Investigating the Effect of Microbial Activity and Chemical Concentrations on the Mineralogy and Morphology of Ureolytic Bio-Cementation
Investigating the Effect of Microbial Activity and Chemical Concentrations on the Mineralogy and Morphology of Ureolytic Bio-Cementation
复制标题
研究微生物活性和化学浓度对尿素生物胶结矿物学和形态的影响
DOI：
10.1061/9780784482834.010
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Gomez, Michael G.
中科院分区：
文献类型：
--
作者：
Burdalski, Robert J.;Gomez, Michael G.
在过去的十年中，许多实验室研究已经证明了微生物诱导方解石沉淀（MICP），生物介导的土壤改良方法，有利地改变土壤的工程性质，包括增加剪切强度和刚度，降低水力传导性和孔隙度的能力。尽管在处理应用技术和处理后工程特性的表征方面取得了重大进展，但沉淀过程中的地球化学条件与处理后材料特性之间的关系仍然知之甚少。细菌增强、刺激和胶结处理在研究人员之间的化学成分、浓度和比例可能会有很大差异，尽管对它们的工程意义的理解有限，但特定的配方往往会持续存在。在这项研究中，小规模的批量实验被用来系统地研究沉淀合成过程中的生物地球化学条件可能会影响生物胶结和相关的材料工程行为。及时监测水溶液化学以更好地理解脲解动力学和碳酸钙沉淀以及所得沉淀物之间的关系。在所有实验之后，使用X射线衍射和扫描电子显微镜评估沉淀物以表征矿物学和形态。从这些调查中获得的结果预计将有助于确定合成过程中的主要化学和生物因素，这些因素可能会控制生物胶结材料的性能，并影响工程性能方面，包括长期弹性。
Numerous laboratory studies in the past decade have demonstrated the ability of microbially induced calcite precipitation (MICP), a bio-mediated soil improvement method, to favorably transform a soil’s engineering properties including increased shear strength and stiffness with reductions in hydraulic conductivity and porosity. Despite significant advances in treatment application techniques and characterization of post-treatment engineering properties, relationships between biogeochemical conditions during precipitation and post-treatment material properties have remained poorly understood. Bacterial augmentation, stimulation, and cementation treatments can vary dramatically in their chemical constituents, concentrations, and ratios between researchers, with specific formulas oftentimes perpetuating despite limited understanding of their engineering implications. In this study, small-scale batch experiments were used to systematically investigate how biogeochemical conditions during precipitate synthesis may influence resulting bio-cementation and related material engineering behaviors. Aqueous solution chemistry was monitored in time to better understand the relationship between the kinetics of ureolysis and calcium carbonate precipitation, and resulting precipitates. Following all experiments, precipitates were evaluated using x-ray diffraction and scanning electron microscopy to characterize mineralogy and morphology. Results obtained from these investigations are expected to help identify the primary chemical and biological factors during synthesis that may control bio-cementation material properties and influence engineering performance aspects including long-term resilience.