Supercritical Water Oxidation for PFAS Destruction

Dr. Marc Deshusses

Supercritical water oxidation (SCWO) is waste destruction method that hold enormous potential for the safe and sustainable treatment of organic wastes, in particular concentrated wet wastes such as biosolids, sludges, landfill leachates, agricultural or chemical wastes, and problematic wastes such as PFAS and organofluorine-containing wastes (AFFF, spent sorbents or ion exchange resins loaded with PFAS, concentrates).

SCWO relies on the unique reactivity and transport properties when an aqueous waste stream is heated and compressed above the critical point of water (374 °C and 220 bars). At these conditions, and in the presence of oxygen, all organic contaminants (including PFAS) are rapidly mineralized to inorganic species: CO2, water, and inorganic fluoride in the case of PFAS. However, there remains several gaps in our current understanding of the technology and its application to PFAS treatment. These gaps include the effects of reaction conditions on the fate of fluorine, the reaction kinetics and factors that affect kinetics, and identifying conditions that could lead to emissions of gaseous fluorinated species. This project aims to mitigate these gaps, ultimately lowering the risk and enhancing the effectiveness of deploying SCWO systems for PFAS waste treatment.

Benefit to North Carolina

This project will contribute to a better understanding of the conditions leading to complete destruction and mineralization of PFAS and organo-fluorine compounds during SWCO. This will ultimately enhance our ability to destroy PFAS-containing waste, help accelerate safe destruction of PFAS or organofluorine-containing waste, and reduce the cost of waste disposal.