Odor and Gas Emission from Anaerobic Treatment
of Swine Manure
FINAL REPORT
to
Ms. Renee Carnahan, Director of Grants and Education
Indiana’s Value-Added Agricultural Grant Program
Office of the Commissioner of Agriculture
ISTA Center Suite 414
150 West Market Street
Indianapolis, Indiana 46204
Indianapolis, IN
Phone: 317-232-8769
by
Albert J. Heber, Ph.D., P.E., Associate Professor (1)
Teng Teeh Lim, Graduate Research Assistant (1)
Jiqin Ni, Ph.D., Research Associate (1)
Alan L. Sutton, Ph.D., Professor (2)
(1)
Agricultural and Biological Engineering Department
(2)
Department of Animal Sciences
Purdue University
November 15, 2000
i
Table of Contents
Table of Contents .....................................................................................................................................ii
List of Tables ......................................................................................................................................... iii
List of Figures .........................................................................................................................................iv
Nomenclature ........................................................................................................................................... v
Summary................................................................................................................................................... 1
Introduction .............................................................................................................................................. 1
Objectives ................................................................................................................................................ 5
Experimental Procedure ........................................................................................................................... 6
Lagoons ................................................................................................................................................ 6
Buoyant Convective Flux Chamber (BCFC)......................................................................................... 6
Sampling and Measurement.................................................................................................................. 6
Determination of Odor Detection Thresholds....................................................................................... 7
Determination of Odor Units ................................................................................................................ 8
Determination of Odor Intensity and Hedonic Tone ............................................................................. 9
Measurement of Gas Concentrations .................................................................................................... 9
Calculation of Odor and Gas Emission Fluxes................................................................................... 10
Analysis of Lagoon Influent and Effluent............................................................................................ 10
Sampling of VOC ............................................................................................................................... 10
Analysis of VOC ................................................................................................................................ 11
Results and Discussion........................................................................................................................... 12
Objective 1: Determine Baseline Factors for the New Setback Model.............................................. 12
Objective 2: Evaluate Effect of Loading Rates................................................................................... 14
Objective 3: Evaluate Effect of Ambient Temperature....................................................................... 15
Objective 4: Evaluate Effect of Slurry Characteristics....................................................................... 15
Objective 5: Report Gas Emissions. .................................................................................................. 16
Conclusions ............................................................................................................................................ 16
Acknowledgements................................................................................................................................. 17
References.............................................................................................................................................. 17
ii
List of Tables
Table 1. Concentrations of n-butanol in water and odor intensity categories. ........................................ 22
Table 2. Odor characteristics of BCFC samples taken at lagoon A........................................................ 22
Table 3. Odor characteristics of BCFC samples taken at lagoon B........................................................ 23
Table 4. Gas concentrations in BCFC samples taken at lagoon A.......................................................... 24
Table 5. Gas concentrations in BCFC samples taken at lagoon B. ......................................................... 25
Table 6. Odor characteristics and gas concentrations of samples taken at the downwind berm of the
lagoons................................................................................................................................... 26
Table 7. Correlation coefficients between measured variables.............................................................. 27
Table 8. Mean concentration and emission of trace gas in BCFC outlet air, ng/L.................................. 27
Table 9. Characteristics of lagoon influent............................................................................................. 28
Table 10. Characteristics of lagoon effluent........................................................................................... 28
Table 11. Daily means of BCFC inlet and outlet odor concentrations.................................................... 29
Table 12. Daily means of odor characteristics of downwind berm samples. ......................................... 29
Table 13. Individual measurements of odor and gas emission rates at lagoon A.................................... 30
Table 14. Individual measurements of odor and gas emission rates at lagoon B.................................... 31
Table 15. Daily means of odor and gas emission rates at lagoons A and B............................................ 32
Table 16. Summary of results................................................................................................................. 33
Table 17. Summary of emissions from swine facilities or pig slurry in the literature. ........................... 34
iii
List of Figures
Figure 1. View of underside of BCFC and hairpin airflow path............................................................. 35
Figure 2. BCFC, air supply duct, air supply unit and bag sampling drums. ............................................ 35
Figure 3. Downwind air sampling at the lagoon berm. ........................................................................... 36
Figure 4. Geometric mean odor concentrations at each sampling visits. ................................................ 36
Figure 5. Mean BCFC outlet concentrations of ammonia at each sampling visit. ................................... 37
Figure 6. Mean BCFC outlet concentrations of hydrogen sulfide at each sampling visit. ....................... 37
Figure 7. Odor and hydrogen sulfide concentrations for all inlet and outlet BCFC samples. ................. 38
Figure 8. Odor intensity and concentration for all inlet and outlet BCFC samples................................. 38
Figure 9. Mean odor emissions and temperatures at each sampling visit. .............................................. 39
Figure 10. Mean ammonia emissions at each sampling visits................................................................. 39
Figure 11. Mean hydrogen sulfide emissions at each sampling visits..................................................... 40
iv
Nomenclature
The nomenclature used in this report are as follows:
BCFC=buoyant convective flux chamber
BIW=n-butanol concentration in water
Cb=concentration of n-butanol gas
C2=acetic
C3=propionic
C4=butyric acid
iC4=isobutyric acid
C5=valeric acid
iC5=isovaleric acid
E=emission flux
PL=phenol
PC=p-cresol
IND=indole
SKA=skatole
HT = hedonic tone
Int= intensity
Loc=location
NH4+-N =ammonium nitrogen
ODCb=odor detection concentraion of n-butanol gas
ODT= odor detection threshold
OU=Odor Uint
OUE=European Odor Uint
s.d.=standard deviation
TKN=total Kjeldahl nitrogen
TS =total solids content.
VSLR=volatile solids loading rates
VS = volatile solids content.
v
Odor and Gas Emission from Anaerobic Treatment of Swine Manure
Final Report to the Indiana Office of the Commissioner of Agriculture
A.J. Heber1, T.T. Lim, J.Q. Ni and A.L. Sutton
Summary
Odor and gas emissions from commercial swine lagoons were measured using a buoyant convective
flux chamber (BCFC) and surface air speed of 1 m/s. Anaerobic lagoons with different rates of manure
input were selected to determine the effect of loading rate on odor and gas emission. Odor
concentration, intensity and hedonic tone were evaluated by trained sensory panelists. Odor panel
performance was verified using n-butanol as a reference odorant. Ammonia (NH3), hydrogen sulfide
(H2S), carbon dioxide (CO2), sulfur dioxide (SO2), and nitric oxide (NO) concentrations were
measured from the odor samples collected in 50-L Tedlar® bags. The geometric mean odor
concentrations of the BCFC inlet and outlet and of samples taken at the downwind berm of the lagoons
were 99±28, 155±40 and 67±22 OU/m3 (OU, Odor Unit), respectively. The overall arithmetic mean
odor emission flux for the two lagoons was 4.6±1.5 OU/s-m2 (7.5±2.4 OUE/s-m2. OUE, European Odor
Uint). The arithmetic mean odor emission rate per AU (animal unit =500 kg live body mass) was 66.2
OU/s-AU. Overall mean gas emission fluxes were 101±24 µg/s-m2, 5.7±2.0 µg/s-m2, 852±307 µg/s-m2
and 0.5±0.4 µg/s-m2 for NH3, H2S, CO2 and SO2, respectively. The emission of NO was not detectable.
Introduction
The operations of Indiana and the U.S. livestock industry have become larger and more concentrated
due to economies of scale. Public concerns regarding related air, water and soil pollution have also
increased with the growth of the industry. The environmental pressures facing the swine industry makes
it especially important to obtain scientific information that help address these public concerns. Since
odor emissions is a major air pollution issue, the measurement of baseline odor emissions from
commercial facilities is important for assessing nuisance potential, building a data base of emission
factors, and providing inputs to odor dispersion models. Baseline emission rates of pollutants from
waste storage and treatment facilities are needed for comparing with facilities with abatement
technologies such as aeration, solids separation, and covers (Ritter, 1989; Pain and Bonazzi, 1993;
Zhang et al., 1996). Measurements of character and quantity of odor emissions from waste storage and
treatment facilities are also needed for evaluating odor impacts through science-based setback models
(Williams, 1986; Schauberger and Piringer, 1997; Lim et al., 2000a).
The strength of an odor is measured by determining the dilution factor required to reach the odor
detection threshold (ODT). The ODT is defined as the dilution of an odor sample that cannot be
distinguished from odorless air by 50% of the members of an odor panel. Stated another way, the ODT
is the number of dilutions with odor-free air required for an odor to be just detected by 50% of the odor
1
Associate Professor, Agricultural and Biological Engineering, Purdue University, 1146 ABE Bldg, West
Lafayette, IN 47907. Ph. 765-494-1214. Email: [email protected]. URL: http://www.AgAirQuality.com.
1
panel or until the least definitely perceptible odor is achieved. Thus, the mixture at the ODT is a barely
detectable odor. The dilution factor increases with greater odor strength because more odor-free air is
needed to dilute the sample to its ODT. The dilution ratio of the mixture is the ratio of total diluted
sample flow volume to the odor sample flow volume. For example, a dilution ratio of 10,000 is
achieved with 2 cc/min of sample flow and 20 L/min of total flow.
Odor concentration is expressed as number of odor units (OU) in 1.0 m3 of odorous air (OU/m3). The
number of odor units is a dimensionless number and is defined as equal to the panel ODT. Even though
it is really a dimensionless number, it is expressed as OU/m3 in order to calculate odor emission rate,
thus the panel ODT is an abstract measure of odor concentration. The product of odor concentrations
and volumetric airflow (e.g. from ventilation exhausts of buildings, or across land) gives the rate of
odor emission in OU/s. The odor emission rate can be regarded as the total odor load per unit of time
leaving a particular process. Odor emission values are used in atmospheric dispersion models to
calculate odor nuisance distances.
Odor samples are evaluated by determining odor detection thresholds (ODT), intensity, and hedonic
tone. Measurements of odor concentration alone are insufficient to assess human perception of odor
(Misselbrook et al., 1993). For example, the pleasant smell of a meadow forest and the annoying smell
of sewage may have the same ODT but obviously differ widely in hedonic tone. Some odors judged to
be acceptable or even pleasant at low concentrations could become annoying at higher concentrations
(Punter et al., 1986). Also, some odor abatement processes alter odor quality thus changing the hedonic
tone. Thus, odors can be more thoroughly characterized by including the assessment of intensity and
hedonic tone along with odor concentration.
Odor intensity is the relative perceived psychological strength of an odor that is above its detection
threshold and is independent of the knowledge of the odor concentration (McGinley and McGinley,
2000, Jiang and Sands, 2000). For a single chemical odorant, odor intensity increases as a power
function of its concentration. Intensity can only be used to describe an odor at suprathreshold
concentrations or concentrations above its ODT. Intensity can be assessed using either a category or a
reference scaling. Misselbrook et al. (1993) used the category estimation technique to measure
intensity. Panelists gave their perception of intensity according to the following scale:
0
1
2
3
4
5
6
No odor
Very faint odor
Faint odor
Distinct odor
Strong odor
Very strong odor
Extremely strong odor
Generally, data generated from category scales are not of equal geometric intervals (Cain and
Moskowitz, 1974), interpretation of the scales varies between individuals, and panelists tend to distort
the intervals during an odor evaluation session (Nicolai et al., 2000). Thus, intensities obtained from
category scales should be used with great caution.
Since category scale numbers do not reference equivalent odorant concentrations and different category
scales are used by different researchers, data cannot be compared between studies, it is preferred to
use reference odorant concentrations as a referencing scale to improve reproducibility and to allow
2
direct comparisons between research studies (Harssema, 1991). Intensity using referencing scales is
assessed by either dynamic or static scale methods (ASTM, 1999). The dynamic scale method utilizes a
special olfactometer that presents a series of specific concentrations of a reference odorant (e.g. nbutanol) in a continuous flow of air to each panelist. The static scale method utilizes a set of bottles
with increasing concentrations of a reference odorant in water.
The scales used with the dynamic and static scale methods are referred to as the Dynamic Odor
Intensity Referencing Scale and the Static Odor Intensity Referencing Scale, respectively. The Dynamic
Odor Intensity Referencing Scale is based on the ppm of n-butanol in air (BIA) whereas the Static Odor
Intensity Referencing Scale is based on the ppm of n-butanol in water (BIW). The observed intensity
values, either the scale number or the equivalent butanol concentration, are used along with other data
in the interpretation of odor dispersion models.
Field odor inspectors, monitors, plant operators and citizens commonly use the static scale referencing
method. Word descriptors assigned to these concentrations are: no odor, very faint, faint, moderate,
strong, and very strong. After familiarizing themselves with the various dilutions of n-butanol, the odor
panel judges the intensity of a sample by objectively matching it to the intensities they sense from the nbutanol dilutions in water (ASTM, 1999). The intensity is reported in ppm equivalent to n-butanol in
water (ASTM, 1999) or BIW.
Odor intensity grows as a power function of the stimulus odor (Stevens, 1957) and follows the
equation:
Int = kCn
(1)
where Int is the odor intensity expressed by equivalent ppm of n-butanol in water (BIW), C is the mass
concentration of the odorant in ppm, and k and n are constants that are different for every odorant.
Hedonic tone (HT) is the degree to which an odor is subjectively perceived as pleasant or unpleasant
(McGinley et al., 2000) and has the closest relationship to odor annoyance than any other odor
measurement variable. Hedonic tone is derived from the word “hedonistic”, the Greek word hedone
means pleasure. The perceptions of HT vary widely among people and are strongly influenced by
individual odor experience, personal odor preference, and the emotional context in which the odor is
perceived.
Anaerobic treatment systems (lagoons) have been used as an integral part of many swine production
systems to provide practical treatment and storage of swine manure (Humenik et al., 1980; PIH, 1998;
NEH, 1999). Lagoons are typically earthen basins used to treat and store manure from pork production
facilities (PIH, 1998) and rely on bacteria to stabilize organic material. Lagoons are relatively simple
to operate and maintain, and are relatively inexpensive compared to other treatment methods (ASAE,
1997a). Lagoons become more odorous when overloaded due to sludge buildups, additional inputs, and
cold weather (Ritter, 1989). During winter, biological activity in lagoons is reduced and organic matter
is incompletely digested. As lagoons warm up in the spring, bacteria are presented with excess organic
matter to stabilize. At this time, very vigorous activity is observed on the lagoon surface and greater
amounts of biogas are produced. This typically is referred to as lagoon turnover (PIH, 1998).
The traditional wisdom of agricultural engineers has been that a properly designed and operated
anaerobic lagoon will have minimal odor problems except in spring when lagoon temperature rises and
3
bacterial action increases. However, all lagoons generate some odor but the quantity has not been well
documented. Odors from anaerobic lagoons can be reduced by maintaining water levels, adding wastes
on a regular basis, and reducing loading rates. Anaerobic lagoons are designed on the basis of volatile
solids loading rate (VSLR) per 1000-m3 (NEH, 1999). Since the rate of solids decomposition in
anaerobic lagoons is a function of temperature, the acceptable VSLR varies from one location to
another.
The design volume of a first stage lagoon in zone 3 (including southern Indiana and Illinois) is 12.45 m3
(440 ft3) per sow and litter (MWPS, 1985). Based on a volatile solids production rate for a sow and
litter of 0.74 kg/d (1.64 lb/d), the design VSLR in zone 3 is 59.7 g/d-m3 (3.73 lb/d-1000ft3). The design
VSLR for anaerobic lagoons located in southern Indiana and Illinois is 64.1 g/d-m3 (4 lb/d-1000ft3)
according to ASAE (1997a), and 72.1 g/d-m3 (4.5 lb/d-1000ft3) according to the National Engineering
Handbook (NEH, 1999). Humenik and Overcash (1976 cited by SRI, 1997) reported that an odor panel
concluded that odor was minimal with loading rates below 60 g COD/d-m3. According to ASAE
(1997b), the COD production rate from swine is approximately the same as volatile solids (8.4 vs 8.5
kg/day per 1,000 kg live animal mass). Sensory-based measurements of lagoon odor emissions as
affected by VSLR are needed to guide design and management for lagoons, but such measurements are
lacking.
Several methods of measuring odor and gas emissions from surfaces have been described in previous
literature (Jiang et al., 1995; Smith and Watts, 1994, Schmidt et al., 1999). A convective buoyant flux
chamber (BCFC) is an open-bottom enclosure placed over emitting surfaces, with ambient or filtered
air blown or drawn through to mix and transport the emissions away from the emitting sirface.
Concentrations of both the incoming and outgoing air streams should be sampled when ambient air is
used (Smith and Watts, 1994). Emission was calculated as the product of the difference between outlet
and inlet air concentrations and the volume of air passing through the hood, while using a modified
Lindvall hood to measure NH3 emission by Misselbrook et al. (1998). A wind tunnel was used to
evaluate emission rates from manure storages and feedlots in Minnesota (Schmidt et al., 1999).
Concentrations of odor and H2S in the exhaust air were measured and emissions were calculated based
on the bulk wind speeds which ranged from 0.19 to 1.14 m/s. Odor samples from 19 animal manure
storage sites were collected by Jacobson, et al. (1999) during the spring, summer and fall of 1998 using
the same wind tunnel (Schmidt et al., 1999). Hydrogen sulfide (H2S) and odor concentrations were
measured using a hydrogen sulfide analyzer and an olfactometer, respectively.
Nitrogen emissions from anaerobic swine lagoons in Georgia were measured using
micrometeorological and gas sensors mounted on a submersible barge by Harper et al. (2000). Most of
the trace gas measurements were made from the primary lagoon. The swine production unit was a
12,000 animal facility with a series of 4 lagoons. Ammonia (NH3) concentrations were obtained by
drawing unfiltered air through 0.1 m H2SO4 at known rate and period, and analyzed for NH4+
concentrations by the colorimetric technique. The authors concluded that NH3 emission varied diurnally
and seasonally, and more highly correlated with wind speed and water temperature. Nitrous oxide
(N2O) emissions were not detectable.
A dynamic flow-through chamber system was used to measure seasonal emission s of atmospheric
ammonia-nitrogen (NH3-N, where NH3-N = (14/17)NH3) from an anaerobic co mmercial swine waste
storage lagoon (Aneja, et al., 2000). The pH and TKN of the surface lagoon water ranged from 7 to 8
pH units, and 500 to 750 mg N L-1, respectively. The largest emissions were observed during the
4
summer (mean NH3-N flux = 4017 ± 987 µg N m-2 min-1). Emissions decreased through the fall months
to a minimum flux during the winter months, and increased during spring.
Hammond et al. (1989) reported observations on the particles and volatile odor compounds (VOCs)
produced by a laboratory-scale lagoon. The lagoon consisted of a 152.5-mm pipe 1.8 m long, with
temperature varied from 30 to 1 oC on a 120-day cycle. The lagoon liquid was analyzed for VOC using
gas chromatography-mass spectrometry (GC-MS). The most important contributors to the odor were
dimethyl disulfide and dimethyl trisulfide, while indole, skatol and cresol made minor contributions.
Major musty odor in the lagoon water remained unidentified. In general, the VOC peaks were smallest
during the temperature minimum and reached amximum values as the temperature rose above 15oC.
Hobbs et al. (1998) designed and constructed a special odor emission chamber to measure odorous
compounds and concentration emitting from slurry under controlled environmental conditions. The
compounds were measured using GC-MS, and odor concentration was measured by olfactometry. The
major odorous compounds were identified as belonging to the sulfide, volatile fatty acid, phenolic and
indolic chemical groups. The mean odor emission from 200 L of stirred slurry samples (surface area =
1 m2, windspeed = 4 m/s) was 1.35 x106 OU/min (2.25x104 OU/s-m2).
A buoyant convective flux chamber (BCFC) was designed, constructed and tested at Purdue University
(Heber et al., 2000). Odor and gas emission measurements with the BCFC appeared to be consistent
and repeatable based on laboratory and field tests conducted to evaluate its performance. Odor
emissions from a surface-aerated anaerobic lagoon were measured at a 6,000-head swine grow-finish
facility in Oklahoma (Heber and Ni, 1999). Mean odor intensity and hedonic tone were also measured
because they provide additional odor descriptors that help establish factors for the odor impact
guideline.
Current methods to measure odors from wastewater in general sometimes rely on the use of H2S as a
surrogate for determining odor strengths because it is a common component of malodors. Hydrogen
sulfide measurements are regarded as easy, more reproducible and cheaper than olfactometry (Stuetz et
al., 1999). A total of 46 odor samples from locations within sewage treatment works were collected
and analyzed, using an electronic nose, a H2S analyzer, and an olfactometer by Stuetz et al. (1999).
Comparison between H2S and odor concentrations showed that there was no clear relationship between
the two concentrations.
The emission of NH3 from livestock facilities has become an important issue in the U.S. SRI (1997)
stated that up to 50% of the total initial nitrogen content can be lost due to volatilization and that the
extent of NH3 losses increases with the area of the liquid surface.
Objectives
This research project has the following objectives relating to odor and gas emissions from anaerobic
treatment systems (lagoons) for swine manure:
1.
2.
3.
4.
Determine baseline factors for the new setback model.
Evaluate effect of loading rates.
Evaluate effect of ambient temperature.
Evaluate effect of slurry characteristics.
5
5. Report hydrogen sulfide, ammonia, carbon dioxide (CO2), sulfur dioxide (SO2), and nitric oxide
(NO) emissions.
Experimental Procedure
Lagoons
Anaerobic swine lagoons with typical and light VSLR were selected for this field measurement survey.
Lagoon A was the first cell of a two-stage lagoon at a 20,000-sow, breed-to-wean facility near Kansas,
Illinois. The surface area and volume of lagoon A was 30,735 m2 and 1.44 x 105 m3 (5.07 x 106 ft3),
respectively. The waste was removed from the buildings with a flush system. The VSLR for lagoon A
was estimated at 58.3 g/d-m3 (3.64 lb/d-1000ft3). Lagoon B was the first cell of a two-stage system for
a 2,900-sow breed-to-wean operation near Bloomfield, Indiana. The surface area and volume of lagoon
B was 12,310 m2 and 5.23 x 104 m3 (1.84 x 106 ft3), respectively. A flush system was used in each
building to daily remove manure. The estimated VSLR for lagoon B was estimated at 22.1 g/d-m3 (1.38
lb/d-1000ft3).
Buoyant Convective Flux Chamber (BCFC)
The BCFC was designed and constructed in 1998 for measuring odor emissions from the lagoon surface
under controlled airflow conditions (Heber et al., 2000). The same BCFC was used in this project, but
with a few practical modifications and improvements. The BCFC covered 0.74 m2 (7.96 ft2) of lagoon
surface over which air was blown at approximately 1 m/s (197 fpm). This was similar to the 0.90 m2
hood used by Misselbrook et al. (1998) that also used 1 m/s air velocity. It was surrounded by rigid
waterproof insulation to cause enough buoyance to keep about 0.17 m (0.56 ft) of the BCFC floating
above the water. The inside walls and ceiling were lined with stainless steel, Figure 1. Air followed a
hairpin path through the chamber that covered a liquid surface. A variable air supply (powered by a
portable generator) forced air through a gas absorption and dust filtering system located on the lagoon
berm and into the floating emission chamber through a long 0.15 m (0.49 ft) diameter air supply duct,
Figure 2. The 9.75 m (32 ft) long air supply duct consisting of a 6.1 m (20 ft) long stainless steel
section and 3.65 m (12 ft) of flexible Teflon™ duct conveyed the filtered air to the floating BCFC. The
air supply duct was supported by three 3.2x3.2x0.32 cm (1.25x1.25x0.125 in.) aluminum channels that
were buoyed by three 19-L (5-gal) polyethylene containers. The aluminum channels were also used as
raceways for gas sampling tubes and thermocouple wires. The BCFC was held stationary in the water
with the berm-anchored channels and two lengths of berm-anchored nylon rope attached to either side
of the chamber.
Sampling and Measurement
Twelve total sampling visits were made (six for each lagoon). Lagoon A was visited between April 24
to July 27, 2000 and Lagoon B was visited between May 4 and July 25, 2000. The following sampling
and measurement were conducted:
1. Four inlet and four outlet samples taken from the Purdue BCFC at two locations on the lagoon
during each visit (48 total for inlet and 48 total for outlet).
2. Two samples taken at the downwind berm during each visit (24 total).
3. One lagoon effluent samples taken near the lagoon surface during each visit (12 total).
6
4. Lagoon influent samples taken once in the spring and once in the summer (4 total).
5. Lagoon surface water and BCFC outlet air temperatures measured with thermocouples at all
visits.
Air samples at the BCFC’s inlet and outlet were simultaneously drawn into chemically-inert 50-L
polyvinyl fluoride (Tedlar) bags through Teflon tubing. A small diaphragm pump (AirPro Model
6000D, BIOS International, Pompton Plains, NJ) was used to evacuate a rigid vacuum drum (114 L or
30 gal) causing an initially-collapsed bag inside the vacuum drum to inflate in about 10 min at an
airflow rate of 5 Lpm. Negative pressure in the drum caused the air sample to directly enter the
sampling bags without going through the pump. The inside surfaces of the BCFC were cleaned with
alcohol between visits. Air sampling lines were flushed between visits with compressed air or N2 to
purge the lines of odor from the previous sampling.
The inlet air entering the BCFC chamber must be sampled because the odor filtering and absorption
device could not remove 100% of the ambient odor on a single pass; and there might be some odors
emitted from the surfaces of air supply ducts. The concentration of inlet air collected before flowing
into the BCFC also serves as background concentration for this study. In order to achieve lower inlet
concentrations, the air supply unit was placed upwind to the lagoons and as far away as possible from
exhaust fans of the nearby swine buildings. Two downwind air samples were also collected at the
berm, about 1 m (3.3 ft) from the edge of the lagoon, and at a height of 1.0 m (3.3 ft), Figure 3. The
samples were taken to compare with the background (inlet samples), and give an assessment of ambient
air quality near the lagoon.
All sampling bags were either new or reused only once. New sampling bags were pre-flushed once
with either compressed air or N2. If the bags were to be reused, they were filled and flushed at least
three times. New bags were used for sampling visit A1, A2, A5, B1, B4, and B5. Bags from these visits
were reused for the other sampling visits. To condition the bags, they were filled ¼ full with odorous
air and emptied before taking the samples. The BCFC was operated at least ten minutes prior to
collecting odor samples. The sampled bags were placed immediately in 3.0 mil thick black garbage
bags to minimize exposure to sunlight and sudden temperature changes. Enough space between bags
was always allowed during transport to prevent mechanical damage.
Influent and effluent samples were collected from the lagoon surface and then put on ice for transporting
to the laboratory.
Surface lagoon effluent samples were collected from several locations along the edges. Influent
samples were collected either from the buildings or directly at the inlets to the lagoons during flushing.
Samples were poured into a bucket and thoroughly mixed. A subsample of each of the mix was taken
and stored in a sealed 8 oz. plastic bottle, placed in a Styrofoam container with ice, and transported to
the laboratory.
Air temperature was measured by securing the thermo couple to the BCFC outlet air sampling point.
Water temperature was measured at about 5 cm below the water surface, by attaching the thermo couple
to the edge of the BCFC. Both temperature readings were recorded during the sampling of each sample.
Determination of Odor Detection Thresholds
7
ODTs of the sampled air were measured at the Purdue Agricultural Air Quality Laboratory with a
dynamic dilution forced-choice olfactometer (AC’SCENT International Olfactometer, St. Croix
Sensory, Stillwater, MN). This unit was constructed to meet the United States olfactometry standard
(ASTM, 1991) and the draft European olfactometry standard prEN13725 (CEN, 1999). The odor panel
consisted of eight people that were screened to determine their odor sensing ability (ASTM, 1986). The
olfactometer delivered a precise mixture of sample and dilution air to a panelist through a Tefloncoated presentation mask.
The olfactometer continuously diluted the odor sample, and, starting with an extremely high dilution
ratio, presented an ascending series of concentrations (step factor = 2) to each panelist at a flow rate of
20 Lpm. The olfactometer can create 14 dilution ratios, ranging from 23 to 216. A triangle test is
conducted whereby the panelist sniffed three sequential sample coded gas streams at each dilution
ratio. One gas stream was randomly assigned to have the odor while the other two gas streams were
odor-free. The three gas streams were directed one at a time to the mask.
In the triangular forced-choice method, the panelist must select which of the three presentations is
“different” (even if no difference is perceived) and thus contains the odor (ASTM, 1991). The panelist
declared by pressing a button whether the selection was a “guess” (no perceived difference),
“detection” (selection is different from the other two), or “recognition” (selection smells like
something). Initial samples were so dilute that they could not be distinguished from odor-free air.
Higher and higher odor concentrations (2-fold increases), or lower and lower sample dilutions (50%
reductions), were presented to each panelist until the sample was correctly detected and recognized.
An individual best-estimate ODT estimate was calculated by taking the geometric mean of the last
nondetectable dilution ratio and the first detectable dilution ratio. The panel ODT was calculated as the
geometric mean of the individual ODTs and is sometimes reported as the log ODT. Retrospective
screening (CEN, 1999) of each panelist threshold was applied to the panel ODT.
Determination of Odor Units
To assess panelist performance, a reference odorant n-butanol gas (40 to 58 ppm) was usually included
in each odor session and evaluated like the other samples. The n-butanol evaluations were used to
assess panelist performance (CEN, 1999) by calculating the ODC for the n-butanol according to CEN
(1999). The ODC of an odorant is the chemical concentration at the chemical’s panel ODT. The nbutanol ODC of each panel was therefore calculated as Eq. 2:
ODC b
=
1000 C b
ODTb
(2)
where ODCb = odor detection concentration of n-butanol gas, ppb,
Cb = concentration of n-butanol gas, ppm, and
ODT b = odor detection threshold of the n-butanol sample.
The draft European standard (CEN, 1999) requires the mean ODC of the last 20 samples of n-butanol to
be somewhere between 20 and 80 ppb for each panelist. Most European olfactometry laboratories
follow this n-butanol performance criterion to achieve more accurate and repeatable measurements
8
(Sneath and Clarkson, 2000). However, most U.S. laboratories do not typically use reference odorants
since U.S. standards do not require it.
Since an n-butanol sample of known concentration was analyzed for each odor session in this study, a
corrected odor concentration can be calculated based on panel sensitivity. Given that 1 European Odor
Unit (OUE) = 123 mg n-butanol = 40 ppb (CEN 1999), the corrected odor concentration OUE could be
calculated with the following equation:
OU E =
ODT × ODCb
40
(3)
where OUE = European Odor Units,
ODT = odor detection threshold of sample.
For example, if the panel average ODCb = 80 ppb, then the corrected odor concentrations OUE of
samples evaluated during that session would be twice the uncorrected sample ODT.
Determination of Odor Intensity and Hedonic Tone
Standardized n-butanol solutions were used to generate a odor intensity reference scale (ASTM, 1999),
Table 1. The static reference scale method was used with five concentrations of n-butanol in water to
assure a geometric interval (3x progression) between each value.
Panelists were required to familiarize themselves with the intensity levels (1-5) of serial dilutions of nbutanol. A small glass funnel was used to present the odorous mixture from the sample bag to the
panelist while the bag was compressed with a weight. The odor panel judged the intensity of the
samples by comparing them to the intensities of the known n-butanol concentrations (ASTM, 1999). The
results were reported as ppm of n-butanol in water (BIW).
The hedonic tone (HT) was also judged by the odor panel. The HT was subjectively rated from –10
(extremely offensive) to 0 (neither pleasant nor offensive) to +10 (extremely pleasant). The hedonic
tone was judged by each panelist. The reported hedonic tone value for a sample was the average of
individual hedonic tone values.
Measurement of Gas Concentrations
Concentrations of H2S, sulfur dioxide (SO2), NH3, nitric oxide (NO), and CO2 were evaluated for each
bag sample. Hydrogen sulfide was measured with an H2S converter (Model 340, Thermal
Environmental Instruments Inc., Mansfield, MA) and a pulsed fluorescence SO2 analyzer (Model 45,
TEI) using a sample flow rate of 1.0 Lpm. The precision of H2S analysis was 1 ppb according to the
manufacturer. Ammonia concentrations were measured with a chemiluminescence NH3 analyzer (Model
17C, TEI, Franklin, MA). The precision of the analyzer was 0.5% of fullscale. The measurement range
of the analyzer was set at 0-200 ppm. Carbon dioxide was measured with a photoacoustic infrared gas
sensor (Model 3600, Mine Safety Appliances Company, Pittsburgh, PA). The maximum noise of the
sensor was ±1% of fullscale as indicated by the manufacturer. The measurement range of the sensor
was set at 0-10,000 ppm.
9
All the instruments were in regular use and were calibrated twice a week using certified gases. The
ammonia analyzer was calibrated with zero air, 23.4 ppm NO, and 165 ppm NH3 in air. The H2S
converter and SO2 analyzer were calibrated with zero air, 2.7 ppm SO2 in air, and 16.5 ppm H2S in
nitrogen (N2). The CO2 sensor was calibrated with zero air and 3990 ppm CO2 in nitrogen.
During concentration measurement, a sample bag was attached to a manifold, to which the three
instruments was connected in parallel. Two internal pumps, one in the SO2 analyzer and another in the
CO2 sensor, and one external pump for the NH3 analyzer drew sample air from the bag and measure the
gas concentrations in the air. The measurement durations of each bag were between 6 to 20 min. Gas
concentration readings were obtained when the instrument outputs were stablized.
Calculation of Odor and Gas Emission Fluxes
The emission fluxes from the lagoons were determined by multiplying airflow rate through the chamber
by the concentration difference between inlet and outlet. Airflow rate in the chamber was determined
by the dimension of the hairpin path above the water surface and the constant surface air velocity of 1
m/s (197 fpm). The emission flux, E, was a measure of the flow of odor or gases per unit area per unit
time. It was calculated by dividing the chamber emission rate by the area covered, AS (0.74 m2) using
Eq. 4, which was similar to the formula given by Smith and Watts (1994):
E=
Q∆C
AS
(4)
where Q is the volumetric flow rate of air entering the chamber, and ∆C is the difference of
concentratioin of inlet and outlet air.
Analysis of Lagoon Influent and Effluent
Using standard methods, the lagoon influent and effluent samples were analyzed for pH, total solids
(TS), volatile solids (VS), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN),
ammoniacal nitrogen (NH4+-N), and phosphorous (P). The TS content was analyzed gravimetrically at
90oC. TKN was determined by the micro-Kjeldahl nitrogen method of Nelson and Sommers (1972),
NH4+-N was determined using the steam distillation method of Bremner and Keeney (1965). For
phosphorous (P), manure samples were wet ashed by refluxing with concentrated HNO3 for 2 h prior to
analysis of the digest, which was conducted according to Murphy and Riley (1962).
Sampling of VOC
Volatile orgnic compounds (VOC) in the air in the Tedlar bags were sampled using traps, which were
constructed from 2.2 mm id, silica-lined, deactivated stainless steel (SilcoSteel® Type 304, Restek
Corporation, Bellefonte, PA) and sonicated and rinsed in acetone. The traps were packed with Tenax®
TA (=poly-(2,6-diphenyl-phenylene oxide)) 60/80, an adsorbent polymer. Glass wool placed into both
ends kept the resin from dislodging from the trap. Each end was then fitted with a stainless steel cap
(Swagelok #SS-200C) to prevent adsorption of compounds from ambient air.
To ensure that the Tenax® resin was free from residue, all traps were baked for 60-120 min at 220°C
(428°F), 7-8 traps at a time with about 20 mL/min of N2 flowing through each trap. A random sampling
10
of at least one of the traps from each batch of eight traps was analyzed to ensure that the resin was free
of detectable compounds. If a randomly selected trap was found to have residue, the baking time and
temperature were increased until no residues were found in randomly selected traps.
Sample air was drawn through the traps using a vacuum pump (SKC, Inc., Eighty-Four, PA), which was
used to sample four bags at a time at a flow rate of 6.9 mL/min per trap. Tygon tubing was used to
connect the pump and traps.
Before withdrawing sample air through the traps, the airflow of each trap was measured sequentially
with all traps attached to the air sample bags. A precision mass flow meter (Digital Flow Check – HR,
Alltech Associates, Deerfield, IL) was connected in the vacuum line between the trap and the bags.
Precalibration airflows of each trap were measured and recorded sequentially. Postcalibration
airflows were measured and recorded before removing the traps at the end of the sampling period. To
minimize adsorption of ambient odors, the sampled traps were sealed with stainless steel caps and
stored in Ziplock® bags at - 6°C (21.2°F) until they were analyzed.
Analysis of VOC
Gaseous compounds adsorbed in each trap were analyzed by gas chromatography (GC). The target
compounds were six fatty acids; acetic (C2), propionic (C3), n-butyric (C4), i-butyric (iC4), n-valeric
(C5), and i-valeric (iC5), and also phenol (PL), p-cresol (PC), indole (IND), skatole (SKA) (Zahn et
al., 1997). An environmental GC (Model 8610C, SRI Instruments, Torrance, CA) equipped with a 30 m
x 0.53 mm capillary wax column (J&W 125-7032) and a flame ionization detector (FID) was used to
analyze compounds collected by the traps. The carrier gas was helium with a flow rate of 18 mL/min at
34.5 kPa (5.0 psi) pressure. The oven temperature started at 40°C. After 5 min it was increased to
110°C (12 min) at 10°C/min, then to 160°C (22 min) at 5°C/min and then to 190°C (22 min) at
10°C/min. The separation was complete after 26 min. The thermal desorption temperature was 260°C.
This temperature was reached within 60 s after turning on the desorber heat, at which time the
compounds were injected into the column. The injector valve remained open for 6 min and the valve
temperature was 180°C. The FID detector temperature was 200°C. The hydrogen and airflow rates to
the FID detector were 20 and 250 mL/min, respectively.
The gas chromatograph was operated using PeakSimple software (SRI Instruments, Torrance, CA). The
software controlled the pressures, sequence of events and temperatures of each trial. The same
parameters were used throughout the experiments as well as for the calibrations and standards. A full
calibration of the GC was conducted by spiking clean traps with known amounts of target compounds
(liquid form) and desorbing them onto the column using the same procedure. A syringe was used to
inject 1 µL of solution into one end of a clean trap installed on the thermal desorber. The trap was
purged with N2 before desorbing. The purge time was chosen based on the measured flow rate of each
trap. Three replications of four concentrations (~25, ~50, ~100 and ~200 mg/L) were analyzed to
establish a calibration curve for each compound.
Although liquid was used for calibration, the GC received it as a gas as it was desorbed from the trap.
Three replicates of each concentration level were used during complete calibrations. Full calibrations
were conducted after every set of 40 samples or every two weeks, whichever was shorter, and
following GC maintenance. Quick calibrations using one concentration level were initially conducted
weekly and later conducted daily.
11
Individual compounds in solvent were injected onto the column to determine retention times to help
name compounds. The only significant change in retention times occurred after the column was
trimmed. This change was accounted for by developing a new calibration curve. A transparency with
the calibration chromatogram was placed on top of chromatograms with questionable peaks. The peaks
were then identified as one of the standard compounds or extraneous compounds. Integrations were
conducted manually and followed the graph of the solvent curve to draw the baseline.
Flow rates for air, helium and hydrogen were calibrated monthly. Gas pressures were regulated by
precision pressure controllers. However, flow rates were checked to assure and document consistency.
The precision mass flow meter was used at the outlet of the column when the gas chromatograph was
cool.
Results and Discussion
The results tabulated in this report include: odor characteristics and gas concentrations of BCFC
samples and of samples taken at the downwind lagoon berm (Table 2 to 6), correlation coefficients
between various measured variables (Table 7), gas chromatography analyses (Table 8), lagoon influent
and effluent characteristics (Tables 9 and 10), mean odor concentrations (Tables 11 and 12), odor and
gas emissions (Tables 13 to 15), and a summary of major results (Table 16).
The mean of OTCb during the 12 odor evaluation sessions was 67.8±4.7 ppb (95% confidence interval)
and it ranged from 51 to 114 ppb. These results compared well to the panel sensitivity required by the
draft European olfactometry standard (CEN 1999).
Objective 1: Determine Baseline Factors for the New Setback Model.
Odor concentrations ranged from 19 to 437 and 20 to 668 OU/m3 for all inlet and outlet samples,
respectively, Table 2 and Table 3. The geometric mean odor concentrations of four samples taken each
at the inlets and outlets were 99 and 155 OU/m3, respectively, Table 16. Mean outlet odor
concentrations at lagoon A were higher (P<0.05) than at lagoon B (257 vs. 93 OU/m3). Odor
concentration for all samples seemed to vary during each sampling visit, Figure 4.
Using the same equipment but with the air supply unit floating on the water adjacent to the BCFC, odor
emission from a surface-aerated anaerobic lagoon was measured by Heber and Ni, (1999). Inlet and
outlet odor concentrations averaged 23.1 and 51.7 OU/m3, respectively, which were lower than the
results of this experiment (99 and 155 OU/m3). The average outlet odor concentrations was in the range
of 41 to 299 OU for six swine manure earthen basins (undiluted manure storage) (Jacobson et al. 1999)
for manure storages.
The mean odor concentrations of the downwind berm samples of lagoon A were higher than of lagoon
B, which were 118 and 38 OU/m3 for lagoon A and B, respectively, Table 16, but the difference was
not significantly different. Berm odor concentrations of both lagoons averaged 67 OU/m3. The mean
corrected berm odor concentrations were 210 and 62 OUE/m3 for lagoons A and B, respectively, and
the difference was statistically significant (P<0.05).
Odor intensity averaged (geometric mean) 1,582, 2,040, and 1,404 ppm of BIW for inlet, outlet, and
downwind berm samples, respectively. The hedonic tone (arithmetic mean) of all samples, judged as
12
unpleasant by the odor panel, averagd –1.8, - 2.4, and - 1.7 for inlet, outlet and downwind berm
samples, respectively (Table 16). Odor intensity values were higher than those reported by Heber and
Ni, (1999) (56.6 and 80.0 ppm BIW for inlet and outlet samples, respectively for surface-aerated
anaerobic lagoon), the HT values were also higher (- 4.1 and - 4.8) for inlet and outlet samples,
respectively). Lim et al. (2000b) reported an higher odor intensity but a lower HT of samples collected
from commercial nursery rooms. The mean values of the two nursery rooms were 1,072 ppm BIW and
–5.88 for odor intensity and HT, respectively.
Ammonia concentration averaged 3.0, 4.5, and 3.8 mg/m3 for inlet, outlet and downwind berm samples,
respectively. Mean inlet and outlet NH3 concentrations of each sampling visit ranged from 2.3 to 5.8
mg/m3, Figure 5. Hydrogen sulfide concentration averaged 171, 256, and 143 µg/m3 for inlet, outlet and
downwind berm samples, respectively. Mean inlet and outlet H2S concentrations seemed to vary much
within each sampling visit, Figure 6. The mean inlet concentrations for CO2 and SO2 were 898 mg/m3
and 32 µg/m3, respectively. The mean outlet concentrations were 910 mg/m3 and 39 µg/m3 for CO2 and
SO2, respectively. The mean outlet were higher than the mean intlet concentrations for both gases. At
the downwind berm the CO2 and SO2 concentrations averaged 875 mg/m3 and 39 µg/m3, respectively.
The mean concentrations of NO were equal to zero at all measurement locations, Table 16. There was
only one sample (lagoon A, outlet on 7/20) out of 119 samples indicating 0.1 mg/m3 of NO (Table 4 to
Table 6). Because of the low concentration, which was within the maximum noise level of the
measurement instrument, and low occurring frequency, the overall NO concentration was considered
undetectable.
Although the mean concentrations in the outlet were higher than the inlet for NH3, H2S, CO2 and SO2,
there were some paired inlet-outlet samples, in which the inlet concentration was higher than the outlet,
Table 4 and Table 5. This caused “negative” emissions, for which the explanations include random
errors in the sampling/measurement and absorption of gas in water.
Correlation coefficients (r) between odor concentrations, intensity and hedonic tone, and NH3, H2S,
CO2, and SO2 concentrations for all BCFC inlet and outlet samples were analyzed, Table 7. Odor
concentration tended to be directly proportional to H2S (r = 0.51), intensity (r = 0.65) and inversely
proportional to hedonic tone (r = - 0.65). Intensity also appeared to be inversely proportional to
hedonic tone (r = - 0.73). However, these trends are not statistically significant. Jacobson et al. (1999)
found little correlation between odor and H2S in their research with manure storages. Stuetz et al.
(1999) also found no clear relationship between odor and H2S concentrations for sewage treatment
samples, and suggested that H2S may be an unsuitable surrogate for the determination of odor
concentration. An empirical power equation (R2 = 0.37) was developed to relate odor and H2S
concentrations for the inlet and outlet air, Figure 7. However, the R2 of 0.37 was low and therefore the
relationship is viewed as only a trend.
A relationship between odor concentrations and intensity (for all inlet and outlet BCFC samples) were
expressed using Stevens Law relationship. The regression equation was: Int (ppm BIW) = 278 ODT0.39
(R2 = 0.39), Figure 8. A similar regression was reported by Lim et al. (2000b) for nursery odor
samples, with a higher R2 value of 0.72.
Odor emissions varied between sampling visits, Figure 9. The arithmetic means of odor emission
fluxes were 6.2 and 2.9 OU/s-m2 for lagoons A and B, respectively, and the geometric means of odor
emission fluxes were 1.8 and 1.3 OU/s-m2 for lagoons A and B, respectively, Table 16. Neither
difference was statistically different at the P<0.05 level. The mean emission values were the means of
13
the four odor emissions determined during each visit. If there was a negative or zero emission (when
inlet concentration was higher than or equal the outlet), the emission flux was set equal to 0.1 OU/s-m2.
The 0.1 value was used to simplify the calculation of geometric mean values, since zero or negative
values could not be included in the geometric calculation. Among the 48 emission values, there were 3
and 5 negative odor emission values for lagoon A and B, respectively, and 4 and 0 zero emission
values for lagoon A and B, respectively. These negative and zero emission values suggest that the
charcoal filter was unable to remove all of the odor in the inlet air under field conditions. Future
research on odor emission measurements from lagoons using the BCFC should first make the odor
removal system more efficient.
The mean odor emission flux of both lagoons was 4.6 OU/s-m2 or 66.2 OU/s-AU (geometric mean = 1.5
OU/s-m2 or 24.0 OU/s-AU). Odor emission from an aerated lagoon with simulated wind speeds of 1.1
m/s (217 fpm) in the BCFC averaged 1.7 OU/s-m2 (Heber and Ni, 1999). Odor emission from two
anaerobic lagoons without surface aeration and twice the VSLR (143 g/d-m3) was 3.1 OU/s-m2 (n=2 to
4). Odor emissions were measured at 2.2 to 17.6 OU/s-m2 by Jacobson, et al. (1999) for six pig manure
earthen basins. As expected, lagoon odor emissions were at the lower end of the range of odor
emissions from manure storages. The mean odor emission values of the two lagoons are similar to those
from deep pit finishing housing reported by Heber et al. (1998) with long term manure storage beneath
fully slatted floors. The geometric mean emissions from the four finishing buildings was 36 OU/s-AU
or 5.0 OU/s per m2 of floor area. Some of the emission values found in the literature are summarized in
Table 17.
Mean concentrations and emissions of trace gas of BCFC outlet air were reported in Table 8. There
was no statistically significant difference between lagoons for any of the compounds. Emission fluxes
were calculated assuming that the trace gas concentrations of inlet air were relatively low. The overall
mean emission of both lagoons was 47, 0.54, 0.24, and 0.14, 0.05 µg/s-m2 for acetic, propionic, butyric
acid, and phenol, and indole, respectively. These values are similar to those reported by Hobbs et al.
(1999) on stirred pig slurries, which were 17.2, 0.77, 0.66, 0.21, and 0.0 µg/s-m3 for acetic, propionic,
butyric acid, and phenol, and indole, respectively.
Objective 2: Evaluate Effect of Loading Rates.
Most of the measured emission parameters of lagoon A were higher than lagoon B, Table 16. Analysis
of variance (ANOVA) was used to test the differences of the measured parameters of lagoons A and B.
The ANOVA results indicated that odor intensity, HT, ODT, OUE, and H2S concentration of BCFC
outlet samples, and NH3, H2S, and CO2 emission were significantly different (P<0.05) between lagoons
A and B. Ammonia, CO2 and SO2 concentrations of BCFC outlet samples, odor emission, CO2
emission, and SO2 emission were not significantly different (P<0.05) between lagoons A and B.
The arithmetic means of odor emission were 6.2 and 2.9 OU/s-m2 for lagoons A and B, respectively.
The odor emission fluxes (OU/s-m2 ) were proportional to the estimated VSLRs, which were 58.3 and
22.1 g/d-m3 (3.64 and 1.38 lb VS/d-1000 ft3) for lagoons A and B, respectively. It is thus reasonable to
assume that lagoons with higher VSLR will emit more odors due to higher solids content and bacterial
activities. The odor emission flux of lagoon A was 114% higher (more than double) than lagoon B and
VSLR of lagoon A was 164% higher, thus suggesting that lagoon odor emission was influenced by
VSLR. According to the information provided by the farm staff, the sludge accumulation in either
lagoon has never been removed. Since lagoon A was newer than lagoon B, sludge accumulation in
lagoon B was probably greater than lagoon A, thus lowering the actual VSLR resulting in a ratio less
14
than 164%. In any case, the difference in odor emission was not statistically significant, probably due
to the small numbers of samples and lagoons.
Higher odor emission rate per animal unit (57.3 and 75.0 OU/s-AU for lagoons A and B, respectively)
were measured for lagoons with lower VSRL, but the difference between the two lagoons was not
statistically significant. The number of animal units for lagoon A was over 600% higher than lagoon B,
but the surface area of lagoon A was only 150% greater than lagoon B, thus resulting in a higher odor
emission per animal unit value for lagoon B.
Objective 3: Evaluate Effect of Ambient Temperature.
The measured temperatures of the lagoon surface water and BCFC outlet air were 25.0±1.9 oC
(77.0±3.4 oF), and 28.0±2.3 oC (82.4±4.1oF), respectively. Lagoon surface water temperatures ranged
from 16.7 to 27.7 oC (62.1 to 81.9 oF); BCFC outlet air temperatures ranged from 23.0 to 37.0 oC (41.4
to 66.6 oF), Figure 9.
The correlation coefficients were 0.18 and –0.10 between odor emission and lagoon surface water
temperature, and between odor emission and outlet air temperature, respectively. The coefficients
indicated that odor emission was not affected by the temperatures over the experiment period.
However, this is properly due to the small temperature variation since the measurements were made
only during warm weather. Even though there were no measurements made in other seasons, the
reported odor and NH3 emissions should be at the higher end of the range. It has been shown that
temperature can significantly affect the emission of odorous materials (Hammond et al., 1989; Aneja, et
al., 2000). More measurements over a longer period of time and at other temperatures are required to
properly study the effects of temperature on odor and gas emission from anaerobic lagoons.
Objective 4: Evaluate Effect of Slurry Characteristics.
A total of 12 lagoon surface (effluent) and 4 lagoon influent samples were collected and analyzed,
(Table 9 and Table 10). The mean pH values were 8.1 and 7.9 for lagoon influent and effluent,
respectively. The mean pH value of lagoon effluent was similar to the reported value of 7.7 by Harper
et al. (2000) and of 7.7 to 8.1 by Aneja et al. (2000). The TS of lagoon A was 33% higher than lagoon
B, but was 26% lower for VS. However, for influent samples, lagoon A was 9 and 91% higher than
lagoon B, for TS and VS, respectively. Emission fluxes seemed related to TS, which were 6.2 OU/s-m2
for 0.45%, and 2.9 OU/s-m2 for 0.34% of TS, for lagoons A and B, respectively. However, the trend is
significantly inconclusive.
Mean TKN concentration of both lagoons was 853 mg/L, which is similar to range of 500 to 750 mg/L
reported by Aneja et al. (2000). The mean NH4+-N and TKN concentration of lagoon A were about
200% higher than of lagoon B. It is reasonable to assume that lagoons with higher loading rate, and thus
higher TS and other concentrations will emit more odors due to higher nutrients, solids content and
bacterial activities. This finding is important especially when applying setback models to anaerobic
lagoons with no actual measurements of odor emission. The measurements in this report will add to the
database from which the relationship between gas and odor production and lagoon effluent
characteristics can be established. However, larger sample sizes of lagoon, lagoon influent and
effluent, and odor will be needed to build the database. There remains a paucity of data in the literature.
15
Objective 5: Report Gas Emissions.
Mean lagoon emission fluxes were 101, 5.7, 852 and 0.5 µg/s-m2 for NH3, H2S, CO2 and SO2,
respectively, Table 16. Gas emissions of lagoon A were 167, 296, 228, and 72% higher than those of
lagoon B for NH3, H2S, CO2 and SO2, respectively. The emissions of NH3, H2S and CO2 were
statistically significant (P<0.05). The NH3 emissions were similar to that reported by Aneja et al.
(2000), of anaerobic swine lagoon at North Carolina, and about an order of magnitude less than that
reported by Harper et al. (2000), from anaerobic swine lagoons in Georgia. The lagoon NH3 emissions
in this test were lower than all the other reported NH3 emissions from swine houses, swine manure
storage basins and stirred swine manure in lab tests, Table 17.
There was no available data of H2S emission from lagoon for comparison. However, the H2S emission
value obtained in this study was within the range of the reported values related to swine builings, swine
manure storage basins and lab manure reactors, Table 17. The mean H2S emissions were near the lower
end of the ranges measured by Jacobson, et al. (1999) and Schmidt et al. (1999) in full strength swine
manure basins. Hydrogen sulfide emissions in this test were considerably lower than those of stirred
slurry surface reported by Hobbs et al. (1999). The high H2S emission of Hobbs et al. (1999) might
represent an extreme case, since stirred manure releases large quantities of H2S and in a short time
(Patni and Clarke, 1991). Emission of H2S from swine manure tends to be much less consistent than
other gases (e.g. NH3) because of burst releases (Ni et al., 2000c; 2000d). Since there is only few data
available, more measurements of lagoon H2S emission seems to be necessary.
The mean CO2 emission of this study was also about ten fold smaller than the emission value reported
by Hobbs et al. (1999) for stirred pig slurry. However, it was well within the range of emission fluxes
obtained in a test conducted in two emptied swine finish buildings (Ni et al., 2000b), Table 17. Carbon
dioxide is an important component of biogas, produced by anaerobic digestion. Biogas usually contains
40 – 60% of CO2. It is not unusual or unexpected that CO2 emissions were detected in the two
anaerobic lagoons. It is also logical to predict that less CO2 is produced from these two lagoons during
winter, when anaerobic fermentation activities are minimized due to low temperatures.
Although the emission of SO2 was not statistically significant by comparing the inlet and outlet
concentrations, SO2 was detected in all the samples with the maximum concentration of 178 µg/m3. This
SO2 was evidently emitted from the lagoons and agreed with another report of SO2 emission from swine
wastes. In a laboratory test using swine manure, Ni et al. (2000c) reported SO2 concentration ranged
from 0 to 970 µg/m3 in the headspace air. The emission flux was about 0.1 µg/s-m2.
Conclusions
1. Odor emissions were estimated to be 6.2 and 2.9 OU/s-m2 for anaerobic swine lagoons with
VSLR of 62.5 and 22.4 kg-VS/d-m3, respectively.
2. The overall mean odor emission flux of both lagoons was 4.6 OU/s-m2 or 66.2 OU/s-AU.
3. Odor concentration appeared to be directly related to H2S (r = 0.51), intensity (r = 0.65) and
inversely related to hedonic tone (r = - 0.65).
4. Odor emission was not significantly affected by water and ambient temperatures in this test.
5. Mean gas emission fluxes were 101, 5.7, 852 and 0.5 µg/s-m2 for NH3, H2S, CO2 and SO2,
respectively.
16
Acknowledgements
The financial support of the Indiana Office of the Commissioner of Agriculture and the Purdue
University Agricultural Research Programs is gratefully acknowledged. The authors also acknowledge
the collaboration and assistance of Heartland Pork, Inc. and Mr. Andy Kigin, Site Manager. The
assistance of Kate Fakhoury and members of the odor panel in evaluating odor samples, Scott Brand
and Garry Williams in setting up, manufacturing, and maintaining equipment, Dan Kelly for manure
analysis, and students Rahul Sinha and Nick Vanlaningham in assisting with laboratory tasks was very
much appreciated.
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21
Table 1. Concentrations of n-butanol in water and odor intensity categories.
Reference
scale #, I
0
1
2
3
4
5
n-butanol in water
BIW (ppm)
log BIW
0
0.00
250
2.40
750
2.88
2250
3.35
6750
3.83
20250
4.31
Odor intensity categories
Strength
Annoyance
No odor
Not annoying
Very faint
Not annoying
Faint
A little annoying
Moderate
Annoying
Strong
Very annoying
Very strong
Extremely annoying
Table 2. Odor characteristics of BCFC samples taken at lagoon A.
Date
Loc
4/28
4/28
4/28
4/28
6/15
6/15
6/15
6/15
6/22
6/22
6/22
6/22
6/29
6/29
6/29
6/29
7/20
7/20
7/20
7/20
7/27
7/27
7/27
7/27
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
Int, ppm BIW
In
Out
1131
1938
813
1006
1069
1875
1250
1542
1750
2313
2313
2500
2250
4375
1500
3813
2688
3375
2313
3018
1688
2018
2250
2250
4750
7500
5625
5438
5813
5250
7688
6000
1875
3000
1688
3000
1438
5250
2063
5250
1313
2438
1875
3000
1688
2063
2250
2881
OU/m3
HT
In
- 2.5
- 1.6
- 1.6
- 1.4
- 2.5
- 2.9
- 3.1
- 3.3
- 3.5
- 2.8
- 3.0
- 2.8
- 4.4
- 4.1
- 4.3
- 4.5
- 0.9
- 1.9
- 1.3
- 2.4
- 3.1
- 3.5
- 3.1
- 2.6
Out
- 2.3
- 2.5
- 3.1
- 2.3
- 3.5
- 3.5
- 4.1
- 3.5
- 3.9
- 3.9
- 4.0
- 3.4
- 4.6
- 4.5
- 4.8
- 4.8
- 2.1
- 2.5
- 2.6
- 2.5
- 3.4
- 4.1
- 2.8
- 4.3
22
In
91
48
52
48
151
210
320
165
73
79
109
93
437
341
309
283
248
125
239
297
334
334
428
283
Out
57
69
97
98
319
347
295
294
235
234
254
201
668
406
311
283
505
440
318
436
334
334
282
283
OUE/m3
In
Out
258
162
135
197
148
277
135
278
194
408
269
444
410
378
211
376
148
476
160
474
220
513
188
406
717
1097
560
667
508
510
465
465
397
806
199
703
382
508
474
696
535
535
535
535
685
452
453
453
Table 3. Odor characteristics of BCFC samples taken at lagoon B.
Date
Loc
5/4
5/4
5/4
5/4
6/1
6/1
6/1
6/1
6/8
6/8
6/8
6/8
6/19
6/19
6/19
6/19
7/19
7/19
7/19
7/19
7/25
7/25
7/25
7/25
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
Int, ppm BIW
In
Out
726
3536
944
1500
806
1750
1889
979
1107
1500
1313
1313
1813
1938
2125
2313
1083
821
750
1083
1083
776
705
1062
938
1063
750
813
750
862
2938
1750
2023
1500
1835
1438
2023
2188
1398
2188
1273
1250
1063
1063
875
1875
1250
1063
OU/m3
HT
In
- 1.0
- 0.8
- 1.3
- 0.2
- 0.7
- 0.8
- 1.1
- 1.6
- 0.5
0.6
- 0.7
- 0.4
0.3
- 0.1
- 1.0
- 2.0
- 2.3
- 1.6
- 1.6
- 1.8
- 0.8
- 0.3
- 0.3
- 1.0
Out
- 2.0
- 1.9
- 2.5
- 2.0
- 2.1
- 2.0
- 0.9
- 1.0
- 1.1
0.2
- 0.6
- 1.4
- 1.3
- 0.6
- 1.9
- 1.3
- 1.5
- 1.9
- 1.6
- 1.8
- 1.0
- 1.5
- 1.8
- 1.3
23
In
33
21
21
19
48
73
62
57
23
36
42
55
142
59
202
117
264
286
189
189
31
23
23
31
Out
30
39
75
57
104
80
146
87
120
110
110
110
185
70
216
202
435
223
243
159
21
20
63
37
OUE/m3
In
Out
79
72
50
95
50
183
46
138
66
144
102
112
86
203
79
122
32
167
50
153
59
153
76
154
217
283
91
108
309
331
179
310
354
581
383
299
252
325
252
213
58
40
44
37
44
119
58
69
Table 4. Gas concentrations of BCFC samples taken at lagoon A.
Date
Loc
4/28
4/28
4/28
4/28
6/15
6/15
6/15
6/15
6/22
6/22
6/22
6/22
6/29
6/29
6/29
6/29
7/20
7/20
7/20
7/20
7/27
7/27
7/27
7/27
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
NH3, mg/m3
in
out
2.6
2.9
3.6
4.2
2.5
3.2
2.5
3.9
2.4
5.7
2.4
4.6
2.9
5.3
2.5
5.8
2.6
5.3
2.2
4.4
2.3
4.8
3.0
7.1
2.5
4.4
2.4
5.1
2.8
4.6
3.1
4.9
2.9
5.7
3.0
5.4
2.6
5.7
4.3
5.4
3.0
4.9
2.9
4.8
2.3
5.9
3.7
5.2
H2S, µg/m3
in
out
141
309
113
337
141
364
113
336
189
299
217
412
217
271
216
273
188
298
188
326
214
298
188
271
244
494
305
522
300
381
300
382
133
273
134
272
134
245
162
273
160
298
160
299
160
243
131
215
CO2 mg/m3
in
out
771
807
809
803
785
816
783
805
895
911
877
909
872
891
863
899
870
901
870
873
855
892
849
864
947
968
937
942
915
922
915
935
999
1023
983
1002
957
986
962
975
925
949
909
925
891
893
893
907
24
SO2, µg/m3
in
out
21
21
21
21
16
21
21
21
58
115
58
110
58
58
58
63
57
57
57
57
57
57
57
57
5.2
57
5.2
57
5.2
5.2
5.2
5.2
5.3
5.3
5.3
5.3
5.3
5.3
5.3
5.3
5.2
5.2
5.2
5.2
5.2
5.2
5.2
5.2
NO, mg/m3
in
out
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.1
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Table 5. Gas concentrations of BCFC samples taken at lagoon B.
Date
Loc
5/4
5/4
5/4
5/4
6/1
6/1
6/1
6/1
6/8
6/8
6/8
6/8
6/19
6/19
6/19
6/19
7/19
7/19
7/19
7/19
7/25
7/25
7/25
7/25
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
NH3, mg/m3
in
out
3.1
4.0
4.1
4.3
4.1
4.1
4.3
3.9
5.5
5.6
6.1
7.5
4.2
4.8
4.8
5.3
2.4
3.6
2.5
3.3
4.0
6.4
5.5
5.3
2.6
3.2
2.5
3.1
2.4
3.2
2.2
5.3
2.7
2.4
2.9
2.4
2.0
3.0
2.0
3.0
2.7
2.8
2.6
2.7
2.0
5.9
2.0
3.4
H2S, µg/m3
in
out
29
92
28
85
56
78
29
57
305
555
249
165
186
138
138
138
124
247
137
247
137
275
164
385
295
161
189
133
189
160
189
105
189
273
161
247
162
273
158
409
161
93
132
105
187
78
189
105
CO2 mg/m3
in
out
887
913
932
892
854
864
820
840
1042
1074
1013
1039
912
925
917
941
871
888
868
878
863
877
866
875
874
881
861
858
859
863
854
849
971
985
972
975
968
969
976
971
908
907
879
878
906
877
875
872
25
SO2, µg/m3
in
out
73
126
126
126
73
73
126
126
68
68
16
16
10
10
16
16
16
16
10
68
47
68
68
68
57
57
57
57
57
57
57
57
5.3
5.3
5.2
5.3
5.3
5.3
5.3
5.3
5.2
5.2
5.2
5.2
5.2
5.2
5.2
5.2
NO, mg/m3
in
out
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Table 6. Odor characteristics and gas concentrations of taken at the downwind berm samples of
both lagoons.
Date
4/28
4/28
6/15
6/15
6/22
6/22
6/29
6/29
7/20
7/20
7/27
7/27
5/4
5/4
6/1
6/1
6/8
6/8
6/19
6/19
7/19
7/19
7/25
7/25
Lag
A
A
A
A
A
A
A
A
A
A
A
A
B
B
B
B
B
B
B
B
B
B
B
B
Loc
1
2
1
2
1
2
1
2
1
2
1
2
1
2
1
2
1
2
1
2
1
2
1
2
Int
ppm BIW
565
2000
1125
1143
2563
1813
5250
5813
2000
2179
1381
1381
536
550
3188
1250
586
850
1237
3250
960
585
1063
1438
HT
- 1.3
- 1.1
- 2.0
- 1.8
- 3.4
- 3.3
- 4.3
- 4.0
- 2.1
- 1.6
- 3.8
- 3.6
- 1.0
0.2
- 1.3
- 1.8
- 0.7
0.0
- 1.0
- 0.6
- 1.0
- 1.5
- 0.5
- 0.1
ODT
EOU
52
63
219
70
202
218
150
150
76
69
203
144
25
16
67
62
60
39
19
27
34
48
40
75
147
179
280
90
408
440
246
246
121
110
324
231
60
39
94
86
83
54
30
42
45
64
76
141
26
NH3
mg/m
5.1
6.5
3.1
2.2
4.2
4.0
4.2
4.0
4.1
4.6
3.6
4.0
4.1
3.9
5.0
4.4
3.5
2.1
1.8
2.3
2.3
4.1
4.0
H2S
3
CO2
3
µg/m
114
139
161
160
221
188
217
216
106
134
134
133
0.0
1.4
82
mg/m
788
794
858
858
852
855
932
928
921
919
870
870
810
806
910
164
596
78
50
106
130
78
78
884
880
847
841
976
976
873
867
SO2
3
NO
3
µg/m
21
21
58
58
57
57
5.2
5.2
5.3
5.3
5.2
5.2
178
126
16
mg/m3
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
68
68
57
57
5.3
5.3
5.2
5.2
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Table 7. Correlation coefficients between measured variables.
OUE
NH3
H2S
CO2
SO2
Int
HT
ODT
0.98
0.16
0.51
0.44
- 0.23
0.65
- 0.65
OUE
NH3
H2S
CO2
SO2
Int
0.18
0.52
0.36
- 0.24
0.67
- 0.65
0.28
0.28
0.19
0.20
- 0.18
0.30
- 0.07
0.50
- 0.51
- 0.27
0.29
- 0.09
- 0.13
0.06
- 0.73
Table 8. Mean concentrations and emissions of trace gases in BCFC outlet air.
Lagoon
A
A
A
A
A
A
B
B
B
B
B
B
A
B
Both
Emission
Date
4/28
6/15
6/22
6/29
7/20
7/27
5/4
6/1
6/8
6/19
7/19
7/25
Mean
Mean
Mean
Mean
Unit
ng/L
ng/L
ng/L
ng/L
ng/L
ng/L
ng/L
ng/L
ng/L
ng/L
ng/L
ng/L
ng/L
ng/L
ng/L
µg/s-m2
C2
10
99
1559
1674
1466
1525
32
50
2.8
588
404
957
1055
339
697
47
C3
5.2
10.0
9.9
14.9
8.9
12.3
11
2.9
2.8
7.3
3.7
6.5
10.2
5.8
8.0
0.54
iC4
2.0
0.5
0.0
1.5
0.9
0.3
1.9
0.8
3.5
0.1
1.1
0.3
0.9
1.3
1.1
0.07
C4
3.2
3.1
4.5
5.8
1.6
1.8
9.5
4.3
0.6
2.7
4.3
2.0
3.3
3.9
3.6
0.24
27
iC5
6.4
3.8
1.6
2.1
2.0
1.2
11.1
6.0
4.8
1.8
6.7
2.0
2.9
5.4
4.1
0.28
C5
6.5
6.4
2.7
3.3
5.3
4.0
4.2
0.0
2.5
3.2
1.9
3.4
4.7
2.5
3.6
0.24
PL
2.7
3.2
1.6
1.4
3.7
0.9
2.1
1.0
3.4
1.5
1.7
1.5
2.3
1.9
2.1
0.14
PC
0.7
0.5
0.2
0.3
6.3
0.3
0.7
0.0
1.7
0.4
4.4
2.1
1.4
1.5
1.5
0.10
IND
0.0
0.5
4.0
1.5
0.1
0.5
0.0
0.0
1.3
0.2
0.4
0.2
1.1
0.4
0.7
0.05
SKA
1.0
0.7
2.1
2.2
0.7
0.7
0.0
0.0
0.9
0.5
0.5
0.3
1.2
0.4
0.8
0.05
Table 9. Characteristics of lagoon influent.
Lagoon Date
TKN NH4+-N
TS
P
VS
pH
mg/L
mg/L
%
mg/L
%
C2
C3
iC4
C4
iC5
C5
Total
Volatile Fatty Acids, mM/L
A
A
4/28
7/20
8.2
7.9
3262
1399
2787
1328
1.39
1.54
49.9
40.3
4.19
4.38
51.5
25.0
6.41
1.99
1.24
0.46
2.5
0.8
0.90
0.43
0.29
0.09
62.8
28.8
B
B
5/4
7/25
8.4
7.3
475
1549
450
1178
0.41
2.38
43.0
30.9
4.47
0.00
9.2
32.1
0.77
7.11
0.10
0.84
0.5
2.9
0.18
0.81
0.13
0.51
10.9
44.3
A
Mean
8.0
2331
2058
1.47
45.1
4.28
38.3
4.20
0.85
1.7
0.66
0.19
45.8
B
s.d.
Mean
0.2
7.8
1317
1012
1032
814
0.11
1.40
6.9
37.0
0.14
2.24
18.7
20.7
3.12
3.94
0.55
0.47
1.2
1.7
0.33
0.50
0.14
0.32
24.1
27.6
Both
s.d.
Mean
0.7
7.9
759
1671
515
1436
1.39
1.43
8.6
41.0
3.16
3.26
16.2
28.6
4.48
3.06
0.52
0.60
1.7
1.3
0.44
0.50
0.27
0.17
23.6
34.2
s.d.
0.5
1162
979
0.81
7.9
2.18
17.5
3.16
0.49
1.2
0.33
0.19
22.1
Table 10. Characteristics of lagoon effluent.
TKN
NH4-N
TS
P
VS
mg/L
1083
1076
1143
1046
978
%
0.5
0.5
0.5
0.4
0.4
mg/L
67.9
67.4
63.9
68.5
69.2
%
2.58
2.65
2.93
2.54
2.44
1006
357
350
367
326
310
387
1055
59
350
28
702
371
0.4
0.3
0.3
0.6
0.3
0.3
0.3
0.45
0.02
0.34
0.11
0.39
0.09
67.9
56.6
62.4
68.1
55.5
47.2
48.0
67.5
1.9
56.3
8.1
61.9
8.1
2.63
3.51
3.02
2.57
3.61
4.29
4.25
2.63
0.16
3.54
0.68
3.08
0.67
Lagoon
Date
pH
A
A
A
A
A
4/28
6/15
6/22
6/29
7/20
8.0
8.1
8.1
8.1
8.1
mg/L
1119
1537
1422
1311
1072
A
B
B
B
B
B
B
A
A
B
B
Both
Both
7/27
5/4
6/1
6/8
6/19
7/19
7/25
Mean
s.d.
Mean
s.d.
Mean
s.d.
8.2
8.0
8.1
8.0
8.1
8.1
7.9
8.1
0.1
8.0
0.1
8.1
0.1
1176
383
374
414
628
388
417
1273
183
434
97
853
460
28
Table 11. Daily means of odor characteristics of BCFC inlet and outlet samples.
OU/m3
Lagoon Date
A
A
A
A
A
A
B
B
B
B
B
B
4/28
6/15
6/22
6/29
7/20
7/27
5/4
6/1
6/8
6/19
7/19
7/25
Arithmetic
inlet
outlet
60
80
212
314
89
231
343
417
227
425
345
309
23
50
60
104
39
113
130
168
232
265
27
35
OUE/m3
Arithmetic
Geometric
inlet
outlet
inlet
outlet
169
229
163
223
271
401
259
400
179
467
177
466
562
685
555
646
363
678
346
669
552
494
546
492
56
122
55
114
83
145
82
141
54
157
52
157
199
258
182
237
310
355
305
331
51
66
50
59
Geometric
inlet
outlet
57
78
203
313
87
230
338
393
217
419
341
307
23
47
59
101
37
113
118
154
228
248
27
31
Int1
out
1066
1953
2234
5969
1766
1781
1091
1589
905
1344
1820
1115
HT
out
- 2.5
- 3.7
- 3.8
- 4.7
- 2.4
- 3.6
- 2.1
- 1.5
- 0.7
- 1.2
- 1.7
- 1.4
Int1
HT
1282
1134
2188
5531
- 1.2
- 1.9
- 3.3
- 4.1
2089
1381
543
2219
718
2243
773
1250
- 1.8
- 3.7
- 0.4
- 1.5
- 0.3
- 0.8
- 1.3
- 0.3
1
: ppm BIW.
Table 12. Daily means of odor characteristics of downwind berm samples.
Lagoon
Date
n-butanol
ODC, ppb
A
A
A
A
4/28
6/15
6/22
6/29
114
51
81
66
A
A
B
B
B
B
B
B
7/20
7/27
5/4
6/1
6/8
6/19
7/19
7/25
64
64
97
56
56
61
54
75
Concentration, OU/m3
Arithmetric
Geometric
57
57
145
124
210
209
150
150
72
173
20
65
49
23
41
57
72
171
20
64
48
23
40
55
1
: ppm BIW.
29
Concentration, OUE/m3
Arithmetic
Geometric
163
162
185
159
424
424
246
246
115
278
49
90
69
36
55
108
115
274
48
90
67
35
54
103
Table 13. Individual measurements of odor and gas emissions at lagoon A.
Date
Loc
4/28
4/28
4/28
4/28
6/15
6/15
6/15
6/15
6/22
6/22
6/22
6/22
6/29
6/29
6/29
6/29
7/20
7/20
7/20
7/20
7/27
7/27
7/27
7/27
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
Odor
OU/s-m2
0.1
1.5
3.1
3.4
11
9.2
0.1
8.7
11
10
9.8
7.3
16
4.4
0.1
0.1
17
21
5.3
9.4
0.1
0.1
0.1
0.1
NH3
µg/s-m2
18
37
47
94
226
150
164
226
186
145
173
280
131
187
122
117
188
160
208
71
128
132
245
103
H2S
µg/s-m2
11
15
15
15
7.4
13
3.7
3.9
7.4
9.3
5.7
5.6
17
15
5.5
5.5
9.4
9.4
7.5
7.5
9.3
9.4
5.6
5.7
30
CO2
µg/s-m2
2411
- 371
2089
1461
1094
2154
1304
2432
2074
220
2525
966
1408
346
437
1333
1610
1290
1935
881
1600
1073
180
901
SO2
µg/s-m2
0.0
0.0
0.4
0.0
3.9
3.5
0.0
0.4
0.0
0.0
0.0
0.0
3.5
3.5
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
NO
µg/s-m2
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
8.1
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Table 14. Individual measurements of odor and gas emissions at lagoon B.
Date
Loc
5/4
5/4
5/4
5/4
6/1
6/1
6/1
6/1
6/8
6/8
6/8
6/8
6/19
6/19
6/19
6/19
7/19
7/19
7/19
7/19
7/25
7/25
7/25
7/25
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
Odor
OU/s-m2
0.1
1.2
3.7
2.6
3.8
0.5
5.7
2.1
6.6
5.0
4.6
3.7
2.9
0.8
1.0
5.8
11
0.1
3.7
0.1
0.1
0.1
2.7
0.4
NH3
µg/s-m2
65
18
- 0.4
- 29
9.2
98
44
30
84
56
159
- 19
38
38
56
206
- 19
- 28
66
66
9.2
9.1
263
93
H2S
µg/s-m2
4.2
3.9
1.5
1.9
17
- 5.7
- 3.2
0.0
8.3
7.4
9.3
15
- 9.1
- 3.7
- 2.0
- 5.6
5.6
5.8
7.5
17
- 4.6
- 1.8
- 7.4
- 5.6
31
CO2
µg/s-m2
1767
- 2689
640
1348
2201
1746
877
1604
1098
648
945
615
495
- 199
264
- 353
915
241
28
- 340
- 60
- 91
- 1948
- 212
SO2
µg/s-m2
3.5
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
3.9
1.4
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
NO
µg/s-m2
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Table 15. Daily means of odor and gas emissions at lagoons A and B.
Date
Loc
4/28
6/15
6/22
6/29
7/20
7/27
5/4
6/1
6/8
6/19
7/19
7/25
A
A
A
A
A
A
B
B
B
B
B
B
Odor
OU/s-m2 OUE/s-m2
2.0
5.6
7.3
9.4
9.6
19
5.1
8.3
13
21
0.1
0.1
1.9
4.6
3.0
4.2
5.0
6.9
2.6
4.0
3.8
5.1
0.8
1.5
NH3
µg/s-m2
49
191
196
139
157
152
13
45
70
84
21
94
H2S
µg/s-m2
14
7.0
7.0
11
8.5
7.5
2.9
2.0
10
- 5.1
9.0
- 4.8
32
CO2
µg/s-m2
1397
1746
1446
881
1429
939
266
1607
826
52
211
- 577
SO2
µg/s-m2
0.1
1.9
0.0
1.8
0.0
0.0
0.9
0.0
1.3
0.0
0.0
0.0
NO
µg/s-m2
0.0
0.0
0.0
0.0
2.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Table 16. Summary of results.
Variable
Water temperature, °C
N-butanol ODC, ppb
Lagoon Berm
Odor intensityg, ppm BIW
Hedonic a tone
Odorg, OU/m3
Odorg, OUE/m3
Ammonia, mg/m3
Hydrogen sulfide, mg/m3
Carbon dioxide, mg/m3
Sulfur dioxide, mg/m3
Nitric oxide, mg/m3
BCFC Inlet
Odor intensityg, ppm BIW
Hedonic a tone
Odora, OU/s-m3
Odora, OUE/m3
Odorg, OU/s-m3
Odorg, OUE/m3
Ammonia, mg/m3
Hydrogen sulfide, mg/m3
Carbon dioxide, mg/m3
Sulfur dioxide, mg/m3
Nitric oxide, mg/m3
BCFC Outlet
Air temperature, °C
Odor intensityg, ppm BIW
Hedonic a tone
Odora, OU/m2
Odora, OUE/m2
Odorg, OU/m2
Odorg, OUE/m2
Ammonia, mg/m3
Hydrogen sulfide, mg/m3
Carbon dioxide, mg/m3
Sulfur dioxide, mg/m3
Nitric oxide, mg/m3
Emission Rates
Odora, OU/s-m2
Odora, OUE/s-m2
Odorg, OU/s-m2
Odorg, OUE/s-m2
Ammonia, µg/s-m2
Hydrogen sulfide, µg/s-m2
Carbon dioxide, µg/s-m2
Sulfur dioxide, µg/s-m2
a
: Arithmetic mean, g: Geometric mean
Lagoon A
Mean
95% CI
25
1.6
71
7.5
Lagoon B
Mean 95% CI
25
0.9
65
5.9
Both
Mean 95% CI
25
0.9
67.8
4.7
2268
- 2.7
118
210
4.1
160
870
25
0.0
1622
0.69
40
66
0.6
25
29
15
0.0
1060
- 0.76
38
62
3.4
124
879
54
0.0
573
0.36
40
17
0.7
104
36
36
0.0
1404
- 1.7
67
114
3.8
143
875
39
0.0
581
0.6
22
38
0.5
49
22
19
0.0
2077
- 2.8
212
349
171
303
2.8
185
889
25
0.0
719
0.4
52
76
52
71
0.2
24
26
10
0.0
1205
- 0.9
85
126
57
93
3.3
158
906
38
0.0
242
0.3
34
45
22
30
0.5
30
24
16
0.0
1582
- 1.8
149
238
99
168
3.0
171
898
32
0.0
408
0.4
36
54
28
44
0.3
19
17
9.3
0.0
27
3026
- 3.4
296
492
257
455
5.0
320
908
34
0.0
1.1
682
0.4
58
83
66
80
0.4
31
25
14
0.0
29
1375
- 1.4
123
184
93
151
4.1
192
912
44
0.0
2.1
266
0.3
39
51
31
42
0.6
52
25
17
0.0
28
2040
- 2.4
209
338
155
262
4.5
256
910
39
0.0
1.2
454
0.4
43
66
40
60
0.4
35
18
11
0.0
6.2
10.7
1.8
2.7
147
9.1
1306
0.6
2.6
4.2
1.9
3.2
28
1.6
325
0.6
2.9
4.4
1.3
1.9
55
2.3
398
0.4
1.2
1.6
0.9
1.5
30
3.2
462
0.4
4.6
7.5
1.5
2.3
101
5.7
852
0.5
1.5
2.4
0.9
1.5
24
2.0
307
0.4
33
Table 17. Summary of emissions from swine facilities or pig slurry in the literature.
ODTg Odor Emissiong NH3
Authors
Type of source
OU/m3 OU/s-AU OU/s-m2 µg/s-m2
This study
Anaerobic lagoons
155
24
1.5
101
Harper et al., 2000
Anaerobic lagoon
14.0
Aneja et al., 2000
Anaerobic lagoon
109-163
Heber and Ni, 1999 Anaerobic lagoons
3.1
Aerobic lagoon
89-123
24
1.7
Lim et al., 2000a
Nursery buildings
190g
34
2.0
Zhu et al., 1999
Nursery buildings
50max
Finishing house
170 max
Heber et al., 1998
Finishing buildings
142
36
5.0
Jacobson et al., 1999 Manure earthen basins 76-299
2.2-18
Schmidt et al., 1999 Manure storage basin 134-588
16-180
Hobbs et al., 1999
Stirred slurry
1.34x104 50
Stirred slurry
2.25x104
Ni et al., 2000a
Finishing building
162
Ni et al., 2000b
Empty buildings
24-58
Ni et al., 2000c
Lab manure reactor
: maximum value. ODTg and Odor Emissiong: geometric means.
max
34
H2S
CO2
SO2
2
2
µg/s-m µg/s-m µg/s-m2
5.7
852
0.5
140 max
2.9-43
7.8-48
771
7,245
1.3-2.1 778-1389
0.2-0.4
0.1
Airflow path
Figure 1. View of underside of BCFC and hairpin airflow path.
Sampling drums
BCFC
Air supply duct
Air supply unit
Figure 2. BCFC, air supply duct, air supply unit and bag sampling drums.
35
Figure 3. Downwind air sampling at the lagoon berm.
600
Inlet
Outlet
Berm
Odor Concenration, OU/m3
500
400
300
200
100
0
A1
A2
A3
A4
A5
A6
B1
B2
B3
B4
B5
B6
Sampling Visit
Figure 4. Geometric mean odor concentrations at each sampling visits.
The error bars indicate the 95% confidence intervals.
36
10
NH3 Concenration, mg/m
3
inlet
outlet
8
6
4
2
0
A1
A2
A3
A4
A5
A6
B1
B2
B3
B4
B5
B6
Sampling Visit
Figure 5. Mean BCFC outlet concentrations of ammonia at each sampling visit.
600
inlet
outlet
H2S Concenration, µg/m
3
500
400
300
200
100
0
A1
A2
A3
A4
A5
A6
B1
B2
B3
B4
B5
B6
Sampling Visit
Figure 6. Mean BCFC outlet concentrations of hydrogen sulfide at each sampling visit.
37
Odor Concentration, OU/m3
800
600
ODT = 0.66x1.00
R2 = 0.38
400
200
0
0
100
200
300
400
500
H2 S Concentration, µg/m3
600
Figure 7. Odor and hydrogen sulfide concentrations for all inlet and outlet BCFC samples.
Odor Intensity, BIW, ppm
10000
1000
0.39
BIW = 278ODT
2
R = 0.39
100
10
100
1000
3
Odor Concentration, OU/m
Figure 8. Odor intensity and concentration for all inlet and outlet BCFC samples.
38
25
40
Air
Water
30
15
10
20
Temperature, o C
Odor Emission, OU/s-m2
Odor
20
5
0
10
A1
A2
A3
A4
A5
A6
B1
B2
B3
B4
B5
B6
Sampling Visit
Figure 9. Mean odor emissions and temperatures at each sampling visit.
300
NH3 Emission, µg/s-m2
250
200
150
100
50
0
A1
A2
A3
A4
A5
A6
B1
B2
B3
B4
B5
Sampling Visit
Figure 10. Mean ammonia emissions at each sampling visit.
39
B6
H2 S Emission, µg/s-m2
20
15
10
5
0
A1
A2
A3
A4
A5
A6
B1
B2
B3
B4
B5
B6
Sampling Visit
Figure 11. Mean hydrogen sulfide emissions at each sampling visit.
40