University of Arkansas researchers take part in NSF-funded effort to turn wastewater into commercial fertilizer

A team of science and agriculture researchers at the University of Arkansas are working with researchers from two other institutions on a project to develop a chemical process that converts nitrogen and phosphorous from wastewater into commercial fertilizer. The effort is aimed at developing energy-efficient fertilizer that is as effective as other commercially available fertilizers, and it is funded by a $2.4 million grant from the National Science Foundation, according to the UA.

“Excess nitrogen and phosphorous in wastewater, due primarily to human impact, cause serious environmental problems,” Lauren Greenlee, assistant professor of chemical engineering at the UA and the lead principal investigator for the project, said in a statement. “We’re engineering a technology that takes these nutrients from the environment and recycles them, turning them into a commercial product that is energy efficient and environmentally less harmful to produce.”

According to a UA press release: “The technology is based on the same general concept that has been used to develop commercialized fuel cells and electrolyzers, wherein two electrodes are separated by a membrane, which allows control of the reactions taking place and the flow of electricity in and out. The researchers will design electrodes to precipitate fertilizer struvite, a crystallized mineral composed of magnesium, ammonium and phosphate. The researchers will then collect the struvite in particulate form.”

The electrochemical-engineering team consists of principal investigators Greenlee, Andrew Herring at the Colorado School of Mines and Julie Renner at Case Western Reserve University. They will focus on electrode design, water chemistry, electrochemical operations, struvite precipitation and the engineering of bench-scale reactor design.

The three other principal investigators are from the UA and include Greg Thoma, professor of chemical engineering; Jennie Popp, professor of agricultural economics and agricultural business; and Kristofor Brye, professor of applied soil physics and pedology. Thoma will develop a life-cycle assessment of the proposed technology, Popp will examine the economics of implementing the technology and Brye will study the composition, chemistry and viability of the fertilizer struvite created by the engineering team, comparing it to commercial fertilizers, according to the press release.

Greenlee said the project will seek input from the community through annual workshops at the UA, which will invite regional stakeholders from across the food supply chain.

“We want to develop an understanding of the needs and opportunities regarding food production, water conservation, and nutrient recycling,” Greenlee said in the statement.

The project also will support the education and training of six full-time graduate students, one post-doctoral researcher and multiple undergraduate researchers, according to the UA.

Greenlee holds the Louis Owen Professorship in Chemical Engineering. Thoma holds the Bates Teaching Endowed Professorship in Chemical Engineering.