An experimental investigation of bacteria-producing calcareous cement in wind erosion prevention

Abstract

Soil stabilization is essential in different fields, such as the environment, to prevent wind erosion and dust. Microbial-induced carbonate precipitation (MICP) is a soil healing method in which bacteria with CaCO3 precipitation among soil particles increase the soil erosion resistance against wind erosion. In this study, by culturing a bacterium species with the scientific name of “Sporosarcina pasteurii” in the laboratory and preparing the solution with three levels of urea and calcium chloride (concentrations of 0.1, 0.2, and 0.4 M) as a nutrient, the status of CaCO3 precipitation was investigated. The erosion of the cemented samples was simulated at a speed of 10–20 km h−1 at the height of 10 cm from the tunnel bottom using a wind tunnel apparatus. The results showed that the highest CaCO3 precipitation occurred in treatments of 0.1 M calcium chloride with 0.2 M and 0.4 M urea. At both wind speeds, MICP treatments significantly reduced soil erosion as compared with the control samples. The FTIR test confirmed the CaCO3 precipitations. Further, the study of CaCO3 precipitation using XRD and SEM analysis showed that it is more in the form of vitriol crystals, binding together loose soil particles and increasing their resistance to the shear stress of wind.