Biocementation for desert sand against wind-induced erosion with different treatment processes

Wind-induced erosion is a serious problem that yields soil degradation and environmental pollution. Biocementation technologies have shown potential for sand fixation and wind erosion control in deserts and arid regions. The topic of this study is to investigate the effectiveness of biocementation against wind-induced erosion with different treatment processes.

Biocementation was achieved through soybean-urease induced calcium carbonate precipitation. Three different volumes of treatment solution were used to treat sand specimens by spraying, mixing and the combination methods in this study. The characteristics of sprayed and mixed crust were shown, and the properties of all the biotreated specimens including CaCO₃ distribution, wind erosion rate, and penetration resistance were measured.

The carbonate content in the soil increased with the amount of treatment solution. At the same dosage, the spraying method concentrated 1.0%-1.4% CaCO₃ in the surface soil, while the mixing method generated 0.8% CaCO₃ in a uniform spatial distribution. The top-concentrated CaCO₃ resulted in a lower initial wind erosion rate of the sprayed specimen. The overall reinforcement of the soil by the mixing method produced higher penetration resistance and inhibited the development of wind erosion. The combination of the two methods increased penetration resistance to 200 N and reduced the wind erosion rate to almost 0 g·m⁻²·min⁻¹.

The spraying and mixing methods induced different distribution patterns of CaCO₃ precipitations in soil, leading to varying biocementation effectiveness. To resist severe and continuous wind-induced erosion, a combination of the two methods can be considered to improve the uniformity and strength of biocementation within a certain depth of the soil.