Recent Advances in Low-Carbon Bio-mediated Soil Improvement Techniques

In recent years, significant progress has been made in the development of sustainable and low-carbon methods for soil improvement within geotechnical engineering. Traditional chemical stabilization techniques, which rely heavily on Portland cement and lime, have been increasingly criticized due to their high embodied carbon emissions and adverse environmental impacts. In contrast, bio-mediated approaches, particularly Microbial-Induced Calcite Precipitation (MICP) and Enzyme-Induced Carbonate Precipitation (EICP), have emerged as promising alternatives. These techniques utilize biological or bio-inspired processes to induce calcium carbonate precipitation, thereby cementing soil particles, enhancing shear strength, reducing permeability, and improving overall geotechnical performance in an environmentally friendly manner. Recent studies conducted between ۲۰۲۴ and ۲۰۲۶ have focused on optimizing treatment protocols, addressing uniformity issues in large-scale applications, mitigating by-product emissions (such as ammonia), and integrating additives (e.g., biopolymers, Persian gum, basalt fibers, and polyaspartic acid) to improve efficiency and microstructural homogeneity. Notable advancements include the use of plant-derived crude enzymes for EICP to reduce costs, hybrid reinforcement combining carbonate precipitation with fibers for expansive soil stabilization, and innovative strategies for fine-grained and underwater soils. Furthermore, field-scale trials and life-cycle assessments have demonstrated substantial reductions in carbon footprint compared to conventional methods, alongside comparable or superior mechanical improvements in many cases. Challenges such as bacterial/enzyme activity control, treatment uniformity, long-term durability under environmental stresses, and economic scalability continue to be addressed through multiscale modeling, bioaugmentation/biostimulation refinements, and waste-stream utilization. These developments position bio-mediated soil improvement as a key contributor to sustainable infrastructure and climate-resilient geotechnical practice. The present review synthesizes the latest findings and outlines future research directions toward broader practical implementation

کلیدواژه ها:

MICP ، EICP ، Bio-cementation ، Soil stabilization ، Low-carbon ، Sustainable geotechnics