A Green Alternative for Dissolved Nutrient Recovery in Wastewater Sidestreams

Ostara Nutrient Recovery Technologies (Ostara) manufactures a centrate treatment technology to beneficially recover both phosphorus and nitrogen from wastewater by creating a sustainable end-product which can be marketed as a slow-release fertilizer.The Ostara process allows the Nansemond Treatment Plant (NTP) to capture nitrogen and phosphorus which would be discharged to the James River, a tributary of the Chesapeake Bay, and convert it to an agriculturally beneficial product. With Ostara, additional chemicals and infrastructure would be needed to prevent these nutrient discharges. Hazen and Sawyer evaluated this technology against more traditional side stream treatment applications, such as phosphorus removal by ferric chloride addition, and demonstrated that Ostara's Pearl® Process was a cost effective solution at the NTP. This economic analysis also included a comparison of two procurement alternatives available through Ostara: Capital Purchase and Performance Fee. Analysis showed that HRSD should elect to utilize the capital purchase option. HRSD procured a contract with Ostara for the purchase of the equipment, and secured a contractor to construct the Struvite Recovery Facility, which houses the equipment.This paper will discuss the evaluation, design, construction, and operational aspects of the Ostara facility, which has been operational since April 2010 and is the largest full-scale Ostara installation in the United States. Results show that during the Ostara facility's first seven months of operation an average of 33% of sidestream ammonia and 82% of sidestream ortho-phosphorus was converted to struvite. The Ostara process is currently being optimized at the NTP to increase removal percentages.