Bio-Mediated-Highway Systems

Microbial Induced Calcite Precipitation (MICP)

Microbial-induced carbonate precipitation (MICP) is one of the more promising biomediated soil improvement techniques being investigated recently. MICP occurs through biologically driven urea hydrolysis, which primes soil conditions for calcium carbonate precipitation at particle-particle contacts by producing carbonate in the presence of calcium. For practical application in soil, MICP requires the existence of ureolytic bacteria and urea- and calcium-rich solutions to drive the MICP biogeochemical reaction. Several studies have shown the effectiveness of MICP for various applications such as geotechnical soil improvement, environmental re- mediation of heavy metals, CO2 sequestration, and repair of concrete structures. However, most of this demonstration research has been performed at the laboratory scale; few studies have been performed at the meter scale. As a result, one of the universal research priorities is to better understand and control the MICP biogeochemical process under conditions that increasingly resemble natural systems.

A major research effort is on-going in University of California-Davis (UC-Davis) under the supervision of Dr. Jason DeJong to optimize the treatment process for the MICP and to develop a treatment model that may be implemented in the field. Dr. Tanyu has been one of the collaborators of Dr. DeJong over the last five years. The research also involves practitioners from Geosyntec Consultants (Dr. Martines, Dr. David Major, and Dr. Chris Hunt) along with other researchers in UC-Davis.

Some of the outcomes of this research that involves Dr. Tanyu can be found under the publications listed in the SGI web site. For related publications see: Martinez et al. (2013) and DeJong et al. (2014)