Simulation of reactive groundwater flow and salinization in carbonate-rock aquifers

Abstract

This study focuses on computer simulations of groundwater flow and salinization with the presence of geochemical reaction processes in carbonate-rock aquifers. The mathematical model for this phenomenon is based on the fluid mass conservation equation, Darcy’s equation and transport equations for reactive salt, dissoluble minerals and reaction products. The simulations are obtained by implementing a pseudospectral numerical method with the aid of parallelization, which reduces the total computational time to one-half the time needed for performing corresponding serial computations. This study is carried out for different cases depending on how the liquid density varies with the concentrations of the salt and products. For the case of the strong dependence of the liquid density on the salt concentration, the results show that the average salt flux from the source into the system significantly increases with the increasing salt reaction rate. Furthermore, when the liquid density is strongly dependent on the concentrations of both salt and products, the products generated by the reactive infiltration affect the flow structure and salt transport in the system. These results form the basis for further theoretical and computational research in more complex natural settings. The research findings can be used to enhance groundwater security and prevent widespread contamination of groundwater reserves in the carbonate-rock aquifers.