Reactive Transport Modeling of Microbial Induced Calcium Carbonate Precipitation Utilizing Various Configurations of Injection Wells

While experimental studies on the use of microbial-induced calcium carbonate precipitation (MICP) for soil improvement have focused on assessment of cemented soil properties, there is a gap between small-scale laboratory experiments and modeling for the design of large-scale field implementation. Numerical analyses are conducted herein to explore the influence of various layouts and configurations of injection wells in delivering effective deployment of the MICP process. Metrics of evaluation include continuity and level of cementation as well as associated by-products. The bacterial transport/attachment/decay, and ureolysis rate parameters are included in the transport model. The model is calibrated using column-scale experimental data. Under the same flow rate and injected volumetric solutions, results indicated that 2-, 3-, and 4-well configurations with distance between wells equal to 1 m produce the highest average CaCO3 in the target area. Among the well configurations which induce the highest CaCO3 content, 4-well configuration with 1 m distance between wells provided more uniform distribution of CaCO3 (less standard deviation), with relatively lower by-product ammonium (NH4).