Poultry

Practice: Use pull-plug housing rather than deep-pit houses

Jacobsen, L.D., et al. 2006. Aerial Pollutants Emissions from Confined Animal Buildings. Workshop on Agricultural Air Quality, page 775

Conclusions

Ammonia levels in the finishing barns were twice as high in the deep pit barns (20 ppm) compared to the pull plug (9 ppm) facility but H2S concentrations were similar in both types of barns, varying from 0.4 to 0.6 ppm. NH3 emissions from the deep pit finishing barns were also higher (50 to 60 g NH3/d-AU) than from the pull plug building (35 to 40 g NH3/d-AU) but H2S emissions were somewhat similar, 3.0 to 4.0 and 4.0 to 4.5 g H2S/d-AU for the pull-plug and deep-pit barns respectively. The pull plug finishing barns experienced higher PM10 concentrations (450 to 500 vs. 150 to 170 _g PM10/m3) and emissions (3.0 vs 0.75 g PM10/d-AU) than the deep pit finishing barns. However, the deep-pit barns had higher odor concentrations (1350 to 1650 vs. 600 to 750 OU/m3) and emissions (87 to 93 vs. 66 to 80 OU/s-AU) than the pull-plug finishing buildings. Although not specifically reported in this paper, the laying hen buildings monitored in the project had much higher ammonia concentrations and emissions (by an order of magnitude) than the pig barns monitored but had very low hydrogen sulfide concentrations and emissions when compared to pig facilities. Also, some short term spikes in gas/PM/odor concentrations and emissions were found that typically were caused by some weather or manure management event and which could have ramifications when dealing with complying with the EPA’s CERCLA and EPCRA reporting requirements. As a general rule, the magnitude of the gas and dust emissions measured in this study, did not vary much over the year, however the concentrations of these parameters were quite seasonal with high levels in the winter during times of low air exchange rates and low levels in the summer when high rates of ventilation air was provided.

Practice: Install biofilters on ventilation exhausts

T.L. Jensen and M.J. Hansen. 2006. A Biotrickling Filter for Removing Ammonia and Odour in Ventilation Air from a Unit with Growing-Finishing Pigs. The National Committee for Pig Production, DANISH BACON & MEAT COUNCIL Copenhagen, Denmark. Workshop on Agricultural Air Quality, page 844.

Abstract

The present study was carried out to investigate the ammonia and odour removal with a commercial biotrickling filter (SKOV A/S, Glyngøre, Denmark) in a unit with growing-finishing pigs. The results demonstrated that the filter significantly reduced the ammonia concentration (ppm) in the outlet air (P<0.05). Even though, the ammonia concentration before the filter ranged between 8.1 and 9.0 ppm during the winter period and 4.1 and 5.9 ppm during the summer period, the ammonia concentration after the filter was in the range of 1.2 to 2.4 ppm during the entire study. The filter significantly reduced the odour concentration (OUE/m3) in the outlet air (P<0.05). However, there were large variations in the odour removal efficiency, which ranged from an average of 54 % during the winter period and 28 % during the summer period. A possible explanation for the reduced odour removal efficiency during the summer was the increased ventilation rate, which reduced the retention time of the outlet air in the filter. It was observed that some areas on the filter were clogged up with dust and biofilm and this may also have impaired the odour removal. In conclusion, the filter was able to reduce the ammonia and odour concentrations in the outlet air from a unit with growing-finishing pigs. However, it is required to improve the odour removal efficiency and to find methods to increase the retention time and prevent the clogging with dust and biofilm.

Biofiltration reduces odors

S.J. Hoff and J.D. Harmon. 2006. Biofiltration of the Critical Minimum Ventilation Exhaust Air. Workshop on Agricultural Air Quality, page 760.

Conclusions

This on-going research on biofilter technology applied to fan ventilated animal housing facilities concentrated on the biofiltration of the critical minimum exhaust air (CMEA). This was defined as the amount of ventilation air required by swine finishing facilities during night-time summer periods. For this research project the CMEA was fixed at 75 m 3-h-1 -pig-1. The preliminary results indicate an ammonia reduction of the pit-exhaust air of 44 percent, a hydrogen sulfide reduction of 58 percent, and an odor reduction of 54 percent. Further research will be conducted on biofilter additives to improve gas reduction efficiencies without increasing back-pressure on the exhaust fans. The authors would like to thank the Iowa Pork Producers Association and the USDA-Special Grants program for funding this on-going research.