A nitrogen-starving isolation strategy was developed for the first time to screen bacteria with high calcium-precipitating activity (CPA) for bioremediation of damage in porous media. Meanwhile, a novel mini-tube method based on the detection of insoluble Ca was established to evaluate the CPA of the isolates. A low-nitrogen-demanding strain B6, identified as Bacillus sp., was screened to exhibit the highest CPA (55 mM insoluble Ca). Furthermore, the effects of environmental factors and nutrient availability on B6-induced calcium precipitation were evaluated. The results show that nitrate and starch are the best nitrogen source and carbon source with optimal concentration being 4 and 2 g L, respectively. The suitable pH range for B6 to precipitate calcium is from 8.5 to 10.5. B6 can maintain the highest CPA at an initial spore concentration of 1.0 × 10 spores·mL. The optimal CaO dosage is 10 g L. Finally, the calcite precipitation is confirmed by ESEM, EDS, and XRD analysis.
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http://dx.doi.org/10.1007/s00253-019-10066-z | DOI Listing |
J Contam Hydrol
December 2024
Department of Soil Science, Faculty of Agricultural Sciences, University of Guilan, Rasht 41635-1314, Iran.
Microbially induced calcite precipitation (MICP) while neutralizing soil pH, can lead to pore clogging which in turn may reduce bacteria transport. This study aimed to evaluate the effectiveness of the MICP process for E. coli filtration in two acidic soils.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Department of Civil Engineering, National Institute of Technology Warangal, Warangal, 506004, India.
Granite sludge dust (GSD), a significant byproduct of granite processing globally, poses severe environmental and public health challenges, with India alone generating 200 million tons annually. The conventional use of GSD in soil stabilization and construction materials is limited to 20-30%, underscoring the urgent need for sustainable repurposing solutions within the circular economy catering to broader bulk utilization. Unlike traditional techniques, repurposing granite dust using microbially induced calcite precipitation (MICP) offers a sustainable low-impact and eco-friendly ground improvement solution.
View Article and Find Full Text PDFSci Rep
January 2025
Guangxi Academy of Sciences, Nanning, 530000, People's Republic of China.
It is essential to understand the modification mechanism of hydrophobicity nano-CaCO to their potential application in different fields of chemistry. However, the water absorption of hydrophobicity nano-CaCO is seldom studied. In this study, Raman, BET and TGA experiments were performed on nano-CaCO samples to obtain surfactants contents and microstructure characteristics.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Civil and Smart Construction Engineering, Shantou University, Shantou, 515063, Guangdong, China.
Saline soil is widely distributed in China and poses significant challenges to engineering construction due to its harmful effects, such as salt heaving, dissolution collapse, and frost heaving. The Microbial-Induced Calcite Precipitation (MICP) method is an emerging environmental-friendly modification that can reduce or eliminate the environmental and engineering hazards of saline soil. To verify the feasibility of the MICP method for improving the properties of saline soil, laboratory tests were conducted to study the effects of salt content, activated carbon content and freeze-thaw cycles on the compression and water retention behavior of MICP modified saline soil.
View Article and Find Full Text PDFSci Rep
December 2024
Nanyang Vocational College, Nanyang, 473000, China.
In the course of pipe jacking construction, the carrying-soil effect frequently arises, influenced by factors such as excavation unloading, ongoing disturbance from successive pipe sections, and the progressive accumulation of soil adhesion. The pipe jacking slurry serves as a critical agent for friction reduction and strata support, essential for the secure advancement of the construction process. This study introduces the Microbial-Induced Calcium Carbonate Precipitation (MICP) technology into the realm of pipe jacking slurry, aiming to enhance its friction-reduction capabilities and the stability of the soil enveloping the pipe.
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