Research Projects

Ground improvement and erosion control are critical for ensuring infrastructure safety, especially in areas prone to soil instability and environmental degradation. While traditional methods like compaction and chemical grouting (e.g., jet, permeation) offer some effectiveness, they suffer from major drawbacks such as shallow treatment depth (typically 1–2 meters), poor control in heterogeneous soils, and high costs. Moreover, chemical grouts often introduce harmful substances into the ground, posing risks to groundwater quality, soil permeability, and long-term ecosystem health. These limitations highlight the urgent need for sustainable, eco-friendly alternatives in modern ground improvement practices. Microbially Induced Carbonate Precipitation (MICP) is a sustainable ground improvement technique that uses urease-producing bacteria like Sporosarcina pasteurii to hydrolyze urea, generating carbonate ions that react with calcium to form calcium carbonate (CaCO₃), which enhances soil strength and reduces permeability by binding particles and filling voids within the soil matrix. Despite growing interest in MICP, most studies rely on lab-grown single-type bacteria and costly reagents, limiting large-scale feasibility. The potential of using naturally derived or waste-sourced urea and calcium remains underexplored, hindering cost-effectiveness and environmental sustainability. These gaps restrict MICP’s scalability and practical field application for ground improvement and erosion control in problematic soils. The proposed research project has aimed to use indigenous soil bacteria (particularly mixed types of bacteria) and naturally derived urea and calcium sources in the MICP process for establishing it as an eco-environmentally viable ground improvement technique. Instead of relying on industry-grade synthetic urea and calcium chloride, the proposed study will explore the use of low-cost alternatives derived from waste and natural resources. Wastewater-derived urea (i.e., urine-rich domestic or agricultural wastewater streams) and natural calcium (i.e., crushed limestone, eggshell powder, and industrial lime sludge) will be used as alternatives to industry-grade urea and calcium. The proposed research will be carried out in five key steps: 1. Isolation and Culturing of Native Ureolytic Bacteria: Native soil bacterial strains will be isolated and screened for urease activity and survivability under natural geochemical conditions. 2. Characterization of Selected Bacteria: These strains will be further analyzed to assess their potential in facilitating MICP-based soil improvement. 3. Identification and Optimization of Reagents: Waste-derived urea (from urine-rich domestic/agricultural wastewater) and natural calcium sources (such as crushed limestone, eggshell powder, and industrial lime sludge) will be tested and optimized for maximum urease activity and calcite precipitation using both single and mixed bacterial strains. 4. Laboratory-Scale MICP Soil Treatment: Soil samples will be treated under controlled conditions to evaluate improvements in geotechnical properties like UCS, shear strength, permeability, and erosion resistance. Results will be compared with treatments using industry-grade reagents to assess effectiveness and potential for scale-up. 5. Pilot-Scale Field Demonstration: The optimized MICP technique will be tested in real-world settings (e.g., canals, slopes, riverbanks) to assess its practical applicability, scalability, and environmental benefits, culminating in the development of standardized implementation protocols. The proposed research aims to develop a scalable, cost-effective, and eco-friendly biogrouting solution using local and waste-derived resources, emphasizing environmental sustainability. Unlike conventional MICP methods that depend on expensive industrial reagents, this study builds on earlier TRL 1 work and targets advancement to TRL 6 for sustainable ground improvement and erosion control.

Biogrouting, Erosion Control, Ground Improvement, Indigenous Soil Bacteria, MICP, Natural Urea-Cementation