On modeling the potential impacts of CO2 sequestration on shallow groundwater: Transport of organics and co-injected H2S by supercritical CO2 to shallow aquifers

► Simulations on upward migration of organic compounds and co-injected H2S were conducted. ► The intrusion of CO2 + H2S mixtures into a shallow fresh water aquifer has been simulated. ► Models show that benzene could co-migrate with CO2 into an overlying aquifer. ► Models show preferential dissolution of H2S at the edge of the advancing CO2 + H2S plume. ► The leakage of CO2 + H2S into an anoxic aquifer could lead to higher arsenic release in groundwater.