Engaging Students in Waste-to-Energy Research Using Model Biodigesters

Abstract

Anaerobic digestion (AD) is a natural process whereby microorganisms break down organic material in the absence of ­oxygen. Biodigesters (sealed tanks where AD occurs) are complex ecological systems where different microorganisms work together to produce biogas (a mixture of methane and carbon dioxide). They are used to produce energy and fertilizers from organic wastes, such as food waste, crop residues, and animal manure. This article describes the use of simple model ­biodigesters, built from low-cost or repurposed materials, as a way to introduce students to physical and conceptual models while learning about resource recovery, waste management and sustainability. This article provides an overview of how teachers can implement this in their science classrooms to engage students in science and engineering practices (SEPs). When used in schools in Ghana and the US, students learned about AD, developed research questions, and built a model biodigester as a tool for scientific inquiry. They collected and analyzed data (e.g., daily biogas and methane production), and they interpreted their results to answer their research questions and make recommendations for local ­biodigester construction. More complete information about engaging students in authentic science using biodigesters is available on our website.

Keywords::

• Science and engineering practices
• authentic science
• Ghanaian science education
• anaerobic biodigesters
• science education
• science teaching
• environmental education

ACKNOWLEDGEMENTS

This material is based upon work supported by the National Science Foundation under Grant No. OISE-1827132. The authors wish to acknowledge the 2022 participants of the NSF-IRES program in Ghana: Elizabeth Vicario, Erica Dasi, Mourin Jarin, Rita Ortiz, and Nicholas Stewart. The authors also wish to thank Ghanaian teachers Doris Osei-Antwi, Ishmael Yussef, Elijah Asare and the staff at Ghana National College (high school) for all the support and assistance they provided, and the University of Cape Coast for their support of the IRES program and its participants.

SUPPLEMENTAL MATERIAL

Supplemental data for this article can be accessed online at http://dx.doi.org/10.1080/00368555.2023.2292331.

ONLINE RESOURCES

Project website with curriculum materials and instructions for building and using the model biodigesters: https://www.usf.edu/nsf-ires/research/

American Biogas Council: https://americanbiogascouncil.org/

UF IFAS Extension: https://biogas.ifas.ufl.edu/biogas/index.asp

Virtual Tour of on-farm AD system in Middlebury Vermont https://youtu.be/TYozO4Ded6U

Additional information

Notes on contributors

Elizabeth Vicario

Elizabeth Vicario (ORCID: 0009-0000-6081-2076) is a PhD Candidate in the Civil and Environmental Engineering Department at the University of South Florida. Her research is focused on water, sanitation, and sustainability. She is currently conducting a study with urban water vendors in low-income neighborhoods in Accra, Ghana through the Fulbright U.S. Student Program. Much of her research uses a systems-thinking methodology, which considers the smaller components of complex systems and how they interact and affect each other. Her doctoral dissertation research uses this approach to understand how drinking water utilities in Tampa Bay, Florida maintain resilience in a competitive urban landscape.

Rita Ortiz

Rita Ortiz (ORCID: 0000-0001-8015-6221) is a Ph.D. candidate in the College of Education at the University of South Florida. Her research focuses on science teacher education, particularly on ecojustice education for preservice teachers. Her background also includes experience serving as an in-field supervisor for secondary clinical education. She was a high school biology teacher before starting her doctoral studies.

Kofi Acheaw Owusu

Dr. Kofi Acheaw Owusu (ORCID: 0000-0001-6842-9354) is a senior lecturer at the Department of Science Education of the University of Cape Coast, Ghana. His research focuses on Science and Biology Education, Innovative pedagogies in science, Science teachers’ TPACK and STEM education. He supervises students at postgraduate level and teaches courses such as Science Concept Formation, Topics in Science Education, Methods of Teaching Biology, Psychological Basis of Teaching and Learning Science and Pedagogical Content Knowledge in Biology. He is a facilitator for organizing continuous professional development for lecturers and teachers in institutions affiliated to the University of Cape Coast.

Allan Feldman

Dr. Allan Feldman (ORCID: 0000-0002-8420-6289) is Emeritus Professor of Science Education at the University of South Florida and the University of Massachusetts. He studies how people learn to do scientific research, and how inservice science teachers learn through action research. His books include “Teachers investigate their work: An introduction to action research across the professions (2018)”, “Educating Science Teachers for Sustainability (2015)”, and “Dialogic Collaborative Action Research in Science Education (2023)”.

Kebreab Ghebremichael

Dr. Kebreab Ghebremichael (ORCID: 0000-0001-9954-6131) is Professor of Instruction at the Patel College of Global Sustainability (PCGS), University of South Florida (USF), Tampa, FL. He is Director of the Water Sustainability Concentration at PCGS. He teaches several graduate and undergraduate courses in sustainability, water resources planning and management. His research area focusses on water resources management and water/wastewater treatment processes, particularly in the development of low cost and appropriate technology. Currently, he is involved in two projects funded by NSF and EPA: i) Water Sanitation and Hygiene (WASH), and ii) Climate Pollution Reduction Grant (CPRG).

Sarina J. Ergas

Dr. Sarina J. Ergas (ORCID: 0000-0001-6820-7196) is a professor and graduate program director in the Department of Civil & Environmental Engineering at the University of South Florida. She teaches Biological Processes in Environmental Engineering, Environmental & Water Resources Engineering Design and Mentoring Novice Researchers. She leads an active research group focused on finding new ways of using microbes to transform nutrients and recover water, energy and nutrients from urban and agricultural wastes. Dr. Ergas is a fellow of the Association of Environmental Engineering and Science Professors and the Water Environment Federation.