By Sara Jerome,
Finnish researchers claim they have developed a new method for converting the nutrients in wastewater into fertilizer.
In lab tests, their method separated 99 percent of the nitrogen and up to 99 percent of phosphorus in wastewater, producing “granular ammonium sulphate (NH4)2SO4 and phosphorus precipitate suitable for fertilizers,” according to a statement from Aalto University in Finland.
Riku Vahala, a researcher and professor at Aalto University, described the significance of the study.
"There are many different methods for removing nitrogen and phosphorus from wastewater, but none of them meets the need of capturing their nutrients. It is estimated that the industrial production of nitrogen used for fertilisers is responsible for approximately 2 percent of the entire world's energy consumption. By capture of nutrients from communities' wastewater it is possible to supplement 6 percent of the industrially produced ammoniacal nitrogen and about one-tenth of phosphorus used for fertilisers," he said.
The goal of the project is to create a cost-effective way to recycle the nutrients in wastewater, according to a statement from the university. Researchers will begin building pilot equipment to test their method this year.
Industry pros are increasingly trying to make use of the components of wastewater. Chicago, for instance, is trying to move to a “zero waste” model and recover more nutrients from wastewater.
To that end, the city built the world’s largest phosphorus recovery facility at the Stickney Water Reclamation Plant. “All of this ... is moving Chicago in the direction of a zero waste model,” Next City reported.
Nutrients can be a valuable asset to farmers. “We’re going to run out of phosphorus probably in 30 to 50 years,” said Robert F. Kennedy Jr., a board member for the company operating the Chicago plant, per WTTW’s Chicago Tonight. “So here’s a way that we can produce it locally, at the sewage treatment plant.”
To read more about nitrogen and phosphorus visit Water Online’s Nutrient Removal Solutions Center.