Innovative Nano-Process Removes Pollutants from Groundwater

Researchers from Rice University, DuPont Central Research and Development, and Stanford University have announced a full-scale field test of a new process that gently but quickly destroys contaminants. The technology is called PGClear and it originated from basic scientific research at Rice during a ten-year, federally funded initiative to use nanotechnology to clean the environment. PGClear uses a combination of palladium and gold metal to break down hazardous compounds like vinyl chloride, trichloroethene (TCE), and chloroform into nontoxic byproducts. "Chlorinated compounds were widely used as solvents for many decades, and they are common groundwater contaminants the world over," says Michael Wong, a professor of chemical and biomolecular engineering at Rice. These compounds are found at more than 60 percent of the contaminated waste sites on the Superfund National Priorities List.

Transcript

00:00:01 [Music] I want to create something that can solve our problem of dirty water you can't do it in one day you can't do it in one year and so my whole idea has been what can we develop from the nanotechnology point of view that we can grow into a real working technology to address the issue of dirty water so this is what I'm talking about

00:00:30 here these are pellet particles that we're going to insert into our reactor and these alumina pellets are normally white looking but in this case here they're violet colored and that's because it's infused with small bits of gold and Palladium one of the first things that we did when uh my program was starting up at Rice was to look at the problem of

00:00:52 tror ethylene contamination of water tce tce is this organic solvent molecule that is very popular to use uh when you're working with Metals you use it to degrease Metals basically uh the problem is is that this TC has been used in such large volumes that inevitably a lot of this tce ends up in the groundwater and so how do you get rid of something that's underground that's in contact

00:01:23 with groundwater that's flowing slowly and picking up small amounts of tce every minute and that's a problem that we're trying to solve once we discovered the problem and realized just how tremendous this problem was in the US but also in other parts of the world we decided to set on this course of finding a new technology to help solve this problem and we felt that nanotechnology

00:01:48 and catalysis would be able to do the trick what we didn't realize was just how good the materials that we made turned out to be turns out that small bits of padium and gold metal two metals that you wouldn't normally associate for cleaning water turns out cleans water very very well what we have here is our mini flow reactor this is where we have been doing our preliminary studies it

00:02:15 consists of a water reservoir where we have a chloroform water and hydrogen the water will be saturated with hydrogen it will flow through our system the pump is going to flow the water through our reactors where we have these Paladium gold pellets what's going to happen is that the chloroform and the hydrogen will uh react in the surface of the Paladium and will be converted into

00:02:40 methane after publishing these papers we then expanded our directions to look at other types of contaminants to understand better just why did padium and gold bits of metal was able to do the trick so much better than what's out there now so one of the projects that I'm really excited about nowadays is the the chloroform water cleanup project that I have in

00:03:02 collaboration with Dupont Dupont has a site that's been contaminated accidentally with chloroform this chloroform is soaked into the ground and they're currently have contained it and they're cleaning it up now they heard about our hyperactive Plum gold materials and now we're partnering up with them with Stanford to create and build this

00:03:23 reactor which will contain our pellet that contains the platium gold and we're going to place this reactor at that site to do and initiate the field testing at that contaminated chloroform site I'm pretty excited about it that something that I develop is going to be actually going to be used in a real world conditions