Biomediated control of colloidal silica grouting using microbial fermentation
Abstract Colloidal silica grouting is a ground improvement technique capable of stabilizing weak problematic soils and achieving large reductions in soil hydraulic conductivities for applications including earthquake-induced liquefaction mitigation and groundwater flow control. In the conventional a...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2023-08-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-023-41402-z |
| _version_ | 1797452871582613504 |
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| author | Michael G. Gomez Samantha T. Muchongwe Charles M. R. Graddy |
| author_facet | Michael G. Gomez Samantha T. Muchongwe Charles M. R. Graddy |
| author_sort | Michael G. Gomez |
| collection | DOAJ |
| description | Abstract Colloidal silica grouting is a ground improvement technique capable of stabilizing weak problematic soils and achieving large reductions in soil hydraulic conductivities for applications including earthquake-induced liquefaction mitigation and groundwater flow control. In the conventional approach, chemical accelerants are added to colloidal silica suspensions that are introduced into soils targeted for improvement and the formation of a semi-solid silica gel occurs over time at a rate controlled by suspension chemistry and in situ geochemical conditions. Although the process has been extensively investigated, controlling the rate of gel formation in the presence of varying subsurface conditions and the limited ability of conventional methods to effectively monitor the gel formation process has posed practical challenges. In this study, a biomediated soil improvement process is proposed which utilizes enriched fermentative microorganisms to control the gelation of colloidal silica grouts through solution pH reductions and ionic strength increases. Four series of batch experiments were performed to investigate the ability of glucose fermenting microorganisms to be enriched in natural sands to induce geochemical changes capable of mediating silica gel formation and assess the effect of treatment solution composition on pH reduction behaviors. Complementary batch and soil column experiments were subsequently performed to upscale the process and explore the effectiveness of chemical, hydraulic, and geophysical methods to monitor microbial activity, gel formation, and engineering improvements. Results demonstrate that fermentative microorganisms can be successfully enriched and mediate gel formation in suspensions that would otherwise remain highly stable, thereby forgoing the need for chemical accelerants, increasing the reliability and control of colloidal silica grouting, enabling new monitoring approaches, and affording engineering enhancements comparable to conventional colloidal silica grouts. |
| first_indexed | 2024-03-09T15:14:55Z |
| format | Article |
| id | doaj.art-b94b9c4ca2c14d59b8790e2402abf750 |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-03-09T15:14:55Z |
| publishDate | 2023-08-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-b94b9c4ca2c14d59b8790e2402abf7502023-11-26T13:11:16ZengNature PortfolioScientific Reports2045-23222023-08-0113112210.1038/s41598-023-41402-zBiomediated control of colloidal silica grouting using microbial fermentationMichael G. Gomez0Samantha T. Muchongwe1Charles M. R. Graddy2Department of Civil and Environmental Engineering, University of WashingtonDepartment of Civil and Environmental Engineering, University of WashingtonDepartment of Microbiology and Molecular Genetics, University of CaliforniaAbstract Colloidal silica grouting is a ground improvement technique capable of stabilizing weak problematic soils and achieving large reductions in soil hydraulic conductivities for applications including earthquake-induced liquefaction mitigation and groundwater flow control. In the conventional approach, chemical accelerants are added to colloidal silica suspensions that are introduced into soils targeted for improvement and the formation of a semi-solid silica gel occurs over time at a rate controlled by suspension chemistry and in situ geochemical conditions. Although the process has been extensively investigated, controlling the rate of gel formation in the presence of varying subsurface conditions and the limited ability of conventional methods to effectively monitor the gel formation process has posed practical challenges. In this study, a biomediated soil improvement process is proposed which utilizes enriched fermentative microorganisms to control the gelation of colloidal silica grouts through solution pH reductions and ionic strength increases. Four series of batch experiments were performed to investigate the ability of glucose fermenting microorganisms to be enriched in natural sands to induce geochemical changes capable of mediating silica gel formation and assess the effect of treatment solution composition on pH reduction behaviors. Complementary batch and soil column experiments were subsequently performed to upscale the process and explore the effectiveness of chemical, hydraulic, and geophysical methods to monitor microbial activity, gel formation, and engineering improvements. Results demonstrate that fermentative microorganisms can be successfully enriched and mediate gel formation in suspensions that would otherwise remain highly stable, thereby forgoing the need for chemical accelerants, increasing the reliability and control of colloidal silica grouting, enabling new monitoring approaches, and affording engineering enhancements comparable to conventional colloidal silica grouts.https://doi.org/10.1038/s41598-023-41402-z |
| spellingShingle | Michael G. Gomez Samantha T. Muchongwe Charles M. R. Graddy Biomediated control of colloidal silica grouting using microbial fermentation Scientific Reports |
| title | Biomediated control of colloidal silica grouting using microbial fermentation |
| title_full | Biomediated control of colloidal silica grouting using microbial fermentation |
| title_fullStr | Biomediated control of colloidal silica grouting using microbial fermentation |
| title_full_unstemmed | Biomediated control of colloidal silica grouting using microbial fermentation |
| title_short | Biomediated control of colloidal silica grouting using microbial fermentation |
| title_sort | biomediated control of colloidal silica grouting using microbial fermentation |
| url | https://doi.org/10.1038/s41598-023-41402-z |
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