基于尿素水解机制的微生物固化土体的影响因素分析

Analysis of Factors Influencing Microbial Solidification of Soil Based on Urea Hydrolysis Mechanism

微生物诱导碳酸钙沉淀(MICP)加固土体是一种新型绿色环保的土体改良技术,具有广阔的应用前景。基于尿素水解机制的MICP固化土体的效果受多种因素影响和制约,包括生物原料、细菌类型、菌液浓度等生物因素和胶结溶液的成分与浓度、pH值、温度、土的粒径与矿物类型等非生物因素。结论表明,使用较高的菌液浓度和脲钙比可改善土体固化效果。环境温度和pH值的升高会增加碳酸钙沉淀生成量,但碳酸钙晶体的平均尺寸会随温度和pH值的增加而减小,应根据需求寻求最优范围。MICP可用于加固粒径范围在2~400μm之间的土体,用于方解石类的土体时可提高沉淀速率,黏土矿物对生物活性有一定抑制作用。

Microbial induced carbonate precipitation(MICP)is a new green soil improvement technology with broad application prospects.As a biogeochemical process,the effect of soil solidification by MICP is affected and restricted by many factors.The effect of MICP based on urea hydrolysis mechanism on soil solidification is influenced and constrained by various factors,including biological factors such as biological materials,bacterial types,bacterial concentration,and non biological factors such as the composition and concentration of the cementation solution,pH,temperature,soil particle size,and mineral type.The conclusion indicates that using higher bacterial concentration and urea calcium ratio can improve the soil solidification effect.The increase in environmental temperature and pH will increase the amount of calcium carbonate precipitation generated,but the average size of calcium carbonate crystals will decrease with the increase in temperature and pH,and the optimal range should be sought based on demand.MICP can be used to reinforce soil with a particle size range of 2~400μm.When used in calcite soil,it can increase the sedimentation rate,and clay minerals have an inhibitory effect on biological activity.