Laboratory Study in the Treatment of Burned Soils with Microbial Augmentation for Erosion Control

Several studies have been performed by researchers worldwide on the effective cementation of soils via microbially induced calcite precipitation (MICP). As part of these studies, the focus has generally been on the compressive strength, shear strength, shear wave velocity, and hydraulic conductivity of the treated soil as a function of treatment level. A few studies have also shown that MICP treatment of sandy soils contributes to reduced internal or surface erosion. Other studies, have shown that MICP may be effective for fugitive dust control. In this study, burned soil samples from forest fires in Western South Dakota were treated with several different concentrations of Sporosarcina pasteurii bacteria and growth media. Treated specimens were then subjected to turbulent wind flow of varying velocities in an innovative soil wing erosion testing device. During testing, mass loss of specimens was measured over the wind exposure time to determine surface erodibility of the treated materials as a function of MICP treatment level, fluid velocity, and fluid exposure time. This study shows that for both burned soils, that use of MICP has promise for reduction of surface erosion treated in unsaturated conditions under laboratory conditions.