Paul Ruehl

Encapsulation of PFAS in Landfill Leachate Forming an Alternate Daily Cover

Paul Ruehl, Environmental Remediation Specialist, Geocycle North America

Encapsulation of PFAS in Landfill Leachate- Forming an Alternate Daily Cover  Abstract-Paul Ruehl Geocycle North America  Encapsulation of PFAS from Landfill Leachate-This presentation describes the state-of-practice, and demonstrates typical results of the successful use of cement products for solidification/stabilization (S/S) of landfill leachate concentrate (concentrate). A typical landfill might have 10,000-100,000 gallons or more of leachate to manage. As much as one third of the operating costs at a landfill is the management of leachate. The concentrated leachate will nearly always have PFAS in significant amounts. The author developed a patented method for encapsulating PFAS from the concentrate, dramatically reducing the availability of PFAS to the environment. Typical analytical results indicate two to five orders of magnitude reduction between the concentration of PFAS in the concentrate and the extraction fluid. The method describes how PFAS is encapsulated in an inorganic matrix formed by mixing the contaminated concentrate with a mineral binder. The slurried concentrate can be sprayed onto the landfill working face shortly after it has been treated. In this fashion, the landfill can increase its capacity and extend its useful life by using the treated leachate as an Alternate Daily Cover instead of the usual six inches of “free” dirt from onsite. This increased capacity can significantly offset the price of the binder and provide a permanent solution to recapturing PFAS contaminated leachate each day. This method eliminates off-site disposal costs for leachate and the need to recirculate leachate into the landfill. This process eliminates the endless cycle of PFAS from landfill to POTW and back again. This constitutes 100% resource recovery.

Paul Ruehl Environmental Remediation Specialist Geocycle North America  BS/MS Chemistry  Paul Ruehl has 48 years of experience as an environmental chemist, 44 years in the cement industry.  Since 1982, Paul has been involved in more than 500 site remediations using cement solidification/stabilization. He actively conducts research, using cementitious mix designs to encapsulate PFAS in landfill leachate for use as an alternate daily cover. A Patent was allowed for the leachate process in August 2021. His most recent R&D has focused on the encapsulation of PFAS in soil. The DoD is considering using this technology at multiple military sites. Results of that work are now available and will be discussed in this presentation.