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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. NienaberUSDA ARS US Meat Animal Research Center,
Clay Center, Nebraska USA
The ProblemThe Feedlot Environment
• Spatial & temporal variation:• Moisture• Temperature• Soil characteristics• Manure deposition
The ProblemPotential Gaseous Emissions from Feedlot Surface
AmidesAmmonia
MethylaminesDiamines
AromaticsBenzoates
IndolesPhenols
SulfidesHydrogen sulfideMethyl sulfides
Alcohols (Straight & Branch Chain)Ethanol, Propanol, Butanol, etc.
VFAs (Straight & Branch Chain) Acetate Octanoate
Isobutyrate, Isovalerate
ObjectivesFeedlot Surface Emissions
•Design a cost-effective headspace chamber suitable for laboratory and field studies
•Evaluate its flow characteristics
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
The Design“The Real Salad Bowl Study”
• Hemispherical headspace chamber
• Measure VOC w/SPME• Ammonia trap
Item Cost
Chamber $5.00
Air Pump $130.00
Bubbler $50.00
Battery $25.00
Connectors/Fan $190.00
Total $400.00
Sampling Port With Septa Seal
Inside View With Internal Mixing Fan
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
Time (sec)
0 500 1000 1500 2000 2500
Cu
mm
ula
tive
Mas
so
f C
H4
Co
llec
ted
0
20
40
60
80
100
120
140
96%
Mass Balance
CH4 Break-Through-Curve
• At 1 dilution• 32%
• At 3 dilutions• 5%
• Ideal reactor • 37 & 5%, respectively
Time (sec)0 500 1000 1500 2000 2500
CH
4 C
on
c. ( g
m-3
)
0
1e+6
2e+6
3e+6
4e+6
5e+6
32%
5%
Theoretical And Experimental Headspace Chamber Properties
HRT V Q (min) (L) (L min-1)
Calculated 6.5 7.6 1.16Experimental 6.3 7.3 1.16
Gaseous Output
Flow rate, L/min0 1 2 3 4 5
To
tal
ion
cu
rren
t, a
rea x
10
9
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
y = 0.0578x + 1.704R2 = 0.745
Microbiologist: One return port would be enoughEngineers: Four would be better
Gaseous Output
• Linear with manure surface area
Surface area, cm20 100 200 300 400 500 600
To
tal
ion
cu
rren
t, a
rea
x 10
8
0
2
4
6
8
10
12
14
16
y = 0.0214x + 0.878R2 = 0.973
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
•Laboratory Studies•Field Studies
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
1e+07
1.1e+07
1.2e+07
1.3e+07
1.4e+07
1.5e+07
1.6e+07
Time-->
Abundance
TIC: 0003.D
Laboratory StudiesFresh Manures: Cattle vs. Swine
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
1e+07
1.1e+07
1.2e+07
1.3e+07
1.4e+07
1.5e+07
1.6e+07
Time-->
Abundance
TIC: 0009.D
Cattle—Ground corn/corn silage
Swine—Grower diet
Abu
ndan
ce,
peak
are
a x
106
5
15
10
5
15
10
Run time, minutes
1 2 3 4 5 9876
Laboratory StudiesVolatiles Composition & Cattle Diets
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
1e+07
1.1e+07
1.2e+07
1.3e+07
1.4e+07
1.5e+07
1.6e+07
Time-->
Abundance
TIC: 0003.D
Ground corn/corn silage dietA
bund
ance
, pe
ak a
rea
x 10
6
5
15
10
5
15
10
Run time, minutes
1 2 3 4 5 98761.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
1e+07
1.1e+07
1.2e+07
1.3e+07
1.4e+07
1.5e+07
1.6e+07
Time-->
Abundance
TIC: 0008.D
Alfalfa maintenance diet
Cattle—Ground corn/corn silage diet
Laboratory StudiesManure Incubation
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
1e+07
1.1e+07
1.2e+07
1.3e+07
1.4e+07
1.5e+07
1.6e+07
Time-->
Abundance
TIC: 0003.D
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
1e+07
1.1e+07
1.2e+07
1.3e+07
1.4e+07
1.5e+07
1.6e+07
Time-->
Abundance
TIC: 0009.D
Abu
ndan
ce,
peak
are
a x
106
5
15
10
Run time, minutes1 2 3 4 5 9876
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
1e+07
1.1e+07
1.2e+07
1.3e+07
1.4e+07
1.5e+07
1.6e+07
Time-->
Abundance
TIC: 0008.D
5
15
10
5
15
10
Fresh
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
1e+07
1.1e+07
1.2e+07
1.3e+07
1.4e+07
1.5e+07
1.6e+07
Time-->
Abundance
TIC: 0003.D
Cattle—Alfalfa maintenance diet
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
1e+07
1.1e+07
1.2e+07
1.3e+07
1.4e+07
1.5e+07
1.6e+07
Time-->
Abundance
TIC: 0003.D
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
1e+07
1.1e+07
1.2e+07
1.3e+07
1.4e+07
1.5e+07
1.6e+07
Time-->
Abundance
TIC: 0011.D
Swine—Grower diet
Incubated
Run time, minutes1 2 3 4 5 9876
• Manure can be from 10 to 100 times more conductive than typical soil
Field StudiesPrecision Feedlot Surface Management
TX RX
S
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.
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.
Electromagnetic Induction Principles
570330 570340 570350 570360
44
89
81
04
48
98
30
4489
850
44
89
87
044
8989
0Bunk
Waterer
Mound
0.10.20.30.40.50.60.70.80.911.11.21.31.41.51.61.71.81.922.12.22.32.42.52.6
Oct
ob
er 2
004
570330 570340 570350 570360
4489
810
44
89
83
04
48
98
50
44
89
87
044
898
90
Bunk
Waterer
Mound
Jun
e 20
04
570330 570340 570350 570360
4489
810
4489
830
4489
850
4489
870
4489
890
Bunk
Waterer
Mound
July
200
4
Association of volatile solids (manure) to ECa
EMI, mS m-10 50 100 150 200 250
% V
ola
tile
So
lids
0.0
0.1
0.2
0.3
0.4
0.5y = 0.0022x - 0.0961r2 = 0.7661
Total Phosphorus
Volatile Solids, %0.0 0.1 0.2 0.3 0.4 0.5
To
tal P
0
2000
4000
6000
8000
10000y = 18094x - 8.9472r2 = 0.7996
Total Nitorgen
Volatile Solids, %0.0 0.1 0.2 0.3 0.4 0.5
To
tal N
, pp
m
0
5000
10000
15000
20000
25000
30000y = 65549x - 2299r2 = 0.9247
Area based on Conductivity
050
100150200250300350400
Electrical Conductivity, mS/m
Rel
ativ
e A
rea
050
100150200250300350400
Electrical Conductivity, mS/m
Rel
ativ
e A
rea
570340 570350 570360
4489
810
4489
820
4489
830
4489
840
4489
850
4489
860
4489
870
4489
880
4489
890
Less than 25% of the area is high conductivityHigh Conductivity = Manure Accumulation?
HighLow
Ammonia Flux Across Pen
BUNK
NH
3 f
lux
M
/m2/h
r
Sample Location
MOUND
Feedlot pen
0
5
10
15
20
25
30
35
1 2 3 4 5 6 7 8 9 10 11 12 13
8X more VOC
Feedlot Survey in Cooperation with ARS-USDA, Bushland, TX
Feedlot Survey in Cooperation with ARS-USDA, Bushland, TX
217370 217380 217390 217400 217410 217420 217430
3896
690
3896
700
3896
710
3896
720
3896
730
3896
740
0 .10.20.30.40.50.60.70.80.911.11.21.31.41.51.61.71.81.922.12.22.32.42.52.6
217370 217380 217390 217400 217410 217420 217430
3896
690
3896
700
3896
710
3896
720
3896
730
3896
740
0 .10.20.30.40.50.60.70.80.911.11.21.31.41.51.61.71.81.922.12.22.32.42.52.6
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