Reducing Soil Permeability Using Microbial Induced Carbonate Precipitation (MICP) Method: A Case Study of Shiraz Landfill Soil

• Published in: Geomicrobiology journal Vol. 37; no. 2; pp. 147 - 158
• Main Authors: Hataf, Nader, Baharifard, Alireza
• Format: Journal Article
• Language: English
• Published: New York Taylor & Francis 07.02.2020; Taylor & Francis Ltd
• Subjects: Bacillus sphaericus; Bacteria; biochemistry; Biological; Biological products; Biological treatment; Biology; Calcite; Calcium; Calcium chloride; Carbonates; case studies; Chemical precipitation; Civil engineering; Civil engineers; Curing; Curing (processing); Density; falling head test; Groundwater; hydraulic conductivity; Landfill; Landfills; Methods; microbial calcite precipitation; Microorganisms; Nutrient content; Permeability; permeability of soil; Shiraz landfill soil; Soil; Soil improvement; Soil permeability; Soil properties; soil sampling; Soil testing; Soil treatment; Soils; Substrata; Waste disposal sites; wastes
• ISSN: 0149-0451; 1521-0529; 1521-0529
• DOI: 10.1080/01490451.2019.1678703

Improvement of engineering properties of soils to meet project requirements has long been subject of interest to civil engineers. One of the environment-friendly methods that have recently been used for this purpose is the biological method. These methods that actually benefit from various sciences such as biology, biochemistry, and civil engineering, use biological products or organisms such as bacteria that are commonly found in soils. In this study, the reduction of permeability or hydraulic conductivity of Shiraz landfill base soil using microbial induced calcite precipitation (MICP) has been explored. B. sphaericus was used to treat the soil. Falling head permeability tests are conducted to measure soil samples' permeability before and after biological treatment. The target variables were the curing time, bacterial density, optimal nutrient content, and soil unit weight. The test results demonstrated that the permeability of the samples treated with Bacillus sphaericus decreases by increasing curing time, the density of calcium chloride solution and bacterial density of samples. This study showed that the MICP can be utilized as a new environment-friendly method for reducing the soil permeability at the base and walls of the landfill to form a barrier between the waste and the groundwater and substrata.