Dr. Jacqueline Quinn, Environmental Engineer, NASA’s Surface Systems Office, Kennedy Space Center, Florida
- Tuesday, 01 March 2011
NTB: What led you and your colleagues to believe that a simple mixture of iron particles, vegetable oil, water, and a surficant would have the effect it does on these chlorinated solvents? Was this a theory your team developed from the start, or the fortuitous result of research into some other area?
Dr. Quinn: Well, when we first started working on this, which was in the late 1990s, there was a lot of emphasis out there on using iron to clean up chlorinated solvents. Iron and water will degrade chlorinated contaminants when it’s in the groundwater and it’s in a dissolved phase. That means it’s not existing as a pure product, but it’s dissolved in the groundwater. That technology, although it works great and has wonderful applications, does take a long time to clean up a product if you’re dealing with really high concentration contamination because you have a product that has to dissolve into the groundwater, flow through a bunch of iron and water that’s put into the ground – little chiplets of iron – and then come out the other side clean. So it doesn’t really address the high-concentration contaminants.
Our vision was to take the reactants and encapsulate them within an oil bubble. So the reactants are water and iron, and the oil bubble is vegetable oil. If you go by the old adage that “like likes like,” what we’re trying to do is we’re trying to encapsulate the reactants in something that we know the contaminant is attracted to. Because they tend to aggregate together, we knew that the contaminant would move over into the vegetable oil and there would be a concentration thing that would drive into the reactive portion of this bubble. So it really, truly was not just a fortuitous thing that we stumbled upon, but a design element that was implemented with a chemical background.
NTB: How were these chlorinated solvents typically treated before the invention of EZVI?
Dr. Quinn: In the 1980s and 90s most of the accepted remedies were to pump the water to the surface and treat it in some sort of surface reaction chemistry to get the contaminants out of the groundwater, and then you would pump the groundwater back into the ground. That was pretty much the standard status quo. Of course, you know, you’re only getting out a hundred gallons of contamination or a hundred pounds of contamination over a year, or over a lifetime of operations. So you’re only getting that dissolve phase affected.
That was pretty much the nominal way of doing things, or through this passive treatment through the iron walls, which is something that was evolving in the 1990s. But as we got to the end of the decade, towards the 2000s, there started to be a lot of emphasis on how do you clean up the product, the really high concentration stuff.
NTB: Will this remediation technique work on any other forms of pollution?
Dr. Quinn: Yes. It works on any halogenated compound, which in basic terms means it works on pesticides. It works on your dry cleaning fluids that may have ended up in the subsurface as well. It will work on Freon and fluorinated compounds. Interesting research has recently come out of similar science compatriots out in Colorado. They’ve done some recent tests that showed that it works for polychlorinated biphenyls, or PCBs. They’ve recently been in the news as a contaminant of interest.
NTB: Has EZVI technology been licensed for commercial use yet?
Dr. Quinn: Oh yes. It has at least 7 or 8 licenses now, and it’s been used in over 16 states throughout the U.S. They’re in the process of being used overseas in Europe and Asia as well.
NTB: You are currently working on the RESOLVE project, RESOLVE being an acronym for Regolith and Environment Science and Oxygen and Lunar Volatile Extraction. What is the RESOLVE project, and what is it designed to accomplish?
Dr. Quinn: RESOLVE is a prospecting instrument. It prospects for volatiles and resources that NASA may be able to use on a different planetary body to help with their exploration or human habitation of the body of interest.
RESOLVE is an instrument that’s mounted on a rover and it has a drill that accompanies it, and the drill takes a meter-deep core sample of soil, or regolith as we call it when you get off the Earth. It takes a core of that regolith; brings it up; crushes it; puts it into a reactor, or an advanced [ ? ]; and heats it up causing any volatiles such as helium, argon, carbon dioxide, carbon monoxide, water ice – which is of particular interest – and it causes those to volatize. We then detect those volatiles of interest using analytical instruments such as a gas chromatograph and a mass spectrometer. We get those quantified and qualified as to how much material, how much resources are there.
In certain instances – if it’s water for example – we can actually capture that water and store it. We also have the capability of taking that soil and extracting the oxygen from the mineral content and collecting it in the form of water, which could be used later to either make propellants for propulsion, or it could make oxygen for human habitation breathing air. So it’s a prospecting tool, kind of like a miner. It goes out and says, “What do we have here that we can use for either continued habitation, or to get to another location, or to return to Earth?”