North Carolina is the country's second largest hog-producing state.  Reducing the environmental and health-related risks stemming from hog waste management and disposal is one of the state's most pressing public health problems.  Effectively managing and disposing of hog waste could translate into hundreds of millions of dollars in health benefits for our state alone.  Therefore, exploring the conversion of hog waste to energy, while also reducing air and water pollution, is urgent and crucial for North Carolina.

 

Typically, managing hog waste in North Carolina involves storing the waste in uncovered lagoons, then periodically spraying lagoon liquid onto crop fields.  This process releases ammonia into the atmosphere and overloads the soil and surface waters with nitrogen.  Ammonia in the air not only has an unpleasant odor, but this gas contributes to the formation of fine particles in the atmosphere, causing respiratory illnesses such as asthma.  Current practices for managing hog waste also lead to greenhouse gas emissions.

 

This innovation lab, operating on-site at a swine farm in Harnett County, N.C., is investigating the technical and economic feasibility of coupling existing technologies for methane production with a new approach to nitrogen removal from swine waste.  The new approach will increase the organic matter available for conversion to methane, while significantly reducing air and land pollutants.  This innovative, integrated system for managing hog waste will greatly reduce both the release of ammonia to the atmosphere and nitrogen to land and surface waters.

 

 

Michael Aitken, PhD, professor and chair of UNC's department of environmental sciences and engineering, leads this collaborative effort that includes experts in environmental policy and engineering design.  inVentures Technologies, Inc. is loaning equipment for investigating a high-efficiency device to transfer oxygen to hog waste for the ammonia conversion process.

 

Partners include: the UNC department of environmental sciences and engineering, Environmental Credit Corp, the Environmental Defense Fund, inVentures Technologies Inc., the North Carolina Cooperative Extension Service at N.C. State University and Butler Farm, Lillington, N.C.