Cementation of sand grains based on carbonate precipitation induced by microorganism

Microbes can produce CO (3) (2-) in an environment conductive to precipitation, so the incompact sands will be consolidated. This technology is environmentally friendly not only because it gives strength to the sand body, but also it allows water to penetrate into the sand body, which is unlike silicate cement that will destroy the ecosystem of the earth. After comparing the activity of three kinds of bacteria, the most suitable one was chosen for the study. However, the activity of this bacterium was still not high enough for the purpose, so it was purified. A suitable program for the consolidation and cementation of sands was also found in the experiment. The compressive strength and the porosity of the cemented sand body were tested to characterize the cementation effectiveness. XRD analysis showed that a new phase of calcite was produced between sand grains. The content of calcite was detected by TG. The study showed that the precipitation program was quite important to obtain a sound cemented sand body in addition to the activity of the bacteria.