November 14, 2024
Mizzou Engineer Caixia “Ellen” Wan is filtering clean water using new materials created from lignocellulosic biomass waste.
Providing access to clean water is a grand challenge of 21st century engineering, and Mizzou Engineer Caixia “Ellen” Wan is addressing it by putting biowaste materials to work.
She is currently researching two projects sponsored by the USDA Forest Service to take lignocellulosic waste and turn it into different materials to be used in environmental remediation.
“Environmental remediation is the process of eliminating or neutralizing pollutants from the environment to return it to a safe and healthy condition,” Wan, an associate professor of biological engineering, said. “We want to do what we can to protect the environment while reducing waste products that need to be disposed of.”
Wan is an expert in converting biomass into value-added products. Her prior research includes converting both algae and food waste into biodegradable plastics. Now, she’s turned her attention to removing contaminants from water, including forever chemicals (PFAS) and heavy metals like mercury and lead.
For the first project, Wan’s team is researching biochar, a carbon-rich powder-like substance. Biochar is created by decomposing organic material, such as wood or plants, at elevated temperature in an oxygen-deficient environment. It is very absorbent, and Wan’s team is examining how it can be used to absorb these harmful substances out of drinking water, ponds and streams.
To do so, they’re working with the Forest Products Laboratory (FPL) to create panels out of biochar.
“Biochar powder is difficult to remove from the environment once it has done its job and is at its maximum absorption capacity,” Wan said. “Panels are compact and can be used similarly to a home’s air filter. Once the biochar panel ‘filter’ is full, it can easily be replaced with a new panel.”
The team is researching the most effective panel design for the removal of pollutants. Based on their recommendations, the FPL is creating the biochar panels that Wan is testing for their filtration. She is then using the information gained to optimize the design of the panels.
Currently, Wan is researching biochar panels that remove forever chemicals and heavy metals, optimizing the effectiveness in adsorbing those pollutants. She said the current work will be extended to creating a biochar panel that simultaneously filters both types of pollutants and beyond.
The team’s other project is investigating another type of lignocellulosic material—nanocellulose, a cellular building block of wood, agricultural plants and algae—as an environmental remediation method. Nanocellulose, which is thousands of times smaller than a human hair, can be extracted from lignocellulosic biomass waste such as forest residues.
“Nanocellulose has great potential in filtering out forever chemicals and doing adsorption synergistically with biochar,” Wan said. “We would like to eventually combine this material with biochar to engineer a more powerful material for pollutant removal and environmental remediation.”
Wan says this work is key to creating a better world because it both improves the quality of our natural resources and reduces natural waste.
“It is important for the bioeconomy to create valuable products from recycled materials,” she said. “Biochar and nanocellulose can be used across applications, decreasing production needs and promoting global sustainability.”
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