This project was awarded through the "National Science Foundation (NSF) / National Natural Science Foundation of China (NSFC) Joint Research on Environmental Sustainability Challenges" opportunity. The Food-Energy-Water (FEW) Nexus, from a global perspective, can be described as the interconnected and interdependent resource systems of food, energy, and water. Growing and well-documented concerns are associated with the ability of interdependent FEW systems to adapt to stresses resulting from population growth, climate variability, land use changes, and environmental pollution. Developing innovative and sustainable technological solutions that work across all 3 system components to overcome implications associated with anticipated demands is critical to ensure future societal food, energy, and water needs are met. Resource recovery from wastes will play an important role in such solutions, but this recovery will require a change in how waste streams are currently managed. Waste management practices must transition from the "take-make-consume and dispose" model currently practiced, to that of a circular economy (CE) model, during which wastes are reduced and resources from the wastes are efficiently extracted and reused. This reuse will minimize reliance on natural resources, reduce environmental impacts, and promote a sustainable economy. This project focuses on exploring the role food production-related wastes may play in a circular economy. This work, a collaborative project between the University of South Carolina-Columbia, the University of Utah, California State University Fresno, and Nanjing Agricultural University in China, will be conducted to determine whether extracting, reusing resources, and creating products of value from wet food-production wastes using a process called hydrothermal carbonization (HTC) is a more sustainable and economically viable approach than traditionally used processes.
This work will advance the science and technology needed to: (1) improve fundamental knowledge associated with the link between waste properties, HTC process conditions, and HTC-generated product characteristics to promote sustainable and successful integration within the FEW systems, (2) systematically evaluate how HTC-generated products can be recycled to minimize anticipated challenges in FEW systems, including soil health, microbial population dynamics, and energy and water scarcity, and (3) develop implementation strategies for global application of the CE model under various scenarios by using life cycle assessment (LCA) and technoeconomic analysis (TEA) modeling. This project has a strong international component with China. A series of laboratory and greenhouse-scale experiments will be conducted to understand how changes in food, agricultural, and livestock wastes influence the HTC process, and to understand the ability of the generated solid and liquid products to impact FEW systems. In addition, data-driven models describing the resource recovery and subsequent recycling processes will be generated and integrated into LCA and TEA models to detail how FEW system water footprints, energy balances, and nutrient requirements are influenced by HTC product introduction to the environment. Laboratory-scale testing and modeling will be conducted in the United States, and greenhouse and small field-scale testing of carbonization products will be performed in China. Results from this work will determine the ability of a waste conversion technique to make a significant impact in reducing reliance on dwindling virgin resource consumption. Additionally, the project could provide the scientific basis needed to initiate shifts in the current waste treatment/management paradigm to promote sustainable material recovery and management, rather than focusing only on waste disposal. It is anticipated that a large population of potential future engineers and scientists and community members and leaders will be reached through community engagement, undergraduate research experiences for underrepresented populations in engineering, undergraduate education, graduate student mentoring, and international research experiences.
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.
