This study develops a numerical framework to investigate the impacts of hydrogen leakage from subsurface storage on shallow aquifers. The model describes multiphase flow and biogeochemical processes, including microbial hydrogen consumption, with CO 2 speciation treated at thermodynamic equilibrium and microbial reactions governed by kinetic rate laws. The system is formulated as a coupled set of partial differential equations combined with ordinary differential equations. A fully implicit finite volume scheme is implemented in DuMu X . Microbial activity is modeled using the thermodynamic formulation of Jin and Bethke, compared with a classical Double Monod model. Numerical investigations assess their effects on hydrogen consumption, biochemical consistency, and leakage-driven hydrogen migration. The results highlight the role of microbial processes in hydrogen attenuation: over a two-year period, about 3.5% of injected hydrogen is consumed, with metabolic pathways exhibiting spatial and temporal variability. These results provide valuable insights for underground hydrogen storage risk assessment and monitoring.
Amaziane et al. (Mon,) studied this question.