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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #378802
Research Project: Sustaining Agroecosystems and Water Resources in the Northeastern U.S.

Location: Pasture Systems & Watershed Management Research

Title: Struvite production at commercial dairies with use of a mobile system and comparisons to alternative nutrient recovery systems

Author
item HARRISON, JOE - WASHINGTON STATE UNIVERSITY
item FULLERTON, KEVIN - WASHINGTON STATE UNIVERSITY
item WHITEFIELD, ELIZABETH - WASHINGTON STATE UNIVERSITY
item BOWERS, KEITH - CONSULTANT
item CHURCH, CLINTON
item DUBE, PATRICK
item Vanotti, Matias

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/30/2022
Publication Date: 1/30/2022
Citation: Harrison, J., Fullerton, K., Whitefield, E., Bowers, K., Church, C., Dube, P.J., Vanotti, M.B. 2022. Struvite production at commercial dairies with use of a mobile system and comparisons to alternative nutrient recovery systems. Journal of Environmental Quality. 38(2):361-373. https://doi.org/10.13031/aea.14836.
DOI: https://doi.org/10.13031/aea.14836

Interpretive Summary: A mobile system was used to evaluate the variability in capture of P from from liquid dairy manure in the form of struvite (magnesium-ammonium phosphate) from undigested (raw) or anaerobically digested liquid dairy manure at 32 dairies in Washington State. Ortho P capture using typical (non-anaerobically digested) dairy manure averaged 34 % over the course of a 7–9 h nutrient recovery run. A comparison to two other treatment technologies, the MAnure PHosphorus EXtraction System and the Ammonium and New-P Recovery System, is also provided.

Technical Abstract: A mobile system was used to evaluate the variability in capture of P from from liquid dairy manure in the form of struvite (magnesium-ammonium phosphate) from undigested (raw) or anaerobically digested liquid dairy manure at 32 dairies in Washington State. The struvite system consisted of a fluidized bed technology with a 3,200 L cone mounted on a 8-m trailer, allowing easy transport from farm to farm. Batches of 13,000 L of manure were evaluated and the system was operated at a flow rate of 20 – 28 L min**-1. Manure was pre-treated with sulfuric acid or oxalic acid, and magnesium chloride prior to pumping the manure through the cone. Sodium hydroxide or aqueous ammonia were pumped into the base of the cone to raise the pH and form struvite. Ortho P capture using typical (non-anaerobically digested) dairy manure varied from 1–76%, averaging 34 % over the course of a 7–9 h nutrient recovery run. Average ortho P capture was highest at 84%, and total P capture of 62 % using anaerobically digested manure with pH modifiers of oxalic and/or sulfuric acid and aqueous ammonia. Major factors affecting the formation of struvite were: total suspended solids (less than 10,000 mg L**-1), Ca (less than 600 mg L**-1), Fe (less than 25 mg L**-1) and ortho P (greater than 50 mg L**-1). Partial budget economic analysis indicated that number of lactating cows and cropland were critical factors for achieving whole farm P balance. A comparison to two other treatment technologies, the MAnure PHosphorus EXtraction System and the Ammonium and New-P Recovery System, is also provided.