Green Alternative for Dissolved Nutrient Recovery in Wastewater Side Streams


  • Laurissa Cubbage , Alan Stone, Katya Bilyk, Paul Pitt – Hazen and Sawyer
  • Bill Balzer, John Dano, Charles Bott – Hampton Roads Sanitation District, VA
  • Ahren Britton, Aynul Dharas– Ostara Nutrient Removal Technologies, Inc.

Construction of the Struvite Recovery Facility at the 30-mgd Nansemond Treatment Plant. For more images, view the press release.

Wastewater treatment utilities expend significant sums of money and energy every year to remove nitrogen and phosphorus from wastewater, yet these same nutrients can be valuable feedstocks in other applications, such as agriculture. It is predicted that sufficient, readily available, minable phosphorus will not be available in the near future to support current and future agricultural demand. One process to beneficially recover these nutrients from wastewater is a centrate treatment process aimed at simultaneously recovering both phosphorus and nitrogen by creating a sustainable end-product which can be marketed as a slow-release fertilizer. The centrate treatment technology evaluated for this nutrient recovery project is manufactured by Ostara Nutrient Removal Technologies (Ostara).

This paper will present the results of the technical and economic evaluation of the Ostara-Pearl® process for the 30-mgd Hampton Roads Sanitation district (HRSD) Nansemond Treatment Plant (NTP). The Ostara process allows the 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. Based on the pilot tests, the Ostara-Pearl® process is expected to reduce the centrate phosphorus load up to 90%, and centrate ammonia load up to 10%. The Ostara process was compared with a more traditional nutrient removal alternative of ferric chloride precipitation of phosphorus for the evaluation. The cost evaluation demonstrated that the Ostara process is cost competitive compared to ferric chloride addition and these results will be presented in the paper.

Design, construction, and operational aspects of the Ostara facility, named the Struvite Recovery Facility (SRF), will also be discussed in this paper. Due to time constraints set forth by the Chesapeake Bay Initiative, the SRF will be delivered using a fast-track design and construction schedule, with the SRF expected to be complete by April 2010, and producing twenty (20) tons of fertilizer per month by May 2010. When completed, the NTP facility will be the second and the largest full-scale Ostara-Pearl® installation in the United States. Operational data is expected to show reductions in recycle side stream phosphorus and nitrogen loads and increased liquid stream process efficiency, which will be presented with this evaluation when available.

To request a copy of the full paper, please contact the author at

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