Bio-Mediate Cementation Technique
The utilization of aerobic and anaerobic bacterial processes provides a unique opportunity to harness natural biological processes for engineering purposes. In this study bacterial (microbial) mineral precipitation of calcium carbonate (calcite) was performed. The creation of calcium carbonate (calcite) cement occurs as a consequence of bacterial metabolic activity which raises the pH of the proximal environment. The local pH rise may be achieved by the production of ammonia and carbon dioxide resulting from the enzymatic hydrolysis of urea. Bacillus pasteurii, a common soil bacteria, uses urea as an energy source and produces ammonia which increases pH, in turn causing Ca2+ and CO32- to precipitate as CaCO3. Microbiologically-induced calcite precipitation occurs according to the reactions: