Colloidal Polyaniline for Cleanup of PFAS Contaminated Groundwater

This invention is an injectable colloidal polymer designed for in situ removal of per- and polyfluoroalkyl substances (PFAS) from contaminated groundwater. The technology uses a colloidal form of polyaniline that can be injected directly into sand and gravel aquifers, where it adheres to mineral surfaces and forms a permeable adsorptive barrier for PFAS capture. Unlike many conventional groundwater treatment methods, this approach is intended to treat contamination below ground without excavation or large above-ground treatment systems. Laboratory testing showed that the colloidal polyaniline remains suspended in water long enough for injection, adheres to both positively and negatively charged sand matrices, and removes about 90% of PFAS concentrations over thousands of pore volumes under test conditions. The material also showed strong performance at environmentally relevant PFAS concentrations and in complex groundwater samples.

Background: 
PFAS are persistent environmental contaminants commonly associated with firefighting foams, industrial operations, and military sites. Because these compounds are highly mobile and resistant to degradation, they can spread through groundwater and create long-term contamination plumes that are difficult and expensive to remediate. Current treatment methods often rely on pumping groundwater to the surface for treatment with activated carbon or related adsorbents. These methods can be costly, energy-intensive, and difficult to apply across large aquifers. In situ carbon-based approaches are available, but activated carbon can be harder to distribute evenly underground. It may be less effective for shorter-chain PFAS compounds and low-concentration contamination. The injectable colloidal polymer technology was developed to address these limits by combining strong PFAS adsorption with subsurface mobility and retention, offering a more practical option for forming long-lasting treatment zones.

Applications: 

• Environmental remediation
• Groundwater treatment
• PFAS remediation
• In situ treatment of contaminated aquifers
• Remediation of military, industrial, and firefighting training sites
• Protection of drinking water resources

Advantages: 

• Injectable directly into sand and gravel aquifers
• Creates a permeable adsorptive barrier without excavation
• Reduces reliance on large surface treatment systems
• Shows strong PFAS adsorption at low concentrations
• Performs in complex groundwater with competing contaminants