Manure Foaming in Deep Pit Facilities Illinois Pork Expo What is Going On? 2 4 foam being produced in deep pit swine facilities. Photo courtesy of University of Minnesota Why Is this a Problem? Coming up through the slats into living area. Shuts down pit ventilation Accumulates gases in pit and is causing fires & explosions. Photo courtesy of University of Minnesota What is the Cause? DDGS in feed? More fiber/solids excreted in manure than with corn/soy diet High solids in manure is a historic, but unproven, link to foam issues What is the Cause? Manure characteristics (pH, microorganisms, etc.) Manure storage conditions (anaerobic, aerobic) Pit additives or disinfectants disturbing the microbiological balance in the manure Photo courtesy of AquaServe How is the Foam causing explosions? Thick foam is trapping biogas produced by the manure Pit ventilation is not able to remove these gases How is the Foam causing Explosions? Furnace pilot light or other ignition source An ignition source (e.g. welding) near undisturbed foam How can the Foam be eliminated? Less gas productionshut down the bacteria that make biogas (CO 2 and methane) Change surface characteristics of the liquid (i.e. life of the bubbles) so the bubbles break and gas is dissipated Knock down the bubbles periodically as needed (commercial defoaming agent) Some combination of these Safe operation around foaming pits Ventilate the pit and the building Shut down ignition sources Pump manure down some without agitation DO NOT AGITATE AT FULL THROTTLE TO START!!! Ramp up agitation to start Do not fully throttle agitator Summary Foaming is a special case More hazards during manure agitation If you have experience with foaming pits to share, please contact us!
