Conservation and recovery of ammonia and phosphorus from agricultural and municipal effluents are important because of economic and environmental reasons. In this paper we present a novel USDA patented technology for separation and recovery of ammonia and phosphorus from liquid swine manure and side-stream municipal effluents. Phosphorus recovery via magnesium precipitation was enhanced by combining it with ammonia recovery through gas-permeable membranes and low-rate aeration. The combination 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: 44% P2O5 from a municipal centrate, and 46% P2O5 from a swine manure anaerobic digester effluent. The phosphate grade obtained is 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.

Recovery of ammonia and phosphate minerals from agricultural wastewater

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.