scholarly journals Staphylococcus Derived from Desert and Its Solidified Ability on Aeolian Sandy Soil

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yu Gao ◽  
De Yao ◽  
Cuiyan Wang ◽  
Yanxing Wang ◽  
Chi Li
Keyword(s):  
Field Test ◽  
Sandy Soil ◽  
Soil Improvement ◽  
Carbonate Precipitation ◽  
Calcium Carbonate Precipitation ◽  
Particle Size Range ◽  
Autogenous Strain ◽  
Molar Amount ◽  
Calcium Source ◽  
First Time

Many soil microorganisms in nature induce carbonate precipitation, which is used in soil improvement to reduce the pollution of soil environment by traditional chemical improvement. With the goal of expanding the geotechnical applications of biomineralizing bacteria, this study investigated the characteristics of a newly identified strain of soil bacteria, including its mineralization ability, its effect on Aeolian sandy soil, and biomineralization crust effect in the desert field test. The autogenous mineralized strain was isolated and purified from desert Aeolian sandy soil, and the strain was identified as Staphylococcus using 16SrRNA sequence homology. It is a kind of mineralized bacteria seldom used in geotechnical engineering at present, and it was found to have good mineralization ability; the living conditions of Staphylococcus were optimized. Under the determined amount of bacteria liquid, the amount of calcium carbonate precipitation after the bacteria liquid reacted with different volumes of calcium source solution was studied to determine the appropriate ratio of bacteria liquid and calcium source solution and the molar amount of calcium source solution. This study also investigated the effect of mineralization on the strength of sand and determined the particle size range of sand and suitable bacteria concentration that Staphylococcus can effectively stabilize. Field test results verified desert autogenous Staphylococcus had a good mineralization effect on sand. It was suitable for Aeolian sandy soil crust and improvement. In this paper, the autogenous strain was applied to the surface of the desert for the first time to form an in situ microbial mineralization crust. The research results can provide a theoretical basis for the better application of autogenous strain in the desert.

scholarly journals The investigation of microbial induced calcium carbonate precipitation for soil improvement

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Jamie Haystead ◽  
Martyn Dade-Robertson ◽  
Thora Arnardottir ◽  
Beate Christgen ◽  
Meng Zhang
Keyword(s):  
Experimental Data ◽  
Calcium Carbonate ◽  
Computational Models ◽  
Soil Improvement ◽  
Gas Production ◽  
Sand Particle ◽  
Growth Media ◽  
Growth Stages ◽  
Carbonate Precipitation ◽  
Calcium Carbonate Precipitation

Weak and unstable soils can limit the building of new infrastructure. Current soil strengthening techniques such as chemical grouting have detrimental effects on the environment from greenhouse gas production, soil pH modification and groundwater contamination. Microbial-induced calcium carbonate precipitation (MICCP) is a technique that utilises the ability of bacteria to precipitate calcium carbonate, which can be used for a variety of applications including binding adjacent soil particles and filling the pore spaces of soils to increase their mechanical properties. A commonly used bacterium is Sporosarcina pasteurii. A range of factors influences MICCP which presents challenges with process optimisation. Some studies have made use of computational models to predict biocementation at a larger scale, however aspects of models are based on assumption of conditions instead of experimental data. An aim of this project is to investigate urease activity in S. pasteurii by comparing different growth media, growth stages, pH and temperatures. Ureolysis kinetics of S. pasteurii will be investigated at different urea and calcium chloride concentrations in liquid media. Finally, the biocementation of S. pasteurii in sand syringe setups will also be investigated to compare the effects of changing influencing factors such as growth stage and cell concentration of S. pasteurii, sand particle size, cementation media concentration, duration between cementation media applications and overall number of cementation treatments. Experimental work will be particularly focused towards gaps in the experimental data used in computational models, to help improve these models and bring MICCP biocementation closer to commercial use.

Increasing wind erosion resistance of aeolian sandy soil by microbially induced calcium carbonate precipitation

2018 ◽  
Vol 29 (12) ◽  
pp. 4271-4281 ◽  
Author(s):  
Kanliang Tian ◽  
Yuyao Wu ◽  
Huili Zhang ◽  
Duo Li ◽  
Kangyi Nie ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Sandy Soil ◽  
Wind Erosion ◽  
Erosion Resistance ◽  
Carbonate Precipitation ◽  
Calcium Carbonate Precipitation

scholarly journals Role of Na-Montmorillonite on Microbially Induced Calcium Carbonate Precipitation

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6211
Author(s):  
Guowang Tang ◽  
Cangqin Jia ◽  
Guihe Wang ◽  
Peizhi Yu ◽  
Haonan Zhang
Keyword(s):  
Calcium Carbonate ◽  
Sandy Soil ◽  
Carbonate Precipitation ◽  
Soil Consolidation ◽  
X Ray Diffraction ◽  
Calcium Carbonate Precipitation ◽  
X Ray ◽  
Significant Attention ◽  
Previous Reaction

The use of additives has generated significant attention due to their extensive application in the microbially induced calcium carbonate precipitation (MICP) process. This study aims to discuss the effects of Na-montmorillonite (Na-MMT) on CaCO3 crystallization and sandy soil consolidation through the MICP process. Compared with the traditional MICP method, a larger amount of CaCO3 precipitate was obtained. Moreover, the reaction of Ca2+ ions was accelerated, and bacteria were absorbed by a small amount of Na-MMT. Meanwhile, an increase in the total cementing solution (TCS) was not conducive to the previous reaction. This problem was solved by conducting the reaction with Na-MMT. The polymorphs and morphologies of the CaCO3 precipitates were tested by using X-ray diffraction and scanning electron microscopy. Further, when Na-MMT was used, the morphology of CaCO3 changed from an individual precipitate to agglomerations of the precipitate. Compared to the experiments without Na-MMT in the MICP process, the addition of Na-MMT significantly reduced the hydraulic conductivity (HC) of sandy soil consolidated.

Improvement of a sandy soil by enzymatic calcium carbonate precipitation

2018 ◽  
Vol 171 (1) ◽  
pp. 3-15 ◽  
Author(s):  
João P. S. F. Carmona ◽  
Paulo J. Venda Oliveira ◽  
Luís J. L. Lemos ◽  
António M. G. Pedro
Keyword(s):  
Calcium Carbonate ◽  
Sandy Soil ◽  
Carbonate Precipitation ◽  
Calcium Carbonate Precipitation

scholarly journals Biostabilization of a Sandy Soil Using Enzymatic Calcium Carbonate Precipitation

2016 ◽  
Vol 143 ◽  
pp. 1301-1308 ◽  
Author(s):  
João P.S.F. Carmona ◽  
Paulo J. Venda Oliveira ◽  
Luís J.L. Lemos
Keyword(s):  
Calcium Carbonate ◽  
Sandy Soil ◽  
Carbonate Precipitation ◽  
Calcium Carbonate Precipitation

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.

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