Clogging Modes of Microbially Induced Calcium Carbonate Precipitation Under Continuous Flow Conditions and Mode Transitions

Abstract Microbially induced calcium carbonate precipitation (MICP) holds vast potential for soil reinforcement, material repair, and permeability control. However, the pore structure evolution and clogging modes under continuous flow conditions remain elusive, which limits the optimization of MICP technology. Through microfluidic experiments, we investigate the effects of porosity, particle size, injection rate, and cementation solution concentration on the clogging and migration of precipitates during the MICP process. We perform the spatial correlation analysis to characterize the pore structure evolution and identify three MICP clogging modes under continuous flow conditions, ranging from selective channel clogging to pore bridging clogging and to homogeneous clogging. Two dimensionless parameters are calculated to characterize the pore structure and reaction kinetics. Combining these parameters with the observed clogging morphologies, we construct a clogging mode phase diagram to predict MICP clogging mode transitions, which reveals the complex influence of pore structure and solution state on MICP. This work elucidates the clogging modes of MICP and their transitions under continuous flow conditions, providing theoretical support for solving the problem of uneven clogging in MICP and the prediction of clogging behavior, and is of practical significance for enhancing the controllability and applicability of this technology.