Honors College Theses

Publication Date



Civil Engineering (B.S.)

Document Type and Release Option

Thesis (restricted to Georgia Southern)

Faculty Mentor

Dr. Francisco Cubas


Because of its desirable characteristics, plastic is often used in manufacturing. Its production and consumption produce abundant plastic waste found in wastewater and receiving waters. This waste breaks down via sunshine exposure, abrasion, and erosion releasing microplastics (MPs) into the environment. With their slow disintegration and vast profusion, MPs can remain in the environment for centuries generating significant pollution and toxicity in freshwater. While studies show that MPs can accumulate in sediments, whether MPs may be absorbed, degraded, or released back into the water column remains poorly understood. Our research project investigates the fate of MPs in freshwater to determine if sediments act as a long-term sink or source. Specifically, this study aims to 1) determine the adsorption capacity of sediments from Southeast Georgia streambeds; 2) identify correlations between MP characteristics like size, material, shape, and sediment sorption capacity; and 3) compare sediment absorption capacity between aerobic and anaerobic sediments. Our experimental approach is unique as four sediment environments (aerobic, anoxic, anaerobic, and mixed) will be tested using microcosms to determine sediments’ storage and degradation potential for MPs. Sediment MPs characterization will be done using advanced analytical techniques Ultraviolet-Visible and Fourier Transformed Infrared spectroscopy. It is expected that MP levels will decrease at a higher rate when continuously subject to aerobic/anaerobic environments within the sediments. In addition, it is expected that aerobic sediments will act as a sink for MPs. These findings can be used to monitor plastic sources and establish degradation processes, making surface water management more efficient.

Available for download on Friday, May 05, 2028