You’ll learn from Bryan Staley, President & CEO, Environmental Research & Education Foundation (EREF), and Kevin Torrens, VP, Brown and Caldwell. The discussion covered cover treatment options and technologies for per- and polyfluoroalkyl substances (PFAS).
Here’s a sneak peek into the discussion:
Torrens presented first and observed that, “This is my own perspective, but landfills are a great place for PFAS to be. It's a secure place; well controlled and well managed.” But, “how do we manage PFAS and leachate?” It's very different, he noted, than most of the work that has been done thus far in dealing with PFAS. “Everybody thinks drinking water and groundwater and so forth, that's really easy. The reality when I think about it compared to leachate…you don't have all these other co-contaminants that can adversely impact whatever technology you're looking at.”
He went on to note that, it is “really important to recognize that one size does not fit all” when it comes to technologies to tackle PFAS in leachate; “it's a matter of fitting the tool to the problem and making sure we're using the best technology for the particular situation at hand.”
For now, the options are to “zero discharge, evaporate it, or deep well.” And, broken down into two levels, there are non-destructive technologies and destruction technologies. “The non-destructive technologies that are suitable for leachate, those are the ones that are available to us today. Destruction technologies, they're not ready for prime time.”
Torrens went on to elaborate on the pros and cons of the various options available today, and what may be possible in the future. But, “at the end of the day, if society wants PFAS controlled, there's a cost for doing that, and landfill are a great place to do it. It can be regulated, but there's going to be an impact to the public, depending on what the industry does.”
Staley then shared his perspectives on research regarding PFAS: “When we think about research, we tend to look at a landfill really in the form of a mass balance. You've got PFAS coming in and the incoming waste. You've got the PFAS and the leachate going out. That's pretty much what the primary focus of the discussion has been.” Then, “you also have potential PFAS exiting in the form of emissions.” He also talked about “the concept of sequestration of PFAS in the landfill; when we think about this from a research or a data gap standpoint, we're looking at all of these entry and exit points or these reservoir points and asking the question, what's happening along the way as this PFAS is dynamically moving into the landfill and conceivably moving out of the landfill or staying in the landfill?”
“As I think about managing PFAS from a lay perspective,” Staley observed, “we're either we're going to sieve it out, we're going to have it stick to something and then pull that out, or we're going to try to completely destroy it or partially destroy it. Those technologies that Kevin mentioned are embodied in these three primary mechanisms for the most part.”
“One of the things that's interesting about this forever chemical, PFAS,” Staley noted, “is really, why is this different than anything else that we have to deal with in leachate?” A lot of it, he said, deals with “the energy that it takes to break the bond. Maybe the picture to put in your head, if you have two kitchen magnets and you put them together and you pull those apart, that's pretty easy.”
But, “imagine if you had two industrial grade magnets and you put them together, it would probably take two or three people to actually pull it apart,” which he compared to the bond energy between carbon and flourine. “When you're talking about treating BOD or other kinds of organics in leachate, that's a much easier proposition than having to deal with breaking apart the carbon-flourine bond, which is why a lot of the current on-the-shelf technologies deal with really filtering it out and then figuring out what to deal with that more concentrated form later.”
He went on to talk about several technologies in the research phase, including electrical plasma discharge, hydrothermal processes, and advanced combined processes, “which really are additive or in combination.” He also looked at potential PFAS exposure pathways and current research around such, aiming to put this topic into context “as we look at what the road ahead holds for us in terms of managing PFAS.”
Listen to the full episode here.