Microbially induced calcite precipitation is an emerging environmentally friendly ground improvement technique for a range of geotechnical applications. One of the remaining issues for field implementation of this technique is poor uniformity of calcite, with concentrated precipitation near the injection point, particularly for treatments with continuous injection or in fine sand. Therefore, the work described in this paper performed an experimental investigation to test the hypothesis that using kaolinite particles can increase the number of calcite nucleation sites throughout the sand medium to increase the mass of calcite deposited and provide better distribution of calcite. Both batch and column tests were performed to quantify the impact of kaolinite particles on calcite precipitation. The results indicated that the kaolinite particles may play a role as nucleation sites and facilitate the heterogeneous nucleation of calcite, with observed deposition profiles of kaolinite and breakthrough curves of both kaolinite and bacteria demonstrating that the uniform distribution of deposited kaolinite particles at relatively low inlet concentration (100 mg/l) most effectively increased the amount of calcite, producing a uniform calcite deposition profile. In addition, the results also showed that the well-predicted deposition profile of kaolinite correlated well with the deposited calcite profile.

中文翻译：

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高岭石成核促进微生物诱导方解石沉淀

微生物诱导方解石沉淀是一种新兴的环境友好型地面改良技术，适用于一系列岩土工程应用。现场实施该技术的剩余问题之一是方解石的均匀性差，注入点附近沉淀物集中，特别是对于连续注入或细砂处理。因此，本文中描述的工作进行了一项实验研究，以检验以下假设：使用高岭石颗粒可以增加整个砂介质中方解石成核点的数量，从而增加沉积的方解石质量并提供更好的方解石分布。进行批量和柱测试以量化高岭石颗粒对方解石沉淀的影响。结果表明，高岭石颗粒可能起到成核位点的作用，促进方解石的异质成核，观察到的高岭石沉积剖面和高岭石和细菌的穿透曲线表明，沉积的高岭石颗粒在相对较低的入口浓度下分布均匀。 (100 mg/l) 最有效地增加方解石的量，产生均匀的方解石沉积剖面。此外，结果还表明，预测良好的高岭石沉积剖面与沉积的方解石剖面具有良好的相关性。观察到的高岭石沉积剖面以及高岭石和细菌的穿透曲线表明，在相对较低的入口浓度 (100 mg/l) 下沉积的高岭石颗粒的均匀分布最有效地增加了方解石的数量，从而产生了均匀的方解石沉积剖面。此外，结果还表明，预测良好的高岭石沉积剖面与沉积的方解石剖面具有良好的相关性。观察到的高岭石沉积剖面以及高岭石和细菌的穿透曲线表明，在相对较低的入口浓度 (100 mg/l) 下沉积的高岭石颗粒的均匀分布最有效地增加了方解石的数量，从而产生了均匀的方解石沉积剖面。此外，结果还表明，预测良好的高岭石沉积剖面与沉积的方解石剖面具有良好的相关性。