Discussion on the Review and Outlook of Microbial Geotechnical Mineralization Technology

Abstract

Microbially Induced Calcite Precipitation (MICP) has grown up to be a hot topic in geotechnical engineering. MICP is a technology that controls and utilizes microbial reactions to produce calcium carbonate cement. It can be used to solve problems in geotechnical engineering, such as improving rock and soil strength, reducing permeability, treating the polluted soil. Microbial mineralization involves a series of biochemical reactions, and the curing process is of particular importance. Therefore, the curing effect of MICP is restricted and impacted by many factors. Built on the factors of microbial mineralized calcium carbonate reaction and microbial mineralization, the principles of urea hydrolysis, denitrification and sulfur reduction were summarized. The effects of air conditions, environmental factors, fiber addition amount, soil water content, and treatment solution concentration on microbial mineralization technology were analyzed. The conclusion is as follows: in the aerated state, the calcium carbonate content is the highest; the low urease concentration, the natural climatic temperature (the best in summer), the pH value between 7-9 produces the most calcium carbonate and the compressive strength is the largest; When soil fiber content is 3%-5%, MICP technology works best; the low concentration treatment liquid is more suitable for the MICP technology; the microbial mineralization technology is suitable for the sand, but it can also produce good effects for other complex soil.