3/6/2025
WT Staff
 Got water questions? Give us a call at 877-52-WATER (877-529-2837), or email us at info@wtny.us
March 7, 2025 1012 am EST
University of Georgia Professor on a mission to "separate and destroy" PFAS
An interview with Dr. Jack Huang, UGA Griffin
WT: Thank you for joining me. We've got professor Jack Huang here to speak about his research with PFAS filtration systems for drinking water facilities. Dr. Huang, give us a bit of background on your research program.
Jack Huang: It's my pleasure to have the chance to talk about my research here. I am a professor at the University of Georgia, located at the Griffin campus. I have a water chemistry lab here. In in the past ten years we have been working on PFAS. My research is on development of new technologies to address PFAS (per- and polyfluoroalkyl substances) contamination, particularly in water. I develop new technologies to treat PFAS more efficiently, more effectively.
WT: Are there particular PFAS that you are doing your research on, or is it the general class of PFAS?
Dr. Huang: We are targeting the general PFAS. For most of our studies we like to use PFOS and PFOA as the model compounds simply because these are the most representative, the most widely detected PFAS and the hardest to treat. So for those reasons, we usually use those as model compounds to work with. With the technology we develop, we want to cover a wide range of PFAS.
WT: I understand there are three major stages involved to deal with PFAS: to separate, to concentrate and to destroy the compounds. Is this correct? Is it a filter you are building? Tell us about your system, what is the mechanism?
Dr. Huang: Generally speaking, this is correct. With drinking water or wastewater, it is a large volume bulk water we are dealing with. There are two types of technology involved, the waste separation technology which simply moves the PFAS from one phase to another, concentrating the PFAS without destroying them. For example, we can use granular activated carbon or ion exchange resin, or a membrane technology. These are very efficient ways to remove PFAS from water, but the PFAS are still there. The special property of PFAS is that they do not degrade easily. Although you transfer PFAS to another phase, you still face a problem. So the challenge is, how to dispose of this waste so the PFAS does not get back to the environment. That is why another class of technologies are also important, we call them destruction technologies.
The common understanding for utilities is a "whole package solution", a separation technology coupled with a destruction technology. My lab has focused on developing new destruction technologies, particularly electro-chemical oxidation (EO). We have found the best approach is to combine EO with a promising separation technology, the so-called ion exchange resin. Most of the PFAS class have a charge, so we can effectively remove PFAS with ion exchange. Eventually those PFAS compounds will break through the resin material, reaching its capacity where it cannot remove any more PFAS. At that point you can regenerate the ion exchange resin, you wash that column with a solution of organic solvents so it can be used again, saving cost. Now the wash solution will contain very high concentrations of PFAS, but a much smaller volume than the original contaminated water.
Usually, the destruction technologies are concentration-dependent. The higher concentration waste stream has high energy, so the next phase, the destruction stage will be energy efficient. This is certainly the case for the EO technology that we have developed. We have been studying how to couple EO technology with some other separation technologies, like nano-filtration, we have tested that as well. Our development is focused on new destruction technologies but we also do research on separation technologies for how to couple these together, in the most energy efficient way.
WT: I see the importance of having the PFAS completely destroyed within the facility. Is there a risk associated with handling the toxic concentrate? Will this change the requirements for water operators, some specialized skill level required?
Dr. Huang: The highly concentrated waste is certainly one factor to be considered. Generally speaking, if you do destruction in your facility, you do need some skills. More consideration should be given to the technology itself. Some may demand higher level of logistics or special skills. Some systems may be more difficult to operate, these are factors to be considered, for the utilities.
WT: I understand there is a legal challenge against the US EPA on the new PFAS regulation, though this is not expected to extend the timeline for drinking water facilities to be ready for compliance in April 2029. Where are you at in your research and development timeline? What's your technology readiness level for the EO?
Dr. Huang: We have an industrial partner, AECOM, working on marketing the technology in partnership with another company called Aquatech. They are calling it DE-FLUORO. We do have communications with the industrial part, they come to me if they have questions. In the past our research was funded by the Department of Defense DOD, for (removing PFAS from) contaminated groundwater, they were also working on that. As you know, the drinking water regulation for PFAS came in last year, so it is kind of a new thing. In terms of technology readiness, it is at the full scale, whatever the highest level is.
See DE-FLUORO PFAS DESTRUCTION TECHNOLOGY, here.
WT: Concerning the the capital cost and the operating cost of the new technology, is AECOM working out the construction plan, most effective configuration for each facility?
Dr. Huang: The technical and economics is in their hands, they are working on that. Each facility is going to have some limited differences, for example the daily volume of water through the plant. AECOM said it is going to be a case-by-case scenario, depending on the water quality and volume. They provide a complete service from the beginning, testing the bulk water and then provide the solution, provide the equipment and they even help to operate it. I believe that is how they provide service, that's the kind of approach they are taking.
WT: I see there are considerations for certain contaminants like iron and manganese, these will reduce the efficiency of the Phase I separation technology. Do the utilities need to remove these contaminants before PFAS separation process?
Dr. Huang: We did a lot of experiments with different kinds of water and different waste streams, including dirty water. Obviously if you have other components in the water, it will have some sort of impact on the equipment performance. The kind of service that AECOM is envisioning is starting with testing the bulk water. Based on water quality they design the process. Another thing, with EO everything happens on the anode. The anode is the interface, anode conditions are more important than the bulk solution conditions. Bulk water quality will have some impact, but not as much as you would expect.
Our patent is on the anode materials. We work with a material known for many years as promising and with great potential. It has a lot of advantages, but it hasn't been used so widely. The materials requirement is very stringent because it has to sustain very aggressive oxidative conditions at the anode. So there are only certain materials we are able to use for that purpose.
WT: Are you saying that the materials you have patented are going to work on a wide range of bulk water quality?
Dr. Huang:That's right. Our patent covers not the material itself, but the application of that material on PFAS, the water treatment with PFAS destruction.
WT: Are those materials difficult to find or replace? Are they rare? Can you get them in the US?
Dr. Huang: It is common, the material itself is not hard to find. It is not hard to fabricate either. That's another advantage compared to other materials for the anode. The thing right now, it is not so commercially available yet, because it depends on the market. I think when there are more applications, more uses of these materials then it's the economy of scale. When you use more, the cost will go down, availability will increase.
WT: So are there people that will be manufacturing your anodes, will AECOM also take part in that?
Dr. Huang: I believe AECOM, in partnership with some suppliers.
WT: Have you had any recent breakthroughs or was there anything that surprised you along the way as you have been doing your research with this material?
Dr. Huang: Yes. As researchers, we always try to further improve. There are new findings around this technology and we believe with these new findings we will probably be able to further improve. We have further thoughts, some different thinking for better efficiency. We are working on it.
WT: Do you have colleagues at other universities that you can collaborate with in this field?
Dr. Huang: We collaborate with a lot of people including people from Georgia Tech, we have ongoing projects working with Georgia Tech professors. We go to academic meetings, industrial meetings working with different types of people. We also communicate our research with publications, and presentations at conferences.
Interview with Erik Olson, Natural Resources Defence Council on new US EPA regulations for PFAS in drinking water, here.
|
|
|
