Using Enzyme-Induced Calcite Precipitation (EICP) to Improve Strength of Sandy Soils

This study uses a biochemical reaction by employing enzyme-induced calcite precipitation (EICP) technique to improve the strength of two different sands. Jack beans are employed as a substrate to catalyze the urea hydrolysis in the study. The sources of calcium used in the experiments were calcium chloride and eggshell. In addition, both seawater and distilled water are used as a reaction medium to distinguish the effect on calcium carbonate precipitation. The results showed that a concentration of 7 gm of urea and 7 gm of jack bean at 60 mL of distilled water with eggshells as calcium source is the best reaction conditions to precipitate calcium carbonate. Further, the technique is employed on two different types of sands sampled from desert and wadi (perennial flow). The results showed a considerable improvement in the strength of sand. This new technique would help in replacing the traditional cementation for sand stabilization and promise an environmentally friendly practice.