|GARCIA-GONZALEZ, M - Instituto Tecnológico Agrario De Castilla Y León (ITACYL)|
Submitted to: Waste to Worth Conference
Publication Type: Proceedings
Publication Acceptance Date: 3/10/2017
Publication Date: 3/19/2017
Citation: Vanotti, M.B., Dube, P.J., Szogi, A.A., Garcia-Gonzalez, M.C. 2017. Recovery of ammonia and production of high-grade phosphates from digester effluents. Proceedings of Waste to Worth Conference, April 19-20, 2017, Raleigh, North Carolina.
Technical Abstract: Conservation and recovery of nitrogen and phosphorus from animal wastes and municipal effluents is important because of economic and environmental reasons. In this paper we present a novel technology for separation and recovery of ammonia and phosphorus from liquid swine manure. Phosphorus recovery via magnesium (MgCl2) precipitation was enhanced by combining it with ammonia recovery through gas-permeable membranes and low-rate aeration. The combination of low-rate aeration and gas-permeable membrane N recovery destroyed the natural carbonate alkalinity in the wastewater and increased pH, which accelerated ammonia uptake in the gas-permeable membrane system and improved the phosphate recovery. The process provided 100% phosphorus recovery efficiencies. Surprisingly, the magnesium phosphates produced contained very-high phosphate grade (46% P2O5) similar to commercial superphosphate fertilizer and consistent with the composition of a rare biomineral called newberyite that is found in guano deposits. This is an important finding because we were able to produce from wastes a valuable phosphate product with high P2O5 content favored by the fertilizer industry.