Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/19/2002
Publication Date: 8/19/2002
Citation: Szogi, A.A., Vanotti, M.B., Hunt, P.G. 2002. Extraction and recovery of phosphorus from animal wastewater [abstract]. American Chemical Society National Meeting, August 18-22, 2002, Boston, Massachusetts.
Technical Abstract: Past research efforts on phosphorus removal from animal wastewater using chemical precipitation have been frustrating due to the large chemical demand and limited value of by-products such as alum sludge, or because of the large chemical demand and losses of nitrogen at the high pH required to precipitate phosphorus with calcium salts. A treatment system was developed that requires minimal chemical addition, reduces problems of ammonia emissions during separation of phosphorus from the aqueous phase, and recovers phosphorus in a reusable form. Phosphorus is selectively precipitated using an alkaline earth metal after carbon and ammonia buffers are reduced with a nitrification pretreatment. The method was successfully tested in nine hog lagoons and in a prototype system without lagoon in North Carolina. In all cases the soluble phosphorus was effectively recovered as phosphate (about 17% P2O5). The product is further dewatered to >50% solids using charged polymer and filter bags.