Experimental Determination of Metal Sorption and Transport Parameters for Graphene Oxide

The goal of this dissertation is to measure the ability of graphene oxide (GO) to adsorb protons and metals, and to assess its mobility in saturated porous media. In Chapter 2 and Chapter 3, we illustrate that multi-layered GO (MLGO) exhibits a striking capacity to buffer aqueous solutions and sorb metals, with the sorption behaviors being influenced in varying degrees by pH and ionic strength. We use surface complexation modeling to calculate equilibrium constants for the surface sorption reactions between MLGO and protons, Cd, Pb, and U(VI), and we account for ionic strength effects as a competition between the target adsorbate and Na from the background electrolyte. In Chapter 4, we use deposition rate coefficient measurements to establish that pH, ionic strength, and sand surface coatings all play critical roles in determining the transport of single-layered GO (SLGO) through laboratory columns. Collectively, the sorption and mobility measurements in this dissertation are tailored to better inform remediation strategies that employ GO as a sorbent in natural and engineered systems.