Emissions from Animal Production Systems John W. Worley.
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Transcript of Emissions from Animal Production Systems John W. Worley.
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?