ECO-CBET: Transforming the Nitrogen Bioeconomy

Non-point source water pollution generally results from land runoff, drainage, or seepage where tracing pollution back to a single source is difficult. Non-point source pollution remains a significant cause of impairment to water bodies despite decades of investment in management strategies. Agriculture is a major activity linked to non-point source pollution from which massive amounts of nutrients (carbon, nitrogen, phosphorus) are currently released into the environment as waste. However, via novel engineered solutions these waste nutrients hypothetically could be recovered and transformed back into agricultural resources, such as soil amendments and feed supplements. Fast growing aquatic plants, like duckweed, have the potential to treat agricultural run-off and extract the unused nutrients. By using recovery processes based upon duckweed, local farms and communities could manage their own polluted water and generate a resource that could help reduce farmers' operating costs. Doing so near the point of use would reduce energy consumption and greenhouse gas emissions that would otherwise be required to produce and transport new nutrient supply. The retention of nutrient run-off locally would also reduce downstream water pollution and contribute to global ecosystem health. In this project, a series of interconnected experiments will be used to evaluate the mechanisms of nutrient recovery and upcycling via duckweed, and the best processing and implementation practices for duckweed as an animal feed and soil amendment will be explored.

This project will evaluate the mechanisms and environmental benefits of using duckweed to capture nutrients from agricultural waste sources within the context of the nutrient-impaired Chesapeake Bay Watershed. Rather than nutrient treatment being a burden, this project aims to demonstrate how leveraging duckweed can generate significant economic value when returned into the agricultural system as a protein-rich feed supplement for dairy cattle or as a soil amendment for crop production. A successful project will have global relevance for creation of a unique and sustainable nitrogen bioeconomy. Both techno-economic and life cycle analysis will be used to evaluate the overall cost efficiency and environmental sustainability of the system. Focus groups and surveys with local stakeholders in the Chesapeake Bay Watershed will be employed with the target of ensuring feasibility of the approach and preparing for pilot implementation. This circular bioeconomy strategy represents a new paradigm for nutrient management that could help decrease the severity of the looming food-energy-water crisis by making ecological water treatment and regenerative agriculture more practical.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.