Stabilization of expansive black cotton soil using bioenzymes produced by ureolytic bacteria
Abstract Soil stabilization is the art and science of improving the engineering properties of soils. The properties of problematic soils can be improved by blending appropriate amount of insitu soil, aggregates and bioenzymes. In the present study, four bacterial strains: Sporosarcina pasteurii, Bac...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2022-08-01
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| Series: | International Journal of Geo-Engineering |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s40703-022-00175-6 |
| _version_ | 1811285893028249600 |
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| author | Eshetu Mekonnen Yared Amdie Habtamu Etefa Nurelign Tefera Mesfin Tafesse |
| author_facet | Eshetu Mekonnen Yared Amdie Habtamu Etefa Nurelign Tefera Mesfin Tafesse |
| author_sort | Eshetu Mekonnen |
| collection | DOAJ |
| description | Abstract Soil stabilization is the art and science of improving the engineering properties of soils. The properties of problematic soils can be improved by blending appropriate amount of insitu soil, aggregates and bioenzymes. In the present study, four bacterial strains: Sporosarcina pasteurii, Bacillus paramycoides, Citrobacter sedlakii, and Enterobacter bugadensis were used to produce bioenzymes using urea supplemented molasses as a substrate via submerged fermentation. The crude bioenzyme was mixed with modified soil blended with 40% black cotton soil, 30% aggregate and 30% river sand; then tested after curing for 7 days. The test results revealed that except soil samples treated with bioenzyme of Enterobacter bugadensis, all treated soil samples showed improved plasticity index (18–55%) and liquid limit (5–44%). Soil samples treated with bioenzyme of Bacillus paramycoides, Citrobacter sedlakii and Sporosarcina pasteurii showed higher CBR values of 12.9%, 12.27%, and 11.95% respectively. On the other hand, free swell showed reduction in soil samples treated with bioenzymes of Sporosarcina pasteurii (47.37%), Bacillus paramycoides (30%), and Citrobacter sedlakii (10.53%). The highest percentage improvement of linear shrinkage was recorded for soil sample treated with bioenzymes of Sporosarcina pasteuri (39.65%), followed by Permazyme (10.44%), Citrobacter sedlakii (8.4%) and Bacillus paramycoides (8.34%). Whereas, the highest percentage improvement in MDD was recorded in permazyme treated soil (11.92%) followed by molasses (8.29%), Bacillus paramycoides (1.92%), and Enterobacter bugadensis (0.73%). The lowest optimum moisture content (9.3%) was recorded in soil treated with permazyme. Triaxial test analysis also showed improvement in both cohesion and angle of friction in bioenzyme treated soils. From the test results it was concluded that it is possible to treat expansive black cotton soils using bioenzymes produced from low cost substrates such as molasses and reduce the cost of construction and environmental carbon emission. |
| first_indexed | 2024-04-13T02:50:51Z |
| format | Article |
| id | doaj.art-bc316b50e31a4b63a9deb6e97f164d92 |
| institution | Directory Open Access Journal |
| issn | 2092-9196 2198-2783 |
| language | English |
| last_indexed | 2024-04-13T02:50:51Z |
| publishDate | 2022-08-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | International Journal of Geo-Engineering |
| spelling | doaj.art-bc316b50e31a4b63a9deb6e97f164d922022-12-22T03:05:51ZengSpringerOpenInternational Journal of Geo-Engineering2092-91962198-27832022-08-0113112210.1186/s40703-022-00175-6Stabilization of expansive black cotton soil using bioenzymes produced by ureolytic bacteriaEshetu Mekonnen0Yared Amdie1Habtamu Etefa2Nurelign Tefera3Mesfin Tafesse4Department of Biology, College of Natural and Computational Sciences, Dire-Dawa UniversityDepartment of Biotechnology, College of Biological and Chemical Engineering, Addis Ababa Science and Technology UniversityDepartment of Biotechnology, College of Biological and Chemical Engineering, Addis Ababa Science and Technology UniversityDepartment of Biotechnology, College of Biological and Chemical Engineering, Addis Ababa Science and Technology UniversityDepartment of Biotechnology, College of Biological and Chemical Engineering, Addis Ababa Science and Technology UniversityAbstract Soil stabilization is the art and science of improving the engineering properties of soils. The properties of problematic soils can be improved by blending appropriate amount of insitu soil, aggregates and bioenzymes. In the present study, four bacterial strains: Sporosarcina pasteurii, Bacillus paramycoides, Citrobacter sedlakii, and Enterobacter bugadensis were used to produce bioenzymes using urea supplemented molasses as a substrate via submerged fermentation. The crude bioenzyme was mixed with modified soil blended with 40% black cotton soil, 30% aggregate and 30% river sand; then tested after curing for 7 days. The test results revealed that except soil samples treated with bioenzyme of Enterobacter bugadensis, all treated soil samples showed improved plasticity index (18–55%) and liquid limit (5–44%). Soil samples treated with bioenzyme of Bacillus paramycoides, Citrobacter sedlakii and Sporosarcina pasteurii showed higher CBR values of 12.9%, 12.27%, and 11.95% respectively. On the other hand, free swell showed reduction in soil samples treated with bioenzymes of Sporosarcina pasteurii (47.37%), Bacillus paramycoides (30%), and Citrobacter sedlakii (10.53%). The highest percentage improvement of linear shrinkage was recorded for soil sample treated with bioenzymes of Sporosarcina pasteuri (39.65%), followed by Permazyme (10.44%), Citrobacter sedlakii (8.4%) and Bacillus paramycoides (8.34%). Whereas, the highest percentage improvement in MDD was recorded in permazyme treated soil (11.92%) followed by molasses (8.29%), Bacillus paramycoides (1.92%), and Enterobacter bugadensis (0.73%). The lowest optimum moisture content (9.3%) was recorded in soil treated with permazyme. Triaxial test analysis also showed improvement in both cohesion and angle of friction in bioenzyme treated soils. From the test results it was concluded that it is possible to treat expansive black cotton soils using bioenzymes produced from low cost substrates such as molasses and reduce the cost of construction and environmental carbon emission.https://doi.org/10.1186/s40703-022-00175-6BioenzymeUreolytic bacteriaSoil stabilizationFermentationEngineering propertiesExpansive soil |
| spellingShingle | Eshetu Mekonnen Yared Amdie Habtamu Etefa Nurelign Tefera Mesfin Tafesse Stabilization of expansive black cotton soil using bioenzymes produced by ureolytic bacteria International Journal of Geo-Engineering Bioenzyme Ureolytic bacteria Soil stabilization Fermentation Engineering properties Expansive soil |
| title | Stabilization of expansive black cotton soil using bioenzymes produced by ureolytic bacteria |
| title_full | Stabilization of expansive black cotton soil using bioenzymes produced by ureolytic bacteria |
| title_fullStr | Stabilization of expansive black cotton soil using bioenzymes produced by ureolytic bacteria |
| title_full_unstemmed | Stabilization of expansive black cotton soil using bioenzymes produced by ureolytic bacteria |
| title_short | Stabilization of expansive black cotton soil using bioenzymes produced by ureolytic bacteria |
| title_sort | stabilization of expansive black cotton soil using bioenzymes produced by ureolytic bacteria |
| topic | Bioenzyme Ureolytic bacteria Soil stabilization Fermentation Engineering properties Expansive soil |
| url | https://doi.org/10.1186/s40703-022-00175-6 |
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