Date of Award
2025
Degree Type
Thesis
Degree Name
Master of Science in Chemical Engineering (MSChE)
Department
Chemical Engineering
First Advisor
Geoffrey Bothun
Abstract
Plastic pollution has become an increasing threat to marine and coastal environments. Macroplastics derived from consumer waste are broken down by chemical and physical degradation processes, resulting in micro- and nano-plastics (MPs and NPs). This thesis presents an investigation into the MP and NP pollution in the sea surface microlayer (SSML). The SSML contains surface active compounds and natural and anthropogenic matter. This study provides insight into the deeper impacts on the transport and fate of MPs and NPs and on marine bacteria. The first chapter works through the breakdown of plastic particles with the use of a top-down approach and how these processes alter the properties of the plastic itself. The environmental degradation of macroplastics were found to lead to decreasing size ranges and changes in the physical morphology and surface chemistry of the MPs and NPs. The plastic particles engineered in this section highlight the transformation that plastics in the ocean endure and the need for environmentally relevant MPs and NPs in research studies. The second chapter involves the introduction of the engineered MPs into cultures of a marine bacterium, Cobetia marina to monitor how they are impacted. The growth kinetics, production of extracellular polymeric substances (EPS), and visual examination of the bacteria before and after the addition of plastics were studied in this section. The presence of MPs demonstrated a decrease in growth and an increase in EPS production in the cultures as well as an increase in particle aggregation for the MPs. This research addresses not only the impacts of the changes in plastics as they undergo degradation in the ocean environment, but also how their interactions with other components in seawater can alter their fate and transport.
Recommended Citation
Lamothe, Lauren, "MICRO- AND NANO-PLASTICS PREPARATION AND THEIR IMPACT ON COBETIA MARINA" (2025). Open Access Master's Theses. Paper 2635.
https://digitalcommons.uri.edu/theses/2635