The inspiration for Angel Palomino’s latest research came while watching the national news about the flooding in Houston, Texas, caused by Hurricane Harvey in 2017.
Palomino, an associate professor in the Department of Civil and Environmental Engineering, had a personal connection to the unfolding destruction. Her husband’s family lives in Houston.
The reporters were warning residents about walking in the floodwaters because of the potential contaminants floating around and how dangerous they could be to their health.
“Water picks up everything. It doesn’t care,” Palomino said. “This hasn’t been addressed very well, so to have new, easily adoptable and easily impenetrable materials to help prevent this from happening would be advantageous.”
Palomino launched a research project to minimize the impact of contaminated floodwaters on society. She is collaborating with Krishna Reddy, the director of the geotechnical and environmental engineering laboratory and sustainable engineering research laboratory for civil, materials, and environmental engineering at the University of Illinois Chicago.
They are trying to develop a novel chitosan-biochar-bentonite composite barrier resilient to changing climate, which has been linked to a steady increase in the occurrence and severity of flooding events worldwide. Flooding can have a major impact on introducing a broad range of contaminants into groundwater.
The three-year project, which runs through 2025 but will likely receive an extension, received nearly $630,000 in funding from the National Science Foundation.
Reddy is an expert in clay barriers of slurry walls that create a seal to prevent water from passing through. The subsurface barriers consist of a mixture of bentonite clay and water that are poured into trenches to impede or stop groundwater flow.
Palomino’s specialties in teaching and research include micro-scale soil mechanics, clay particle surface modification, and the beneficial uses of coal combustion products.
The project’s goal is to develop a sustainable, adaptive, and resilient barrier made from low-cost waste materials (chitosan and biochar) and bentonite. Chitosan is a sugar that comes from the outer skeleton of shellfish, including crab, lobster, and shrimp. Biochar is black carbon produced from biomass sources like wood chips, plant residues, manure, or other agricultural waste.
Not only would the barrier be cost effective, but it would be healthier for the environment. It could also be adapted for many containment applications, including lined retention ponds and landfill liners.
The key innovation of the research work is the ability of the combined synthesized materials to remove a wide range of contaminant molecules of varying size and charge—such as heavy metals, nutrients, and organics—from floodwater while functioning as a containment barrier.
“The technologies are out there now, but most of the designs are limited to one or two types of contaminants and are very limited from that perspective,” Palomino said. “You can go from really, really tiny things all the way up to these long-chain molecules and everything in between. Most of the time people adopt technologies that capture one end of the spectrum or the other. There isn’t a lot out there to address everything and address the ability to handle large volumes of contaminated water.”
Palomino is bringing in a student worker at UT to help with a large portion of the research. The NSF prioritizes the training of the next generation of PhD students. The expectation is for the student worker to get his PhD by the end of the project.
“His expertise will be a lot broader than a traditional geotechnical engineer by the time he enters the job market,” Palomino said. “He will have a good understanding of not only geotechnical engineering but also biopolymer chemistry to make him more versatile and able to contribute to more complex problems.”
Given the amount of severe weather events across the country and the world, Palomino hopes her research can play a role in finding a solution to contamination that will potentially saves lives.
“Flooding can happen anywhere and have really negative consequences on society,” Palomino said. “If we can find a low-cost way to prevent people from being exposed to a wide-range dangerous contaminants, it would be a major breakthrough.”
Contact
Rhiannon Potkey (865-974-0683, rpotkey@utk.edu)