Industrial pond

Destroying the Forever Chemical

A Novel Concept to Remove and Eliminate PFAS

Per- and polyfluoroalkyl substances, or PFAS, have earned the nickname “Forever Chemicals” because of their extremely slow degradation times and retention in the food chain. They also present a clear health hazard.  To date, there are only a small number of methods to both treat and eliminate PFAS compounds in wastewater. But a project currently underway at HDR will be one of the world’s first processes to do it, and in a cost-effective manner.

John Schubert, industrial process technology lead, is advancing our options for tackling this growing problem. He was selected to HDR’s Fellowship Program to develop a process that aims to remove and destroy PFAS concentrations from landfill and industrial wastewater streams. We sat down with him to chat about the work and potential applications for our waste, industrial and drinking water clients.

What is your fellowship project, and how does it address PFAS in water?

Froth flotation
Froth flotation in action to remove PFAS from landfill leachate. 

Current PFAS treatment technologies can reduce concentrations, but they don’t destroy the chemicals. Instead, PFAS are removed from water and transferred into another medium.

My goal is to remove and destroy PFAS. The PFAS separation process uses air bubbles to pull PFAS ions to the surface. The bubbles rise to the top, where a froth layer forms, which helps us capture more than 99% of PFAS. That’s the first, and more understood and studied, phase.

The second phase of the project is more novel. We are researching a process that will destroy PFAS. What’s left is carbon dioxide, water and fluoride ions. We’ve done bench testing and have encouraging results. After receipt of the last round of testing, we plan to start testing along with our separation process pilot work.

What has inspired you to find a way to destroy PFAS?

Anyone I’ve worked with will tell you I’m not an environmental alarmist, but I see PFAS as the environmental challenge of our time. PFAS were first developed about 70 years ago, and today every human being has a few parts per trillion in their body. They’ve been found in arctic ice.  They build up substantially in the food chain. PFAS are everywhere, and they’re strongly suspected to be a carcinogen, and have been proven to be an endocrine disruptor. If we don’t get them under control, the problem is going to get worse.

This work presents an opportunity to not just move the PFAS from industrial or landfill wastewater to a solid or concentrate, but to destroy them, so they don’t find their way back into the environment.

Why are landfills a PFAS target? Could other industries benefit from this concept?

The initial focus of our work has been treating landfill leachate, a major pathway for PFAS into groundwater from legacy unlined landfills and surface water, since most wastewater treatment plans are not able to remove it effectively. [For example, Minnesota found PFAS contamination in groundwater at 97% of its closed landfills. About 58% exceeded the state’s drinking water standards.] We’re performing some pilot tests for landfills around the country. Early results have been encouraging.

Eventually we hope this can also be used in drinking water treatment plants that use reverse osmosis processes. There are also a number of industrial or manufacturing clients who may have PFAS contamination in their wastewater that could benefit from this process.

What’s your ultimate goal for PFAS treatment?

Simply put, to create a cost-effective PFAS removal and destruction process. More specifically, we’re hoping to capture the PFAS in less than 1% of the flow being treated. For the PFAS destruction phase, the goal is to reduce the concentration in treated water to under 1% of the initial PFAS concentration.

Connect with John Schubert or Landfills Practice Leader Jeff Murray if you’re interested in learning more.