Transcript Animal Agriculture in Georgia - Animal Waste

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
amines, H2S, VFA’s, indoles, skatole,
phenols, mercaptans, alcohols, carbonyls
 NH3,
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
– Ozonation
cover
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
Mechanically Ventilated Building
Exhaust Fan
Odorous
Air
Biof ilter
Media
Treated Air Exhaust
Media Support
Manure Pit
Air Duct
Air Plenum
Emission Control Strategies:
Buildings and Storage Structures
 Windbreak
Walls
– Disperses exhaust stream
– May remove some dust
Dispersion effect
Dust deposition
Tunnel-ventilated barn
Windbreak wall
Emission Control Strategies:
Buildings and Storage Structures
 Washing
Walls
– Prototype worked well at low flow rate
– Not effective at high airflows
Evaporative Cooling Pads
In 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?