UNS: A Novel Algal-Bacterial Shortcut Nitrogen Removal Process for Wastewater Treatment

1511439氮气循环管理被美国国家工程院(NAE)确定为21世纪的重大挑战之一。高氨氮浓度的废水，如厌氧消化废水，由于其毒性和对氧气的高要求，在传统的生物脱氮系统中难以处理且成本高昂。PIS的总体目标是研究藻类细菌短程脱氮中的氮代谢，并确定维持这一新工艺所需的最佳条件。这项拟议的研究意义重大，因为它有可能减少与废水脱氮相关的成本、能源需求和温室气体排放。通过跨学科和国际合作，PIS建议：1)通过跨学科和国际合作，调查不同的操作条件和基质对系统动力学和性能的影响；2)使用分子工具调查包括藻类、氨氧化细菌、亚硝酸盐氧化细菌和反硝化细菌在内的微生物群体；3)通过耦合过程优化建模来优化系统设计；以及4)通过国际合作培养美国学生的全球能力。将使用在不同光照、温度和负荷率下运行的小规模SBPR来研究氮负荷、光穿透和氧气生产之间的相互关系。藻类氮代谢微生物的存在和活动将通过测量关键化学成分和使用分子生物学工具来定位编码与硝化/反硝化有关的N循环步骤的功能基因。其他实验将研究使用从禽畜粪便发酵中获得的挥发性脂肪酸作为电子供体进行反硝化，并将部分藻类-细菌氨氧化与厌氧氨氧化技术结合起来，以提高系统的经济性。以目标总氮去除为约束，采用藻类-细菌捷径氮素过程模型和优化模型相结合的框架来最小化系统足迹。优化模型将允许PI找到最佳运行条件，以最大限度地减少不同地理区域的反应堆足迹。PIS在美国和荷兰组建了一支研究团队，他们在生物脱氮和藻类生产、自养细菌生理学以及废水处理和优化建模方面具有专业知识。研究生和本科生、中学科学教师和HS学生将在发达和发展中世界的背景下接受跨学科、全球化的科学和工程研究方面的培训。我们将在南佛罗里达大学与荷兰代尔夫特的联合国教科文组织-国际基础结构、水利和环境工程学院与南佛罗里达大学和平队硕士国际项目之间的学生交流的基础上，获得额外的资源(学生、设施和研究专业知识)，建设发展中国家的可持续水处理能力，并继续共同开发藻类-细菌脱氮的捷径工艺。

1511439ErgasManagement of the nitrogen cycle was identified by the National Academy of Engineering (NAE) as one of the grand challenges of the 21st century. High ammonia strength wastewaters, such as anaerobic digestion effluents, are difficult and costly to treat in conventional biological nitrogen removal systems due to their toxicity and high oxygen requirements. The PIs overall goal is to investigate nitrogen metabolism in algal-bacterial shortcut nitrogen removal and identify the optimum conditions needed to sustain this novel process. The proposed research is significant because it has the potential to reduce the costs, energy requirements and greenhouse gas emissions associated with nitrogen removal from wastewaters. The guiding hypothesis is that the close association of algae and bacteria and light/dark cycles results in conditions within biological particles that favor shortcut nitrogen removal.Through interdisciplinary and international collaboration, the PIs propose to: 1) investigate the effects of varying operating conditions and substrates on system kinetics and performance, 2) investigate the microbial consortium, which includes algae, ammonia oxidizing bacteria, nitrite oxidizing bacteria, and denitrifying bacteria using molecular tools, 3) optimize the system design through coupled process-optimization modeling, and, 4) develop global competency in US students though an international collaboration. The interrelationships between nitrogen loading, light penetration and oxygen production will be studied using bench-scale SBPRs operated at varying illumination, temperature and loading rates. The presence and activities of algae nitrogen metabolizing microorganisms will be tracked via measurements of key chemical constituents and by using molecular biological tools to target functional genes encoding steps in the N cycle relevant to nitrification/ denitrification. Additional experiments will investigate the use of volatile fatty acids harvested from livestock waste fermentation as an electron donor for denitrification and coupling of partial algal-bacterial ammonia oxidation with anammox technology to improve system economics. A framework that couples an algal-bacterial shortcut nitrogen process models and an optimization models will be used to minimize system footprint with target total nitrogen removal as a constraint. The optimization model will allow the PIs to find the optimal operating conditions to minimize reactor footprint for different geographic regions. The PIs have assembled a team of researchers in the US and Netherlands with expertise in biological nitrogen removal and algae production, autotrophic bacterial physiology, and wastewater process and optimization modeling. Graduate and undergraduate students, secondary science teachers and HS students will receive training in interdisciplinary, globalized science and engineering research in developed and developing world contexts. We will build on student exchanges between University of South Florida and UNESCO-IHE in Delft, the Netherlands and University of South Florida's Peace Corps Masters International Program to gain additional resources (students, facilities, and research expertise), build developing world sustainable water treatment capacity and continue co-development of the shortcut algal-bacterial nitrogen removal process.