Wastewater, sewage sludge, and liquid manure are valuable sources of fertilizer for food production. Aalto University researchers have developed a new, feasible method for capturing nitrogen and phosphorus from different liquid waste fractions.
The new method makes it possible to separate 99 percent of the nitrogen and up to 99 percent of phosphorus in wastewater. These nutrients are used to make granular ammonium sulphate (NH4)2SO4 and phosphorus precipitate suitable for fertilizers.
According to Riku Vahala, a researcher, and professor at Aalto University, there are tons of ways to remove nitrogen and phosphorus from wastewater, but none of it meets the need of getting the nutrients. Extracting nutrients from communities' wastewater will make it possible to supplement about one-tenth of phosphorus and 6 percent of the industrially produced ammoniac nitrogen that is used for fertilizers.
According to Plant and Soil Sciences, phosphorus helps the plant convert other nutrients into usable building blocks with which to grow. Phosphorus is one of the main nutrients most commonly found in fertilizers.
Creating a cost-effective way to recycle the nutrients in wastewater is the goal of the project. According to Aalto University, they will begin the construction of a pilot equipment at the Laboratory of Water and Environmental Technology in spring 2017.
Industry giants are constantly trying to make use of the components of wastewater. One of the biggest wastewater treatment plant, the Metropolitan Water Reclamation District of Greater Chicago, is moving towards a "zero waste" model and recovering more nutrients from wastewater, as reported by Next City.
Nutrients can be a valuable asset to farmers. Robert F. Kennedy Jr., a board member for the company operating the Chicago plant said, "We're going to run out of phosphorus probably in 30 to 50 years. So here's a way that we can produce it locally, at the sewage treatment plant."
