Effects of Fly Ash on Sand Fixation with Microbial-Induced Carbonate

Different samples of eolian sand were treated to study the sand-fixing effect of microbial-induced mineralization after mixing fly ash with eolian sand. The effects of blending fly ash on microbial-induced mineralization and sand fixation were investigated by measuring permeability, water retention, surface strength, and wind erosion resistance. After three times of microbial-induced mineralization treatment with 30% fly ash, the permeability coefficient decreased by 79.4%, the cumulative evaporation decreased by 26.5%, the surface strength increased by 19.9%, and the wind erosion rate decreased by 21.2%. The yield of calcium carbonate was negatively correlated with wind erosion rate and positively correlated with surface strength. In conclusion, mixing fly ash is more practical than simply using microbial-induced mineralization to fix sand, which can considerably reduce the permeability and improve the water retention, surface strength, and wind erosion resistance of the solidified layer of aeolian sand.