scholarly journals Experimental Study on MICP Technology for Strengthening Tail Sand under a Seepage Field

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Zhi-jun Zhang ◽  
Biao Li ◽  
Lin Hu ◽  
Huai-miao Zheng ◽  
Gui-cheng He ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Calcium Ion ◽  
Soil Stabilization ◽  
Comparative Experiment ◽  
Penetration Test ◽  
Calcium Carbonate Precipitation ◽  
Ion Content ◽  
Seepage Field ◽  
Main Factor

Microbial-induced calcium carbonate precipitation (MICP) technology is a new green reinforcing technology in soil stabilization. Targeting on the problem that seepage is the main factor of causing the instability of a tailings dam, a comparative experiment is conducted, which includes the MICP technology on reinforcing tailings with or without the effect of a seepage field. The results of the comparative experiment are as follow: the mercury penetration test indicates that, under the function of a seepage field, the total pore in the tailing is relatively decreased; SEM shows that under the function of a seepage field, the intergranular pore increases; the direct shear test shows that under the function of a seepage field, the tailings’ shear strength decreases; the determination of calcium ion content shows that the distribution of calcium carbonate in the tailings under the action of a seepage field is more uneven.

scholarly journals Preliminary research for identification of bacteria useful in microbially induced calcium carbonate precipitation

2018 ◽  
Vol 44 ◽  
pp. 00115
Author(s):  
Katarzyna Misiołek ◽  
Paweł Popielski ◽  
Katarzyna Affek
Keyword(s):  
Calcium Carbonate ◽  
Soil Stabilization ◽  
Carbonate Precipitation ◽  
Calcium Carbonate Precipitation ◽  
Construction Sites ◽  
Calcite Precipitation ◽  
Strength Parameters ◽  
Gram Staining ◽  
Identification Of Bacteria

MICP (Microbially Induced Calcite Precipitation) is a new biological method in soil stabilization. This cheap and eco-friendly technique improves strength parameters of the ground such as shear strength and decreases the permeability of gravelly and sandy soil. There are variety of microorganisms that can be used in calcite precipitation. The most popular method is precipitation of calcium carbonate by bacteria. The main purpose of the article is to present the results from Gram staining of bacteria isolated from construction sites, which is the first step of their identification. Gram’s method allows to find out which morphological groups of bacteria are adapted to conditions present in soil from construction sites and therefore are potentially able to produce calcite. The article describes the methodology of isolation, staining and determination of morphological types of bacteria.

scholarly journals An experimental approach to microbial carbonate precipitation in improving the engineering properties of sandy soils

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Baki Bagriacik ◽  
Zahraddeen Kabir Sani ◽  
Fatima Masume Uslu ◽  
Esra Sunduz Yigittekin ◽  
Sadik Dincer
Keyword(s):  
Calcium Carbonate ◽  
Soil Stabilization ◽  
Soil Improvement ◽  
Engineering Properties ◽  
Carbonate Precipitation ◽  
Bacillus Sp ◽  
Calcium Carbonate Precipitation ◽  
Weak Soil ◽  
Direct Shear Tests ◽  
Microbial Carbonate Precipitation

Abstract Purpose Stabilization of weak soil can be achieved through different methods, some of which include jet column, cement stabilization and fly ash stabilization. Unfortunately, the use of the aforementioned methods of soil improvement affects the environment negatively thereby leading to environmental degradation. With the aforesaid impediment in mind, the need for devising methods of weak soil improvement becomes pertinent. Methods Bacillus sp. — a non-pathogenic organism found abundantly in soil — was investigated in this study as a potential agent of soil improvement. The usability of Bacillus sp. in soil improvement was investigated with direct shear tests and permeability tests under optimum conditions in this study. Result Time-dependent study on the effect of the ureolytic bacteria Bacillus sp.-induced calcium carbonate precipitation shows reduction in permeability and increase in the strength of the soil under study. On exhaustion of the available nutrients in the soil, however, the strength of the soil is not negatively impacted. Conclusion Microbially induced calcium precipitation by Bacillus sp. is effective in soil improvement as such it may serve as substitute for conventional soil stabilization techniques. The ability of the bacteria to precipitate calcium carbonate in the soil leads to reduction in the permeability and increase in the shear strength of the soil.

scholarly journals LAB-SCALE EXPERIMENTS FOR SOIL CEMENTING THROUGH BIO-CHEMICAL PROCESS

2021 ◽  
Vol 11 (4) ◽  
pp. 255-265
Author(s):  
Nguyen Ngoc Tri Huynh ◽  
Tran Anh Tu ◽  
Nguyen Pham Huong Huyen ◽  
Nguyen Khanh Son
Keyword(s):  
Calcium Carbonate ◽  
Soil Stabilization ◽  
Mechanical Stability ◽  
Self Healing ◽  
Calcium Carbonate Precipitation ◽  
Promising Technique ◽  
Concrete Material ◽  
Moisture Condition ◽  
Water Percolation ◽  
Unconventional Method

Ureolytic bacteria strains of Bacillus show its ability of calcium carbonate precipitation through metabolic activity. Different studies related to self-healing concrete material were reported associated with the generated calcium carbonate of Bacillus subtilis HU58 metabolism in recent communications. In this paper, recent findings of soil cementing with a combination of such precipitated products were presented. The experiments relied on the lab-scale studies with the use of sand-clay mixture as the controlled soil specimens. Bacillus bacteria and nutrients were mixed to introduce in the sand matrix and then curing in high moisture condition. The composition and morphology of soil specimens were characterized after solidifying by FTIR, XRD, and SEM. Water percolation and mechanical stability for the physicomechanical properties were also tested with the unconventional method. Discussing the relevant results can help to figure out the next experiments in the field of geotechnical engineering. From the perspective of this study, the sustainability factor should be considered to apply this promising technique for soil stabilization and improvement and/or for the formulation of bio-brick as an alternative to sintered clay-based brick. From the perspective of this study, this technique for soil stabilization and improvement and/or for the formulation of bio-brick can be considered a promising sustainable alternative to sintered clay-based brick.

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