Albert J. Heber, Associate Professor Director, Purdue Agricultural Air Quality Lab Agricultural and Biological Engineering Purdue University Building Environment Research & Education AgAirQuality.com

“A Buoyant Convective Flux Chamber for Measuring Liquid Surface Emissions” hoodsunny A.J. Heber, T.T. Lim, J.Q. Ni and K.J. Fakhoury AgAirQuality.com

Objectives n Develop floating emission chamber n Evaluate performance Field Tests Lab Tests

Air Supply Unit Blower Adsorbent Filter

Air Supply Blower 198 m 3 /h (117 cfm)

Air Supply Unit

Air Supply Filter 22.4 kg of adsorbent Charcoal Permanganate Zeolite

Top View Air outlet Sampling location Air velocity probe Stainless steel divider Air inlet Styrofoam boards for buoyancy Liquid surface area = 0.76 m 2

BCFC Inlet

Stainless Steel Lining

“Hairpin” Airflow Path 2.4 m path length 2.2 sec residence time

1.1 m/s Sampling location Air velocity probe Air outlet Side View Air inlet

End View Air Inlet Air Outlet Divider 31 cm Sampling point

Lab Tests N-butanol at ,250 ppm in 200 L water Odor emission only. Lagoon effluent: 100, 50 and 25% dilution H 2 S, NH 3, CO 2 and odor emission.

Gas Analyzers n Ammonia (0 to 200 ppm) Ammonia converted to nitric oxide with a SS converter, 875 C Chemiluminescense: PMT detects light emission from reaction of nitric oxide with ozone. Sample flow rate = 0.5 Lpm n Hydrogen sulfide (0 to 10,000 ppb) Hydrogen sulfide converted to sulfur dioxide, SO 2 Pulsed fluorescence: PMT detects UV from decaying SO 2 molecules Sample flow rate = 1.0 Lpm n Carbon dioxide (0 to 5,000 ppm) Photoacoustic infrared sensor Sample flow rate = 1.0 Lpm.

Instrumentation Room Manifolds PC Gas sensors

Odor Threshold Measurement 1 of 8 panelists Olfactometer Tedlar bag Panel leader’s hand PC

N-Butanol Test Results n Blank: 9 OU n Inlet mean: 10.4 OU (8 to 13 OU) n Odor emission: 0.5 to 11.2 OU/s-m 2

Emission Rate of N-Butanol Emission Rate = 5.10 Log(C) R 2 = Concentration of N-butanol in Tank, ppm Emission Rate, OU/s-m

Lagoon Effluent Test Results n Inlet mean: 22 OU n Outlet mean: 27 OU n Odor emission: 0.8 OU/s-m 2 at 100% n Hydrogen sulfide too low to measure n Inlet ammonia mean: 1.8 ppm n Outlet ammonia mean: 2.9 ppm n Ammonia emission proportional to effluent concentration. n Ammonia levels below odor threshold

Lagoon Effluent: NH 3 Emission Emission Rate = 4.15x R 2 = Lagoon Effluent Dilution, % Emission Rate, mg/hr-m 2 Solids: 0.16%

Field Tests n Swine grow-finish facility n Four consecutive days n Day 1: Effect of air speed crustincorner

Anaerobic Treatment Lagoons 2nd Stage Basin 1st Stage Basin Six Swine Buildings

Deployment

Odor Emission Tests hoodwtwovacs 3 Lpm pumps Air velocity control Hammer Evacuation chamber Raceway (6 m)

Chamber Inlet and Outlet Samples hebervacus

Emission vs. Air Speed Emission = 1.85 x 0.93 R 2 = Surface Air Speed, m/s MeasuredPredicted Emission, OU/m 2 -s

Field Test Results n Inlet mean: 23 OU (12 to 42 OU) n Outlet mean: 52 OU n Odor emission: 1.5 to 2.1 OU/s-m 2 n Mean of 1.7 OU/s-m 2 corresponded to 1,000 ppm n-butanol.

Advantages n Large air filtration and cleaning unit n Inlet air sampling n Large liquid surface area n Long air path

Disadvantages n Size (van or pickup required) n Weight (2-4 people required) n Gentle berm slopes required, >3:1 n Limited reach (five meters)

Future Research n Reduce size and weight n Evaluate and improve internal air profiles n Study effect of flow rate on emission

Conclusions Good comparative measurements of gas and odor emission rates

Conclusions Low sampling variance

Conclusions Lower detection limit: ppm n-butanol.

Conclusions Lower limit reached with properly designed swine lagoon 0.16% solids “Low odor” lagoon

Conclusions hood5-7 Odor emission rate increased for ,000 ppm n-butanol

Acknowledgements n Purdue University Agricultural Research Program n State of Indiana Value Added Research Program n Ramco Sales, Inc.

Questions? float2 Check out AgAirQuality.com