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Treating PFAS in the Toughest U.S. Leachates

Foam fractionation technology offers an effective solutions to PFAS for landfill operators.

A look at any landfill will show an array of discarded items that contain PFAS—ranging from fast-food packaging, kitchenware, cleaning products to carpets, and beyond. They all contribute PFAS compounds to a landfill’s leachate.

As receivers of this waste, landfill operators are grappling with how to best deal with PFAS in leachate. There are instances where wastewater treatment plants are issuing notices ceasing the acceptance of this industrial wastewater, leaving landfill operators with a significant challenge.

The EPA has been actively intensifying its efforts to combat PFAS since the release of the PFAS Strategic Roadmap in 2021. One of their recent initiatives, announced in March 2023, involves proposing nationally enforceable limits for six PFAS compounds that are commonly found in drinking water.

Anticipated to be implemented by the end of 2023, this regulation will require various industries, including landfill operators and those involved in leachate management, to proactively prepare for compliance well in advance.

Unique Foam Fractionation Technology
The Low Energy Evaporative Fractionation (LEEF) System®, was developed in Australia by The Water & Carbon Group (WCG). It is a patented foam fractionation technology that offers an effective solution to PFAS for landfill operators. The technology was developed and refined over the past five years and is operating at full-scale in Australia. Over the past year, major demonstrations of the LEEF System® have been undertaken in the U.S. treating some of the most challenging leachates across several states including Alabama, Georgia, New York, North Carolina, Pennsylvania, Tennessee, Vermont, and Virginia.

LEEF uses a foam fractionation technique, effective for directly removing PFAS from raw leachate. This method capitalizes on the unique properties of PFAS, particularly their tendency to concentrate on the surfaces of bubbles generated in the system.

The process involves mixing air through the contaminated leachate to produce a foam extract. As the foam rises to the surface, it carries PFAS molecules, forming a concentrated foam layer. This foam can then be separated from the main body of leachate as a low-volume liquid as the PFAS is removed. The LEEF System® specifically targets PFAS and is not influenced by the other contaminants found in leachate.

Shoal Bay Leachate Treatment Plant
As a proven technology, the LEEF System® has been in full operation at the Shoal Bay Leachate Treatment Plant in Darwin, Australia, for 12 months where it is successfully treating 11 million gallons of leachate each year.

The landfill is owned by the City of Darwin and receives more than 180,000 tons of waste each year from its 164,000 residents. Due to the region’s rainfall (approximately 70 inches per year), the facility generates large volumes of leachate.

Nick Fewster, Executive Manager Environment and Waste Services, City of Darwin said the LEEF System® not only presented huge benefits to the City of Darwin and the surrounding environment, but also provided a blueprint for other councils facing similar challenges. “During the process of working with WCG, we were presented with a forward-thinking program to design, construct, and operate a tailored leachate treatment plant that suited our unique environment.”

Fewster continued, “The LEEF System® is a smart and much-needed PFAS treatment system, which has been a game changer. The results so far are assisting us to meet regulatory environmental license requirements.”

Results Speak for Themselves
From 2022 to 2023, the LEEF demonstration system treated 14 distinct leachates for four of the largest solid waste companies in the U.S. This was without requiring pre-treatment and included processing two reverse osmosis concentrates. These leachates were highly complex, containing:

  • Ammonia between 600 and 3,800 mg/L
  • Total dss solved Solids between 5,700 and 54,000 mg/L
  • Chemical oxygen demand between 2,000 and 84,000 mg/L
  • Alkalinity between 1,500 and 21,600 mg/L
  • PFAS compounds – PFOA in the streams ranged from 140 to 12,500 ng/L and PFOS between 70 and 3,600 ng/L

The LEEF System® demonstration results were exceptional, consistently removing priority PFAS compounds to below the level of detection, while concentrating the resulting foamate into a very small volume. For example, the system reduced PFOA from 5,110 ng/L down to < 8.9 ng/L as its foamate concentrated the compound to 233,000 ng/L, demonstrating highly successful removal. In another test, PFOA in foamate exceeded 9,000,000 ng/L.

In another leachate source, PFOS started out at 659 ng/L and was removed to < 10 ng/L with its foamate as high as 6,000 ng/L. PFHpA (a short-chain molecule) also showed successful removal efficiency, including in one leachate starting at 3,940 ng/L down to < 7.62 ng/L and foamate at 143,000 ng/L. LEEF has shown to be able to remove up to 100 percent of priority PFAS compounds and has proven significant reductions for other PFAS, including short-chain compounds like PFHxA, PFBS, and PFPeS.

Bethlehem Landfill Taking Proactive Action
Building on demonstration results, the LEEF System® will soon be deployed at Pennsylvania’s Bethlehem Landfill, owned and managed by the Bethlehem Landfill Company—a subsidiary of Waste Connections.

Jim Hunter, WCG CEO, said that the LEEF System® represented a significant step forward in treating PFAS in leachate. “The LEEF System® uses an advanced foam fractionation process and proprietary techniques to consistently achieve PFAS removal from water and high-strength wastewater such as landfill leachate.”

“It was developed treating landfill leachate involving years of research and rigorous testing on a wide range of waste streams, including those with high levels of co-contamination. It has already achieved great success demonstrating treatment of some of the most challenging leachates in the United States,” said Hunter.

Leachate Management Specialists (LMS) has come on board as a partner with WCG, bringing along their extensive expertise in leachate management. Brad Granley, President of LMS, said, “The results we have seen have been phenomenal. We are talking leachates that have extremely complex background chemistry and contain PFAS, then being treated through the LEEF System® and becoming suitable for discharge to wastewater treatment plants. Bethlehem Landfill Company is leading the way and will be the first of many LEEF System® installations across the country, ensuring continuous disposal access for landfill operators.”

He added, “It’s hard to overstate the environmental and financial advantages for our clients as early adopters of this type of technology. The importance of being prepared for what is to come is clear, as are the consequences for those who are not.” | WA

The LEEF System® was developed in Australia by leading environmental engineers from the Water & Carbon Group (WCG) to address PFAS contamination in leachate, water, and wastewater. WCG has partnered with trusted U.S. firm Leachate Management Specialists (www.leachate.us) to introduce the LEEF System® PFAS removal solution to the U.S. solid waste market. WCG will have the first LEEF System® in the U.S. operational later this year. For more information about the LEEF System® PFAS treatment technology, visit leefsystem.com.

Originally published in Waste Advantage Magazine

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