Karen McGuire-Diemer
Oklahoma State University, MS Environmental Engineering
Robert J. Riethmiller/PTR Baler and Compactor Scholar 2024
Evaluating the Life Cycle and Biodegradability of Green Plastics for Effective Plastic Waste Management
Plastic is an incredibly versatile product, due to its lightweight nature, low cost, and resistance to corrosion from microorganisms. However, between massive growth in production and its inability to decompose quickly at end of life, single-use plastic pollution and waste are increasing rapidly. One alternative to traditional plastics are biodegradable plastics, which are defined as plastics that break down naturally once they have reached the end of their life cycle. Use of these polymers in place of single-use plastics can reduce the overall lifetime of plastic waste in the environment. The objectives of this research project are to quantify the biodegradability of two biodegradable plastics in natural water systems. The two biodegradable plastics being investigated are polylactic acid (PLA) and polyhydroxyalkanoate (PHA). To test biodegradability, water samples are collected from a lake, river, and marine environment. Plastic samples are added to the water samples and sealed, with gas samples taken periodically to quantify biodegradation as a function of carbon dioxide production. Gas samples will be analyzed for CO2 using gas chromatography. This project also aims to quantify life cycle environmental impacts of traditional single-use plastics compared to PLA and PHA. To do this, a life cycle assessment (LCA) is conducted. The system boundary includes the entire life cycle of each plastic type, with emphasis placed on end-of-life disposal. The LCA will generate emissions at each life cycle stage that are then converted into environmental impacts within SimaPro software. The LCA results will be used to draw conclusions regarding the overall sustainability of both traditional and biodegradable plastics, and recommendations can be given regarding overall environmental sustainability.
Biography
Karen is originally from Terre Haute, Indiana. For her undergraduate studies, she attended Villanova University where she majored in Chemical Engineering and Peace and Justice from 2017-2021. Her undergraduate research focused on sustainable water purification systems and management of shared water resources. Following her undergraduate completion, she committed to two years of service through City Year in Columbus, OH. She served in an elementary school with third and fourth graders. Karen then began her graduate studies at Oklahoma State University in 2023 where she is majoring in Environmental Engineering. Her research investigates biodegradable plastics and their environmental impact in natural aquatic ecosystems. Additionally, her research investigates the environmental impacts of the plastics industry, with particular emphasis on waste management of traditional and biodegradable plastics. She plans to graduate in December of 2024.
