Application of Enzyme-Induced Carbonate Precipitation for Dune Sand Stabilization

Enhancing the mechanical properties of dune sand is critical for improving its stability and load bearing capacity in geotechnical applications. This study investigates the treatment of dune sand using the Enzyme-Induced Carbonate Precipitation (EICP) technique, focusing on the percolation method as a sustainable and effective approach. In this method, dune sand samples were first fully saturated with water, followed by the sequential addition of urease enzyme and a cementing solution to facilitate carbonate precipitation within the sand matrix. Comprehensive laboratory experiments were conducted to evaluate the efficacy of the treatment. Unconfined Compressive Strength (UCS) tests were performed to assess the mechanical improvement in treated samples, while ammonia activity measurements provided insight into the enzymatic efficiency of the EICP process. The calcium content percentage was also analyzed to quantify the extent of carbonate precipitation and its influence on the structural integrity of the sand. The results demonstrate significant improvements in the strength and stability of dune sand, correlating the observed mechanical enhancements with the precipitation of calcium carbonate within the pore spaces. This study provides valuable insights into the optimization of the EICP process and its potential for practical applications in ground improvement techniques. This research contributes to advancing the use of bio-inspired soil stabilization techniques, offering a sustainable alternative for improving the engineering properties of problematic soils.