Enzyme Induced Calcite Precipitation (EICP) for Engineering Application by Using Plant Based Biomaterials

Abstract

This research investigated the effect of reactant concentrations, reaction medium, urease enzyme source, and calcium source on the precipitation rate of calcium carbonate (CaCO3). This project is aiming to develop a biochemical reaction by using Enzyme Induced Calcite Precipitation (EICP) technique. This new technique would help in replacing the traditional cementation for the dune sand stabilization and promise an environmentally friendly and sustainable approach in the field of construction materials. Jack beans and soybeans were employed as a substrate to catalyze the urea hydrolysis in the study. The sources of calcium used in the experiments were calcium chloride (CaCl2), eggshell and sesame. In addition, both seawater and distilled water were used as a reaction medium to distinguish the effect on calcium carbonate precipitation. The experiments showed that using sesame at a concentration of 4.5 g, 5 g of urea and 6 g of jack bean at 60 mL of distilled water, is the best reaction conditions to precipitate 100.288 g of calcium carbonate. Further, the results indicated that the calcium carbonate precipitation enhanced by using 5 g of urea, 5 g of CaCl2 and 5 g of soybean at 50 mL of seawater. The precipitation amount was 25.593 g. These results provide a useful way for the bio cementation by following the EICP technique to address the issues of environment friendly practice of ground improvement.