Developing New Tools to Address the PFAS Challenge

Before you can solve a problem, you have to fully understand it. At Battelle, we are working to address the looming problem with the country’s overarching issues with per- and polyfluoroalkyl substances (PFAS), a group of compounds widely used for their heat, water and oil resistance. And each location around the country contaminated with PFAS needs to be understood before it can be remediated effectively.

Understanding the behavior of PFAS in groundwater has been identified as a key challenge for addressing these chemicals of concern. Battelle has created a digital tool that aims to identify where PFAS is going once introduced to groundwater. The PFAS Predict™ program simulates PFAS fate and transport in groundwater with specific inputs for PFAS chemical properties, source parameters and aquifer characteristics.

To create this tool, our researchers leveraged previous experience with modeling and visualization for a number of government agencies and commercial clients. Previously, Battelle has applied models for projects such as plume management for petroleum hydrocarbons and multiple-phase simulation of deep well injection of supercritical carbon dioxide into saline reservoirs.

“Development of PFAS Predict benefited greatly from previous Battelle IR&D investments,” said Joel Sminchak, a Battelle senior research scientist. “The program is very effective for simulating the behavior of PFAS in groundwater. I was genuinely surprised at how well it worked.”

And, while it’s important to know where PFAS is going, it’s equally as important to know where it is coming from. Groundwater and soil contamination at impacted sites often cover large areas and may come from multiple sources. Understanding where these substances originated is important for determining potential cleanup liabilities.

Battelle is developing a chemical forensic technique for PFAS source differentiation and tracking. The PFAS Signature™ capability is an approach for determining concentration and composition trends of PFAS from various contamination source scenarios using high-resolution mass spectrometry techniques in combination with advanced statistical analysis.

“When we’re looking at a particular sample, there may be commonalities across multiple sources,” said Kavitha Dasu, a Battelle principal research scientist. “The PFAS Signature tool will help us see beyond the commonalities of particular chemicals and identify the distinct signatures of different applications.”

Comparing samples to a Battelle-built source library, the method can identify sources of contamination based on chemical signatures, isomeric profiles, manufacturing, age of release, fate and transport, and biotransformation products.

And, like all research, the analysis is only as good as the data collected. While the simplest way to obtain a water sample is to collect a vial from the water source, currently available PFAS sampling methods suffer from potential cross-contamination because of the abundant use of PFAS in commercial products, laboratory ware and field equipment.

Passive samplers have been valued by the scientific community for decades because of their ability to collect time-integrated data at improved detection limits, which is particularly important when monitoring for contaminants that can cause risk even at very low concertation levels. Unfortunately, traditional passive samplers do not work for PFAS due to their relatively high solubility in water.

To address these issues, Battelle has developed a PFAS passive sampling prototype that is currently undergoing field testing.

“The differences in the chemical properties of different PFAS compounds is what made the development of a suitable passive sampler so challenging,” said Eliza Kaltenberg, a Battelle research scientist. “It took many rounds of testing before we decided that we have a product that performs well with a wide range of PFAS analytes.”