Click on “Download PDF” for the PDF version or on the title for the HTML version.
If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.
Anaerobic fermentation of swine manure to increase P removal by struvite precipitation
Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.orgCitation: 2011 Louisville, Kentucky, August 7-10, 2011 1110618.(doi:10.13031/2013.37251)
Authors: Joe Nelson Ackerman, Nazim Cicek, Jan Oleszkiewicz
Keywords: Phosphorus, manure, struvite, anaerobic fermentation
The precipitation reaction to form struvite (MgNH4PO4 6 H2O) or calcium phosphate from nutrient rich manure supernatants and slurries is limited by the concentration of phosphorus in dissolved form (P-PO4) . Liquid hog manure holds ~10% of total phosphate (TP) as P-PO4, the rest bound in either organic or inorganic solids. In order to increase P recovery from this resource, P must be converted to the dissolved phase where it can be precipitated. The purpose of this experiment was to investigate the effect of anaerobic fermentation and resulting acidification on the abundance of P-PO4 and other struvite constituents in hog manure. Manure (2.5% solids) was stirred anaerobically at 4, 8, and 12 day hydraulic retention times (HRT) in two continuously fed reactors. Anaerobic fermentation was effective in decreasing the pH of manure (from pH 7.4 to 5.8) and caused P-PO4 to increase from 10 to 27% of TP in the 12 d HRT effluent. On a mass balance basis, manure P removable as struvite increased from 16 to 41% assuming all P-PO4 could be successfully removed as struvite.(Download PDF) (Export to EndNotes)