Mitigation of odor and pathogens from CAFOs with UV/TiO2: Exploring the cost effectiveness

Livestock operations are sources of aerial emissions of odor, volatile organic compounds (VOCs), ammonia, hydrogen sulfide, and bioaerosols, including pathogens (National Research Council, 2003). At the same time these operations are potentially threatened with infectious diseases impacting national economies and food supply security. Comprehensive solutions to these multidisciplinary problems are needed. Our long-term objective is to develop and apply a novel treatment technology that would minimize the environmental impact of swine operations and at the same time would protect them and the public from the spread of infectious diseases. This paper reports feasibility tests of lab-scale treatment of aerial emissions of selected VOCs responsible for livestock odor and inactivation of airborne pathogens by low-wattage UV light. The long-term goal is to develop cost-effective technology for the simultaneous treatment of odor and pathogens in livestock housing through logical progression of testing from lab-scale, through pilot-scale and finally at commercial scale. Such treatment would be applicable to both the inflow (for airborne pathogen control) and outflow air (for odor and pathogen control) at typical existing and new mechanically-ventilated barns. Several target VOCs responsible for livestock odors were selected for testing effectiveness of UV light on odor. The selection of key odorants for lab-scale tests was based on previous work (Wright et al., 2005; Koziel et al., 2006, Bulliner et al., 2006). These include p-cresol, sulfur-containing VOCs, and volatile fatty acids. The effects of UV treatment time on the effectiveness of gas and odor removal were tested. The treatment times, gas flow rates, and UV energy used were then extrapolated to estimate theoretical cost of UV treatment of odor for typical ventilation rates and electricity cost at a swine finish operation in Iowa