Air Emissions from Animal Feeding Operations Current Knowledge, Future Needs (2003) / Chapter Skim
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Appendix L: Emisson Factors in Published Literature
Appendix L: Emisson Factors in Published Literature
Pages 241-254
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From page 241... ...
With so many sources of variation in NH3 emissions, it is unreasonable to apply a factor determined in one system, over a short period of time, to all animal feeding operations (AFOs) within a broad classification.
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From page 242... ...
A single measurement over a short period of time will not capture the total emission for the entire life cycle of the animal. In addition, most measurements for manure storage represent only part of the storage period.
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Dividing the total manure nitrogen that leaves the farm by the total nitrogen excreted can identify some potential overestimation of emission factors. For example, using emission factors in Table 8-21 of EPA (2001a)
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From page 244... ...
emissions from livestock facilities were conducted recently and included current animal housing and manure management practices. Several recent publications from Purdue University document H2S emissions from mechanically ventilated swine buildings (Ni et al., 2002a, 2002b, 2002c, 2002d)
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Based on emission data analysis and field observation, researchers noticed that different gases had different gas release mechanisms. Release of H2S from the stored manure, similar to carbon dioxide and sulfur dioxide, was through both convective mass transfer and bubble release mechanisms.
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Estimating direct soil N2O emissions is subject to the same uncertainties as NO emissions. The fraction of applied nitrogen emitted as N2O varies with land use, chemical composition of the fertilizer, soil moisture, temperature, and organic content of the soil.
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as approximately 2.1 Tg N/yr. These estimates are based on an assumed average fraction of manure nitrogen converted to N2O and are subject to variability due to temperature, moisture content, and other environmental factors in a manner similar to soil emissions.
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From page 248... ...
In estimating the CH4 emission factor for the model farm, EPA (2001a) did not take several factors into consideration, such as the difficulty associated with measuring emissions without having a negative impact on animals.
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PARTICULATE MATTER A limited number of studies have reported emission factors for particulate matter (PM) for various confinement systems.
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. For PM, unlike most other air pollutants, emission factors developed for use in emission inventories and for dispersion modeling can, ideally, be reconciled using receptor modeling techniques.
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From page 251... ...
The applicability of these efforts to VOC emissions from AFOs is unknown at this time. Ongoing studies to determine emission rates of VOCs were not included in EPA (2001a)
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From page 252... ...
Physical factors such as temperature, irradiance, and wind are also major factors in the emission rates of sparingly soluble VOCs from liquid or semisolid surfaces (MacIntyre et al., 1995; Zahn et al., 1997~. The differences in wind and temperature exposures between outdoor and indoor manure management systems can account for between 51 and 93 percent of the observed differences in VOC emissions (MacIntyre et al., 1995~.
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From page 253... ...
Standard measurement protocols and consistent units for odor emission rates and factors have to be developed. As shown in a recent review (Sweeten et al., 2001)
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From page 254... ...
Indiana 1.8a Limet al., 2001 Nursery pigsb Netherlands 6.7 Oginket al., 1997; Verdoes and Ogink, 1997 Nursery pigs Minnesota 7.3-47.7 Zhu et al., 1999 Finishing pigs Minnesota 3.4-11.9 Zhu et al., 1999 Finishing pigsC Netherlands 19.2 Oginket al., 1997; Verdoes and Ogink, 1997 Finishing pigsty Netherlands 13.7 Oginket al., 1997; Verdoes and Ogink, 1997 Finishing pigs (daily flush) e Indiana 2.1 Heber et al., 2001 Finishing pigs (pull-plug)
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