Dan Griffiths, Parsons’ Emerging Contaminants Practice Director
For many years, airports worldwide were required to use aqueous film-forming foam (AFFF) for fire suppression. While effective in extinguishing fires, AFFF contains per- and poly-fluoroalkyl substances (PFAS), a class of chemicals now recognized as emerging contaminants due to their persistence in the environment and potential health risks. Unfortunately, the recommended fire response protocols and training requirements led to widespread PFAS releases into soil and water, posing significant environmental challenges.
With the EPA’s new PFAS requirements, emerging contaminants are an area of concern for many airports. Recognizing the pressing need for an effective solution, Parsons has developed a new patented technology called Hot in-situ chemical oxidation (Hot ISCO) to address the issue of PFAS contamination in soil and groundwater. This groundbreaking technology is a significant step forward in environmental remediation and cost-effectively destroying PFAS underground, ensuring that aviation clients can meet the latest regulatory compliance requirements and maintain the highest standards of environmental stewardship.
Understanding PFAS Contamination
PFAS are synthetic chemicals that are resistant to heat, water, and oil, making them useful in various industrial applications. However, the chemical properties that make them so useful also make them persistent in the environment and difficult to address. Traditional remediation methods have been shown to be ineffective or only partially effective at addressing PFAS, often transferring or transforming PFAS rather than destroying these compounds.
The persistence of PFAS has led to widespread contamination of groundwater sources near airports and other sites where AFFF was used extensively. This contamination poses risks not only to human health but also to ecosystems that rely on clean water sources.
Introducing Hot ISCO: An Innovative Solution
Parsons’ Hot ISCO technology offers a promising solution by combining a slight temperature increase above ambient conditions with a metals-based catalyst and an off-the-shelf low-cost oxidant. This combination produces high-energy radicals capable of destroying PFAS, leaving non-toxic products including carbon dioxide and fluoride salts.
Key Components of Hot ISCO:
- Temperature Rise: Unlike traditional thermal treatments that require high temperatures, Hot ISCO operates with only a modest increase above ambient temperature.
- Metals-Based Catalyst: The inclusion of specific metals acts as a catalyst that uses the thermal energy more efficiently to produce free radicals of sufficient energy to breaking down PFAS molecules.
- Oxidant: An oxidizing agent is introduced into the contaminated medium, which reacts with catalysts and the PFAS compounds under the influence of heat to completely degrade the PFAS to non-toxic end products.
Benefits of Hot ISCO Technology
- Efficiency: By targeting both soil and water contamination simultaneously using low-cost reactants.
- Cost-Effectiveness: The modest temperature rise required reduces energy consumption compared to traditional thermal methods.
- Environmental Safety: The process degrades PFAS into non-toxic products rather than merely transferring contaminants between media or transforming regulated PFAS into other PFAS molecules.
- Scalability: This technology can be scaled up for large-scale applications at various contaminated sites.
Laboratory Work and Field Trials
The development of Hot ISCO involved extensive laboratory research followed by field trials. Initial lab results demonstrated significant reductions in PFAS concentrations within treated samples.
Field trials confirmed these findings after the successful application at contaminated sites without causing secondary pollution or adverse effects on surrounding environments.
Delivering a cleaner world
Hot ISCO technology marks an important step forward in PFAS management, protecting the environment and enhancing the operational efficiency and sustainability of aviation clients globally. Leveraging this advanced approach offers an efficient yet environmentally safe means for degrading persistent pollutants like PFAS into harmless end products—a significant development for addressing remediation needs from the historical use of AFFF at airports and other environmental remediation efforts worldwide.
About the Author
Dan Griffiths, Parsons’ Emerging Contaminants Practice Director, has +28 years of experience designing and implementing investigation plans/remedies for complex sites impacted by emerging contaminants, chlorinated solvents, metals, and explosives. He leads Parsons’ R&D for remediation advancement and contributes to the company’s in-situ guidance documents for the Air Force and ITRC.
DISCLAIMER
This article was provided by a third party and, as such, the views expressed therein and/or presented are their own and may not represent or reflect the views of Airports Council International-North America (ACI-NA), its management, Board, or members. Readers should not act on the basis of any information contained in the blog without referring to applicable laws and regulations and/or without appropriate professional advice.
