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We found that soluble phosphorus can be easily removed from animal wastewater, which has had a nitrification pre-treatment, in the form of calcium phosphate that can be used as a fertilizer. In the process, carbonate and ammonium buffers contained in liquid waste must be at least reduced or eliminated during the nitrification pre-treatment. This substantially reduces the overall chemical demand needed for optimum phosphorus precipitation and removal.

This research showed that the concept can be used in systems without lagoons. The proposed system uses polymer enhanced solid-liquid separation to remove organic nutrients and oxygendemanding compounds, and biological N removal to eliminate ammonia and carbonate buffers.

Efficiencies of 98% phosphate removal were obtained. This technology not only has potential to solve current problems with excessive accumulation of phosphorus in soils receiving liquid manure, it also produces a valuable phosphorus fertilizer material and reduces the presence of pathogens due to the high pH in the process.