Experimental assessment of CO2-mineral-toxic ion interactions in a simplified freshwater aquifer: implications for CO2 leakage from deep geological storage.

The possible intrusion of CO2 into a given freshwater aquifer due to leakage from deep geological storage involves a decrease in pH, which has been directly associated with the remobilization of hazardous trace elements via mineral dissolution and/or via desorption processes. In an effort to evaluate the potential risks to potable water quality, the present study is devoted to experimental investigation of the effects of CO2 intrusion on the mobility of toxic ions in simplified equilibrated aquifers. We demonstrate that remobilization of trace elements by CO2 intrusion is not a universal physicochemical effect.