International Dairy Meet

Biography

Biography: Jactone Arogo Ogejo

Abstract

Manure management is a challenge in animal feeding operations, particularly, in sensitive ecosystems like the Chesapeake Bay watershed, where these operations have been associated with water and air pollution and are facing extra scrutiny by state and federal regulation agencies. Our work is focused on phosphorus (P) recovery and uses the “designer manures” concept to generate manure products with balanced nitrogen and P content to meet specific fertilizer requirements of different crops. We have developed and successfully implemented chemical based P recovery processes at field scale (treating large batch volumes >500,000 gal) for liquid dairy manure and also, conducted lab scale tests to develop a process suitable for dairies that scrape manure from barn floors. Our lab studies, the focus of this presentation, have shown how to effectively use process liquid to dilute manure before dosing with chemicals to minimize the effect of the organics in the manure and improve the efficiency of P recovery and chemical use. Results using aluminum (chloride and sulfate) salts showed that dosing 600 mg Al/L generated process liquid (supernatant) with low total P (i.e. recover over 95% of the total P in the sludge). The quality of the recovered process liquid for diluting the manure (4% total solids) to recover P, was not compromised, despite multiple recycling. We have used these results to scale up the process at pilot scale and is currently being deployed on a farm.