Utilization of bacterial biofilms and extracellular polymeric substances (EPS) for engineered bioclogging has recently garnered increasing attention in various geotechnical practices, such as leakage sealing in water-front structures, soil erosion protection, earthquake-induced liquefaction mitigation, and hydraulic barrier installation. However, the long-term durability is still questioned as to how long the biofilm-associated bioclogging would last as the biofilms readily degrade in nutrient-poor conditions. Therefore, we explore the feasibility of using fine clay particles to enhance the durability of biofilm-induced bioclogging. A series of column experiments were performed to compare the clogging durability of bentonite-associated biofilms against that of biofilms only. The results confirmed that a continuous feed of nutrients to the model bacteria, Bacillus subtilis, stimulated biofilm formation and caused a ~ 99% reduction in hydraulic conductivity of sands. However, nutrient-poor fluid flow caused instantaneous sloughing of biofilms and removal of bioclogging. By contrast, bioclogging associated with bentonite–biofilm aggregates demonstrated enhanced durability against shear detachment by fluid flows in a starved condition. EPS analysis and SEM imaging revealed that bentonite particles in the introduced suspension formed aggregates with biofilms by coating and being embedded within biofilms. This study suggests that the exploitation of bentonite–biofilm aggregations can remarkably enhance bioclogging durability in nutrient-poor conditions. This coupled clay–biofilm clogging approach is expected to provide benefits in developing a strategy for engineered bioclogging in geotechnical practices.

最近，利用细菌生物膜和细胞外聚合物质（EPS）进行工程生物堵塞已经引起了各种岩土实践的关注，例如水边结构的泄漏密封，土壤侵蚀防护，减轻地震引起的液化和水力屏障的安装。然而，关于生物膜相关的生物阻塞在营养缺乏条件下容易降解的情况下，与生物膜相关的生物阻塞将持续多长时间仍存在疑问。因此，我们探讨了使用细粘土颗粒来增强生物膜诱导的生物阻塞的持久性的可行性。进行了一系列的柱实验，以比较与膨润土相关的生物膜的堵塞耐久性和仅与生物膜的堵塞耐久性。枯草芽孢杆菌刺激了生物膜的形成，并使沙子的水力传导率降低了约99％。然而，缺乏营养的流体流动导致生物膜的瞬时脱落和生物堵塞的消除。相比之下，与膨润土-生物膜聚集体相关的生物阻塞表明，在饥饿状态下，流体流动对剪切剥离具有增强的耐久性。EPS分析和SEM成像表明，引入的悬浮液中的膨润土颗粒通过涂覆并包埋在生物膜中而与生物膜形成聚集体。这项研究表明，在营养缺乏的情况下，利用膨润土-生物膜聚集体可以显着提高生物阻塞的持久性。这种耦合的黏土-生物膜堵塞方法有望为开发岩土工程中工程化生物堵塞的策略提供好处。