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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 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?
