A Lagrangian Method for Reactive Transport with Solid/Aqueous Chemical Phase Interaction

TL;DR

This paper introduces a Lagrangian particle-tracking method that accurately models solid-liquid chemical interactions, such as dissolution and precipitation, without artificial mixing, improving reactive transport simulations.

Contribution

It develops a mass-transfer algorithm enabling reactive interactions between mobile aqueous and stationary solid particles within a Lagrangian framework.

Findings

The algorithm accurately solves the diffusion equation without spurious mixing.

It can simulate arbitrarily small diffusion levels in reactive systems.

The method effectively models solid-liquid chemical phase interactions.

Abstract

A significant drawback of Lagrangian (particle-tracking) reactive transport models has been their inability to properly simulate interactions between solid and liquid chemical phases, such as dissolution and precipitation reactions. This work addresses that problem by implementing a mass-transfer algorithm between mobile and immobile sets of particles that allows aqueous species of reactant that are undergoing transport to interact with stationary solid species. This mass-transfer algorithm is demonstrated to solve the diffusion equation and thus does not introduce any spurious mixing. The algorithm is capable of simulating an arbitrarily small level of diffusion, and can be combined with diffusive random walks to simulate the desired level of diffusion in a reactive transport system.