Soil stabilization using calcium carbonate precipitation via urea hydrolysis

Abstract

Soil improvement techniques of granular soils via Microbially Induced Calcite Precipitation (MICP) and Enzyme Induced Calcite Precipitation (EICP) techniques have attracted an increasing attention over the past decade. MICP and EICP rely upon the hydrolysis of urea catalyzed by the urease enzyme. However, the MICP is a process in which living organisms produce the urease enzyme. These techniques use biogeochemical reactions to precipitate calcium carbonate (CaCO3) especially in granular soils. Calcite precipitation improves the soil shear strength by introducing calcite to fill pores and bind soil particles. In this study, a review on successful development and implementation of the urea hydrolysis techniques is presented. In addition, discussion on potential advantages and limitations of urea hydrolysis techniques is included.