金属离子种类对珊瑚砂微生物固化影响研究

摘要

选用巴斯德芽孢杆菌, 对微生物诱导钙离子、镁离子以及铁离子形成碳酸盐固化松散珊瑚砂颗粒的效果进行对比研究.试验结果表明, 在相同试验方法、相同注入次数的条件下, 微生物诱导形成的碳酸钙和碳酸镁能将珊瑚砂松散颗粒固化成为整体, 加入铁离子的试样因为反应过程的原因没有成功.通过渗透性、干密度变化、无侧限抗压强度及微观结构等方面进行对比分析, 钙离子试样相对于镁离子试样, 具有固化过程平稳、干密度增量大、强度高、微观颗粒包裹更好的优点.综合试验结果得出, 钙离子是现阶段微生物固化珊瑚砂较为理想的金属离子.本试验首次探讨了金属离子种类对珊瑚砂微生物固化效果的影响, 为微生物固化技术提供了一定理论基础, 对该技术的进一步应用具有一定借鉴意义.%Using calcium, magnesium, and iron ions with Bacillus pasteurii to biocement coral sand, we investi-gated and compared the effect of coral sand biocementation with different types of metal ions. The results show that coral sand can be cemented tightly by calcium carbonate and magnesium carbonate produced by Bacillus pasteurii, whereas in the same test conditions, the biocementation of iron ions was unsuccessful in the reaction process. Our analyses of permeability, dry density, unconfined compressive strength, and microstructure suggest that compared with specimens biocemented with magnesium ions, specimens biocemented with calcium ions undergo a more sta-ble biocementation process, have a wider range of dry density, and better strength and particle packaging. Our test results indicate that calcium ions are ideal metal ions for the biocementation of coral sand. In this paper, we discuss the influence of metal ion type on coral sand biocementation for the first time, which provides a theoretical basis for the development of microbial biocementation technology and a certain reference value for further applications of this technology.