Pollution and Emissions from CAFOs
Viney P. Aneja
Department of Marine, Earth, and Atmospheric SciencesNorth Carolina State University
Raleigh, NC 27695-8208, U.S.A.
The True Cost of American FoodSan Francisco, CAApril 15, 2016.
http://www.meas.ncsu.edu/airquality
Intensification of Agriculture
Wind Speed/ Direction
Air TemperatureRelative
Humidity
Solar Radiation
MobileLaboratory
On-Site Measurement Locations
Lagoon
Ambient MeasurementsConfinement House
10 m Ambient Sample Line
U.S. Agricultural Emissions• Ammonia ~ 80%• Nitrogen Oxides ~ 20%• Reduced Sulfur unquantified• PM2.5 ~ 16%• PM10 ~ 18%• Methane ~ 29%• Nitrous Oxide ~ 72%
• Odor unquantified• Pathogens unquantified• VOCs/HAPS unquantified
Source: Aneja, Schlesinger, and Erisman, ES&T, 2009.
Agriculture and air quality: emissions and issues
Direct:- NH3
- NOy
- N2O- PM- CH4- VOCs/HAPs- SO2, H2S- Odour- Pesticides- CO2
Indirect:- Secondary PM- CO2 sequestration and loss (managed soils)- Indirect N2O (N deposition)
0% 20% 40% 60% 80% 100%
Particulate Matter
EutrophyingSubstances
Acidifying Substances
Climate change
0
5
10
15
20
25
30
Ambient Air
Con
cent
ratio
n (p
pbC
)
Barham04/02 11/02
Grinnells04/02 11/02
Howard06/02 12/02
Stokes*09/02 01/03
Moore10/02 02/03
RECIP*03/03
Average U.S. Background Concentration Reference Concentration
Sample Measurements of a Hazardous Air Pollutant – Acetaldehyde
* Natural ventilation systemVentilation Exhaust
Source: Blunden, Aneja, and Lonneman, Atmospheric Environment, 2005.
Ammonia is the Largest Volume Pollutant
Breakdown of U.S. NH3 emissions, total ~4 Tg/yr
Source: U.S. EPA 2008 National Emissions Inventory
Impacts of Ammonia on the Environment
• Particulate matter (PM) formation– Can contribute to exceedances of PM2.5 NAAQS– Visibility degradation
• Impacts on dynamics of acid precipitation• Nitrogen deposition• Nitrogen cycle perturbations• Climate • Impacts on ground water quality• Odor
NH3 Impacts – PM2.5 Case Study for Eastern NC
Case I: Transported from High SO2 producing area.
Case II: Transported from Marine (High HCl) and
Rural (High NH3) Area.
< Backward Trajectories >8/12/98
8/29/98
9/28/98
C a se I
8/21/98
8/25/98
8/27/98
Backward trajectories of Case I (8/12/98, 8/28/98, and 9/28/98) and Case II (8/21/98, 8/25/98, and 8/27/98).
C a se II
NH3 Impacts – PM2.5 Case Study for Eastern NC
PM2.5 Component (ug/m3)
Case 1: Continental
flow
Case 2: Automotive and Agricultural Air
MassAmmonium sulfates 17.8 2.51
Ammonium nitrate 2.33 30.9
Ammonium chloride 0.87 0.98
Total 21.0 34.4NAAQS – annual 15NAAQS – daily 35Source: Aneja and Back, 1998.
NH3 Impacts – Nitrogen Deposition
Algal blooms(NASA MODIS)
Measured wet depositionas NH4
+ (USEPA NADP 2013)
NH3 Impacts – Climate
• Enhanced N2O formation– Agriculture accounts for ~70% of US N2O emissions
– N2O warming potential is about 300 times CO2
– N2O concentrations are increasing
• Impacts on organic aerosols– NH3 may cause ‘browning’ of otherwise reflective
particles causing increased light absorption• Impacts on cloud formation through particle
nucleation
Satellite Observations of NH3 – the Big Picture
Average summer concentrations of NH3 in the mixing layer over the measured by the Tropospheric Emission Spectrometer (TES) on the Aura satellite from 2004 through 2014
Source: Battye and Aneja, 2015.
Satellite Observations of NH3 – Focus on NC
Source: Aura-TES, figure shows individual satellite measurements
Looking forwardTrends are ominous …but
• Mitigation measures are available
Sources: USDA and Census historical data, USDA projections(1 animal unit = 1000 lb)
Europe NH3 Abatement Measures
• Maximum manure application per land use• Decrease of N in concentrates: lowering urea concentration in milk• Housing cattle at night• No slurry application in winter• Good agricultural practice
Slurry injection
Mineral accounting
Coverage of storage facilities
Emission poor housing systems
Manureprocessing
Nitrification
Denitrification
Module
Phosphorus
Removal
Module
Effluent
CalciumPhosphate
Solid-liquid
Separation
Module
Separated Solids
Novel Process: Swine Waste Treatment System
Super Soil Systems, North Carolina
Potential Environmentally Superior Technology
Reuse
Source: Vanotti et al., 2006.
Challenges for the Research and Regulatory Communities
What are the potential health effects from exposures to ambient levels of NH3 and other pollutants?
Is it prudent to regulate NH3 or to address the total N cycle? How to inventory emissions of other pollutants? How to augment air monitoring networks for NH3 to better
understand ecological and climate impacts? How to make use of satellite measurements or other remote
sensing technologies? How to encourage mitigation measures? How to account for impacts on N2O
NC STATE UNIVERSITY - 2013
Pollution and Emissions from CAFOs
Central Estimates for Benefits of Reductions in Ambient PMFine Levels
Source: Murray et al., Benefits of Adopting Environmentally Superior Swine Waste Management Technologies in North Carolina: An Environmental and Economic Assessment, RTI Project Number 08252.000, November 2003.