Structure of Mineral Surface/Water/Organic compound interfaces on the Earth Surface Environment

我们发现，使用密度泛函理论，MgSO 4掺入方解石（碳酸钙）表面呈现更多的水润湿的表面。这是使用溶解有MgSO 4的人工海水提高石油采收率的机理。我们用密度泛函理论预测了二价阳离子Ni ~（2+）、Sr ~（2+）、Cd ~（2+）和Pb ~（2+）在与水平衡时进入方解石表面的离子交换能。方解石可以是有毒二价阳离子Ni 2+、Cd 2+、Pb 2+的汇，而Sr 2+吸热取代。Ni 2+取代有利于在矿物-流体界面相比，本体取代，这与实验数据相一致。

We revealed using density functional theory that MgSO4 incorporation in a calcite (CaCO3) surface renders the surface more water wet. This is a mechanism of enhanced oil recovery using MgSO4-dissolved artificial sea water. We have used density functional theory to predict the ion exchange energies for divalent cations Ni2+, Sr2+, Cd2+, and Pb2+ into a calcite surface in equilibrium with water. Calcite can be a sink for toxic divalent cations, Ni2+, Cd2+, Pb2+, whereas Sr2+ substitutes endothermically. Ni2+ substitution is favored at the mineral–fluid interface compared with bulk substitution, which agrees with experimental data.