William Abraham Tarpeh, Ph.D. - US grants

Cities and farms discharge nitrogen-rich compounds into receiving waters, resulting in pollution of the environment. Current technologies to remove nitrogen-rich compounds from water are costly and energy intensive, resulting in great economic and environmental costs to society. The difficulty in addressing this waste problem is why the National Academy of Sciences, Engineering, and Medicine calls managing the nitrogen cycle one of the ?Grand Challenges? of engineering. The goal of this project is to develop new scientific knowledge about how to concentrate, separate, and transform waste nitrogen-rich compounds into animal feed and beneficial products. This outcome will be achieved through cross-disciplinary biology and chemistry research to remove nitrogen-rich compounds from waste streams and to transform them into chemicals that can be used for the production of useful products. The environmental impact and potential for new businesses based on these new technologies will be evaluated. Successful completion of this work will prevent nitrogen pollution, reduce greenhouse gas emissions, and provide a new sustainable feedstock for chemicals. Other benefits from this project will include workforce development and educational outreach to underrepresented grade-school students. These efforts will promote increased diversity in STEM fields and improve scientific literacy of the general public.

Nitrogen-rich waste streams are produced in large quantities from urban and agricultural settings and impose severe environmental burdens to human and ecological health. Conventional nitrogen management treats nitrogen-rich compounds as waste rather than as a recoverable resource. This approach is costly, energy intensive, and results in the release of large amounts of the potent greenhouse gas, nitrous oxide (N2O). The goal of this research project is to develop novel technological approaches to convert nitrogen-rich waste into high-value products beyond fertilizers. This research project has the objectives to: (1) Engineer bacteria to bioconcentrate dilute waste nitrogen, which then can be used as animal feed or for bio-based chemical production; (2) Develop a microbial bioprocess for simultaneous nitrogen removal and nitrous oxide recovery for use as a green oxidant; (3) Design catalytic processes to capture and activate dilute nitrous oxide streams for the selective oxidation of methane; and (4) Identify optimal products, feedstocks, and technology combinations to satisfy diverse stakeholder needs and cost and sustainability objectives. The novelty of the approach lies in the energy-efficient recovery of nitrogen as a building block for bio-based chemicals and animal feed. This approach integrates expertise across chemical, biological, and environmental engineering disciplines. Successful completion of this research will benefit society through sustainable waste nitrogen management and the mitigation of nitrous oxide emissions. Additional benefits will result from educational and industrial outreach. Such efforts include outreach to underrepresented grade-school students in a climate action project. Integrative learning experiences with industrial partners and graduate student exchanges between research groups will enhance the development of a future workforce to address grand challenges in sustainability.

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.

Nitrogen pollution is a Grand Challenge identified by the National Academies. Fertilizer production has outpaced removal of nitrogen from wastewater, leading to continuous losses that threaten aquatic ecosystems and human health. This project aims to meet this challenge by recycling waterborne nitrogen pollutants into high-purity ammonia. The PIs’ approach is unique in its ability to reduce nitrogen emissions and their negative cascade effects; reduce the energy and costs of conventional fertilizer production and wastewater treatment; and address legacy pollution that can persist for decades in coastal ecosystems like the Gulf of Mexico. The overall goal of this EFRI Distributed Chemical Manufacturing research project is to understand, design, and control multifunctional electrochemical processes that enable on-site fertilizer manufacturing and water purification with minimal environmental impacts. The project combines fundamental breakthroughs in novel materials and processes to convert wastewater pollutants into products. The project includes integration of the fundamental discoveries with cost optimization and performance in various wastewaters, as well as prioritizing adoption locations and value propositions for recovery facilities. Because re-engineering the nitrogen cycle is a demanding challenge, it requires the best approaches from the entire U.S. talent pool. Thus, the project team plans to broaden participation by hosting an annual workshop and demonstration day at a Stanford pilot-scale water treatment plant and invite underrepresented K-12 students; local community members; undergraduate researchers; and the project’s industrial advisory board representing fertilizer production, agriculture, and water treatment. The team will also develop workshops for incoming underrepresented undergraduate students, hands-on lab activities in classes, nitrogen-focused modules with K-12 students, and mentored research experiences for high school and undergraduate EFRI Scholars.

Current engineering efforts to rebalance the nitrogen cycle have largely concentrated on the improvement of the Haber-Bosch process to produce ammonia or expansion of nitrogen removal from wastewater. This project puts forward a transformative vision: recycling reactive nitrogen (e.g., ammonia, nitrate) in distributed nitrogen refineries that convert fugitive emissions in waste waters into high-purity ammonia. The overall goal of the research is to understand, design, and control multifunctional electrochemical unit processes that enable distributed ammonia manufacturing and water purification with minimal environmental impacts. The project will utilize electrodialysis and nitrate reduction as a platform to benchmark and characterize ammonia-selective catalysts, as well as a treatment process applicable to two ubiquitous wastewaters: municipal wastewater and fertilizer runoff. The project’s objectives are to: (1) understand and control electrocatalytic microenvironments via selective electrochemical reactive separations; (2) establish quantitative material and process innovation targets for energy-efficient, cost-effective, and adaptive processes; and (3) leverage economic and environmental assessments to prioritize local contexts and products for wastewater-derived ammonia manufacturing.

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.

Black faculty in Environmental Engineering play a significant role in promoting social, economic and environmental justice, training a workforce; and designing, testing and implementing technologies that influence the quality of life for individuals and communities at local, national and global scales. Unfortunately, the number of Black, Environmental Engineering faculty has remained low for the last decade despite targeted recruitment efforts. This is because the toxic and oppressive culture of exclusion, devaluing, and bias discourages many from pursuing an academic career and prevents talented, Black faculty from succeeding. To reduce this racially centered loss from engineering, the goal of this research is to use a variety of community based methods such as surveys and interviews to investigate activities that Environmental engineering programs can adopt to support Black junior faculty in their career progression. The investigators will develop a comprehensive, easy-to-use guidance manual to evaluate the professional success of junior faculty in three areas: professional development, promotion & tenure and job satisfaction & support. The benefit of this work to society results from providing a tool that has the potential to increase recruitment and retention of racially diverse faculty. In turn, this results in the promotion of creative problem solving, economic competitiveness and competency in the engineering workforce.<br/><br/><br/>The aim of this project is to develop a guidance framework for institutions to increase support and retention of Black, junior Environmental Engineering faculty by promoting success in three core areas: professional development, promotion & tenure and job satisfaction & support. This logical framework is an analytical methodology that identifies and analyzes a given situation and defines objectives and activities which should be undertaken to improve the situation. This methodology is common in international community development projects but its applicability for this project lies in its ability to assess conditions, problems and opportunities for monitoring and evaluating success. To build the tenets of the framework, the investigators will: (1) identify evaluation matrix indicators, verification methods and assumptions; (2) engage the engineering faculty and academic leadership through surveys and interviews; and, (3) present findings through focus groups and the Environmental Engineering community at workshops and in peer-reviewed publications. The framework presents an innovative approach by developing a quantitative relationship between determinants of success, perceptions of contribution, and knowledge and activities to promote success. In addition, it can assist academic leadership with faculty retention and improved campus inclusion, and support future generations of Black junior faculty thrive in their institutions. While the activities are first geared towards the needs of Black, junior Environmental Engineering faculty, the approach can be adopted to support other underrepresented faculty in science, technology, engineering and mathematics.<br/><br/>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.