Technology background

Ostara’s lead technology platform is based on a proprietary fluidized bed reactor that recovers ammonia and phosphate from nutrient rich fluids, in the form of a high-value slow-release fertilizer known as struvite. Wastewater treatment plants are an ideal source of nutrient rich fluids.

Ostara’s struvite recovery technology was developed by the University of British Columbia. The research team arrived at a proprietary fluidized bed reactor design which not only removed in excess of 85% of the influent phosphorus, but also resulted in the formation of a fertilizer in granular form consistent with that used in the fertilizer industry.

The implementation of this technology at a wastewater treatment plant not only provides good fertilizer yields (P-Recovery > 85%), but also helps reduce effluent phosphate and ammonia levels, regardless of the wastewater treatment process employed, and reduces or eliminates costly and maintenance intensive struvite scaling problems that often occur in sludge dewatering liquor conveying equipment (pumps, valves and pipes).

Ostara’s process is ideally suited to wastewater treatment plants that employ biological phosphorus removal and anaerobic sludge digestion. These facilities concentrate phosphorus in their sludge dewatering liquor stream, which left untreated results in struvite scaling problems and excessive effluent phosphate levels. By implementing the Ostara struvite recovery technology, the phosphate load returned to the liquid treatment train from sludge treatment is dramatically reduced. This reduction has been shown to stabilize the biological phosphorus removal process, eliminate the struvite scaling problems, and reduce effluent phosphate levels.

The first commercial-scale Ostara nutrient removal reactor has been
operating since May 2007 as part of the City of Edmonton’s Gold Bar
wastewater treatment plant. Pilot scale reactors have been successfully operated at the Greater Vancouver Regional District’s Lulu Island wastewater treatment plant; the Penticton, British Columbia, advanced wastewater treatment plant; the City of Edmonton Gold Bar wastewater treatment plant, the Hampton Roads Sanitation District’s Nansemond wastewater treatment plant in Suffolk, Virginia, and the Durham Advanced Wastewater Treatment Facility in Tigard (Portland), Oregon operated by Clean Water Services.

The technology development was also supported by British Columbia provincial electricity utility BC Hydro, international engineering firm Stantec Inc., Vancouver-based NORAM Engineering and Constructors Ltd., and the Canadian federal government’s Natural Sciences and Engineering Research Council (NSERC), National Research Council (NRC) and Sustainable Development Technology Canada (SDTC).