Enhanced recovery of phosphorus from swine manure using acid precursors contained in other wastes.

A new approach was developed to separate and recover concentrated phosphoruss from animal waste.   It was improved by adding a second waste or product containing sugars, such as molasses, fruit waste, or lactose waste.  They can be used as a natural acid precursor that replaces purchased acids and lowers the overall cost of phosphorus recovery.  The two wastes were swine manure solids (source of extractable phosphorus and proteins) and peach waste, sugar beet molasses and lactose  (source of acid precursors).  A short fermentation time (1 day) was needed to acidify the manure to a point that the phosphorus was solubilized and ready for precipitation with alkaline earth compounds, producing high-grade phosphates.