Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 8/20/2005
Publication Date: 8/25/2005
Citation: Szogi, A.A., Vanotti, M.B. 2005. Removal of phosphorus from animal manures experiences of the USDA - Agricultural Research Service. In: Proceedings of the Workshop on Technologies to Remove Nutrients from Animal Waste, August 25, 2005, Florianopolis - Santa Catarina, Brazil. p. 26-33.
Technical Abstract: A major problem in sustainability of animal production is surplus of manure phosphorus (P) exceeding land assimilative capacity. Land application of manure may result in P buildup in soil and increased potential for P losses through runoff and subsequent eutrophication of surface waters. A wastewater treatment process was developed for removal of P from livestock wastewater. Phosphorus is selectively precipitated using an alkaline earth metal after carbon and ammonia buffers are reduced with a nitrification pretreatment. The method was tested with wastewater collected from nine hog lagoons in North Carolina. In all cases, the soluble P was effectively recovered as P precipitate. When used as a lagoon retrofit, the technology enables precision control of the N:P ratio of the treated effluent to desired levels to match specific crop needs or to solve problems of P accumulation in soil or remediation of contaminated spray fields. The final product is calcium phosphate that can be exported from the farm and reused as fertilizer.