Studies on Nutrient & Algae/Cyanobacteria Removal in Backwater Areas of the Mississippi River

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Objective 1:  Refine and broaden a model similar to the backwater model developed for a backwater pond in Northwest Mississippi. Using Ochs and Shields (2019 and 2020) or a similar starting point, we expect the proposer to develop or use an existing numerical model to estimate on water quality parameters in the backwater system and conduct simulations for a broad number of conditions. The work of Ochs and Shields focused on nitrogen. We ask that the model be expanded to a wider range of constituents, particularly phosphate, and algae. However, simulations on other parameters such as dissolved solids, suspended solids, bacteria (E. coli) and pesticides are also desired. We also propose to study a wide range of flow conditions and different fluxes of nutrients and sediments from runoff. Objective 2:  Apply backwater nutrient, algae/cyanobacteria, and other water quality parameters to estimate effect on the southern Mississippi River. The backwater assumptions determined from Objective 1 will be applied to the southern Mississippi River (900 miles, from Cairo, IL to its discharge) to gain a perspective of the overall impact of backwater areas along the river. A shorter stretch can be agreed upon. Objective 3:  Development of models to assess effects of engineering approaches for small and large scales. This objective would involve a modeling effort to assess engineering approaches that could be used to enhance the beneficial properties of the backwater areas. Some engineering approaches could include: Increasing retention time of water in backwater system. The use of inexpensive materials to bind or remove nutrients from water, such as molecular sieves or ionic exchange materials. Use of algal precipitation or removal technologies to remove algae, cyanobacteria, and their associated nutrients from a water system (Thomas et al. 2020). Use of macrophytic vegetation to remove nutrients.

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