Air Quality Estim ation and Mitigation for Dairies Frank - - PowerPoint PPT Presentation

Air Quality Estim ation and Mitigation for Dairies

Frank Mitloehner, PhD Professor & CE Specialist Dept Animal Science University of California, Davis

Life Cycle Thinking

• Accounts for site-specific design and management practices as

variables and reflects interactions between emission sources

• Reflects mass balance constraints
• Scale specific (e.g., individual AFOs or regional/ national scale)

Manure Soil Crop Feed Herd

Emissions Emissions Emissions

Product I m port/ Export Fertilizer Export I m port/ Export

Emissions Emissions

Bill Schrock; US EPA

W hat are the air quality issues?

• National ambient air quality

standards (PM, ozone)

• Hazardous air pollutants (e.g.,

methyl bromide)

• Visibility (regional haze)
• Air deposition (acid rain,

nitrification)

• Global climate change (greenhouse

gases)

• Odors (nuisance complaints)

W hat are the pollutants of concern?

• PM10 (directly formed particles)
• PM2.5 (secondarily formed particles)
• Ammonia (potential PM precursor)
• Volatile organic compounds (ozone

precursor)

• Hydrogen sulfide (H2S)
• Methane (“greenhouse” gas)
• Nitrogen Oxides (NOx, an ozone

precursor)

Nutrient elem ents and related em issions

NH3 N2O NO H2S CH4 CO2 VOC

N

Nitrogen

C

Carbon

S

Sulfur

Ammonia Nitrous oxide Nitric oxide Hydrogen sulfide Methane Carbon dioxide Volatile organic compound

Six Subm odels

1.NH3, CH4, N2O and VOC production and emission from animal housing facilities driven by housing climate, production of fresh animal manure, and housing management 2.NH3, CH4, N2O and VOC production, consumption and emission under aerobic storage (e.g., vented manure stacks, compost, silage face) conditions, driven by quantity and quality of the composted manure mass as well as environmental factors 3.NH3, CH4, N2O, H2S and VOC production, consumption and emission under anaerobic storage (e.g. silage stacks, slurry tank, and lagoon), driven by quantity and quality of stored manure and environmental factors

Six Subm odels

4.NH3, CH4, N2O and VOC production, consumption and emissions following field application of manure, driven by quantity and quality of the manure applied, other farming practices, and environmental factors;

• 5. Enteric CH4, N2O and VOC production, driven by

quality and quantity of feeding materials as well as animal characteristics; 6.CH4 and VOC production and consumption during anaerobic digestion under digester conditions, driven by quantity and quality of the digested manure as well as environmental factors.

Gas emissions resulting from microbial activity in response to environmental drivers (e.g., pH)

N transport and transform ation at farm scale

Em issions of CH 4, NH 3, N 2O and N 2 are dom inated by different farm com ponents

CH4: >60% from enteric emission N2: 99% from lagoon emission N2O: 60% from field application NH3: 70% from field application

Freestall em issions FL vs SC

1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 1 2 3 4 5 6 7 8 9 10 11 Ammonia Emissions (mg h-1) Time (h) F3 F6 S3 S6 p-value: < 0.001 SEM: 463.15 Treatments

Sources: FAO (2010), for 2007 data; * Univ. Ark (2010), for 2007 data. Note that different studies should not be compared directly.

10.6 10.6 12.2 12.6 12.6 13.5 17.2 28.9 31.9 39.8 64.5 10 20 30 40 50 60 70 lbs CO2e / gal milk

GHG footprint for World Dairy Farms

world average = 20.4

Production Efficiency

Dairy CH4 emission factor (kg/ head/ yr) Milk production (kg/ head/ yr) North America 118 6,700 EU 100 4,200 Latin America 57 800 Africa 36 475

(IPCC, 1996)

Frank Mitloehner, PhD Professor & CE Specialist Animal Science Department University of California, Davis (530) 752-3936 fmmitloehner@ucdavis.edu