GOALI: Elucidating the synergistic role of anammox bacteria with flanking bacterial community members in anammox bioreactors under different environmental conditions

University Of Utah, Salt Lake City UT

Investigators

Abstract

Excessive nitrogen (N) releases from wastewater treatment plants can lead to ecosystem harm through eutrophication. Eutrophication is the excessive growth of algae stimulated by N. In extreme cases, eutrophication can lead to widespread loss of oxygen and fish kills when the algae die. N in wastewater is typically removed by oxidation to nitrate in a process called nitrification and subsequent reduction to gaseous nitrogen in a process called denitrification. Nitrification and denitrification have been used for N removal in wastewater treatment plants for decades. However, this process is highly energy intensive. More recently treatment plants have sought to utilize ANaerobic AMMonia OXidation (ANAMMOX) to remove N with less energy. ANAMMOX has been adopted internationally, with several full-scale plants currently operational. In contrast, the acceptance of ANAMMOX in the United States has been relatively limited. This is due in part to concerns about process inhibition due to external perturbations. In this project, researchers will study the effect of external perturbations by nitrite, sulfide and recalcitrant carbon on ANAMMOX process stability. This will be achieved by studying the response of the microbial community to these perturbations in laboratory scale reactors. The research team will collaborate with the wastewater treatment utility DC Water. Graduate, undergraduate, and K-12 students will obtain industrial and entrepreneurial experiences though this collaboration. This project will significantly enhance our understanding of the ANAMMOX process, potentially leading to successful full-scale applications in the United States. The project focus on managing the N cycle directly addresses one the "14 Grand Challenges of the 21st Century" identified by the National Academy of Engineering. Despite over three decades of extensive research, several factors still prevent widespread implementation of the ANAMMOX process for wastewater treatment. Currently, there are no studies that have focused on understanding the response of ANAMMOX reactors to external perturbations at the proteomic and molecular levels, and very few studies have examined the role of other bacteria (i.e. flanking community) in ANAMMOX enrichments. This project will address these knowledge gaps by generating fundamental information on ANAMMOX communities using metagenomics, metatranscriptomics, and proteomics. These results will enable more robust engineering control and adoption of this innovative nitrogen cycling technology to address managing the nitrogen cycle as one of the National Academy of Engineering "14 Engineering Grand Challenges of the 21st Century". This project will be carried out by a collaboration between researchers at the University of Utah and the wastewater treatment utility DC Water. Utah researchers will provide expertise in fundamental science of reactor operation, bacterial community analysis, bacterial biokinetic and toxicity analysis, while DC Water will provide student training and internship opportunities for the translation of the work into full scale application. The goal of this project is to elucidate the complete functional gene network under different perturbations in the ANAMMOX process. Successful development of this network will help engineers and scientists to understand process upsets and facilitate the design and wider adoption of efficient and resilient ANAMMOX systems. 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.