measuring livestock odors dr. ron e. sheffield lsu agcenter [email protected] 225.205.4533
TRANSCRIPT
Olfaction -- Sense of Smell Complex Evokes a physiological and emotional
reaction Humans detect > 10,000 odors Manure over 150 odorous compounds Mixture of gases Extremely low concentrations Health impacts?
Gas vs Odor Measurement
Gas Identify individual gases Measure concentrations
Odor--Olfactometry Analyze mixture Correlates with odor Uses human sense of
smell
Odor Measurement and Description
Intensity (strength) Duration / Persistence Frequency Offensiveness / Hedonic tone Character descriptor Threshold concentrations (D/T)
Detection Recognition
Odor Test Definition Analytical Method(s)
Intensity (strength) Strength of an odor sample above the detection threshold. N-butanol
Duration / PersistenceMeasure of how easily the odor can be diluted in air: Full strength intensity divided by threshold concentration.
N-butanol and D/Td
Frequency Return interval (hours, days) of a detected odor. No analytical measure.
Offensiveness / Hedonic tone
Measure of unpleasantness of an odor. Typically displayed as a scale: -10 (unpleasant) to +10 (pleasant).
Odor Panel
Character descriptorDescription of an odor. Trained panelists use standardized terms such as sulfide, rancid, putrid, or phenolic.
Odor Panel
Threshold Concentration (D/Td) - Detection
Volume of non-odorous air needed to dilute a unit volume of air to the point where panelist begin to detect an odor.
Olfactometry; field olfactometer (scentometer)
Threshold Concentration (D/Tr) - Recognition
Volume of non-odorous air needed to dilute a unit volume of air to the point where panelist begin to recognize an odor. D/Tr >/= D/Td
Olfactometery
Odor -- Sound Analogy
Odor . . . Sound
Below Detection . . . “I can’t hear it”
Detection . . . “I hear something”
Recognition . . . “It’s Elvis!”
Intensity . . . “How loud is it?”
Odor Intensity Measurement
Table 2. Odor Intensity Reference Scale Based on N - Butanol
Intensity category
Equivalent head space
concentration of N - butanol
in air (ppm)*
Mixture of N - butanol in
water (ppm)
0 No odor 0 0
1 Very Light 25 250
2 Light 75 750
3 Moderate 225 2250
4 Strong 675 6750
5 Very strong 2025 20250
* Based on air temperature of 20.3 °C
Character Descriptor
Smells like Mint – Musty Earth – Rotten Mold – Sewer Sulfur – Sour Ammonia – Pungent Menthol – Burned
Odor Measurement Electronic nose
Correlates gases to odors Similar to indicator gas No accepted tool for manure
odors Olfactometer
Measures concentration ASTM & European Standard
Scentometer
Triangular Forced Choice Olfactometer
Dynamic Triangular Forced choice Standardized procedures
ASTM European Standard
Trained panelists
Odor Modeling Correlate mathematical representations to
the measured effect during real world situations. Used for technology evaluation and planning Not intended for regulatory enforcement Currently no “ag odor” model incorporates
real-world terrain features Field Sniffers Model Comparison
Field Sniffers Trained panelists
Measurements N-butanol intensity scale
Scentometers
Field olfactometers
Charcoal filter masks
Record intensity
Validate dispersion model
Odor Methods StudyEvaluate the differences of odor
concentrations determined by the three field olfactometers using trained panelists
Variability between field olfactometers Correlation to field and laboratory
measured odor intensity (n-butanol) Correlation to laboratory olfactometry
panel Correlation to field and laboratory gas
analysis
Experimental DesignControl
Laboratory olfactometry
Treatments Box scentometer Facial mask field olfactometer “Nasal Ranger” field olfactometer Field n-butanol Laboratory n-butanol Jerome Meter (H2S/TRS) Ammonia GC/MS & GC/SPME
TRS/H2S(mg/l)
NH3
(mg/l)
Food Processor 0.070 0.008
WWPS 0.002 0.039
Dairy Freestall 1.180 0.208
Open-Lot Dairy 1.150 0.033
Feedlot 1.460 0.019
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
WWPS FoodProcessor
Freestall Open-Lot Feedlot
DTFCO
Nasal Ranger
Mask
Scentometer
Standard Deviation of logD/T
Food Processor
WWPS Open-Lot Dairy
Freestall Dairy
Standard Deviation of Intensity
Food Proces-
sor
WWPS Freestall Dairy
Open-Lot Dairy
Feedlot0
1000
2000
3000
4000
5000
6000
7000
Field
UI Lab
WTAMU Lab
n-b
uta
no
l (m
g/l
)
Emissions from Livestock FarmsMethodology 38 dairy and 15 beef feeding operations August, 2003 and the April, 2004
Three measurements Summer (August & September) Fall (October & November) Spring (April)
“Blind” data set Trained panelists – subset of panelists from
Phase 1
Average Dairy Odor Emissions
Location Distance Detection Threshold
Odor Intensity
H2S/TRS NH3
Range - units meters ( 1.4 – 60 ) ( 0 – 6 ) ppm ppm
Openlot Dairies <1,000 hd
Source 11.4 2.8 0.063 0.41050 meters 8.4 2.7 0.038 0.420
200 meters 3.1 1.5 0.020 0.290
Openlot Dairies >1,000 hd
Source 17.0 3.7 0.078 0.36050 meters 4.8 1.8 0.042 0.270
200 meters 4.5 1.9 0.024 0.270
Scraped Freestall Dairies
Source 29.0 4.4 0.223 0.53050 meters 13.4 3.3 0.161 0.430
200 meters 6.3 2.5 0.078 0.260
Flushed Freestall Dairies
Source 22.2 4.2 0.379 0.66050 meters 12.4 3.3 0.173 0.430
200 meters 8.5 2.8 0.117 0.300
Average Feedlot Odor Emissions
Location Distance Detection Threshold
Odor Intensity
H2S/TRS NH3
Range - units meters ( 1.4 – 60 ) ( 0 – 6 ) ppm ppm
Calf HutchesSource 6.6 1.4 0.007 0.125
50 meters - - - - - - - -200 meters - - - - - - - -
Heifer PensSource 29.1 3.8 0.061 0.050
50 meters - - - - - - - -200 meters - - - - - - - -
FeedlotsSource 16.3 3.2 0.019 0.185
50 meters 11.0 2.4 0.012 0.086200 meters 5.9 1.8 0.006 0.000
Feedlot + Heifer Pens
Source 17.6 3.3 0.022 0.17750 meters - - - - - - - -
200 meters - - - - - - - -
Seasonal Variability - Source
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
< 1000 > 1000 Scrape Flush < 1000 > 1000 Scrape Flush < 1000 > 1000 Scrape Flush
Per
cen
t o
f F
arm
s ab
ove
Det
ecti
on
Lev
el
>7 D/T
>15 D/T
>30 D/T
Summer SpringFall
Seasonal Variability – 200m
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
< 1000 > 1000 Scrape Flush < 1000 > 1000 Scrape Flush < 1000 > 1000 Scrape Flush
Per
cen
t o
f F
arm
s ab
ove
Det
ecti
on
Lev
el
>7 DT
>15DT
>30 DT
Summer Fall Spring
Compost – Static Compost – Turning of Fresh
Manure Compost - Turning Corn Silage Bunker Corral Cleaning Slurry - Fresh/Vacuumed
Manure Broadcast Application Solid Manure - Corral Manure
Application
Pivot Irrigation – Drag Tube @100% Manure
Pivot Irrigation – Spray Nozzles @100% Manure
Pivot Irrigation – Rotating Nozzles @100% Manure
Pivot Irrigation – “Wobble” Nozzles @100% Manure
Separated Solids Broadcast Application
Settling Basin Settling Basin – covered
Land Application and Manure Management Practices
Solid & Slurry Manure Application
Practice Distance Detection Threshold
Odor Intensity
H2S/TRS NH3
Range - units meters ( 1.4 – 60 ) ( 0 – 6 ) ppm ppm
Dry Corral Manure 75 10.4 3.4 0.087 4.00
maximum 21.2 6.0 0.087 4.00
Dry Corral Manure 100 23.4 4.2 0.009 0.05
maximum 42.4 6.0 0.010 0.10
Settled Dairy Solids 70 9.3 3.2 0.044 0.50
maximum 42.4 5.0 0.061 0.75
Vacuumed Manure Slurry 100 11.8 3.2 0.031 0.83
maximum 42.4 5.0 0.046 1.2
Practice Distance Detection Threshold
Odor Intensity
H2S/TRS NH3
Range - units meters ( 1.4 – 60 ) ( 0 – 6 ) ppm ppm
Drag Tube 100 15.2 3.5 0.058 0.00
maximum 42.4 5.0 0.005 0.000
“Rotator” Nozzles 100 26.5 4.6 ---- 0.13
maximum 60.0 5.0 ---- 0.25
“Spray” Nozzles 150 12.5 4.8 0.222 0.28maximum 60.0 6.0 0.295 0.30
“Wobbler” Nozzles 100 24.1 4.9 0.079 0.30
maximum 42.4 6.0 0.085 0.35
Liquid Effluent Land Application
Odor AcceptabilityIs the odor present acceptable ……….
( -10 ”Unacceptable” … 0 … 10 “great”)
as an odor on the farm property? _________as an odor across the property line? _________as an odor at a rural residence? _________as an odor at a public event or private party? _________
Unacceptable Odors (</= -5)
Unacceptable Odors (</= -5) Measured by Trained Odor Panelists at the Odor Source
0
10
20
30
40
50
60
70
80
90
100
>2 2 4 7 15 30 60
Dilutions to Threshold (Odor Concentration)
Pe
rce
nt
Un
ac
ce
tab
ilit
y
Property Line
Rural Residence
Party or Event
Buffer Requirements Most buffers are targeted
on odors (even when states only have authority to minimize risk to water)
New or expanding construction
Distances vary greatly between areas
Most based on arbitrary distances rather than scientific procedures to reduce occurrence
OFFSET: Odor From Feedlots Setback Estimation Tool
Scientific process to establish odor based setbacks
Developed by Univ. of Minnesota, adopted by MN and MI
Develops an Odor Emission Factor for all existing and proposed facilities
Values shown are for Midwestern (IA, MN, MI) conditions, and assumes flat terrain
Odor Emission Factor
Odor Emission Number x Area (sq.ft) x Odor Control Factor
10,000
Odor Emission Number x Area (sq.ft) x Odor Control Factor
10,00010,000
Odor Emission Number x Area (sq.ft) x Odor Control Factor
10,000
Determine Odor Emission Factor for each odor source on the farm
• Barns• Manure Storage/Stockpiles• Feed Storage
Odor Emission NumbersBeef: dirt/concrete lot; freestall, scrape 4/ft2
Dairy: Freestall deep pit; Loose housing, scrape 6/ft2
Dairy: Tie stall, scrape 2/ft2
Earthen manure basin: 1st,2nd cell 20,8/ft2
Anaerobic Lagoon 4/ft2
Steel or concrete tank, above or below ground 28/ft2
Crusted Stockpile 2/ft2
Values shown are for Midwestern (IA, MN, MI) conditions, and assumes flat terrain
Odor Control FactorsNo odor control technology 0
Biofilter on 100% for building exhaust fans
0.1
Geotextile cover (>2.4 mm) 0.5
Straw or natural crust on manure 4-inches = 0.58-inches = 0.3
Impermeable cover 0.1
Values shown are for Midwestern (IA, MN, MI) conditions, and assumes flat terrain
Determining Setback Distances
7 hrs/mo
22 hrs/mo29 hrs/mo44 hrs/mo66 hrs/mo
15 hrs/mo
Suggested odor annoyance free frequencies• 99% ~ cities w/population >5000, hospitals• 98% ~ cities w/population <5000• 97% ~ residential area w/ >50 homes, churches, parks• 96% ~ residential area w/ <50 homes, churches• 94% ~ < 5 rural homes• 91% ~ < 2 rural homes Values shown are for Midwestern (IA,
MN, MI) conditions, and assumes flat terrain