Assessing the potential application of bacteria-based self-healing cementitious materials for enhancing durability of wastewater treatment infrastructure
Assessing the potential application of bacteria-based self-healing cementitious materials for enhancing durability of wastewater treatment infrastructure
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DOI：
10.1016/j.cemconcomp.2023.105259
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发表时间：
2023-08
影响因子：
10.5
通讯作者：
M. Bagga;Ismael Justo-Reinoso;Charlotte Hamley-Bennett;George O. T. Merces;Saimir Luli;A. Akono;E. Masoero;K. Paine;S. Gebhard;I. D. Ofiţeru
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作者：
M. Bagga;Ismael Justo-Reinoso;Charlotte Hamley-Bennett;George O. T. Merces;Saimir Luli;A. Akono;E. Masoero;K. Paine;S. Gebhard;I. D. Ofiţeru
世界各地的污水处理厂（WWTPs）主要使用混凝土建造。持续暴露在废水中会影响混凝土结构的耐久性，需要昂贵的维护或更换。混凝土生产和维修占全球人为二氧化碳排放量的1.8%，这是由于使用水泥，从而导致气候变化。因此，这一重要的卫生基础设施需要开发更可持续的水泥材料。在这项研究中，使用细菌为基础的自我修复（BBSH）水泥材料的污水处理厂的可行性进行评估，暴露BBSH砂浆棱镜连续的城市污水流和比较其自我修复能力，相当于砂浆棱镜暴露于自来水。通过显微成像、水流试验和显微CT分析评价了砂浆棱柱的自修复效率，并采用SEM-EDX和拉曼光谱对修复产物进行了表征。我们的工作代表了第一次系统研究的愈合潜力BBSH砂浆暴露于废水。结果表明，当暴露于废水条件时，特意添加的细菌能够诱导碳酸钙沉淀。此外，如果将额外的钙和碳源嵌入水泥基质中，则即使没有特意向砂浆中添加细菌，废水中固有存在的丰富细菌群落也能够诱导碳酸钙沉淀。这项研究的结果为建设更可持续的废水基础设施提供了有希望的途径，有可能显着降低成本，简化BBSH混凝土的生产过程。
Wastewater treatment plants (WWTPs) around the world are mainly built using concrete. The continuous exposure to wastewater affects the durability of concrete structures and requires costly maintenance or replacement. Concrete production and repair represents ∼8% of the global anthropogenic CO2emissions due to the use of cement, thus contributing to climate change. Developing a more sustainable cementitious material is therefore required for this vital health infrastructure. In this study, the feasibility of using bacteria-based self-healing (BBSH) cementitious materials for WWTPs is assessed by exposing BBSH mortar prisms to a continuous municipal wastewater flow and comparing their self-healing capacity to equivalent mortar prisms exposed to tap water. Microscopy imaging, water-flow tests and micro-CT analyses were performed to evaluate the self-healing efficiency of the mortar prisms, while SEM-EDX and Raman spectroscopy were used to characterise the healing products. Our work represents the first systematic study of the healing potential of BBSH in mortar exposed to wastewater. The results indicate that the purposely added bacteria are able to induce calcium carbonate precipitation when exposed to wastewater conditions. Moreover, if additional sources of calcium and carbon are embedded within the cement matrix, the rich bacterial community inherently present in the wastewater is capable of inducing calcium carbonate precipitation, even if no bacteria are purposely added to the mortar. The results of this study offer promising avenues for the construction of more sustainable wastewater infrastructure, with the potential of significantly reducing costs and simplifying the production process of BBSH concretes for this specific application.