EAGER: Feasibility Study of Micro-Level Sensing and Process Control of Nitrification

1025685 Attinger智力价值该项目的目的是证明具有集成的“芯片上”传感的微生物反应器可以在广泛的剪切应力和传质条件下研究微生物的过程动力学的概念。这种微型生物反应器的概念将允许低剪切应力与快速传质相结合的研究，这是目前较大的实验室规模反应器中无法实现的条件。本项目研究的目标微生物为硝化细菌。这些细菌依次将氨氧化为亚硝酸盐和硝酸盐，从而使其适合随后还原为二氮气体。硝化细菌由于其在全球氮循环中的作用（例如与废物管理有关）而在自然和工程环境中发挥重要作用。微生物反应器与目前使用的实验室规模反应器相比具有固有的变革优势。它们具有比大型反应器更均匀的流动条件，直接光学访问和大的表面体积比，以增强传质。例如，渗透膜用于气体扩散，而不是传统的鼓泡技术，随着剪切应力的增加。 将使用光学和微加工技术实现亚硝酸盐浓度和温度的控制和测量。更广泛的影响PI将在他们的研究生课程“微尺度传输现象”中传播结果。本科生和高中生将参与这项跨学科研究，这是PI和co-PI研究实验室的惯例。 这项探索性的研究将为提交一个全尺寸的提案提供基础，以设计用于废水处理的硝化生物反应器，有效地克服目前观察到的传质限制。这项研究将整合到哥伦比亚大学与工业（IBM“智慧城市”）和化学工程系的协同活动中，以使这项工作成为一个可能的NSF研究中心。

1025685AttingerIntellectual meritThe aim of this project is to prove the concept that microbioreactors with integrated "on-chip" sensing can investigate the process kinetics of microorganisms under a wide array of shear stress and mass transport conditions. This microbioreactor concept will allow the study of low shear stress in combination with fast mass transport, conditions that are not attainable in current larger bench scale reactors. The target microorganisms investigated in this project are nitrifying bacteria. These bacteria sequentially oxidize ammonia to nitrite and nitrate and thus render it amenable for subsequent reduction to dinitrogen gas. Nitrifying bacteria play an important role in both natural and engineered environments due to their role in the global nitrogen cycle, for instance in relation to waste management. Microbioreactors have inherent, transformative advantages over currently used benchscale reactors. They feature more homogeneous flow conditions than larger reactors, direct optical access and large surface to volume ratio, for enhanced mass transfer. For instance, permeable membranes are used for gas diffusion, rather than traditional bubbling techniques that come with increases in shear stress. Control and measurement of nitrite concentration and temperature will be implemented using optical and microfabrication techniques.Broader impactThe PIs will disseminate the results in their graduate course "Microscale Transport Phenomena". Undergraduate and High School students will be involved in this interdisciplinary research, a practice that is customary to the research laboratories of both the PI and co-PI. This exploratory research will provide a foundation for the submission of a full size proposal to engineer nitrifying bioreactors for wastewater treatment, effectively overcoming currently observed mass-transfer limitations. This research will integrate into synergistic activities of Columbia University with industry (IBM "Smarter Cities") and with the Department of Chemical Engineering to grow this effort into a possible NSF research Center.