Livestock Waste Recycling & Value Added Byproducts

  The U.S. dairy industry produces more than 400,000 million pounds of dairy manure and 520 million gallons in liquid manure. More efficient agricultural use of P, and recycling of existing P resources, has been suggested as possible solutions to unsustainable P-mining practices. Animal excreted dairy manure at a Dairy Farm yield 0.18 lbs. P/cow day (Roa Et al 2016). Anaerobic digestion (AD) technology is notable in its ability to produce a more uniform effluent while stabilizing organic solids, removing pathogens and mitigating methane emissions on farms and facilitating the manure separation into fibers, solids and clean water. 

At the present, the excess P in the effluent is recovered by the Nutrient Isolation-DAF-Polymer platform in a continuous basis before solids are stored to be spread as solids at low moisture content <40% or exported in granular form. This nutrient isolation and recycle of P, reduce environmental concerns about water quality, eutrophication, excess P-loading, and improve dairy economics through a saleable manure cake with higher content of P fertilizer.

 Manure separation and management consists of several steps from the time that the manure is removed from the stalls until it is used for bioenergy production, fertilize crops and the excess water with varied contents of N-P-K. The dairy manure separation system approach utilizes 1) fiber removal, 2) GEM solids separation in raw and digested cake and production of low nutrient effluent, 3) multidisc press dewater of the cake for bio-fertilizer production, 4) separation of the colloidal suspended particle in the bloom tank effluent, 5) production of low N-P-K and micronutrients irrigation clean water. By separating dairy manure into bio-components creates new opportunities such as transportability of the bio-fertilizer, utilization of EPA nutrient content clean dischargeable water, flexibility and timing of the manure bio-fertilizer, a change in the ratio of organo-mineral fertilizer application for crop yields. Dairy manure separation, recycling of organic matter, clean water recycling for alley flushing. clean water for irrigation and plant nutrients recovery, contributes to the optimization of crop fertilization by reducing the need for external supplies of N, P, K, and micronutrients