Advances in Mechanism and Simulation of Microbially Induced Calcite Precipitation at Pore Scale

Abstract:

Microbially induced calcite precipitation （MICP） is an emerging reinforcement technology known for its high bonding strength and minimal environmental impact. However， its engineering applications still face challenges， such as non-uniform precipitation distribution， high costs， and difficulties in field monitoring. To explore the mechanisms of microbial reinforcement， we investigate the key biochemical reactions and mass transport processes involved in MICP at the pore scale. During MICP， the microbial metabolism produces urease， which catalyzes the hydrolysis of urea， inducing calcite precipitation. The precipitation fills the interparticle voids in porous media， reducing the porosity and permeability， and significantly enhancing the structural strength. Based on microfluidic chip experimental results， we investigate the impact of factors on the precipitation distribution and reinforcement effectiveness， such as bacterial concentration， urease activity， cementation solution concentration， temperature， injection strategies， and soil properties. Furthermore， we review the progress and limitations of pore-scale MICP numerical models， focusing on model completeness and multi-physics coupling. Finally， we discuss potential research directions.