Mitigation Technologies

Summary of air emission mitigation technologies for swine production facilities

The currently available mitigation technologies for air emissions from swine production facilities are summarized in the following table. Among these technologies, anaerobic digestion system, bio-filter, and scrubber have demonstrated high effectiveness in reducing multiple air pollutants. However, high costs are great limitations of these technologies and they may only be feasible for large operations. Dietary strategy has potential to be cost-effective; but the proven effectiveness is on NH3 emission only, and there are upper limits to crude protein reduction and fiber addition in diets because of concerns on growth performance. Overhead spray has limitations as droplets themselves may be a respirable health hazard and may cause slippery walkways. A permeable cover on a manure storage may be a practical measure although more research is needed on its effect on multiple air species. Cheap permeable covers usually have short effective lives while long-lasting covers have high cost. Vegetative environmental buffers (VEBs) are potential cost-effective strategy for reducing multiple air pollutants from farms, although effectiveness and costs are highly variable and depend on site specific design; further research is needed for development of technical guidelines for VEBs.

Summary of air emission mitigation technologies for swine production facilities
Reduction Effectiveness
Anaerobic digestion (AD)1 Odor is destroyed when biogas is combusted A covered lagoon AD system cost $88,000-$162,000
Bio-filter1 Up to 95% reduction in H2S,
65% reduction in NH3
Installation: $150-$375 per 1,700 m3/hr;
Operation: $5-$10 per year per 1,700 m3/hr.
Scrubber1 Up to 83%, 40% and 43% reduction in NH3, odor, and PM10, respectively Installation: €32-€50 per pig-space;
Operation: €11-€14 per year per pig-space
Dietary strategy3 Up to 36% reduction in NH3. Uncertainty in cost-benefit analysis
Overhead spray1 No data Installation: $4900 for 42’×200’ house; Operation: ~$0.73 per pig for odorgon
Permeable cover1 40-90% reduction in odor,
40-80% reduction in NH3.
$0.10-$1.75 per ft2
VEB3 Up to 50% reduction in in NH3 and dust,
6-15% reduction in odor.
Total cost: ~$0.20 per pig.
Photocatalytic technology4 80-100% reduction in VOC and H2S;
NH3, CH4, N2O, CO2 were reduced by 30%, 15%, 4% and 11% respectively (P<0.001) when the wall in swine house is coated with the photocatalytic paint.
Installation: vary depending on specific design; main cost is UV lamps; TiO2 coating has low cost;
Operation (energy): ~$0.15-$0.37 per pig.
1 Data are adapted from resources of eXtension. Available online at
2 Powers et al., 2005.
3 Tyndall et al., 2008; cost data are from Iowa demonstration cooperators.
4 Guarino et al., 2008; and Koziel et al., 2008.