Research team investigates source separation of wastewater with NSF grant

Wastewater treatment plants and city sewer systems are often stretched to the limit and need pricey upgrades to sustain operations. At the same time, farmers need healthy, nitrogen-filled fertilizer for their crops. The question is, how do the two issues relate?

Marisa Manheim, assistant professor in the Department of Environment and Sustainability, is co-principal investigator on a team receiving a $650,000 award from the U.S. National Science Foundation (NSF) Convergence Accelerator (Phase 1 in Track K: Equitable Water Solutions). The Convergence Accelerator grants are designed to addresses national-scale societal challenges through use-inspired research. According to the NSF, funded projects “seek to transition basic research and discovery into practice — to solve high-impact societal challenges aligned with specific research themes (tracks).”

Manheim’s team was selected for its transdisciplinary, multi-institutional project “Advancing Source Separation for Equitable Transitions (ASSETs)” that is taking a systems approach to tackle how source separation of wastewater can be adopted more broadly. In other words, developing solutions to separate urine from solid human waste to be used later in environmentally and economically beneficial applications.

“There are surprisingly a lot of opportunities around human urine, partially because it contains a significant level of nitrogen, phosphorus, potassium and other elements,” says Manheim. “It is very valuable.

“Our team’s goal is to find ways to reclaim urine and turn it into fertilizer in an effort to help offset conventional fertilizer,” Manheim continues. “There’s a great potential here to enable nutrient recovery while reducing nitrogen and phosphorus pollution, which causes a lot of problems in waterways, groundwater and freshwater systems, and subsequently the communities that rely on them.”

While source-separation technology in toilets already exists — especially in urinals — the team plans to identify how technologies, private and public sector workforces and services, regulations and people’s habits and ideas about wastewater reuse need to adapt in order for separating wastewater at the source to effectively work toward a circular economy. The research seeks to answer the questions of who is collecting and processing; what commercialization could look like; and how the technology gets in the hands of those who need it most.

The team sees the potential of launching initial prototypes at the University of Michigan thanks to principal investigator Nancy G. Love, Borchardt and Glysson Collegiate Professor and Joann Silverstein Distinguished University Professor at the university. A variety of models are being considered, including a portable unit for use during tailgating.

While agriculture will be the primary benefactor from the study’s results, developing alternative wastewater management strategies has potential to help the housing crisis, rural communities and increase access to public sanitation facilities.

“Places like New York City are facing extreme affordable housing challenges,” Manheim says. “One of the reasons is because of their wastewater systems. The watersheds that receive discharged wastewater from their treatment plants cannot handle anymore nitrogen. This creates limits on how much housing can be added to a given area.

“By reducing the amount of nitrogen sent to wastewater treatment plants, we can potentially remove some of those barriers to affordable housing while meeting regulatory requirements.”

Rural areas, tiny homes and other portable units rely on septic systems or costly efforts to tie into sewer systems. The potential to offer different options to communities provides equitable water solutions and ecologically sound housing designs.

A total of 16 teams are competing in the current Phase I funding process and will have until the fall to develop their prototypes. In September, the teams will compete for the next phase of the award. If the ASSETs team advances, they will be one of six teams granted Phase 2 of the award, with funding up to $5 million.

In addition to Manheim and Love, the ASSET team includes Jennifer Blesh, Lesli Hoey, Joe Lybik, Mathew Lippincott and Lanika Sanders from University of Michigan; Julia Cavicchi, Abe Noe Hays, Tatiana Schreiber and Jamina Shupack from Rich Earth Institute; Miriam Hacker and Jeff Moeller from The Water Research Foundation; Kim Nace from Brightwater Tools; George Wells from Northwestern University; Julia Dorr, a UB master’s student in sustainability leadership; and, Kartik Chandran from Columbia University.