人民长江

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微生物诱导CaCO3沉淀胶结砂室内试验研究进展

王绪民,崔芮,王铖   

  • 出版日期:2019-09-28 发布日期:2019-09-28

Research progress on laboratory cementitious sand experiments by microbial induced CaCO3 precipitation

WANG Xuming, CUI Rui, WANG Cheng   

  • Online:2019-09-28 Published:2019-09-28

摘要: 微生物诱导CaCO3沉淀(MICP)是将微生物学中生物矿化技术应用到土体加固过程中的一种方法,它具有低成本、环保等特点,国内外研究人员从不同角度对该技术开展了大量室内研究,分析与探讨了MICP技术的原理、影响因素及对土体性质的影响等。以胶结砂试验为主,归纳总结了影响MICP技术产生沉淀物的因素(离子源、pH值、温度、营养液浓度、注入速率与孔隙率),以及MICP胶结砂的土力学特性。归纳分析表明:不同钙离子源处理后生成的碳酸钙结晶形态有方解石、文石和球霰石,钙离子浓度的增加有抑制脲酶活性的作用;当细菌培养基的pH范围在8.0~9.0之间、温度在30℃~37℃时,MICP技术生成的沉淀物含量最多;营养液浓度在1.5 mol/L以下时可以有效增加沉淀物含量;不同的孔隙率、钙离子源、pH、温度都会对生成的沉淀物总量和结晶形态造成影响。

关键词: MICP, CaCO3沉淀, 胶结砂试验, 土力学特性

Abstract: The microbial induced CaCO3 precipitation (MICP) is a method for applying the biological mineralization technology in microbiology to strengthening soil, which has the characteristics of low cost, environmental friendly and the researchers at home and abroad have carried out a large number of laboratory studies on this technology from different angles, and analyzed the working principle and influence factors, as well as its influence on the soil nature. The paper summarized the factors that affect precipitation yield by MICP technology, such as ion source, pH value, temperature, concentration of nutrient solution, injection rate and porosity ratio, and the soil mechanical properties of the cement sand by MICP were also analyzed. The results showed that the crystal form of calcium carbonate treated by different calcium ion sources is calcite, aragonite and chalcopyrite, and the increase of calcium ion concentration can inhibit urease activity. When the pH range of the bacterial culture medium is between 8 and 9 and the temperature is between 30℃and 37℃, precipitation content is the highest, the content of the precipitation can be effectively increased when the concentration of the nutrient solution is less than 1.5 mol/ L; the different porosity ratio, calcium ion source, pH and temperature influence total amount of the precipitation yielding and the crystalline form.

Key words: microbial induced CaCO3 precipitate, CaCO3 precipitation, cementitious sand, soil mechanical property