Aeration Could Speed Carcass Disposal

The researchers tested lab-scale aerobic digestion using tanks containing chicken carcasses, water and low levels of oxygen. Further research may test the concepts at field scale. ( Jacek Koziel, Iowa State University )

When disease outbreaks, fire or severe weather events result in high death loss among livestock, safe and sanitary carcass disposal becomes a significant challenge for producers and health officials. Mass burial provides a potential solution, but can result in slow decomposition, contamination of ground and surface water and other problems.

To address the issue, researchers at Iowa State University have tested methods for improving the safety of emergency mass burials, specifically looking at the potential for aerating burial pits.

The researchers drew on experiences from the National Institute of Animal Science in South Korea, following that country’s FMD outbreak in 2011. They simulated mass burials using chicken carcasses to test various liners and levels of aeration, while measuring decomposition times, composition of liquid and gas emissions and pathogen levels.

Anaerobic conditions typically inhibit decomposition in burial pits, resulting in higher risk for hazardous emissions. The researchers found though, that by injecting low levels of air in to the bottom of the trench, while also using flexible geomembrane liners to prevent seepage, they reduced carcass mass by 95 percent within 13 weeks, while similar tests without air produced no noticeable decay. Resulting liquid waste met EPA standards for surface-water discharge and greatly reduced odors and levels of pathogens including salmonella and staphylococcus.

Results of the study are published in the journal Waste Management.