  Solute transport in fluid-particle systems is a fundamental process in
numerous scientific and engineering disciplines. The simulation of it
necessitates the consideration of solid particles with intricate shapes and
sizes. To address this challenge, this study proposes the Random-Walk
Metaball-Imaging Discrete Element Lattice Boltzmann Method (RW-MI-DELBM). In
this model, we reconstruct particle geometries with the Metaball-Imaging
algorithm, capture the particle behavior using the Discrete Element Method
(DEM), simulate fluid behavior by the Lattice Boltzmann Method (LBM), and
represent solute behavior through the Random Walk Method (RWM). Through the
integration of these techniques with specially designed boundary conditions, we
achieve to simulate the solute transport in fluid-particle systems comprising
complex particle morphologies. Thorough validations, including analytical
soluutions and experiments, are performed to assess the robustness and accuracy
of this framework. The results demonstrate that the proposed framework can
accurately capture the complex dynamics of solute transport under strict mass
conservation. In particular, an investigation is carried out to assess the
influence of particle morphologies on solute transport in a 3D oscillator, with
a focus on identifying correlations between shape features and dispersion
coefficients. Notably, all selected shape features exhibited strong
correlations with the dispersion coefficient, indicating the significant
influence of particle shapes on transport phenomena. However, due to the
complexity of the relationship and the limited number of simulations, no clear
patterns could be observed. Further comprehensive analyses incorporating a
broader range of shape features and varying conditions are necessary to fully
comprehend their collective influence on the dispersion coefficient.
