Induced carbonate precipitation (ICP), through microbial (MICP) and enzyme-induced (EICP) pathways, offers a sustainable means of reinforcing porous media, tuning permeability, and enhancing thermal performance across soils, engineered backfills, and subsurface formations for applications in carbon storage, geothermal energy, and construction. Yet its wider deployment is prevented by limited understanding of how pore-scale precipitation processes shape bulk material behaviour, particularly when relying on crude, low-cost enzyme extracts essential for scalable treatments.
This thesis aims to show how pore-scale precipitation processes govern material performance and how they can be directed to achieve specific outcomes. Time-lapse X-ray computed tomography and flow modelling revealed that density driven mixing controls where and when CaCO3 forms, with precipitation concentrated in regions of high enzyme availability. This highlights that density driven flow, such as injecting cementing solution above enzyme solution in deep formations, can be exploited to deliberately control where precipitation occurs.
By varying enzyme source, organic additives, flow regimes, and pH, new levers were identified for modulating reaction kinetics and lag periods. Crude soybean urease generates extended protein-mediated lag phases that allow cementing and enzyme solutions to be mixed ex situ prior to injection. This strategy produced more uniform precipitation, even across fine layers (
| Date of Award | 14 Apr 2026 |
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| Original language | English |
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| Awarding Institution | - University Of Strathclyde
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| Sponsors | University of Strathclyde |
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| Supervisor | Kate Dobson (Supervisor) & James Minto (Supervisor) |
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