PhD Defence: carbonate minerals and heavy metals

The formation of carbonate minerals and the mobility of heavy metals during water-CO2-mafic rock interactions

Jonas Olsson, cand. scient.

NanoGeoScience Group, Nano-Science Center
Department of Chemistry, University of Copenhagen

Capture and storage of CO2 by carbonate minerals in the subsurface has been proposed as a safe way to dispose of large quantities of CO2. In the CO2 injection project on Iceland, called CarbFix, a big question was how fast and how much the heavy metals released during water-CO2-mafic rock interactions would be taken up during the formation of secondary minerals. The results obtained by combining the study of natural analogues, applied computer models, lab experiments and analyses with nanotechniques show that secondary phases immobilize a wide range of metals, thus ultimately reducing the risk of polluting water supplies during CO2 injection into basalt.