Method for solidifying desert sands with enzyme-catalysed mineralization

Sandstorms have been recognized as severe natural disasters worldwide and are currently occurring with increasing frequently due to global warming and land desertification. This study aims to mitigate their development and combat erosion caused by sandstorms and wind by improving sand-surface stability via enzyme-catalysed mineralization. It is an environment-friendly method. The novelty of the reported enzymatically induced carbonate precipitation (EICP) lies in the usage of an enzyme catalyst extracted from soybeans. In contrast to the commonly used method of microbial-induced carbonate precipitation, which is active at room temperatures between 20 and 30°C, EICP achieves high production efficiency at broader temperatures (ranging from 10 to 70°C). Four methods in appendix to EICP were chosen to solidify desert sands at the test site. Polyacrylamide (PAM) is a harmless and nonionic macromolecular flocculating agent, which forms a hydrogel network in desert sands and has a synergistic effect with EICP. An innovative method combined EICP and PAM and was used to solidify desert sand at a field trial site, realizing high-performance. Solidifying desert sand field tests demonstrated that the solidification strength of EICP+PAM is 6.0–7.0% higher compared with the EICP method alone under identical conditions. This method could obtain higher resistance for strong wind erosion. © 2019 John Wiley & Sons, Ltd.