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Explore strategies and technologies for controlling odors and emissions in animal production systems. Topics include health effects, measurement methods, control strategies for buildings and storage structures, and more.
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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
Emission Control Strategies:Buildings and Storage Structures • Windbreak Walls • Disperses exhaust stream • May remove some dust
Emission Control Strategies:Buildings and Storage Structures • Washing Walls • Prototype worked well at low flow rate • Not effective at high airflows
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