37-6 Comparing the Effectiveness of Bentonite Clays for Nitrate Remediation

Session: Geoscience Research Poster Showcase by 2YC and 4YCU Undergraduate Students

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This project evaluates the nitrate removal efficiency of bentonite clays sourced from two geologically distinct U.S. regions: the Upper Cretaceous Tombigbee Sand Formation of Mississippi and the Bighorn Basin of Wyoming. The goal is to determine how regional mineralogical differences influence adsorption performance. Each clay sample was tested in its natural state and after thermal activation at 400°C and 700°C to assess how heat treatment altered surface area, porosity, and the availability of adsorption sites. Batch experiments were conducted using a controlled 150 ppm nitrate solution prepared by dissolving 0.20 g of sodium nitrate (NaNO₃) in 1.0 L of water, allowing for direct comparison of nitrate uptake across clay types and treatment conditions. Nitrate concentrations before and after treatment were measured using a Vis spectrophotometer, with nitrate test strips used as a secondary method to verify results and provide rapid, comparative readings. SEM and EDS analyses will be used to document compositional and textural changes associated with thermal activation. By integrating adsorption measurements with mineralogical characterization, this study aims to identify a low-cost, scalable bentonite material capable of reducing nitrate pollution before it enters major waterways. The results will support broader efforts to mitigate nutrient-driven hypoxia in the Gulf of Mexico and contribute to the development of practical remediation strategies for agricultural regions.

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