Construction of porous calcite structure using microbially induced calcite precipitation

Abstract

Sporosarcina pasteurii is a well-known ureolytic bacteria that promotes the microbially induced calcite precipitation (MICP) process for several environmental and engineering purposes. In our work, for the first time, MICP has been implemented to form pure, porous calcite structures. The maximum urease activity of S. pasteurii was 1.91 mM urea hydrolyzed min−1 at the late-exponentially phase. A reactor has been designed to achieve semi-continuous treatments, and reagents were introduced to it by a peristaltic pump. A new alternating injection pattern was adopted to obtain well-distributed precipitation. SEM images of treated structures indicated the shapes of CaCO3 crystals at a microscale level and revealed the successful formation of calcite-calcite bonds, which has contributed to achieving a consolidated porous structure. Such synthetic pure, porous calcite structure has found growing industrial interest where chemically intrusive procedures (e.g., acidizing, fracturing) should be performed on expensively excavated core samples.