Odor ManagementCurrent Challenges and Future Strategies:

Environmental Management in Swine Production in North DakotaJan 11-12, 2007Casselton, ND

Larry D. JacobsonDept of Bioproducts and Biosystems Engineering

University of MinnesotaSt. Paul, MN

Presentation OutlineOdor Measurement Fundamentals

OFFSET (Odor From Feedlot-Setback Estimation Tool) Fundamentals

Odor Management and Use of Control Technologies

Olfaction-Sense of Smell

ComplexEvokes a physiological and emotional reaction Humans detect > 10,000 odorsMixtures of gasesExtremely low concentrations

Animal Building Odor

Odor vs Gas MeasurementOdor – Sensory or Olfactometry

Analyze mixtureCorrelates with odorUses human sense of smell

Gas – Chemical AnalysisIdentify individual gases Measure concentrationsPoor correlation with odor

Odor Measurement Parameters

Threshold concentrationsDetectionRecognition

Intensity (strength)Persistence (“hang time”)Hedonic tone (pleasantness)Character descriptor

Detection ThresholdVolume of non-odorous air needed to dilute an odorous sample to point where trained panelists just detect a difference from non-odorous airReported as odor units (OU or DT) or as OU/m3 or DT/m3

Air Sample CollectionFrom buildings

Vacuum boxTedlar bagSampling line

Olfactometer

Three air streamsOne mixtureTwo non-odorousDetect the different oneRandomizedMixture - little odor

First set

Second set

Third set

Normal Olfactory Sensitivity

0

10

20

30

40

50

60

70

80

90

100

Low HighOdor Concentration

Freq

uenc

y of

resp

onse

s

Hypersensitive Normal Anosmic

Field OlfactometerNasal RangerTM

IntensityOdor strengthN-butanol scale (0 to 5)Calibrate panelists’ noses

Odor Intensity Scale

Intensity Odor0 None1 Very light2 Light3 Moderate4 Strong5 Very strong

Field SniffersTrained panelistsN-butanol intensity scaleCharcoal filter masksRecord intensity

Uses of IntensityResearch

Uses of IntensityResearchRegulationCommunity monitoring

Community MonitorsRecord odor eventsOdor event recording form

Sky, Precipitation & Wind infoOdor intensity

Training is necessary

Key PointsOdors evoke physiological and emotional reactionsMixtures of gases at extremely low concentrationsOlfactometry uses human nosesComplex

Air Quality Regulations and Livestock Operations

Odor From Feedlot – Setback Estimation Tool - OFFSET

History of OFFSET

In 1996, 12 member Livestock Odor Task Force (appointed by the Feedlot Manure Management Advisory Committee (FMMAC)) recommended that an “odor ratings” system be developed to assist in determining separation distances between livestock facilities and other land uses in Minnesota.

History of OFFSETFunds were appropriated during the 1997 legislative session to the U of M’s BAE Dept through the MN Dept. of Ag (MDA) to develop an “odor ratings”system

Initial copy of the OFFSET released in fall of 1999 for use on pilot basis by counties/townships and others. Revision made in 2001 and currently published as U of M Extension Folder: FO-07680-C

Air Samples taken from Odor Sources from Farms

Used wind tunnel on outdoor manure storage units

Sampled directly frombuilding’s fans or curtains

Air Samples collected/analyzed

Air collected in tedlar bagsusing vacuum box

Samples analyzed byolfactometer in detection thresholds, Odor Units (OU)

Air Flow also measured - so odor units per time (OU/s)

Measured Odor Emissions

Reported in table form for Buildings AND Manure Storage Systems

Tabulated on area (ft2) basis

Odor emission numbers for animal buildings with average management level.

Species Animal Type Housing Type Odor Emission Number(OEN)

Cattle Beef/Dairy Dirt/concrete lot 4Dairy Free stall, scrape; 4

Free stall, deep pit; 6Loose housing, scrape 6Tie stall, scrape 2

Swine Gestation Deep pit, natural or mechanical 50Pull plug, natural or mechanical 30

Farrowing Pull plug, natural or mechanical 14Nursery Deep pit, natural or mechanical; 42

Pull plug, natural or mechanicalFinishing Deep pit, natural or mechanical 34

Pull plug, natural or mechanical 20Hoop bar, deep bedded, scrape 4Cargill (open front), scrape; 11Loose housing, scrape;Open concrete lot, scrape

Poultry Broiler Litter 1Turkey Litter 2

Odor emission number for liquid or solid manure storage units

Storage Type Odor Emission Number(OEN)

Earthen basin, single or multiple cells 13Steel or concrete tank, above or below ground 28Crusted stockpile 2

Department of Biosystems and Agricultural Engineering, University of Minnesota

Odor Dispersion Model usedto establish Setback Distances

State Weather Data used in INPUFF-2 Dispersion Model

AVG of FIVE MN CITIES (1984-1992)

0

1

2

3

4

5

6

7

8N

NNE

NE

ENE

E

ESE

SE

SSE

S

SSW

SW

WSW

W

WNW

NW

NNW

F<1.3F<3.1E<3.1E<5.4D<5.4D<8.0

Weather Stability Classes & wind velocities used in OFFSET

Stability F with wind < 1.3 m/s - 1 %Stability F with wind < 3.1 m/s - 2 %Stability E with wind < 3.1 m/s - 3 %Stability E with wind < 5.4 m/s - 4 %Stability D with wind < 5.4 m/s - 6 %Stability D with wind < 8.0 m/s- 9 %

OFFSET Assumptions

Constant weather (wind, temp, etc) for 2 hours

Topography - assume flat

Source Emissions - single source & constant, 1.5 m emission height

Odor Annoyance free = intensity 2 (0 to 5 scale)

INPUFF-2 Results-MN Weather

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

2.50

2.75

0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400

Odor emission factor (X104)

Dis

tanc

e (m

ile)

99% annoyance free

98% annoyance free

97% annoyance free

96% annoyance free

94% annoyance free91% annoyance free

F, ≤1.3 m/s

F, ≤3.1 m/s

E, ≤3.1 m/s

E, ≤5.4 m/s

D, ≤5.4 m/s

D, ≤8.0 m/s

Steps for the OFFSET method

Determine odor emission sources and factorsDetermine area of odor sourcesfrequency curve Determine odor control factor for any control technology utilizedMultiply all factors to get TOTAL odor emissionsUse figure to find setback distance for the appropriate

Table used to calculate Total Odor Emission Factor

Column A Column B Column C Column D Column EOdor source Odor Emission

NumberArea (sq. ft) Odor control

factorOdor Emission Factor

(B x C x D/10000)1234

Total Odor Emission Factor (sum of Column E)

Example - 1200 hd sow unit

Earthen basin(200× 200 ft)

Gestation (350×70 ft)

Farrowing (230×70 ft)

Example - OFFSET StepsColumn A Column B Column C Column

DColumn E

Odor sourceOdor

EmissionNumber

Area (sq ft)Odor

ControlFactor

Odor Emisison Factor(B x C X D/10000)

1. Gestation barn 30 24500 1 73.52. Farrowing barn 14 16100 1 22.53. Basin 13 40000 1 52.0

Total Odor Emission Factor (sum of Column E) 148.0

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

2.50

2.75

0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400Odor emission factor (X104)

Dis

tanc

e (m

ile)

99% annoyance free

98% annoyance free

97% annoyance free

96% annoyance free

94% annoyance free91% annoyance free

F, ≤1.3 m/s

F, ≤3.1 m/s

E, ≤3.1 m/s

E, ≤5.4 m/s

D, ≤5.4 m/s

D, ≤8.0 m/s

Odor Graph-worst case Scenario

Separation graph is for the situation where receptor is downwind from prevailing winds so worst case scenario! Any other situation would have lower frequency of occurrence.

FO-07637 2001

Preparing an Odor Management Plan

David Schmidt, Extension EngineerLarry Jacobson, Extension Engineer

Kevin Janni, Extension EngineerDepartment of Biosystems and Agricultural

Engineering

Odor Management and Potential Odor Control Technologies

Odor Management PlansInventory of Odor SourcesIdentify High Odor Sources Identify 1 or 2 Control Strategies for Each Significant Odor SourceDevelop Response Protocol to Odor Complaints

Diet Manipulation

“Good Housekeeping”

Injection of Liquid Manure

Setback Distances

Good Neighbor PolicyAvoid spreading on holidays and weekendsAvoid high odor activities when wind are in the “wrong” directionsTry to time high odor activities like spreading during the heating compared to the cooling parts of the day

Classifications of Air Emission Control Technologies

Increase Dilution or Dispersion of Odor PlumeReduce Emission of Gases (Capture and Treat) Reducing Odor Generation (formation of odorous gases)

Shelterbelts for Air Emission Control

Increase turbulence

Encourage settling of dust from barns by reducing winds

Dust and particulates may be caught by trees and shrubs

Odorous chemicals may be absorbed onto shelterbelt foliage

Windbreak Walls

Tunnel ventilated barn Wind-break wall

Dispersion effect

Dust deposition

Windbreak WallsWindbreak walls deflect exhaust air upward so it mixes with clean air so odors and gases become diluted. Windbreak wall is on the left building.

Reduce Emissions (Capture and Treat)

Biofilters

Manure Pit

Odorous Air

Mechanically Ventilated Building

Exhaust Fan

Treated Air Exhaust

Media SupportAir PlenumAir Duct

Biofilter Media

Field Scale

100% Biofiltered Gestation & Farrowing Barns

Effectiveness

Effectiveness improves with time and moisture control.

% reduction

Odor threshold 80 - 95%

Hydrogen sulfide 85 - 95%

Ammonia 50 - 60%

Permeable Cover (straw)

Permeable Cover (geotextile fabric)

Effectiveness% Reductions

N/A - Not available

Cover Odor H2S NH3Natural crust 60 - 85 N/A 75 - 90Straw 60 - 90 80 - 95 40 - 95Geotextile 10 - 60 10 - 70 10 - 25Clay balls 60 - 90 80 - 90 N/A

Impermeable Cover

Capture nearly all lagoon odorsReduce Gas VolatilizationShould treat captured air emissions

Vegetable Oil Sprinkling-Gases and odor attach to dust particles.

-Oil spray will reduce dustformation and emissions

EffectivenessOdor, NH3, & H2S reductions of 10-30%Good dust reduction – 50 to 70%Oil sprinkling may offer some odor reduction in a naturally ventilated curtain sided pig finishing barn.

Ozonation-Ozone is generatedoutside the barn

. . .and distributed with ventilation air

•Human health hazard ??

•Limited positive research results

Chemical Addition

Add an Odor Control Technology to example farm

Odor Control Technology Odor Control Factor Biofilter on 100% of building exhaust fans 0.1 Geotextile cover (≥ 2.4 mm) 0.5

4” 0.5 Straw or natural crust on manure 8” 0.3 Impermeable cover 0.1 Oil sprinkling 0.8

Add Biofilter to both Barns

Add Geotextile Cover to Basin

Modified Example with Odor Control

Column A Column B Column C Column D

Column E

Odor source Odor

Emission Number

Area (sq ft) Odor

Control Factor

Odor Emisison Factor (B x C X D/10000)

1. Gestation barn 30 24500 0.1 7.4 2. Farrowing barn 14 16100 0.1 2.6 3. Basin 13 40000 0.5 26

Total Odor Emission Factor (sum of Column E) 36

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

2.50

2.75

0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400

Odor emission factor (X104)

Dist

ance

(mile

)

99% annoyance free

98% annoyance free

97% annoyance free

96% annoyance free

94% annoyance free91% annoyance free

F, ≤1.3 m/s

F, ≤3.1 m/s

E, ≤3.1 m/s

E, ≤5.4 m/s

D, ≤5.4 m/s

D, ≤8.0 m/s

Questions?Bioproducts & Biosystems Engineering

University of Minnesota

www.bbe.umn.edu