Comparison of microbially induced calcium carbonate precipitation eligibility using sporosarcina pasteurii and bacillus licheniformis on two different sands

Abstract

The use of biological means for ground improvement have become popular, which generally works through the process called microbially-induced calcium carbonate precipitation (MICP). Many studies indicate successful application of MICP based improvement with multiple bacteria and on several soils. Given the proven performance of MICP, this study aims to examine the MICP process by comparing the calcium carbonate precipitation ability of widely studied bacteria, i.e., Sporosarcina pasteurii and relatively under-recognized bacteria, i.e., Bacillus licheniformis to outline the formation success. For this purpose, two different sands were tested for observing precipitation behavior using a series of syringe tests. Furthermore, the effect of concentration and inclusion of calcium chloride for nutrition of bacteria, saturation with water, and hybrid use of two bacteria were investigated in some tests for diversification. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray spectroscopy (EDS) were used for the interpretation of results. Results indicated that Sporosarcina pasteurii had performed superior over Bacillus licheniformis when achieving calcium carbonate precipitation in tests for both sands. In addition, many intriguing SEM images contributed to the literature of MICP monitoring, highlighting the effects of the variables investigated.

Keywords:

• Bacillus licheniformis
• microbially induced calcium carbonate precipitation (MICP)
• Sporosarcina pasteurii
• syringe experiments

Acknowledgements

Foremost, comments by the reviewer are highly appreciated. The authors also would like to thank TÜBİTAK for providing scholarship through 2228-A program. The authors are also grateful to Middle East Technical University Central Laboratory (ODTÜ-MERLAB) for their help during advanced monitoring studies.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The funding from Middle East Technical University Scientific Research Projects (Project No: BAP-03-03-2014-001) is appreciated.