Influence of Pb2+ and Zn2+ on Calcite Dissolution Using Bragg Coherent Diffraction Imaging

In this proposal we aim to understand the mechanisms by which toxic “heavy metal” ions (e.g., Pb2+, Zn2+) that are dissolved in aqueous solutions influence the dissolution at mineral surfaces. We will focus specifically on calcium carbonate (calcite, CaCO3) surfaces as they are pervasive in the natural environment and can act as sinks of heavy metals (e.g., by adsorption and incorporation). To achieve this goal, we plan to observe these processes by analyzing the changes in external morphology and internal strain distribution of small (~1 mm) calcite crystals in acidic solutions. This includes: 1. dissolution of pure calcite crystals in Pb-containing solutions; and 2. Dissolution of calcite with previously incorporation of Zn. These observations will be achieved using Bragg coherent diffraction imaging (BCDI).