Abstract:

To enhance the effectiveness of the enzyme-induced carbonate precipitation (EICP) technique in solidifying aeolian sand, EICP was combined with polyacrylamide (PAM). Initially, the effects of PAM on urease activity and calcium carbonate production were examined, followed by determining the optimal PAM concentration through sand solidification tests. A wind tunnel test compared the wind erosion resistance of aeolian sand solidified by EICP and EICP+PAM, while the impacts of PAM on EICP water retention and absorption were also assessed. The results show that PAM has a minimal effect on urease activity and calcium carbonate production within the studied concentration range (0−1 g/L). As PAM concentration increases, the surface strength and crust thickness of sand specimens initially rise and then decline. When the PAM concentration is 0.6 g/L, both parameters reach their maximum, identifying 0.6 g/L as the optimal PAM concentration. The wind erosion resistance of sand solidified by EICP+PAM is superior to that of sand solidified by EICP alone. The wind erosion rate of EICP+PAM solidified sand is merely 13.28 g/(m²·min) at a wind speed of 30 m/s. Additionally, the surface crust of PAM-enhanced solidified sand provides improved water retention and long-term stability, suggesting that combining PAM with EICP technology effectively enhances the performance of solidified aeolian sand.

Key words: enzyme-induced carbonate precipitation, polyacrylamide, aeolian sand solidification, surface strength, wind erosion rate