Nadia Ralston ’22
Civil and Environmental Engineering
Mineral-Water-Organic Interactions in Soils
My project observed the wettability of water versus carbon dioxide on quartz in the presence of organic molecules in order to determine the characteristics relevant to carbon sequestration. Wettability is an indication of the interactions between a liquid and a solid surface. I installed the program Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) to simulate atomistic wetting phenomena and Visual Molecular Dynamics (VMD) to visualize the results on my laptop. I produced four molecules: tyrosine, p-Hydroxyphenyl, tannic acid and guaiacyl. After verifying that they moved correctly according to the various Newtonian forces acting on them, I duplicated the organic molecules and added them to the two simulations we are observing — one with water in between two layers of quartz, and a similar system with carbon dioxide in between as well. I plan to continue my work by observing these interactions to see how the results can be applied to multiphase flow through mineral matrices. I also plan to investigate the effects of these organics in mica and clay systems that are more relevant to soil carbon and soil fertility with the ultimate goal of applying this knowledge to agriculture in arid regions.
* This internship is connected to the HMEI Water and the Environment Grand Challenges project, “Adsorption of Emerging Organic Contaminants on Clay Surfaces.”
Water and the Environment
Interfacial Water Group, Department of Civil and Environmental Engineering, Princeton University
Ian Bourg, Assistant Professor of Civil and Environmental Engineering and the High Meadows Environmental Institute; Emily Wei-Hsin Sun, Ph.D. candidate, Civil and Environmental Engineering