Optimization of Carbonate Precipitation of EICP Technique Using Three-Level Full Factorial Design Analysis

This study focuses on optimizing Enzyme-Induced Carbonate Precipitation (EICP) by enhancing soil’s hydraulic and mechanical properties, through a parametric analysis using a three-level full factorial design. The experiment examined the effects of varying enzyme concentrations (60–120 g/L), pH levels (6–8), and temperatures (100°C–500°C) on calcium carbonate precipitation, a crucial aspect of the EICP process. It was found that temperature significantly influences EICP, with enzyme concentration and pH also playing important roles. The relationship between pH and temperature was found to be inversely proportional, while electrical conductivity (EC), indicative of urea hydrolysis, showed a direct proportionality to temperature. Almost the same EC value indicates that urea hydrolysis outweighs carbonate precipitation. The results suggest that temperature is the most significant factor followed by enzyme concentration and pH. Overall, this study demonstrates the potential of full factorial design analysis in optimizing the EICP method for soil improvement. The insights gained from this research contribute to a better understanding of the factors influencing calcium carbonate precipitation, paving the way for more effective soil improvement techniques.