Low-carbon erosion mitigation using bio-stimulating MICP

This study investigates an innovative application of microbial-induced calcium carbonate precipitation (MICP) for enhancing erosion control on unpaved roads, leveraging the unique capabilities of native microorganisms. Aiming to advance disaster-resilient infrastructure, this research employs bio-stimulating treatments to facilitate calcium carbonate (CaCO3) precipitation by way of a novel bio-weathering pathway. Unlike the conventional urea-hydrolysis method commonly used in MICP studies, which generates toxic ammonia as a byproduct, the bio-weathering approach in this study consumes CO2, offering a potentially carbon-negative solution while effectively reducing erosion. Granular material from an unpaved road embankment underwent comprehensive geotechnical characterisation. Inderbitzen tests, which simulate rainfall and runoff, were used to assess erosion resistance. Undisturbed samples were treated either with a bio-stimulating MICP solution or with distilled water as a control. Results indicate significant reductions in soil loss and enhanced stability in bio-stimulating treated samples. While the study primarily focuses on erosion control, it also acknowledges the potential for long-term CO2 sequestration as a beneficial byproduct of the CaCO3 precipitation process. The findings suggest that MICP can be effectively integrated into geotechnical practices to improve the durability and performance of unpaved roads, contributing to sustainable and resilient infrastructure development.