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.