Characterization of Microplastic Pollution in Intentionally Flooded Fields in the Mississippi Delta

Author

Edward G. HeinenFollow

Date of Award

Spring 5-10-2025

Document Type

Undergraduate Thesis

Department

Chemistry and Biochemistry

First Advisor

James Cizdziel

Second Advisor

Vignesh Sundaresan

Third Advisor

John Samonds

Relational Format

Thesis

Abstract

Microplastic (MP) pollution in agricultural environments is spread throughout soil and water due to plasticulture, the use of plastic materials for agricultural applications. In the Mississippi Delta, shallow habitat management for migratory birds involves flooding agricultural fields to resting grounds for birds during migration, as well as to improve soil parameters. In this study, MP concentrations, polymer IDs, and polymer sizes in Delta flood and source water samples were quantified using a Bruker Lumos II μ-FTIR instrument. Average concentrations (MPs/L) in floodwater (n=18) were 72 ± 66, while average concentrations in source water (n=4) and runoff (n=3) were 169 ± 121 and 30 ± 37, respectively. Floodwater concentrations are elevated as compared to other MP studies in agricultural environments. The most common polymers present were PET, PE, PE/EVA, and TPEs, which are some of the most commonly used polymers used in agricultural materials. MPs from the smallest size fraction measured (30- 100 μm) were the most common in all flood water samples, ranging from 75.5%-91% in both fields and years. Using ATR-FTIR, plastic litter from around the field was identified as mostly PE and PET, which were consistent with polymer distributions in the water samples. Lower MP concentrations in source water and runoff after flooding suggest that the MPs are being applied to the field and remain in the soil after flooding. Using recycled floodwater only continues to expose these fields to MP pollution, increasing the likelihood of high MP abundance and biomagnification in crops and migratory birds. Future work is necessary to fully understand the fate of MPs in agricultural fields, especially in other systems that use flooding, such as rice cultivation.

Recommended Citation

Heinen, Edward G., "Characterization of Microplastic Pollution in Intentionally Flooded Fields in the Mississippi Delta" (2025). Honors Theses. 3218.
https://egrove.olemiss.edu/hon_thesis/3218

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.