CAREER: Biological Production of Carbonates for Sustainable Cementitious Materials

这项教师早期职业发展（Career）资助将利用生物过程来创造用于水泥和混凝土的功能性储碳矿物质。混凝土是地球上仅次于水的第二大消耗材料。因此，它的生产、使用和处置具有全球性的环境后果。仅水泥的生产就产生了22亿吨二氧化碳，占全球二氧化碳排放量的6%。鉴于全球对混凝土材料矿物骨料的需求每年超过500亿吨，利用生物过程生产用于水泥浆、砂浆和混凝土的储碳矿物是一个巨大的机会。本研究项目将探索微生物诱导碳酸钙沉淀的生物学机制，以产生储存碳的纳米和微尺度矿物，并将研究它们对混凝土性能的影响。这项研究将辅以教育和指导活动，旨在向公众宣传低碳建筑的好处，同时培养新一代包容、多样化的跨学科材料科学家和土木工程师。该项目的具体研究目标是利用基因工程细菌和其他光合微生物生产具有不同形态结构的生物沉淀碳酸钙纳米颗粒。由工程细菌菌株生产的碳酸盐的形态和纳米力学性能将与天然碳酸盐生产菌株生产的碳酸盐进行比较。每个菌株产生的碳酸盐的碳储存潜力将通过基于过程的生命周期评估进行量化和比较。最后，将研究生物碳酸盐纳米颗粒添加物对水泥浆新鲜状态和硬化状态性能的结构-性能关系，为水泥浆、砂浆和混凝土中使用生物矿物的工程规范提供信息。这个项目的教育目标是：(1)在生活材料实验室的经验中指导新一代的、多样化的材料科学家，这将促进合成生物学和土木工程交叉领域新学科的创建；(2)举办碳智能建材峰会，传播生物建材的好处；(3)通过参与和指导跨学科材料科学研究，为女同性恋、男同性恋、双性恋或跨性别工程专业学生创造研究生入学途径。该项目将为PI实现将建筑环境从碳排放源转变为碳汇的长期职业目标奠定科学基础，同时扩大下一代材料科学家和土木工程师的多样性、包容性、教育和培训。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development (CAREER) grant will leverage biological processes to create functional carbon-storing minerals for use in cement and concrete. Concrete is the second-most consumed material on earth after water. Its production, use, and disposal therefore have global environmental consequences. The production of cement alone accounts for 2.2 billion tons—or 6%—of global carbon dioxide emissions. Given that global demand for mineral aggregates for concrete materials exceeds 50 billion tons per year, a grand opportunity exists to leverage biological processes to produce carbon-storing minerals for use in cement paste, mortar, and concrete. This research project will exploit biological mechanisms of microbial-induced calcium carbonate precipitation to produce carbon-storing nano- and microscale minerals and will study their effect on properties of concrete. The research will be complemented by education and mentoring activities designed to educate the public on the benefits of low-carbon construction, while cultivating a new, inclusive, and diverse generation of interdisciplinary materials scientists and civil engineers.The specific research goal of this project is to use genetically engineered bacteria and other photosynthetic microorganisms to produce biologically precipitated calcium carbonate nanoparticles with distinct morphological architectures. Morphologies and nanomechanical properties of carbonates produced by engineered bacteria strains will be compared to those produced by native carbonate-producing strains. The carbon storage potential of carbonates produced by each strain will be quantified and compared using process-based life cycle assessment. Finally, structure-property relationships of biogenic carbonate nanoparticle additions on both fresh- and hardened-state properties of cement paste will be investigated to inform engineering specifications for biomineral use in cement paste, mortar, and concrete. The education goals of this project are (1) to mentor a new, diverse generation of materials scientists in a Living Materials Laboratory experience that will foster the creation of a new discipline at the intersection of synthetic biology and civil engineering; (2) to disseminate benefits of biological building materials by hosting a Carbon-Smart Building Materials Summit; and (3) to create graduate school pathways for lesbian, gay, bisexual, or transgender engineering students by engaging and mentoring them in interdisciplinary materials science research. This project will lay the scientific foundation for the PI to achieve his long-term career goals of transforming the built environment from a carbon emitter into a carbon sink, while broadening the diversity, inclusion, education, and training of next-generation materials scientists and civil engineers.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.