| Abstract |
Excess phosphorus (P) can lead to eutrophication of aquatic ecosystems and dead zones as recently seen in Lake Erie and the Gulf of Mexico. The potential for wetlands to remove phosphorus from the water column varies based on the mineral composition of the sediments, herbaceous cover, age of the wetland, surrounding land usage, as well as many other variables. Total iron concentration has been found to be a good predictor of P sorption capacity in best management practice urbanized wetlands. In the summer of 2019, I collected sediment samples from open water areas, Typha stands, and mud-flats in three constructed, urbanized wetlands on Kent State University’s campus. To better understand P sorption capacity in the three wetlands, I assessed the phosphate sorption, or “stickiness” of the sediment, with a phosphate sorption index assay. To determine the primary mechanisms of phosphorus retention in each wetland, I measured percent organic matter, total iron oxides, and the proportion of poorly-crystalline iron oxides. Preliminary analysis of PSI results shows the mud-flats and the Typha stands of the youngest wetland sorb the least amount of phosphate. Upon further analysis, I expect to find lower concentrations of total iron oxides and/or a lower proportion of poorly-crystalline iron oxides in these sediments. This information could help guide future construction of wetlands in urbanized areas to maximize phosphorus retention to prevent downstream pollution events.
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