CAREER: Unlocking Recalcitrant Carbon to Enhance Denitrification of Nonpoint Source Nitrogen in Woodchip Bioreactors

职业：释放顽固碳以增强木片生物反应器中非点源氮的反硝化

• 批准号: 2237947
• 负责人: Matthew Reid
• 金额: $ 54.62万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2028-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2237947&HistoricalAwards=false
• 关键词: CAREER; Unlocking; Recalcitrant; Carbon; Enhance

Nonpoint sources of nitrogen (N) such as nitrate from agricultural and stormwater runoff are among the most intractable drivers of pollution and water quality impairments in the United States, contributing to eutrophication, harmful algal blooms, and hypoxia, which adversely impact the ecological health, economic, and recreational values of the Nation’s surface water systems including lakes, rivers, and large estuaries such as the Chesapeake Bay and the Gulf of Mexico. Woodchip bioreactors (WBRs) have emerged as promising and scalable biofiltration systems for removing nitrate from agricultural and stormwater runoff. Most WBRs consist of subsurface trenches filled with a carbon source (woodchip) designed to stimulate microbial denitrification (DN) to remove nitrate from a flowing runoff stream prior to its discharge into a receiving surface water system. The effectiveness of current WBRs is limited by the slow release of the bioavailable carbon (C) from the woodchip media required to support the growth and metabolism of DN bacteria. The overarching goal of this CAREER project is to probe, elucidate, and leverage the redox biogeochemical reactions that control the release and mobilization of bioavailable C from woodchip media to stimulate DN in WBRs. To advance this goal, the Principal Investigator proposes to test the hypothesis that oxic-anoxic cycling during the operation of a woodchip bioreactor enhances denitrification by accelerating the decomposition of recalcitrant, lignocellulosic woodchip biomass into labile C during oxic periods to stimulate the growth and metabolic activity of DN microorganisms during subsequent anoxic periods. The successful completion of this project will benefit society through the generation of new fundamental knowledge to support the development and deployment of more efficient and sustainable solutions to manage and mitigate nonpoint sources of nitrate pollution. Additional benefits to society will be achieved through student education and training including the mentoring of a graduate student at Cornell University. Biogeochemical reactions of iron (Fe) and manganese (Mn) minerals at redox interfaces play an important role in the decomposition of lignocellulosic biomass (LB) in the environment, and mechanistic understanding of these organo-mineral interactions is rapidly evolving. This CAREER project will investigate and unravel the redox active biogeochemical reactions that control the release of labile carbon (C) from the degradation of woodchip media with the goal of leveraging this new knowledge to improve the performance of woodchip bioreactors (WBRs) that utilize LB as C source to stimulate the growth of denitrifying (DN) microorganisms to remove nitrate from agricultural and stormwater runoff. The specific objectives of the research are to 1) probe and elucidate Mn- and Fe- driven redox reactions that control the release of dissolved organic carbon (DOC) from woodchip media in model WBRs using state-of-the-art characterization techniques including synchrotron-based spectroscopy and microscopy (e.g., micro-XANES and micro-XRF) and advanced mass spectrometry (e.g., FT-ICR MS); 2) assess and evaluate the effects of enzymatic vs. nonenzymatic transformations on the quantity and quality of DOC released from woodchip media in model WBRs; and 3) develop and validate process-based models to simulate the effects of redox fluctuations and cycling on the release of DOC and DN efficiency in flow-through WBRs. The successful completion of this project has the potential for transformative impact through the generation of new fundamental knowledge to advance the design and implementation of more efficient WBRs for the removal of nitrate from agricultural and stormwater runoff. To implement the educational and outreach activities of this CAREER project, the Principal Investigator (PI) proposes to leverage existing programs and resources at Cornell University to develop and deliver new hands-on experiential learning opportunities in environmental engineering (EE) for students from underrepresented groups. The proposed activities will include i) an outreach program to high school students and teachers from rural areas of Central New York State and ii) a summer training and mentorship program for undergraduate and community college students. In addition, the PI proposes to leverage the project resources and research findings to develop and integrate new course modules on sensing and control of water infrastructure systems for nitrogen pollution removal into the EE undergraduate curriculum at Cornell University.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.

农业和雨水径流中的硝酸盐等非点源氮 (N) 是美国污染和水质损害最棘手的驱动因素之一，导致富营养化、有害藻华和缺氧，对生态健康产生不利影响。国家地表水系统的经济和娱乐价值，包括湖泊、河流和切萨皮克湾和墨西哥湾等大型河口。 (WBR) 已成为一种有前途且可扩展的生物过滤系统，用于去除农业和雨水径流中的硝酸盐。大多数 WBR 均由充满碳源（木片）的地下沟渠组成，旨在刺激微生物反硝化 (DN)，以去除流动径流中的硝酸盐。在将其排放到接收地表水系统之前，当前 WBR 的有效性受到支持木片介质所需的生物可利用碳 (C) 缓慢释放的限制。该职业项目的首要目标是探测、阐明和利用氧化还原生物地球化学反应来控制木片介质中生物可利用的 C 的释放和动员，以刺激 WBR 中的 DN。首席研究员提议检验以下假设：木片生物反应器运行期间的氧-缺氧循环通过加速分解来增强反硝化作用。该项目的成功完成将通过产生新的基础知识来支持更多的开发和部署，从而造福社会。通过学生教育和培训，包括对康奈尔大学生物地球化学研究生的指导，将实现管理和减轻硝酸盐非点源污染的有效和可持续的解决方案。铁 (Fe) 和锰 (Mn) 矿物在氧化还原界面的反应在环境中木质纤维素生物质 (LB) 的分解中发挥着重要作用，对这些有机矿物相互作用的机制理解正在迅速发展，该职业项目将进行研究。并揭示控制木片介质降解过程中不稳定碳 (C) 释放的氧化还原活性生物地球化学反应，目的是利用这一新知识来提高性能木片生物反应器 (WBR) 利用 LB 作为碳源来刺激反硝化 (DN) 微生物的生长，以去除农业和雨水径流中的硝酸盐。该研究的具体目标是 1) 探测和阐明锰和铁驱动的硝酸盐。使用最先进的表征技术（包括基于同步加速器的技术）控制模型 WBR 中木片介质中溶解有机碳 (DOC) 释放的氧化还原反应光谱学和显微镜（例如，微型 XANES 和微型 XRF）和先进的质谱分析（例如，FT-ICR MS）；2) 评估酶促转化与非酶促转化对木片释放的 DOC 的数量和质量的影响模型 WBR 中的介质；3) 开发和验证基于过程的模型，以模拟氧化还原波动和循环对 DOC 和 DN 效率释放的影响该项目的成功完成有可能通过产生新的基础知识来推进更有效的 WBR 的设计和实施，以去除农业和雨水径流中的硝酸盐，从而产生变革性的影响。和该职业项目的外展活动中，首席研究员（PI）建议利用康奈尔大学的现有项目和资源，为来自弱势群体的学生开发和提供环境工程（EE）方面新的实践体验式学习机会。将包括 i) 针对纽约州中部农村地区的高中生和教师的外展计划，以及 ii) 针对本科生和社区学院学生的暑期培训和指导计划 此外，PI 建议利用项目资源和研究。研究结果开发了关于水基础设施系统传感和控制的新课程模块，以消除氮污染，并将其整合到康奈尔大学的 EE 本科课程中。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和知识进行评估，被认为值得支持。更广泛的影响审查标准。