Pb2+ Uptake by Magnesite: The Competition between Thermodynamic Driving Force and Reaction Kinetics

The thermodynamic properties of carbonate minerals suggest a possibility for the use abundant materials (e.g., magnesite) removing harmful divalent heavy metals Pb2+). Despite favourable condition such transformation, batch experiments performed in this work indicate that kinetic magnesite dissolution at room temperature is very slow. Another set co-precipitation from homogenous solution Mg-PbII-CO2-H2O system reveal solids formed can be grouped into two categories depending on Pb/Mg ratio. atomic ratio about 1 and 10 Mg-rich Pb-rich phases, respectively. Both phases show significant enrichment Pb if compared with initial stoichiometry aqueous solutions (Pb/Mg = × − 2–1 10−4). Finally, growth {10.4} surfaces absence presence Pb2+ was studied by situ force microscopy (AFM) measurements. In foreign ion, ten-fold increase spreading rate obtuse steps observed. Further, effect ageing also tested. We observed nucleation secondary phase quickly grows magnesite. preferential incorporation solid during precipitation catalytic are promising results development environmental remediation processes. These processes, different transformation cerussite, not limited slow Precipitation require an external carbon source, thus they could combined sequestration techniques.