Microbial-Induced Calcite Precipitation and How It Can Help Geotechnical Engineers – Ep 036

In this episode, we talk to Mary J.S. Roth, Ph.D., P.E, a Professor of Civil and Environmental Engineering at Lafayette College, about microbial-induced calcite precipitation (MICP) and how it can help geotechnical engineers in their career as well as be beneficial to engineering students. Here Are Some of the Questions We Ask Mary: What is bio-geotechnics? What is microbial-induced calcite precipitation (MICP)? How did you get involved in MICP work? Why would you say MICP is a potentially useful tool for geotechnical engineers? What are course-based research experiences (CREs)? What are the benefits of having students involved in a CRE related to MICP? Where are you in the process of developing the CRE and what are the next steps? What final piece of advice would you like to give engineers out there? Here Are Some of the Key Points Discussed About Microbial-Induced Calcite Precipitation: Bio-geotechnics is becoming a subfield of geotechnical engineering. The focus is on technologies that have engineering applications that use either naturally occurring bio-geotechnical processes, or that are inspired by biology. Microbial-induced calcite precipitation (MICP) takes advantage of a microbial process to bind soil particles together using calcite. It is an alternative to traditional grouting and is a process to help soils that are loose, weak, or susceptible to liquefaction to become stronger. Large amounts of bacteria are needed to create a chemical called urease. If you add urea to urease-rich soil, the urease splits the urea into ammonia and carbon dioxide. They then become ammonium and carbonic acid, which increases the pH of the soil. It creates an environment where calcium carbonate can come out of solution to become calcite and bind soil particles together. It takes seven days for the pH level in the soil to reach the right level. It takes another seven days for the calcite to come out of the calcium carbonate and start to bind the soil particles together. After 14 to 21 days, the microbial-induced calcite precipitation process is complete. Course-based research experiences are opportunities for all students to have research experiences by including the experiences in their required courses. The students must make discoveries that are of interest to stakeholders outside the classroom. The results of their research must be made publicly available in a large database. Apart from engineers, doctors also look through this database in search of phages that could be a fit to help their patients. If students across the world could collect soil samples and add their findings to a shared database, other researchers and students could look at this database and find out which soils are more suitable for this process. The different bacteria in the soils will also be made available. It will contribute to a lot of information gathered that everyone could learn and benefit from. Course-based research experiences (CRE) are very beneficial to historically unrepresented backgrounds and help to get them interested and persist in the sciences. They have improved the retention of these students in research and have increased the diversity of students engaged in research. To develop a course-based research experience (CRE), you must have the idea and pilot your idea. You must get a better handle on things like how much variability there is in the results of the treatment process on a control sample. You can then approach a national science foundation to get a grant to take your CRE further and get other institutes to take part in the CRE. Any student or geotechnical engineer should spend some time on the work done by bio-geotechnical engineering. Cultivate curiosity because we would not have gotten to where we are if people had stopped asking questi...