This summer, Vancouver-based Ostara Nutrient Recovery Technologies Inc. opened its first Canadian commercial-scale nutrient recovery facility in Saskatoon. The plant will remove phosphorus and nitrogen from wastewater, turning them into commercially valuable fertilizer.
Ostara’s technology, licensed from the University of British Columbia in 2005, revolves around magnesium ammonium phosphate (NH4MgPO4•6H2O) also known as struvite. This mineral is formed by the leftover nitrogen and phosphorus present in wastewater after biological treatment and often precipitates to form crusty deposits that block pipes. Ostara’s solution is a system whereby struvite is created under controlled conditions by adding magnesium chloride in a cone-shaped, fluidized bed reactor. The unique shape allows for different flow regimes in different parts of the reactor, so that instead of deposits, struvite is formed as pellets that can be separated and sold as a slow-release fertilizer. Removing phosphorus this way prevents the nutrient from reaching waterways, where it causes uncontrolled algae growth and eutrophication.
Although it operates a demonstration plant in Edmonton, until now Ostara’s four commercial-scale operations have all been built in the United States. “To finally have a commercial facility operational in Canada is something that we’ve been anxiously awaiting,” says CEO Phillip Abrary. Saskatoon was a good choice because of a 12-kilometre pipe between the main treatment plant and the biosolids facility that was notorious for accumulating struvite. Abrary says the plant is capable of producing more than 700 tonnes of fertilizer per year, but will produce 250 to 350 tonnes to start. Revenue from fertilizer sales is shared with the city to offset the cost of operating the plant.
Ostara has several other installations in development, including its first European facility to be created near London, United Kingdom. It’s also looking at expansion into other markets, such as industrial (as opposed to municipal) wastewater. “People are looking at this as an acceptable and low-risk alternative to treating the phosphorus,” says Abrary. “We see great growth and prospects in the coming years.”
Ostara’s Pearl reactor is designed to precipitate struvite as discrete particles that can be sold as fertilizer. Photo credit: Ostara