Current Research

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Research Projects Related to Air Quality at Purdue University
December 15, 2005

 Ohio Project: Air Emissions from High Rise and Belt Battery Layer Barns in Ohio

This USDA-NRI study by Purdue University and Ohio State University involves 12 months of monitoring of PM10 and ammonia emissions from two deep pit layer barns and one belt battery layer barn located in Ohio . The study is required by a consent decree between the U.S. EPA Region 5 and Buckeye Eggs ( ) and is funded by the producer. The objectives are:

•  Quantify and characterize baseline emissions rates for two types of layer facilities.
•  Determine particulate (PM) and NH3 emissions from high-rise layer barns.
•  Demonstrate efficiency of a PM impaction system in a high-rise layer barn.
•  Demonstrate PM and ammonia emissions from a new variety of hens fed a new diet.
•  Evaluate an enzyme-based manure additive for reducing ammonia from chicken litter.
•  Evaluate a new feed additive for reducing ammonia from a high-rise layer barn.

One deep pit barn was untreated and the other deep pit barn had the PM and ammonia abatement. A cardboard particulate impaction system was tested for six months in the deep pit barn for reducing PM10. It reduced PM10 by about 39% (preliminary unpublished data) but failed structurally in the moist winter conditions. A commercial manure additive (EcoCureT) failed to reduce ammonia in laboratory tests and therefore was not tested in the field. A patented feed modification was introduced to one barn on December 3, 2004. The belt battery barn is being tested without replication and without measurement of external storage emissions.

The measurements, conducted between Aug. 1, 2004 and Jan. 31, 2005 using Purdue's two mobile laboratories, involve two analyzers (chemiluminescence and photoacoustic infrared) that redundantly measure ammonia for a total of 18 barn-months of data. A multipoint gas sampling system is used to present air samples sequentially every 10 minutes from six to seven exhaust locations per barn and ambient air. Two commercial chemiluminescence ammonia analyzers were compared for 10 days. Photoacoustic infrared is used to monitor carbon dioxide concentrations. Five tapered element oscillating microbalances (TEOM) monitor outside and barn exhaust air. Gravimetric samplers are used to measure total suspended particulate and were compared with the EPA Method 17 sampling method. Fan airflow is assessed by monitoring the ventilation stage relays, the vibration of each fan, the exhaust air velocity of several cold weather fans, and the barn static pressure. Each fan was tested with a calibrated portable fan tester. Process variables measured at each barn include manure pH and moisture content, house temperature and relative humidity, bird and worker activity, and operation of feeders, lights, pit fans, and manure belts. A weather station monitors wind speed and direction, solar radiation, and outdoor temperature and relative humidity. A final report of this project will be completed in Spring 2005.

CAELB Project: Characterization and Abatement of Ammonia, Particulate, Pathogen and Odor Emissions from Egg Production Facilities

 Scientific measurements and effective control of air emissions ( odor, pathogen, ammonia and dust) from egg production facilities have become an important research priority .

Therefore, the objectives of t his new collaborative (Purdue and OSU) project funded by USDA-NRI (start date March 1, 2005) are to:

•  Test the hypothesis that belt battery barns emit less air emissions than conventional deep pit barns with replicated field tests and establish emission factors for each type.
•  Quantify effects of litter composting, and wet scrubbers on air emissions from egg production facilities.
•  Transfer knowledge gained about air emission rates, emission factors, and mitigation efficacy information to poultry producers, researchers, regulators, and other stakeholders.

Air emission labs will monitor emissions for 12 months at two high-rise and two belt-battery layer barns, and at the compost operation for a total of 48 barn-months of data. State-of-the-art gas analyzers will cycle through the selected air sampling locations. Real-time PM monitors in the barns will measure specific size fractions of the airborne dust that are regulated by the EPA. These include particles less than 10 microns (PM10) and particles less than 2.5 microns (PM2.5). The presence of the E. Coli and Salmonella pathogens on dust samples will be observed. Odor concentrations will be determined using human subjects. B arn airflow will be monitored continuously. Manure samples will be analyzed for nitrogen, pH and moisture content. Wind speed and direction, solar radiation, b arn and outdoor temperature and humidity, bird and worker activity, and operation of feeders, lights, and manure belts will be monitored. Emission data will reveal trends related to season, bird age, climate, and management. Final results will be reported, published, and delivered to producers, researchers, and regulatory agencies via a special web site, scientific journals, conferences, extension bulletins, engineering guidelines, and special workshops.

RAF2 Project ( Indiana layer site)

•  Air Pollutant Emissions (APE) from Confined Animal Buildings (CAB) (USDA)
•  Improving Measurements of Dust and Ammonia Emissions from CAB (add-on National Center for Manure and Animal Waste Management )
•  Effect of Biocurtains on APE from a Poultry Building (add-on National Center for Manure and Animal Waste Management )
•  Air Quality Tests of Ag-D-Tox in Laying Houses (add on: Ag-D-Tox)
•  Tests of Layer Feed Additive in Laying House (add on: Rose Acre Farms)

This USDA-funded study involves five other universities to measure baseline emissions of odor, ammonia (NH 3 ), hydrogen sulfide (H 2 S), carbon dioxide (CO 2 ) and particulate matter (PM) from mechanically ventilated livestock buildings (Jacobson et al., 2003; 2004). The objectives are to: 1) quantify aerial pollutant emission rates from animal confinement buildings, and 2) provide valid baseline data on aerial emissions from standard U.S. livestock and poultry confinement buildings to regulators, producers, researchers, students, and other stakeholders.

The project is evaluating differences in emissions due to season of year, time of day, building design, growth cycle of the animals, and building management. Mobile laboratories housing continuous gas and PM analyzers are monitoring emissions from a pair of identical buildings for 15 months through winter 2003. Olfactometry is being used to measuring odor emissions. A total of 150 barn-months of data are being collected from six animal housing systems including pig farrowing, gestation, and finishing buildings and chicken layer and broiler facilities. Add-on studies at Indiana involved a biocurtain test, measurements of total suspended particulates, and tests of AgDetoxT and a modified feed for another 6 barn-months of data. A special data analysis program was developed with the help of RSLS Group of Companies, Calgary , Canada to process building emissions. Final results should be available late 2005.

Missouri Project

•  Measurement & Control of APE from Swine Houses in Missouri (EPA)
•  Measurement & Control of APE from Swine Finishing Houses (PSF)
•  Effect of Biocurtains on APE from a Swine Building (add on: National Center )
•  Effect of Misting of Essential Oils and Water on Air Emissions (add on: PSF)
•  Effect of Essential Oils on Swine Odor (add on: PSF)

This study with the University of Missouri involved collection of quasi-continuous emission measurements from two swine production buildings in Missouri (Heber et al., 2004) that was required by a federal consent decree (Maher, 2001). The goal was to obtain estimates of emission rates of several compounds from a "baseline" facility, as well as a facility where new technologies were installed. One barn was unaltered while the other one had a soybean oil sprinkling system. Each tunnel ventilated building housed 1,100 pigs. The barns were flushed with recycled lagoon effluent about 16 times daily. Tests were conducted from July, 2002 until October, 2003. Measured continuously were NH 3 , H 2 S, CO 2 , CH 4 , non-methane hydrocarbons, PM 10 , TSP, temperature, relative humidity, building static pressure, solar radiation, fan airflows, animal activity, and wind speed and direction. Odor emissions using olfactometry were also measured.

RAF1: Air Emissions from a Layer Barn

•  Air Sampling & Measurement Methods for Confined Animal Housing (EPA)
•  Improving Measurement of Emissions from Poultry Houses (add-on: EPA)
•  Odor, Gas and Dust Emission Factors for Caged-Layers (add on: Indiana )

The overall objective of this combined study funded by the U.S. EPA is to develop standard protocols for field sampling and measurement of odor, hydrogen sulfide, ammonia, particulate matter, and carbon dioxide emitted from livestock buildings (Heber et al., 2003; Lim et al., 2004). Baseline emissions were measured for six months (completed June 2002) at a 250,000-hen layer barn and spatial and temporal variation of concentrations and emissions were assessed, for a total of six barn-months. Long path FTIR, electrochemical, photoacoustic infrared and chemiluminescence ammonia analyzers were compared. H ydrogen sulfide and carbon dioxide were measured using pulsed-fluorescence, and infrared sensors, respectively. A carbon dioxide balance will be studied to evaluate its validity for back-calculating ventilation rate. Protocol for use of the tapered element oscillating microbalance (TEOM) for source measurements at livestock buildings was evaluated. Several operating parameters for the TEOM were tested and TSP, PM10 and PM2.5 were measured. Fan operation was monitored along with building static pressure. Accurate measurements of fan airflows were made possible by laboratory testing two fans at the University of Illinois to determine actual derated fan performance. A new FANS (fan assessment numeration system) unit developed by the ARS Poultry Research Unit, Mississippi State University was calibrated and used to measure airflow of several other fans in the barn. Nine large shrouded impeller anemometers were used to continuously monitor airflow rate and a small open impeller anemometer was pilot tested. Odor emission rates were measured using olfactometry. Two different odor sampling methods were compared and the effect of time of day was studied. Finally, concentrations of methane and non-methane VOCs in the exhaust air were measured. Data analysis is ongoing.

SERB Project

A wean-finish swine environmental research building (SERB) was constructed in 2004 for evaluating air quality control techniques, and for measuring and evaluating environmental abatement strategies for air emissions with more experimental control and replication than is possible in field studies. The SERB has a clean instrumentation room, and 12, 60-pig rooms with independent systems for ventilation, feeding, watering, and waste collection. Air temperatures and relative humidity, static pressure, heater, fogger and fan operation, and wind speed and direction are monitored. Real-time measurements of feed consumption and pig weights accurately document animal performance. Two funded projects using the SERB are as follows:

1. Diet Modifications to Reduce Nutrient Excretions and Enhance Air Quality in Swine Operations (USDA)

The overall goals of this project are to study new diet modifications that control waste nutrients and air emissions, develop and test models that predict nutrient outputs and odor emission based on genetics and diet, and to develop decision-making economic tools for the producers. Nutrition studies will be conducted to determine the effects of feed and management on odor emissions.

2. Baseline and Reduced Gas, Odor and Dust Emission Rates from Swine Wean-Finish Facilities (USDA, NPB)

The objectives of this USDA-NRI grant are to:

•  Establish baseline gas, dust and odor emissions from group-fed pigs housed in environmentally controlled facilities at different stages of growth and at different seasons of the year.
•  Conduct nutrition studies to determine the value of new diets formulated with highly available mineral sources (especially sulfur), enzymes, and protein availability and amino acid manipulation effects on excretion of odorous compounds or precursors of odorous compounds in manure, gases emissions and dust in group-fed pig housing facilities.
•  Determine the effect of manure storage time within a housing facility on gas, odor and dust emissions from the group-fed pig housing facilities.
•  Develop prediction models and economic analyses of diet manipulation and manure storage times on nutrient excretion, air quality, pig lean growth, and pork production economic stability and profitability.

BIOLAB Project: Gas Phase Revitalization using Biofilters in Advanced Life Support (ALS)

This is a subproject of a new 5-year NASA NSCORT project that began in early 2003. Studies will be conducted on air quality measurement, management and control for advanced life support systems in the planned space mission to Mars. In the ALS, we must convert carbon dioxide back into oxygen, control the levels of aerial contamination in the cabin, and treat gases from waste treatment systems. Trace contaminants include a variety of compounds, including ammonia, benzene, carbon monoxide, acetone, n-butanol, methanol, ethylene, methane, aldehydes, formaldehyde, and other VOCs. Biofiltration concepts used in industrial scale biofilters will be scaled down for the ALS. Proposed biofilters will be totally enclosed, and will utilize synthetic growth media. The objectives of the biofilter research and development effort are to optimize engineering and microbiological aspects of ALS biofiltration processes by delineating and addressing technical barriers associated with using biofiltration in space, identifying and optimizing system design parameters to maximize treatment efficiency, and evaluating new and emerging biofiltration technologies for application in ALS. Experiments will include both microscale and mesoscale tests to study microkinetics, mass transfer rates, transient responses, time delays, and microbial growth patterns. Continuous monitoring of input and output gas concentrations will allow evaluation of gas removal efficiencies and kinetic parameters of the process. A biofilter test lab for testing 24 biofilters simultaneously is nearly complete. An FTIR spectrometer is currently being calibrated for measuring ammonia, methane, carbon monoxide, acetone, n-butanol, and ethylene.

Analysis of Air Quality Data Collected in a High-Rise Swine Farrowing House

This study compared odor, ammonia and hydrogen sulfide emissions along with odor character at a High-RiseT farrowing facility, patented by Envirologic, compared with a conventional facility. The test was conducted in the Research & Technology Center, Consolidated Nutrition, L.C. in Decatur, Indiana from February to August 2001. The High-RiseT farrowing facility was set over a compost-generating manure storage system. Sixteen odor samples were taken on each of the three sampling days for a total of 48 samples. The study was replicated in February and July of 2001, therefore, 96 samples were collected. Odor concentration converted to European Odor Units (OU E /m 3 ) at the inlet, pig height and exhausts for the High-RiseT barn were about 26%, 54% and 45% lower (P<0.05) than those of the conventional barn, respectively. The average emissions for the five sampling days were 27 and 107 OU s -1 AU -1 for the High-RiseT and conventional barn, respectively. Jim Dunn of Consolidated Nutrition was the PI and presented the results at the 3rd International Conference on Air Pollution from Agricultural Operations in October, 2003.

•  Laboratory Testing of Manure Additives For Odor Control (NPB)
•  Test of an Additive for Municipal Sludge, and Swine and Dairy Manure
•  Test of an Additive for Municipal Sludge, and Beef and Dairy Manure
•  Test of an Additive for Laying Hen Manure

Controlled laboratory tests were conducted in 2000 to evaluate 35 commercial manure additives for control of odor and odorants. Swine manure was added to reactors at regular intervals during 42-d trials during which the reactors were held at 20°C and ventilated at 7 L/min. Ammonia, hydrogen sulfide and carbon dioxide emission from each reactor was measured automatically. Air samples were evaluated for trace gas and odor concentrations using gas chromatography and olfactometry, respectively. Initial and final manure characteristics were analyzed. In September, 2003 and March, 2004, 35-day tests were conducted for a local company using the same protocol.

Elimination of Emissions of Ammonia and Hydrogen Sulfide from Confined Animal and Feeding Operations (CAFO) using an Adsorption/Liquid-Redox Process with Biological Regeneration

This project with Technion - Israel Institute of Technology will develop and test an innovative pollution control method for swine and poultry buildings. The objectives:

•  Measure profiles and analyze available data on NH3 and H2S levels inside CAFOs, with specific accounting for vertical concentration variation above and below grated floors in swine houses and for gradients in the vertical direction near the litter in broiler and laying houses.
•  Design and test a dedicated air capturing system for the removal of waste air with relatively high contaminant concentrations from CAFOs.
•  Develop a physical-chemical-biological process for the conversion of both NH3 and H2S into environmentally-innocuous end-products.
•  Field demonstrate the integrated system and each of its sub modules.

National Air Emission Monitoring Study

The National Air Emission Monitoring Study (NAEMS) is required by a voluntary Consent Agreement between the U.S. EPA and participating livestock industries. The NAEMS is designed to provide quality-assured air emission data from representative swine, egg layer, dairy, and broiler farms. These benchmark data and accompanying analysis and interpretation will allow EPA and producers to reasonably determine which farms are subject to federal regulations. Following sound scientific principles and using proven instrumentation and methods, the NAEMS will collect new data from several farms and evaluate existing emissions data from other studies. Together, they will form a database to which additional studies of air emissions and effectiveness of control technologies can be compared and from which emission factors can be developed. The database will aid environmental consultants and air dispersion modelers to assess and reduce the impact these sources have on neighbors and the environment. Policymakers, regulators, the livestock industries and environmental groups will have increased understanding of air pollution from livestock production.

The specific objectives are to:
• Determine whether individual farms are likely to emit particulate matter (PM) and volatile organic compounds (VOC) in excess of applicable Clean Air Act thresholds.
• Determine whether individual farms are likely to emit ammonia ( NH 3 ) and hydrogen sulfide ( H 2 S) in excess of applicable Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) and Emergency Planning and Community Right-to-Know Act (EPCRA) reporting requirements.

At each of three egg farms and five production sites, an on-farm instrumentation shelter (OFIS) will house equipment for measuring pollutant concentrations at representative air inlets and outlets, barn airflows, operational processes and environmental variables. Sampling will be conducted for 24 months with data logged every 60 s. Data will be retrieved with network-connected PCs, formatted, validated, and delivered to EPA for subsequent calculations of emission factors. A multipoint gas sampling system will draw air sequentially from representative locations and deliver selected streams to a manifold from which on-line gas monitors draw sub samples. Mass concentrations of PM10 and PM2.5 will be measured at a representation exhaust location in each barn using real-time monitors. Total suspended particulate (TSP) will be measured gravimetrically.

Micrometeorological techniques will be used to estimate emissions of NH 3 and H 2 S from three swine lagoons, and a swine manure storage basin. This approach will use optical remote sensing downwind and upwind of the storage coupled with 3D and 2D wind velocity measurements. The concentrations of NH 3 and various VOC will be determined using scanning open path Fourier transform infrared spectroscopy. Measurements of H 2 S and NH 3 will be conducted using UV differential optical absorption spectroscopy. A monitoring team will conduct an 11-day test at each farm each quarter for two years.

The NAEMS will lead to funding for measurement of baseline air emission from other facilities and evaluation of newly developed mitigation technologies and management practices. It will also lead to funding to validate and develop air emission models, establish air quality and emission databases, and develop environmental impact decision support tools for producers, researchers and government agencies.

Facilities and Equipment at the Purdue Agricultural Air Quality Laboratory

  • On-farm instrument shelters with multipoint gas sampling systems (MGSS) (2)
  • Continuous emission measurement (CEM) lab with MGSS
  • Controlled environment manure reaction lab (40 reactors)
  • Biofilter test facility (24 biofilters)
  • 12-room swine environmental research building with MGSS
  • Data acquisition using Labview software and National Instruments hardware (6)
  • FTIR gas spectrometer with 18-L, 48-m path, gas cell
  • INNOVA 1314 Multigas Analyzer
  • Environmental gas chromatographs (2)
  • Chemiluminescence ammonia/NOx analyzers (4)
  • Fluorescence hydrogen sulfide/sulfur dioxide analyzers (4)
  • Photoacoustic infrared ammonia analyzers (3)
  • Carbon dioxide analyzers (4)
  • Methane/NMHC analyzer
  • Gas diluters (3)
  • DirecWay satellite dish
  • Permeation ovens (3)
  • Olfactometry laboratory
  • Bioaerosol sampling equipment (15 samplers)
  • Floating wind tunnel for measuring odor emission from liquid surfaces
  • Weather stations (2)
  • EPA Method 5/17 Graseby-Anderson Auto5 stack sampling system
  • Tapered Element Oscillating Microbalance (TEOM) units (5)
  • PM10 inlets (6)
  • PM2.5 inlets (1)
  • TSP inlets (3)
  • Outdoor enclosures for TEOM (2)
  • UIUC gravimetric TSP samplers (5)
  • Drager sampling pump
  • Personal sampling pumps (6)
  • Flow calibrators, 0-30 L/min (2)
  • Portable fan tester (University of Kentucky FANS unit)
  • Benchtop airflow tunnel with one AMCA flow nozzle up to six inches diameter.
  • Steam generator (12 lb/hr capacity).
  • St. Croix Sensory Nasal Ranger ® field olfactometer
  • Barneby and Sutcliffe Scentometer ® .


Brighton , W.D. 2004. Notice of Lodging of Consent Decree Under the Comprehensive Environmental Response, Compensation, and Liability Act. March 11. FR Doc. 04-5421. Federal Register 69(48. [ ].

Maher, R.E. 2001. Notice of Lodging of Consent Decree Pursuant to Comprehensive Environmental Response, Compensation, and Liability Act. December 27. FR Doc. 04-5421. Federal Register 69(48): 136. FR Doc. fr27de01-134 . Federal Register 66(248): 66935-66936.[ ].

Bueno, V. and M. Merkel. 2001. Premium Standard Farms, Inc., and Continental Grain, Inc., Civil Settlement. November 19, Office of Enforcement and Compliance Assurance.[]

Sachs, H.F., and J.C. Cruden. 2001. Consent Decree between United States of America and Citizens Legal Environmental Action Network, Inc. and Premium Standard Farms, Inc. and Continental Grain Company, Inc. Case No. 98-6099-CV-W-6. U.S. District Court, Western District of Missouri , United States of America . []


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