Emissions from Animal Production Systems

John W. Worley

Odors and Emissions

The Science of Odors and Emissions Emissions Control Strategies

– Buildings and Storage Structures– Land Application Systems

Science of Odors and Emissions Odors - the main reason you are here today Emissions and Health

– Effects are still being debated

– Toxic Effects (H2S)

– Depression– Ear, Nose, and Throat Problems

Odors are a Nuisance (Quality of Life)

Science of Odors and Emissions

Odor– 54% of complaints from swine operations– 50% from land application– At least 168 compounds in swine odor

NH3, amines, H2S, VFA’s, indoles, skatole, phenols, mercaptans, alcohols, carbonyls

Science of Odors and Emissions

Greenhouse gases– CO2, Methane

Acid Rain concerns (ammonia) Dust Pathogens Flies

Science of Odors and Emissions Movement and Dispersion

– Several models available– Worst problem is night and early morning

Low airflow rates

– Prevailing winds don’t always predict this effect– Setbacks are the main regulatory tool– Not enough scientific evidence to accurately

determine setbacks

Science of Odors and Emissions Measurement

– Odor vs. Gas Measurement– Olfaction

Science of Odors and Emissions

Gas Measurement– Indicator Tubes

– Ammonia and H2S meters

– Cassette Tape system– Gas Chromatograph/Mass spectrometer

(GC/MS) Generally accurate, but expensive and are

not a reliable predictor of odors

Science of Odors and Emissions

Olfactometry– Electronic Noses– Scentometer– Dynamic, triangular forced-choice

olfactometer– Field Sniffer– Cotton Swatch

Science of Odors and Emissions

Olfactometry– Concentration– Intensity– Persistence– Hedonic Tone– Character or descriptor

Science of Odors and Emissions

Olfactometry – Uses real or simulated human noses– Some methods filter dust before

measurement– Requires training– Expensive– Subjective

Science of Odors and Emissions

Dust Measurement– Gravimetric Methods (filters and impacters)– Particle Counters– Can add pathogen measurements by

collecting particles on agar plate and incubating

Emission Control Strategies:Buildings and Storage Structures General Management Strategies

– Proper adjustment of feeders– Use of more efficient feeders– Keep surfaces (animal and facility) cleaned

of manure and dry as possible– Keep fans and shutters clean (“odor

episodes”)

Emission Control Strategies:Buildings and Storage Structures Dust and Odor

– Dust absorbs and intensifies odors– Dust enables odors to travel further

Facility Siting– Models– Wind direction in early morning– Buffers

Emission Control Strategies:Buildings and Storage Structures Dietary Manipulation

– For nutrient management– For odor control

Lower protein Additives

Storage in under-floor pits (pull plug)– 5 days– recharge water

Emission Control Strategies:Buildings and Storage Structures Lagoons

– Precharge with water before startup– Load evenly– Fill pipes below water surface– Drain to 2nd stage and pump intake at

least 1 ft. below surface (purple sulfur bacteria)

Emission Control Strategies:Buildings and Storage Structures Manure slurry storage structures

– Cover natural crust straw synthetic cover

– Ozonation

Emission Control Strategies:Buildings and Storage Structures Natural Windbreaks

– Rows of trees around storage pond absorbs odors disperses odors screens view

– Multistoried canopy gives best coverage

Emission Control Strategies:Buildings and Storage Structures Dry Manure Systems

– Hoop or poultry house type structures– Odors generally not as objectionable– Bedding may act as a biofilter

Emission Control Strategies:Buildings and Storage Structures Biofilters

– Biological Treatment of odors in exhaust– Contact Time is critical and difficult to

achieve

Manure Pit

Odorous Air

Mechanically Ventilated Building

Exhaust Fan

Treated Air Exhaust

Media Support

Air PlenumAir Duct

Biofilter Media

Emission Control Strategies:Buildings and Storage Structures Windbreak Walls

– Disperses exhaust stream– May remove some dust

Tunnel-ventilated barn Windbreak wall

Dispersion effect

Dust deposition

Emission Control Strategies:Buildings and Storage Structures Washing Walls

– Prototype worked well at low flow rate– Not effective at high airflows

Evaporative Cooling PadsIn Wall Upwind of Fans

3-5 ft

Emission Control Strategies:Buildings and Storage Structures Biomass Filters

– Similar to washing wall– Mainly for dust removal– Worked well at low rates– Untested at high rates

Emission Control Strategies:Buildings and Storage Structures Vegetable Oil Sprinkling

– Keeps dust out of air– Improves atmosphere in building as well as

exhaust air– Cleaning problem

Emission Control Strategies:Buildings and Storage Structures

Ozonation– Oxidizes odorants– Improves inside air– Ozone levels– Currently expensive

Emission Control Strategies:Buildings and Storage Structures Chemical or Biological Additives

– Some seem to help– Difficult to quantify– Difficult to get repeatable results

Emission Control Strategies:Land Application Systems

Injection and Incorporation

Emission Control Strategies:Land Application Systems

Spray application– Large droplet size– Dilute with water– Drop spouts on

center pivot– Careful Timing

Emission Control Strategies:Land Application Systems

Dry Manure– Compost before application (also

homogenizes the mixture)– Possible chemical pretreatment– Careful Timing

Summary Odor problems are real Odors are hard to measure and are not

predicted well by gas measurement Olfactometry uses the human nose or a

simulation of it Approx. 200 compounds have been identified

in swine odor Most problems at night and early morning

Summary

– Odors adhere to dust particles and are intensified by them

– Removal of dust and/or dispersion of odor plumes should reduce odors

– Cleaning fans– Keep manure either dry or submerged in water– Keep lagoons healthy (purple sulfur bacteria)– Natural windbreaks

Summary

– Cover slurry storages (natural or synthetic)– Inject or incorporate if possible– Minimize drift (wind and droplet size)– Be sensitive to neighbors

Questions?