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DEVELOPMENT AND APPLICATION OF AN INEXPENSIVE CHAMBER FOR ANALYSIS OF VOLATILE ORGANIC CARBON

DEVELOPMENT AND APPLICATION OF AN INEXPENSIVE CHAMBER FOR ANALYSIS OF VOLATILE ORGANIC CARBON. B.L. Woodbury, D.N. Miller, R.A. Eigenberg and J.A. Nienaber USDA ARS US Meat Animal Research Center, Clay Center, Nebraska USA. The Problem The Feedlot Environment. Spatial & temporal variation:

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DEVELOPMENT AND APPLICATION OF AN INEXPENSIVE CHAMBER FOR ANALYSIS OF VOLATILE ORGANIC CARBON

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  1. DEVELOPMENT AND APPLICATION OF AN INEXPENSIVE CHAMBER FOR ANALYSIS OF VOLATILE ORGANIC CARBON B.L. Woodbury, D.N. Miller, R.A. Eigenberg and J.A. Nienaber USDA ARS US Meat Animal Research Center, Clay Center, Nebraska USA

  2. The ProblemThe Feedlot Environment • Spatial & temporal variation: • Moisture • Temperature • Soil characteristics • Manure deposition

  3. VFAs (Straight & Branch Chain) Acetate  Octanoate Isobutyrate, Isovalerate Sulfides Hydrogen sulfide Methyl sulfides Aromatics Benzoates Indoles Phenols Amides Ammonia Methylamines Diamines Alcohols (Straight & Branch Chain) Ethanol, Propanol, Butanol, etc. The ProblemPotential Gaseous Emissions from Feedlot Surface

  4. ObjectivesFeedlot Surface Emissions • Design a cost-effective headspace chamber suitable for laboratory and field studies • Evaluate its flow characteristics

  5. Design Criteria • Portable for use either in lab or field • Internal distribution system to ensure completely mixed conditions • Septa port for gas sampling (i.e., SPME) • Acid trap to collect ammonia • Calculate relative emission rates • Battery operated

  6. The Design“The Real Salad Bowl Study” • Hemispherical headspace chamber • Measure VOC w/SPME • Ammonia trap

  7. Sampling Port With Septa Seal

  8. Inside View With Internal Mixing Fan

  9. Tracer Study • Total headspace volume (V) 7.6 L • Flow rate (Q) 1.18 L min-1 RT = V/Q • 50 ml CH4 injection pulse • Analyzed using a GC/MS with HID detector

  10. Mass Balance

  11. CH4 Break-Through-Curve • At 1 dilution • 32% • At 3 dilutions • 5% • Ideal reactor • 37 & 5%, respectively 32% 5%

  12. Theoretical And Experimental Headspace Chamber Properties HRT V Q (min) (L) (L min-1) Calculated 6.5 7.6 1.16 Experimental 6.3 7.3 1.16

  13. Gaseous Output Microbiologist: One return port would be enough Engineers: Four would be better

  14. Gaseous Output • Linear with manure surface area

  15. Conclusions • Chamber design performed similar to an ideal continuous flow stirred reactor • Concentrations measured at sampling port are indicative of concentrations anywhere in headspace • Chamber was found to be reasonably stable over wide range of flow rates • Linear with respect to surface area of manure • Cost per unit approx. $400.00

  16. Laboratory Studies • Field Studies

  17. Laboratory StudiesFresh Manures: Cattle vs. Swine Cattle—Ground corn/corn silage 15 10 5 Abundance, peak area x 106 Swine—Grower diet 15 10 5 1 2 3 4 5 6 7 8 9 Run time, minutes

  18. Laboratory StudiesVolatiles Composition & Cattle Diets Ground corn/corn silage diet 15 10 5 Abundance, peak area x 106 Alfalfa maintenance diet 15 10 5 1 2 3 4 5 6 7 8 9 Run time, minutes

  19. Laboratory StudiesManure Incubation Incubated Fresh Cattle—Ground corn/corn silage diet 15 10 5 Swine—Grower diet 15 10 Abundance, peak area x 106 5 Cattle—Alfalfa maintenance diet 15 10 5 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 Run time, minutes Run time, minutes

  20. S TX RX Field StudiesPrecision Feedlot Surface Management • Manure can be from 10 to 100 times more conductive than typical soil Electromagnetic Induction Principles The transmitter coil (TX) is placed near the earth and is energized with an alternating current. The small currents induced into the earth generate a secondary signal which is picked up by a receiver coil (RX) at a distance S away. The ratio of the two signals gives a measure of the soil’s conductivity beneath the two coils.

  21. 2.6 2.5 2.4 2.3 2.2 2.1 2 1.9 1.8 1.7 Mound 1.6 June 2004 July 2004 1.5 October 2004 1.4 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 Mound Mound Waterer 0.4 0.3 0.2 0.1 Bunk Waterer Waterer Bunk Bunk

  22. Association of volatile solids (manure) to ECa

  23. Total Phosphorus

  24. Total Nitorgen

  25. Area based on Conductivity Less than 25% of the area is high conductivity High Conductivity = Manure Accumulation? Low High

  26. Ammonia Flux Across Pen 8X more VOC Feedlot pen NH3 flux M/m2/hr MOUND Sample Location BUNK

  27. Feedlot Survey in Cooperation with ARS-USDA, Bushland, TX Target our management strategies?

  28. Questions?

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