VATIS UPDATE Article

Researchers at the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Germany, have developed the electrochemical process ePhos® that would recover phosphorus from wastewater without relying on chemicals or harming the environment. When installed at water treatment plants, it allows fertilizer to be obtained from wastewater, and in a form that is ready for use in food production. At the heart of this technology is an electrolysis cell that makes it possible to extract nitrogen and phosphorus using a magnesium electrode, resulting in either struvite (magnesium ammonium phosphate) or potassium struvite.

“Struvite is free of biomass and can be used directly in agriculture as a high-quality fertilizer that releases nutrients slowly,” explained Dr. Iosif Mariakakis, at Fraunhofer IGB. What’s really special about the process is that it is purely electrochemical: unlike traditional methods, there’s no need to add salt or lye. “This is also good news for water treatment plant operators – the process is very straightforward and doesn’t require them to stock chemicals,” added Mariakakis. A licensing agreement has been signed with Ovivo, the United States, who is marketing the technology in the USA, Canada and Mexico.

Due to the stringent limit values associated with water treatment, there is considerable demand for efficient ways of extracting phosphorous. Moreover, many of the water treatment plant providers in the U.S. that will use this process are also looking to sell the struvite, considering it as an attractive source of income. But ePhos® could also quickly gain a foothold across Europe, where it will soon be mandatory to separate phosphorous from sewage sludge and where demand for cheap fertilizer is expected to grow. Given this situation, IGB is searching further licensees to introduce the technology on the European market as well.