CAREER: Next generation onsite wastewater treatment system for nitrogen management

美国和世界各地数以百万计的家庭依靠现场系统进行废水处理和处置。传统的现场污水处理系统(OWTS)通常由与浸出场相连的化粪池组成，以便通过排水管道网络传输和处置周围土壤中的液体流出物。OWTs的主要设计目的是提供初级处理，在此期间，家庭污水中的有机废物和悬浮固体沉淀到化粪池底部，在那里它们被微生物部分降解。由于OWTs的设计不是为了有效地去除营养物质，化粪池的液体流出物是浅层地下水含水层氮(N)污染的最大来源之一，因为它们泄漏到周围的地下土壤中。这个职业项目的首要目标是探索开发和验证下一代生物过滤系统，用于从OWTS中去除氮(N)。为了推进这一目标，首席调查员建议测试一种假设，即基于厌氧氨氧化(Anammox)微生物与生物炭等吸附剂相结合的生物过滤系统可以为化粪池液体流出物中的氮去除提供有效和经济的解决方案。该项目的成功完成将使社会受益，因为它将产生新的基本知识，以支持开发和部署更有效和可持续的解决方案，以管理和减轻未连接到集中式废水处理系统的家庭和其他设施造成的氮污染。通过学生教育和培训将为社会带来更多好处，包括指导石溪大学的一名研究生和一名本科生。基于土壤的生物过滤系统已成为现场污水处理系统的有前途的附加模块，用于去除化粪池流出物中的氮(N)。然而，目前的土壤生物滤池需要很大的占地面积和外部碳源(如木屑)来刺激和支持反硝化微生物的生长和代谢活动。这一职业项目将探索开发新型土壤生物滤池，用于脱氮，其基础是将生物炭吸附剂与厌氧氨氧化(Anammox)微生物相结合的混合物理/化学和生物处理工艺。这项拟议的研究建立在先前研究结果的基础上，这些研究证实，厌氧氨氧化微生物在土壤、湿地和海洋/淡水沉积物中将氮化合物转化为氮气(N_2)的过程中发挥着关键作用。这项研究的具体目标是：1)研究以生物炭为吸附剂和微生物载体的模拟生物过滤单元中N化合物的部分反硝化/厌氧氨氧化(PDN/AN)；2)评估运行变化和环境参数对PDN/AN生物过滤单元效率的影响；3)调查和优化模块化生物过滤系统的运行，以实现高效脱氮，并使用分子工具和动力学模型评估系统的长期性能。该项目的成功完成有可能通过产生新的基础知识产生变革性的影响，以促进更有效的土基生物过滤器的开发和实施，以从现场废水处理系统的液体流出物中去除氮。为了实施这一职业项目的教育和外展活动，首席调查员(PI)建议利用石溪大学(SBU)现有的课程和资源，为K-12、本科生和研究生开发和提供新的环境工程(EE)学习机会，重点是吸引女性学生。拟议的教育和外展活动将包括1)为期一周的暑期计划，为长岛中学生(7-9年级)提供工程和技术方面的实践学习活动；2)学年期间为期10周的外展计划，接待5-10名女学生，并向她们介绍用于现场污水处理的土壤生物过滤系统的科学和工程。此外，PI计划每月举办一次环境工程研讨会，旨在让SBU的学生接触到广泛的观点和专业知识，以增加他们在EET方面的知识广度和深度。他的获奖反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Millions of households in the United States and worldwide rely on onsite systems for wastewater treatment and disposal. Conventional onsite wastewater treatment systems (OWTS) consist typically of septic tanks connected to leach fields to enable the transport and disposal of liquid effluents in the surrounding soils via networks of drainage pipes. OWTS are predominantly designed to provide primary treatment during which organic wastes and suspended solids in household sewage settle to the bottom of septic tanks where they are partially degraded by microorganisms. Because OWTS are not designed to effectively remove nutrients, the liquid effluents of septic tanks are among the largest sources of nitrogen (N) pollution for shallow groundwater aquifers as they leak into the surrounding subsurface soils. The overarching goal of this CAREER project is to explore the development and validation of the next generation of biofiltration systems for nitrogen (N) removal from OWTS. To advance this goal, the Principal Investigator proposes to test the hypothesis that biofiltration systems based on the integration of anaerobic ammonium oxidation (anammox) microbiomes with sorbents such as biochar could provide efficient and cost-effective solutions for N removal from the liquid effluents of septic tanks. 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 N pollution from households and other facilities that are not connected to centralized wastewater treatment systems. Additional benefits to society will be achieved through student education and training including the mentoring of one graduate student and one undergraduate student at Stony Brook University.Soil-based biofiltration systems have emerged as promising add-on modules to onsite wastewater treatment systems for the removal of nitrogen (N) from the effluents of septic tanks. However, current soil biofilters require a large footprint and an external carbon source (e.g., woodchips) to stimulate and support the growth and metabolic activity of denitrifying microorganisms. This CAREER project will explore the development of novel soil biofilters for N removal based on a hybrid physical/chemical and biological treatment process that integrates biochar sorbents with anaerobic ammonium oxidation (anammox) microbiomes. The proposed research builds upon the results of previous investigations that have established that anammox microbiomes play a critical role in the conversion of N compounds to dinitrogen (N2) gas in soils, wetlands, and marine/freshwater sediments. The specific objectives of the research are to: 1) investigate the partial denitrification/anammox (PDN/An) of N compounds in model biofiltration units using biochar as sorbents and microbiome carriers; 2) evaluate the effects of operational changes and environmental parameters on the efficiency of PDN/An biofiltration units and, 3) investigate and optimize the operation of a modular biofiltration system for efficient N removal and evaluate the system’s long-term performance using molecular tools and kinetic modeling. The successful completion of this project has the potential for transformative impact through the generation of new fundamental knowledge to advance the development and implementation of more efficient soil-based biofilters for removing N from the liquid effluents of onsite wastewater treatment systems. To implement the educational and outreach activities of this CAREER project, the Principal Investigator (PI) proposes to leverage existing programs and resources at Stony Brook University (SBU) to develop and deliver new learning opportunities in environmental engineering (EE) for K-12, undergraduate, and graduate students with a focus on engaging female students. The proposed education and outreach activities will include 1) a one-week summer program to provide Long Island middle school students (7-9th Grade) with hands-on learning activities in engineering and technology and 2) a 10-week outreach program during the academic year to host 5-10 female students and introduce them to the science and engineering of soil-based biofiltration systems for onsite wastewater treatment. In addition, the PI plans to develop and host a monthly environmental engineering seminar designed to expose SBU students to a broad range of perspectives and expertise to increase their breadth and depth of knowledge in EEThis 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.