Process for Recovery of Calcium Phosphates From Solid Manure.

Land application of manure in regions with intense confined livestock and poultry production is an environmental concern when land is limiting because it promotes soil phosphorus (P) surplus and potential pollution of water resources. Although manure can be moved off the farm, its transportation becomes less economical with increasing distances from the farm. Thus, management alternatives to land application are needed to recycle manure P. A treatment process, called “quick wash”, was developed for extraction and recovery of P from poultry litter and animal manure solids. In the quick wash process, P is selectively extracted from solid manure or poultry litter by using mineral or organic acid solutions. Following, P is recovered by addition of liquid lime and an organic poly-electrolyte to the liquid extract to form a calcium-containing P precipitate. The quick wash process generates two products: 1) washed solid residue, and 2) concentrated recovered P material. The washed solid residue has a more balanced N to P (N:P) ratio that  is more environmentally safe for land application. The use of recovered P can provide a recycled P source for use as crop fertilizer while minimizing manure P losses into the environment from confined animal production.