Understanding Livestock Odors Ron Sheffield Animal Waste Extension Specialist

1. Understanding Livestock OdorsRon SheffieldAnimal Waste Extension Specialist

3. Odors from Livestock Facilities Highly emotional issue Rural development Economic importance of livestock industry Only after we understand the problem can we work towards acceptable solutions.

4. Olfaction-Sense of Smell Complex Evokes a reaction Humans detect > 10,000 odors Mixtures of gases Able to detect extremely low concentrations

5. Conception of Odors and Smells Describe a childhood odor memory What is your favorite odor? Why? Describe your most unusual odor memory

6. Breathing vs. Sniffing

7. Normal Olfactory Sensitivity

9. How are odors produced? By-products of microbial degradation of manure and organic matter Uncontrolled anaerobic conditions Highly dependent on the amount and type of microbial activity

10. Manure Decomposition Over 80 to 200 different gasses identified Manure gasses related to anaerobic decomposition Ammonia (NH3+) Methane (CH4) Hydrogen sulfide (H2S) Odorants volatile fatty acids Dust and other particulate matter

11. Manure Gasses Hydrogen Sulfide Methane colder climates, poor ventilation, anaerobic decomposition of stored manure Ammonia (NH3) dominates in warmer climates anaerobic by-product compounded by recycling of lagoon effluent for waste handling

12. Dust Sources Feed Dried Manure Dander (dead skin) Hair Other particulate matter viral, bacterial, and fungal agents endotoxin, glucans Dual role as possible odorant and odor carrier

13. Odor and Gas Emissions Parameters that effect odor and microbe production moisture content temperature pH oxygen concentrations environmental conditions (season, wind patterns)

14. Manure Gases Nose detection at low levels Hydrogen Sulfide (H2S) Nose detection at high level Methane (CH4) Some gases may have a compounding odor effect

16. Odor Emission Sources Livestock buildings Manure storage units Land application sites Method of land application Feed storage Mortality storage or disposal units

17. Odor Sources �Background� odor buildings lagoons or storage ponds Seasonal variations in odor �Short-term� odors agitation land application / spray irrigation

18. Odor and Gas Emissions Can be controlled through design and management ventilation system management and �housekeeping� practices waste management system waste application system

19. Odor Chemistry Odorous Compounds Aliphatic (fatty) Acids Amines Ammonia Aromatics Sulfur (inorganic and organic)

20. Compounds Produced through Anaerobic Decomposition Methane Carbon Dioxide Carbon Monoxide Ammonia Hydrogen Sulfide Acetic, Propionic, Butyric Acids Cadaverine and Putresine - bacterial breakdown of amino acids

21. Osmophores Odors are caused by this group of radicals CHO- Aldehydes CH2OH- Carbinols CO-2 Carbonyls COOH- Carboxyls OH- Hydroxyl compounds SH- Sulphydryls

22. Osmophores Odor/smell is due to the presence of different molecules C2H5OH Ethyl Alcohol, sweet-smelling C3H5OH Allyl Alcohol, irritating smell C9H19OH Nonyl Alcohol, offensive smell

23. Oxygen Transfer Replacement of oxygen by sulfur Non-odorous compounds H2O Water H2O2 Hydrogen Peroxide CO2 Carbon Dioxide Compounds become odorous H2S Hydrogen Sulfide H2S2 Hydrogen Persulfide CS2 Hydrogen Disulfide

24. Biochemical Oxidation Proteins, amino acids & carbohydrates are plentiful energy source for bacteria Aerobic or anaerobic process Bacteria �transfer� oxygen from compounds to a hydrogen acceptor 2NO3- + 12H+ = N2 + 6H2O CO2 + 8H+ = CH4 + 2H2O SO4 + 10H+ = H2S + 4H2O (odorous)

25. Purple Sulfur Bacteria - PSB Biochemical Oxidation in Anaerobic Lagoons in NC and southern US Purple lagoon color Photosynthetic bacteria Use H2S as an electron acceptor instead of O2 and NO3 Reduces emission of sulfur compounds and sulfur based odors

26. Photosynthesis

27. Anaerobic Lagoons Studies have been inconclusive relating environmental conditions to the presence of PSB in lagoons loading rate (TS, VS, NH3, SO4) class of animals Temperature Lagoon start-up procedures

30. Odors and Gases Odor Intensity measure of detection sensed by the nose Gas Concentration actual concentration of gas in the air The relationship between odor intensity and gas concentration is different for each gas

31. Gas vs Odor Measurement Gas Identify individual gases Measure concentrations Odor - Olfactometry Analyze mixture Correlates with odor Uses human sense of smell

32. Gas Measurement Instantaneous Integrated average Precision & detection limit

33. Gas Measurement Patches Tubes - Indicator & Diffusion Jerome� meter - H2S Electronic Sensors GC / Mass Spectrometer

35. Odor Intensity vs. Gas Concentration Weak positive correlation's for some gases Ammonia (NH3) Hydrogen Sulfide (H2S) Example: High odor intensities indicate high gas concentrations of NH3 and H2S However, high gas concentrations do not necessarily indicate a high odor intensity

36. Odor Transport Difficult to document the impact area of gases Transmitted via air currents wind direction wind speed weight of gas adsorption to dust particles

39. Dust & Lagoon Interaction Related to Odor Transport

40. Limits to Measuring Odors Changes in weather or micrometeorological conditions temperature, humidity, inversions Odor emissions change with time Wind speed and direction A snap-shot in time may not reflect the conditions an hour/day before or after a measurement

41. Technologies to Control Odor Prevent odor generation Capture or destroy odors before any release to the atmosphere Dispersion or disguise of odors

42. Odor Prevention Technologies Anaerobic treatment Aeration or Oxidation Feed additives Manure pit or lagoon additives pH control

43. Technologies to Capture Odors Manure storage covers synthetic organic mats Biofilters Biomass filters Washing walls

44. Technologies to Disperse Odors Site Selection Ventilation Design Vegetated Wind Breaks Windbreak Walls Stacks or Chimneys Perfumes Masking Agents