Insight into the mechanism of microbially induced carbonate precipitation treatment of bio-improved calcareous sand particles

Synergistic biocementation: harnessing Comamonas and Bacillus ureolytic bacteria for enhanced sand stabilization

“…1 show that at pH 7 and 30 °C, the bacteria performed significantly better compared to other pH and temperature ranges. Other studies have also identified these as optimum urease activity for superior carbonate precipitation (Zhou et al 2023 ; Sun et al 2021 ; Bai et al 2021 ; Naveed et al 2020 ). Roughly 40–60% of the urea was degraded at 15 and 20 °C at pH 6 and 8 compared to pH 7; this indicates that these bacterial strains prefer neutral pH and higher temperatures.…”

“…The mechanisms underlying bacterial synergy in MICP processes are multifaceted and may involve various factors such as metabolic cooperation, niche complementarity, and nutrient sharing. Different bacterial species can complement each other’s metabolic pathways in a microbial consortium, enhancing overall metabolic efficiency (Zhou et al 2023 ). In a synergetic relationship, one species may be superior in urea hydrolysis; another may be more efficient in mineral nucleation, resulting in superior and efficient MICP performance.…”

“…Central to the MICP phenomenon is the pivotal role of microorganisms, notably bacteria and fungi. These microorganisms serve as catalysts since their metabolic capabilities bring about essential chemical transformations that facilitate the precipitation of calcium carbonate minerals (Seifan and Berenjian 2019 ; Zhou et al 2023 ). Microorganisms effectively augment the local concentration of calcium and carbonate ions by releasing organic acids, urease, or ammonium during their metabolic activities, creating an environment conducive to calcium carbonate nucleation and subsequent crystal growth.…”