When large amounts of organic matter need to be cleared, whether for fire safety or to eliminate invasive plants, they have to go somewhere. Buckthorn, an invasive plant in Minnesota, has historically been dealt with by collecting stacks and igniting it, but that releases a lot of CO2. When burned in an open pile, each pound of wood releases 1.82 pounds of CO2 as it reacts with atmospheric oxygen. Some cities burn the biomass to generate electricity, heating water to spin a turbine with steam, but more rural areas don’t have those facilities. Instead of yielding ash and CO2, nonprofit Green River Greening converts invasive plants into biochar, which can be used to strengthen the soil. 

To create biochar, the invasive wood is loaded into kilns, which are designed to create a flame-cap effect, which limits oxygen levels and the spread of fire. Instead of lighting the biomaterial at the bottom of the pile, the fire is lit at the top to initiate pyrolysis, which keeps the wood in a low oxygen environment. Then, water is poured through a drain in the kilns to extinguish the fire, leaving biochar as a product.

More than half of the carbon in biomass converted into biochar is estimated to be sequestered, which can last for hundreds of years. The enrichment of the soil appears significant, too: studies on the effects of biochar have found enhanced water retention, porosity, nutrient availability, and cation exchange capacity, which increases the effectiveness of fertilizers. Green River Greening is allowing their use by local cities and environmental groups, though they hope to offer renting options to individuals in the future.

In addition to enriching the soil, biochar can also be used to filter wastewater. Some pharmaceuticals remain in their active form even after going through the body, but wastewater treatment plants aren’t designed to process them. Treated water will go back into cycles bearing contaminants from pharmaceuticals and personal care products (PPCPs) that can affect ecosystems and breed antibiotic resistance, in addition to reducing water quality.

Researchers at the University of Illinois Urbana-Champaign, looking to address this issue, turned to woodchips, an existing solution for nitrogen runoff. Lingering nitrogen molecules can cause algal blooms, in which algae overtake bodies of water from the abundance of nutrients, outcompeting other species. These blooms can even be toxic, killing local wildlife. However, by filtering water through woodchips, this issue can be avoided. Microbes living on the woodchips metabolize the nitrogen, converting it into gas that goes back into the atmosphere. The UIUC team ventured to apply that strategy to filter PPCPs, designing a type of biochar with chemical properties and high surface area perfect for sticking to these contaminants. 

To test their invention, they collected and contaminated creek water with various compounds, then let it flow through their biochar filter. The biochar removed an average of “77% of the nitrate, 99% of the phosphorus, and about 70% of the ibuprofen, 74% of the naproxen, 91% of the sitagliptin, and 97% of the estrone” in the sample, though these rates were found to be dependent on the speed the water flowed at. 

In addition to feeding fungi, there are many ways to convert undesirable plant material into a valuable resource. Thanks to science, innovators can repurpose waste to make a cleaner, healthier world, solving problems and inventing opportunities.

Who knew there were so many ways to use a bunch of plant stuff?

Of course, burning biomass for fuel is a great solution because the carbon it releases is the same as what is sequestered as plants grow, but if certain areas don’t have the capacity to collect the energy from burning it, these solutions offer a brilliant alternative.

I had never considered that some drugs remain in their active form even after being used; I figured that whatever made them work resulted in them being processed and rendered inert, but I stand corrected! So many things we have to look out for in this modern age, but I’d rather have that than no ibuprofen. Plus, if we’re solving these problems with sustainable methods, I’m even more enthusiastic.

Stay tuned to learn with me!

https://www.yahoo.com/news/st-paul-nonprofit-uses-technology-113000077.html

https://mediabiasfactcheck.com/yahoo-news/ – Yahoo News has a “high” factual reporting.

https://www.sciencedaily.com/releases/2024/10/241021133243.htm