Podcast: Don't Throw Away Coffee Grounds; They Could Solve The World's Water Crisis!

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Podcast: Don't Throw Away Coffee Grounds; They Could Solve The World's Water Crisis!

In this episode, we discuss research coming out of George Mason University which could provide an affordable and accessible way to get clean water using spent coffee grounds as a filter!

In this episode, we discuss research coming out of George Mason University which could provide an affordable and accessible way to get clean water using spent coffee grounds as a filter!


(1:00) - Don’t Throw Away Coffee Grounds; They Could Solve The World’s Water Crisis!

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Hey folks, think back to this morning when you woke up. You brewed yourself a fresh cup of coffee. Did you throw this coffee grounds away? Well, we're here to tell you why you shouldn't. Don't throw away your coffee grounds because they're gonna help us solve the world's water crisis. So, grab your cup of coffee and snuggle up and listen to this podcast because it's gonna be a great one.

I'm Daniel, and I'm Farbod. And this is the NextByte Podcast. Every week, we explore interesting and impactful tech and engineering content from Wevolver.com and deliver it to you in bite sized episodes that are easy to understand, regardless of your background. 

Daniel: What's up folks? Today we're talking about the reason you should not throw away your coffee grounds because they can help us solve the world's water crisis. And it's a little bit of a sweet spot for Farbod and I. A couple episodes back we mentioned, or I guess used our first article from our alma mater, George Mason University. In this case, we're hitting even closer to home by going back to the department that we studied in and where we met each other at the Department of Mechanical Engineering with Professor Jeff Moran, who happened to be one of our favorite professors while we were there at Mason. So again, if you didn't think we were biased enough the last time we talked about George Mason, you're definitely gonna think there's some bias here now when we're talking about one of our favorite professors from the program that we both graduated from, who actually does research pretty adjacent to the research that we were working on when we met each other. So, I just wanted to put those disclaimers out there so no one comes after us and said, oh no, I know you went to Mason. I know you like Dr. Moran come and try and tarnish our reputations because of that.

Farbod: Look, it took three years for us to talk about our alma mater, and then finally we get to feature something from the department of the school that we worked on. So of course we're gonna be a little biased, like come on, you have to be. But that doesn't discount the fact that they're doing some really cool stuff that's gonna have a great positive impact on the world.

Daniel: Yeah, and then let's just kind of contextualize the problem that they're trying to solve here which is our water problem. A lot of times, and I've heard this saying be used colloquially a lot more, is like the, and let's say the most recent industrial revolution, whoever had the most oil, those are the folks that ended up prospering, those are the folks that ended up, ending up very, very lucrative situation. Think about like all these super rich Saudi princes who inherited oil, or folks in Alaska who get paid every single year from the government because they live in this land that's so rich with natural resources. Well, the most valuable natural resource, a lot of people say moving forward, and the one that will become the most scarce, especially with the increasing size of the population in the world is water, is clean, drinkable water. And dirty water is a huge problem around the world because it's bad for our health, it's bad for the environment. And any way we try to clean bodies of water is very, very expensive. Most of them don't work that well. And most of them have other knock-on effects to the environment. So basically, we don't have that much clean water. The percentage of it that we try to clean, we don't do that well. It costs a lot of money. And it has other knock-on effects that we're worried about. It feels like a lose, lose, lose situation.

Farbod: Yeah. And I think it's worth noting, again, just how big of a this problem this is. The UN has made it one of their, what was it that we talked about a couple episodes ago with the UN's missions for the clean world?

Daniel: I think global sustainability goals.

Farbod: There you go, their global sustainability goals. One of them, one of the most important ones is clean water because they're already predicting that, like you said, it's gonna be one of our most scare resources. And you're absolutely right, there's solutions that exist and if there's this Venn diagram of being too expensive and potentially having byproducts that hurt the environment even more, a lot of them fall right in the middle. So that means it's a crossover of both. But I think where affordable solutions would be the most impactful are in societies or communities right now where they don't have access to clean water. So, water might become more scarce for us in the future where we have to be more conscious about how much we're flushing our toilet or how long of a shower we take. But there are a lot of communities right now that still don't have access to clean water and there are filtration solutions but they're just too pricey for them to use at scale. So, if there was something that was affordable that could scale and still provide high quality filtration then that could like as of today have a great immediate impact.

Daniel: Yeah, and I think one of the awesome things that this team from George Mason has done is they take a lot of these different pain points, right the pain point that it's really, really expensive. It isn't that effective. It's harmful for the environment. They took all those three main pain points and use them to design the three main features of what their coffee bots are so awesome at. And I don't want to beat around the bush too much because I've kind of, kind of let the secrets slip out by using the name, coffee bots, but they made these little tiny cleaning nanobots made from used coffee grounds. I think the scientific term they use in the papers, SPG, spent coffee grounds. I love the scientific term there, but they're using spent coffee grounds, which are biodegradable by the way, using those as a substrate by which they basically do a bunch of nano engineering to it, cover it in a bunch of different nano particles that help them be able to manipulate these tiny, let's call them like coffee bots, super bots through the water, manipulate them to help direct them to areas that need to be clean and then to retrieve them after they're done. Spunk coffee grounds are super abundant. They're everywhere. That really addresses the expensive part. And then they do specific nanoengineering to make sure that these things work really, really, really well. So, they addressed the harming the environment part by making them biodegradable and by making them easily retrievable. They address the part that is super, super expensive right now by using something that a lot of people's favorite drink every single morning. And then they use like the state-of-the-art technology part, the nanoengineering to make sure that they worked really, really well at cleaning water as well. Which again, like there's a lot of scientists and researchers out there who engineer something just to engineer it or discover something just to discover it. Or they make an incremental improvement that doesn't really align with the pain point of what's out there in the real world. I don't hate those researchers, but really it really feels to me...

Farbod: You wanna see real impact.

Daniel: Yeah, it feels like a little bit of a waste of like a lot of energy and effort if you're not solving real problem out there in the world. What Dr. Moran's group has done here is solve a very real problem and basically solve all three aspects of the problem in one fell swoop.

Farbod: And I gotta be honest with you, when I'm thinking about material or a product to use for a new novel application, spent coffee grounds is not something that comes to mind. But it's kind of interesting because a couple years ago, Ford announced that they were partnering with McDonald's to take their spent coffee grounds and make like high performance composites out of it for their headlights. And then now we're seeing this coffee bot that can pick up oil spills. And I think it's also worth noting that, by the way, the idea of coffee being used to clean up oil is not new either. It's something that's been around and investigated. And funny enough, by the way, as I was doing my research I came across this like rough video that was definitely taken by like some handheld camera of a mechanic seven years ago. He's like, yeah, I got an oil spill on the ground. No need to go to the hardware store. Just go to like the diner down the street, grab some coffee grounds, throw it on the ground, come back in the morning. It's absorbed, it washed away. It's good for the environment. So, like these ideas have been around, but what's really pushing the state of the art here is the fact that these coffee bots can move, right? And in addition to that, like you kind of hinted at earlier, is that they've been, are we spilling the sauce here, or are we gonna extend it out? They've been functionalized so that they can do more than just collect oil, they can clean the water to a certain extent that hasn't been done before.

Daniel: Well, yeah, let's, we've beat around the bush enough, let's jump into the secret sauce. The secret behind this technology, what makes it work, what are the ingredients in the secret sauce here? The first one that I'm gonna call out here, like you mentioned is the fact that they're using old coffee grounds. Coffee grounds are known to be an excellent agent at helping clean up oil spills and remove other contaminants from clean water because of their, I think it's, they've got like a really porous surface that helps them adsorb molecules. It basically means they get pollutant molecules, they suck it into the surface and then it's able to retain them there and keep them there.

Farbod: Like a suction cup that's just floating around the water.

Daniel: Basically, a giant or a really, really small suction cup that's floating around the water sucking up tiny particles. But then you mentioned it, they functionalize these particles using two main ingredients. The first of which is these iron oxide particles, which allows them to basically treat these coffee grounds as like little magnetic robots that they're able to control and move around the water. And that's really valuable in that you can use it to direct these coffee bots towards the spill. And we also mentioned earlier, but it makes for really, really easy retrieval of it once you're done. Obviously, unless you like drinking dirty coffee ground water, like if you spilled a bunch of coffee, or I guess used a bunch of coffee bots out in a pond to clean after chemicals spill. You don't want these coffee bots to clean up all the, suck up all the bad chemicals and then just continue to float there in the pond. That kind of defeats the purpose. Then you've still got the contaminant particles in there. And you've also added shredded up coffee grounds. That's not a win. So, by functionalizing these with iron, they're able to make them magnetic so that they can retrieve them very easily. It literally just takes using a magnet the same way that you use a magnet to control them. Yeah. You can use a magnet to pull them out of the water and then what you're left with is clean water.

Farbod: In addition to the adsorption to oils, I think it's worth noting that spent coffee ground is actually hydrophobic too.

Daniel: Okay.

Farbod: So that it's not…

Daniel: Sucking up the water.

Farbod: Exactly. It's not sucking up the water. It's sucking up the oil, which is exactly what you wanted to do.

Daniel: That's awesome.

Farbod: And you're absolutely right. The magnetic portion allows you to round when you're done with them. But what Dr. Moran and the team realized while they were doing this research is that if you're able to move around the coffee solution, you're able to pick up oil much more efficiently than if you, like the previous research, previous folks have done before, just leaving it there and letting it sit. So now you're able to clean it up faster and retrieve it more effectively, which makes this more desirable for a solution that you would actually use in the real world. So, that's already super impressive. But then you have this next layer of water cleaning that comes in the form of dyes. So chemical plants, manufacturers dump a lot of their pollutants into rivers and whatnot. So, if we had a way of extracting those dyes and pulling them out, it would be great. Now, unfortunately, a lot of solutions that can break down those dyes, they themselves are harmful for the environment. So, it's like “shoot, am I really willing to just like, arrest the environment in a different way by just cleaning up these dyes?” No, right? You would want to have a silver bullet solution ideally.

Daniel: And so, what they've done here is, right, they've created a platform. This platform is SCGs, spent coffee grounds, plus iron oxide nanoparticles that make these spent coffee grounds or these coffee bots magnetic. So, they can manipulate them and then they say, well, if we've already been able to add iron oxide nanoparticles to this, why don't we also use the same green chemistry method to nano assemble other particles onto there that can help us treat and remove specific chemicals. So, like you were mentioning, methylene blue is a very common dye in industrial wastewater that ends up getting polluted into our seawater in the ocean. They added ascorbic acid, which is just vitamin C, I think. They add vitamin C, which is like a very environmentally friendly version of these chemicals. You were mentioning that instead of just treating methylene blue and getting rid of it and causing another environmental issue, the vitamin C doesn't cause another environmental issue. It's eco-friendly.

Farbod: It's commonly found actually. Yeah.

Daniel: And they're able to functionalize these coffee bots, adding the ascorbic acid to it, which allows them to be even more effective at effective removing chemicals like methylene blue. And one of the things that I think is awesome there and very similar to the research we worked on in college is, I assume that this nano assembly method that they have to add these nanoparticles onto the spent coffee grounds to make coffee bots, I assume they could use a number of different functionalizing chemicals, right? If they they are able to find an eco-friendly chemical that helps clean up another type of chemical spill, they could also assemble those types onto there to make sure that you've got coffee bots that are specialized to do certain types of cleanups and are really, really effective at it.

Farbod: Yeah, absolutely. And again, something else I want to point out from the research I was doing. It's interesting, I did not know what kind of relationship there was between ascorbic acid and dyes. But I went down the rabbit hole and I realized that there's actually like a long history of people that dye their hair and they have like you know a sense of scalp or very fragile hair and they don't want to use the strippers that you know are alkaline based. They would use ascorbic acid or just vitamin C and work it into their head with dish soap and after about an hour or so it would strip all that out. To me, it's really fascinating to see what some people have been using as a trade secret or industry secret to do maybe just your average tasks for cleanup and now it's being incorporated to create this potentially life-changing solution for millions of people. So yeah, that was really cool to see. And another thing I wanna point out is this is one of those articles that really benefits from folks that are enjoying it going to the article and watching the videos. The researchers have provided this demonstration of a vial of liquid, of water that is contaminated with the dye with coffee bots inside. And over the course of 40 minutes or 60 minutes, you get to see it become cleaner and cleaner and cleaner to the point that it's just pure water. So that was really cool for me to see. Highly recommend our listeners to go and check it out.

Daniel: They also, in another video that we've got linked in the article and the show notes, they've got a video showing the, like precise magnetic control of these coffee pots as well. They were able to spell GMU, which is the name of the college that Farbod and I went to and that they're all researching at. So again, it's them, you know, they're kind of flexing. They're kind of showing off, but they're exercising different, or showing off the different levels of functionality that this has. Again, to go back and address the three big pain points that exist right now with trying to clean up polluted water, which are that they're expensive, they don't work well, and they harm the environment. They again go back to demonstrate, we have something that's low cost and easy to manufacture. We have something that works really, really effectively and we have something that won't harm the environment, which I think is super cool, which is why we wanted to cover it.

Farbod: Yeah, and the next steps for the team, I think are pretty interesting as well. I didn't see it in the article, but I think I saw it in one of the videos. They were hinting at microplastic cleanup as well. Just like you mentioned, this coffee bot is kind of like a platform now that can be upgraded or modified to target specific pollutants that you'd like to pick up. Microplastics are becoming more and more of a hot topic in the field of environmental protection and pollution because of how plastics are becoming more and more intertwined with everything in our lives, from clothing to, you know, I think they're saying everyone has microplastics in their bloodstream at this point. So, it's interesting to see how this plays out and how this grows now that this research is published and other researchers are gonna be able to build off of it as well.

Daniel: Yeah, and I mean, I just think about, like we said, the things that we use to clean and purify water today, not just an oil spill out in an open body water. I'm thinking also about the water purification that happens in the tap water that makes it into the spout in our home. We use things like chlorine which are used to get rid of bacteria, used to get rid of viruses and other microorganisms. I'm wondering if they can help specialized coffee bots to do things like, disinfection of the drinking water without chlorine because chlorine is known to cause harm to us, especially while showering because it like gets in your lungs and gets in your skin and gets in your hair. Chlorine is not great for us in the water, but it's a necessary evil because it's a lot better than having bacteria, viruses and other microorganisms. I'm wondering if similar to chlorine or maybe another chemical, coffee bots can be used to replace one of these stringent chemicals that's being used in our water purification process today that we all end up consuming, whether we like to or not, or you end up spending a lot of money on a filter to get rid of it. I'm wondering if coffee bots can become the low cost, really effective and really environmentally friendly alternative, but in this case, not just environmentally friendly, because it's not just out in the wild. I'm thinking in our closed loop drinking water scenario, if it can become more human friendly as well.

Farbod: Yeah. Absolutely. What do you say you give us a little Eli 5 to wrap up?

Daniel: Yeah, I would love to. Folks, don't throw away your coffee grounds. Don't throw them away. I promise. I'm going to tell you why. They're going to solve our water problem. Imagine if you could take your old coffee grounds, the stuff that's left over after you make your coffee, and you could turn it into tiny little robots that can clean our dirty water. Dirty water is a huge problem around the world. It's bad for our health. It's bad for our environment and the ways that we try to clean water today are really expensive, they don't work well, and they harm the environment even more. So, this team from George Mason University found out a way to make little tiny robots out of coffee, spent coffee grounds. They use nano engineering to make them be able to swim around water, collect up bad stuff like oil and harmful chemicals, and then they can use a magnet to pull them out and clean the water. They work really, really well. They're not expensive at all, and they're great for the environment, which basically means Starbucks, McDonald's, all these people. Diners that have a bunch of spent coffee grounds, espresso addicts, you might be sitting on a treasure trove in the future of this awesome material that we want to help clean up the environment.

Farbod: Yeah, that's awesome. Dr. Moran and team, thank you for giving us this article to talk about. Shout out GMU, shout out Mechanical Engineering Department at GMU and to the folks listening, thank you for listening. And as always, we'll catch you in the next one.

Daniel: Peace.

As always, you can find these and other interesting & impactful engineering articles on Wevolver.com.

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The Next Byte: We're two engineers on a mission to simplify complex science & technology, making it easy to understand. In each episode of our show, we dive into world-changing tech (such as AI, robotics, 3D printing, IoT, & much more), all while keeping it entertaining & engaging along the way.


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