Collaborative Research: Development of a Novel Strategy for Using Waste Concrete to Mitigate Industrial Nitrogen Dioxide Emissions and to Inhibit Corrosion

水泥窑是人为氮氧化物排放的重要贡献者。本研究旨在展示一种有希望的、新颖的空气污染缓解方法。一项合作研究将调查一种利用废弃混凝土材料的创新方法，根据初步调查，这种方法可以经济和可持续地从烟气中去除二氧化氮。含有隔离污染物的混凝土废料可以作为加速凝结或抑制腐蚀的外加剂在新混凝土中回收利用。因此，这种方法有可能将废料转化为有价值的产品。该解决方案的广泛应用范围不仅包括水泥制造，还包括焚烧厂、锅炉、过程加热器、玻璃炉和发电厂。该项目将由石溪大学和克拉克森大学的跨学科团队提供支持，他们在材料科学、环境化学和工程以及土木工程方面具有高度互补的专业知识。该项目的教育部分将集中于实现以下目标：(1)扩大环境工程和化学本科的集中程度；(2)开展案例研究，使学生掌握环境和土木工程的基础知识；(3)增加少数族裔学生接触环境化学、土木工程和可持续发展主题的人数。实现上述结果的技术方法将包括几种实验策略。拆除混凝土的二氧化氮吸收能力与颗粒大小、龄期、骨料类型、成分、水分含量、环境相对湿度和温度有关，将使用最先进的实验方法来确定，包括先进的光谱技术、反应器研究和显微镜。随后，将分析二氧化氮隔离混凝土新获得的性能，如加速凝结和/或抑制腐蚀性能，以应用于新混凝土。更具体地说，综合研究将集中在水化动力学、微观结构发展、体积孔隙度、氯离子结合能力、氯离子扩散阻力和腐蚀速率上，使用各种分析技术，如等温传导量热法、纳米层析成像和动电位极化。这些方法的智力优点在于应用和表征策略的独特新颖性。此外，该项目将创造新的知识，具体说明二氧化氮与混凝土表面相互作用的机制，最大限度地吸收所需的环境条件，最终产品的化学性质，以及最终产品作为新混凝土成分的潜在利用。

Cement kilns are a significant contributor to anthropogenic nitrogen oxides emissions. This study seeks to demonstrate a promising and novel approach to the air pollution mitigation. A collaborative study will investigate an innovative approach to utilizing waste concrete material which, based on preliminary investigations, can economically and sustainably strip nitrogen dioxide from flue gas. The concrete waste containing sequestered pollutants can then be recycled as either set-accelerating or corrosion-inhibiting admixtures in new concrete. As a result, the approach can potentially turn waste materials into valuable products. The broader applications of the solution are not only in cement manufacturing, but also in incineration plants, boilers, process heaters, glass furnaces, and power plants. This project will be supported by an interdisciplinary team from Stony Brook and Clarkson Universities with highly complementary expertise in materials science, environmental chemistry and engineering, and civil engineering. The educational components of this project will focus on achieving the following objectives: (1) Expanding the undergraduate concentration in environmental engineering and chemistry; (2) Developing case studies that will allow students to grasp the fundamentals in environmental and civil engineering; (3) Increasing the number of underrepresented minority students who will be exposed to environmental chemistry, civil engineering and sustainability topics.The technical approach to achieve the above mentioned outcomes will include several experimental strategies. The nitrogen dioxide absorption capacity of the demolished concrete as a function of particle size, age, type of aggregate, composition, moisture content and ambient relative humidity and temperature will be determined using state of the art experimental methods, including advanced spectroscopic techniques, reactor studies, and microscopy. Subsequently, the newly acquired properties of nitrogen dioxide sequestered concrete, such as set-accelerating and/or corrosion-inhibiting properties, will be analyzed for application in new concrete. More specifically, comprehensive studies focused on hydration kinetics, microstructure development, volumetric porosity, chloride binding capacity, chloride diffusion resistance, and corrosion rate will be conducted using various analytical techniques such as isothermal conduction calorimetry, nano-tomography, and potentiodynamic polarization. The intellectual merits of these approaches are in distinct novelties of the applications and characterization strategies. Moreover, this project will create new knowledge specifying mechanisms of nitrogen dioxide interaction with concrete surface, environmental conditions needed to maximize the uptake, the chemistry of the end products, and the potential utilization of the end products as constituents in new concrete.