Daniel Strawn, professor of environmental soil chemistry from the University of Idaho, joins Logan Finney to discuss his research in using biochar to capture nutrients from wastewater and distribute them back into the soil. They also discuss a paper he recently published with in collaboration with the Canadian Light Source and the University of Saskatchewan that showed how the biochar and particular minerals interacted, allowing them to refine the process.
READ: University of Idaho Research into Nutrient Capture
Logan Finney, Idaho Reports: Joining me this week is Daniel Strawn, who is a professor of environmental soil chemistry at the University of Idaho, to discuss some research that he worked on regarding phosphorus absorption in nutrient enhanced biochar. Professor Strawn, thanks for joining us.
Daniel Strawn, University of Idaho: Hi. Thank you for having me.
IR: So, nutrient enhanced biochar sounds very science-y and technical. You’re the one who did the research here and I’m not. Can you give us a layman’s understanding of the science here and the research you were part of?
Strawn: Sure. So, this research project is- this one paper that just came out, it’s a product of a collaborative effort between several investigators and myself and another PI, Greg Möller, have been working on using biochar to recover phosphorus and nitrogen, which are major plant nutrients, and recovering them from wastewater. And we use it in agriculture as plant nutrients. And so, we developed the technology of using this biochar.
So let me explain real quick what biochar is. Biochar is essentially in a very layman’s term, it’s just like the charcoal you use in your barbecue. And now there are differences, but it’s very similar. So this biochar is produced from waste biomass, another probably technical term, but you can think of waste biomass as agricultural residue. For example, when you harvest wheat, we only use the grain, and the stalks and everything else are left over. Well you can recycle that and create this charcoal, what we call biochar, of forest biomass.
IR: And biomass is something that folks might be familiar with in the clean energy space, right? It’s sort of an energy production that’s not relying on fossil fuels.
Strawn: Right. So, yeah, that’s a good point. Take, for example, a lot of the biochar we’re using now, what we call the feedstock or the main ingredient, is actually forest biomass. So that’s perhaps a beetle kill or a forest fire went through and there’s a lot of trees that have died. They’ll harvest those. And that’s what we call biomass. And then so you can use that to produce energy actually in pyrolysis which is essentially heating up that biomass in the absence of oxygen and it’ll produce a biofuel. And so that’s what you’re referring to.
And then a byproduct of that biofuel production is the biochar or charcoal. And so, we’re taking that bio char, and we found that it’s very reactive. It’ll sequester or absorb chemicals from solutions. And so, we developed a process that we can use this biochar to treat wastewater such as municipal wastewater, agricultural drainage, food processing water, or, for example, right now we have a pilot trial going on at a dairy to treat that dairy wastewater.
And what we’re trying to do is use this biochar and if we can, you know, wastewater has a lot of nutrients in it. Phosphorus and nitrogen, that’s what causes algae growth in streams and lakes. And so, we want to take that out, that phosphorus and nitrogen which is a fertilizer, and we put it on the biochar and then we take the biochar and we can use it to grow more plants. And so it kind of replaces the traditional fertilizers that farmers would be purchasing. And so it’s really what I like. The big picture here is recycling. We’re using biochar to recycle nutrients out of water and instead of, you know, them going off into surface waters or just being discarded, we actually can reuse them. So that’s the big picture of what we’re doing.
IR: Yeah, it seemed to me like there’s kind of two ends of this process. There’s using the biochar, almost like a sponge, to soak up the minerals where they would be discarded. And then you can actually use that in fertilizer. Is that the right understanding?
Strawn: Actually, yes. Perfect. What’s really neat about it is a lot of, you know, in agriculture and in social science, there’s a lot of people really interested in adding biochar to soils, it could improve soil health. And what we’re suggesting is that, okay, we can do that. Adding biochar to soil can be good, but why not add some of these recycled nutrients at the same time and offset the fertilizers that you’d traditionally have to buy? A major addition to increasing soil health, it also sequesters carbon. So biochar, when you add it in the soil, it can last for 100 to 1000 years. So that carbon is essentially in that soil and it reduces the overall carbon loading to the atmosphere, or offsets it, I should say, by adding the carbon to the soil.
IR: In terms of soaking up these or capturing these minerals like phosphorus and nitrogen, in wastewater plants, that has environmental benefits as well too, doesn’t it? Personally, I’ve done some reporting and coverage in the Lake Coeur d’Alene Basin. They’re working very, very hard and the state has invested a lot of money in preventing phosphorus loading into the lake for some environmental concerns from historical mining up there. And of course, phosphorus causes algae blooms all over the country. So, is this also an environmental technology possibly?
Strawn: Yes, exactly. I think what was really neat about this project is we really tick off a lot of boxes. I mean, we’re capturing carbon, we’re recycling nutrients, and we’re cleaning water with the technology. We incorporated biochar in a water treatment technology, and that technology, we actually have a patent for that. And with this technology, we can essentially reduce phosphorus down to below detection level. And so that’s great because otherwise a lot of wastewater plants or agricultural industries, they are emitting phosphorus and nitrogen into surface and ground waters. And like you said, it creates a big problem in promoting algae growth. And you may have heard of things like harmful algae blooms. And so all that’s bad, and it’s caused in freshwaters and estuaries and it’s big in the Gulf of Mexico. It’s all caused by excess nutrient loading. And so this technology has the potential to be part of the solution for capturing those nutrients and keeping them out of out of the water.
IR: Like you referenced, the University of Idaho now holds a patent for this biochar water treatment process that you worked on. You also worked with researchers from Washington State University and the University of Saskatchewan, is that right?
Strawn: Yeah, that’s correct. Manuel Garcia-Perez and Derek Peak are professors at those universities, and they were instrumental in moving this project forward. You know, all our research is usually done by a collaboration. So it was really good to work with them. Manuel Garcia-Perez is a professor at Washington State University. He is an expert on biochar production. And so he had some really interesting biochars that we did a research on and reported on in this paper. And Dr. Derek Peak, he’s at University of Saskatchewan, and he’s an expert on phosphorus chemistry and has a similar skill set as I do. But he’s at the University of Saskatchewan, right next to the Canadian Light Source, which is a giant synchrotron up in Canada, so he really is an expert at using that facility. We collaborated and worked together to collect some really unique data to help us understand how this biochar can be used in water treatment.
IR: Yeah, tell us a little bit more about the Canadian Light Source, that giant synchrotron. Tell us not too technically, but tell me, what is this facility and what did it specifically allow you to look at here?
Strawn: Sure. Right. So, um, a synchrotron is essentially- imagine something of a big circle the size of a football field, diameter of a football field. It’s got a ring on the outside and essentially protons go around this ring. As they’re bent around the ring, they emit X-rays. And so, an X-ray is essentially what we call the light source. Um, and so the synchrotron can produce really bright X-rays. I mean, oh I can’t remember off the top of my head, but on the order of 100,000 or a million times brighter than the X-ray that you go to the doctor to get your hand X-rays with. So they’re really bright. And so we can put this biochar in front of those X-rays and it gives us some information about the biochar and the phosphorus, how they’re interacting. So it’s a very advanced technique. These facilities are, you know, hundreds of millions of dollars to build and operate. And so they’re really-they’re very powerful and it’s really, a great opportunity to work with them. It’s very competitive to get time at them. So we were very fortunate because there’s a lot of scientists that want to access them, so they have to limit the availability. So we were really, really fortunate to be able to use the Canadian Light Source to really discover how that phosphorus is interacting with the biochar and by getting information on how they’re interacting, we can customize and tailor the process to work better and really come up with a technology that is optimum for removing the phosphorus and adding it back to the soil and the fertilizer. And so that’s what we did with the Canadian Light Source.
IR: Very cool. So now that you’ve published this paper about the research you did with the Canadian Light source, what are the next steps for you in this research?
Strawn: Yeah, so this paper was in my field, I would say it was a little bit on the fundamental side, discovery side of the research. So the next step is to try to move it a little bit more towards the applied side. So now that we’ve discovered how the biochar and phosphorus interact, we can, like I said, customize the process and we want to test it in growing plants. And so we’re right now, even today, we have a pilot-scale process at a dairy. We’re recovering dairy nutrients on the biochar, and then we’re going to take that biochar and we’re going to do a field trial on a crop in southern Idaho and see how it works for growing plants. As a biochar, like I said, it will improve the soil health and now we’re providing nitrogen and phosphorus into the soil. So it’ll replace some of the conventional fertilizers that farmers will put on. And so that’s really what the next step is for us, is to see how it’s going to work as a soil amendment, plant growth, nutrient supply.
IR: All right. Well, this is a very cool intersection of agriculture and science and academic research. Is there anything else that you think our audience should know about this project that you’re working on?
Strawn: Well, I think, you know, like I said, we’ve been fortunate to have a group of collaborators. The research is supported by the USDA and EPA from competitive grants. The EPA is interested in producing clean water and preventing nutrients from causing algae blooms, so they like the technology. The USDA is interested in making more sustainable, in this case, dairies, so that, you know, the nutrient cycle can be essentially recycled and actually capture those nutrients instead of wasting. So we’re really fortunate to have that support for the research.
IR: All right. Daniel Strawn, professor of environmental soil chemistry at the University of Idaho, thanks for joining us this week.
Strawn: Thanks for having me, Logan.
Logan Finney | Associate Producer
Logan Finney is a North Idaho native with a passion for media production and boring government meetings. He grew up skiing, hunting and hiking in the mountains of Bonner County and has maintained a lifelong interest in the state’s geography, history and politics. Logan joined the Idaho Reports team in 2020 as a legislative session intern and stayed to cover the COVID-19 pandemic. He was hired as an associate producer in 2021 and they haven’t been able to get rid of him since.