Teng T. Lim

EFFECTS OF MANURE REMOVAL STRATEGIES ON ODOR AND GAS EMISSIONS FROM SWINE FINISHING

Odor, ammonia (NH3) and hydrogen sulfide (H2S) concentrations, and emission rates were measured in two small rooms of finishing pigs with various manure removal strategies. The strategies included daily flush, and static pits with 7, 14, and 42 d manure accumulation cycles, with and without pit recharge with some secondary lagoon effluent after emptying. In each room, tests were conducted with three successive groups of 25 pigs, which were fed standard corn-soybean diets. Ammonia and H2S concentrations were measured automatically 15 to 24 times daily at various locations with chemiluminescence and pulsed fluorescence analyzers, respectively. Odor concentration, intensity, and hedonic tone of air samples were evaluated by a panel of eight trained subjects. Flushing and static pit recharge with lagoon effluent resulted in significantly less NH3, H2S, and odor emissions (P < 0.05). Draining static pits more frequently also significantly reduced H2S and odor emissions. Geometric mean odor emission rates were 19, 33, and 29 OUE s-1 AU-1 (OUE = European odor unit equivalent to 123 .g n-butanol, AU = 500 kg live mass) for the 1 d (daily flush), 7 d, and 14 d cycles without pit recharge, respectively, and 2.6 and 25 OUE s-1 AU-1 for the 7 d and 42 d cycles with pit recharge, respectively. Mean NH3 emission rates were 15, 27, and 25 g d-1 AU-1 for the 1, 7, and 14 d cycles without pit recharge, and 10, 12 and 11 g d-1 AU-1 for the 7, 14, and 42 d cycles with pit recharge, respectively. Mean H2S emission rates were 0.11, 0.27, and 0.41 g d-1 AU-1 for the 1, 7, and 14 d cycles without pit recharge, and 0.16, 0.34, and 1.42 g d-1 AU-1 for the 7, 14, and 42 d cycles with pit recharge, respectively. The mean H2S emission rate during daily flushing was 0.40 g d-1 AU-1 when flushing-induced burst emissions were included in the means, as compared with 0.11 g d-1 AU-1 when flushing times were excluded. Sudden emissions during flushing events had a significant influence on mean emissions from these relatively small rooms; however, without valid data from week 1, the mean H2S emission rate of 0.40 g d-1 AU-1 was probably an overestimate. Daily flushing reduced odor emissions by 41% and 34% (P < 0.05) as compared with the 7 d and 14 d cycles, respectively. The 7 d cycle resulted in 35% and 53% lower H2S emissions as compared with the 14 d cycle with and without pit recharge, respectively. The 14 d cycle had 76% less (P < 0.05) H2S emission than the 42 d cycle, both cycles with pit recharge. Mean daily NH3 emissions from the rooms with static pits were 51% to 62% lower (P < 0.05) with recharge than without recharge. Similarly, mean daily H2S emissions were 18% to 40% lower with pit recharge. In summary, lower NH3 and H2S emissions occurred when pits were recharged after emptying, and when pits were emptied more frequently.

CHARACTERISTICS AND EMISSION RATES OF ODOR FROM COMMERCIAL SWINE NURSERIES

Odor emission rates and characteristics were evaluated at two commercial swine nurseries in Indiana during the months of March, April, and May. The nurseries, housing 94 to 250 pigs, were mechanically ventilated with long–term manure storage pits under wire floors. Incoming ventilation air at one of the nurseries was tempered in a heated hallway. An eight–member odor panel evaluated odor concentration with a dynamic olfactometer and odor intensity and hedonic tone at full strength. The odor concentration of incoming ventilation air ranged from 7 to 85 odor units per cubic meter (OU m–3) and averaged 18 OU m–3. It ranged from 94 to 635 OU m–3 and averaged 199 OU m–3 in the ventilation exhaust air. The mean odor emission rates of the two nurseries were 18.3 and 62.5 OU s–1 AU–1 (1.1 and 2.7 OU s–1 m–2), respectively. The overall mean odor emission rate was 34 OU s–1 AU–1 (1.8 OU s–1 m–2). The measured emission rates are expected to be lower than those that follow stringent panel sensitivity requirements not currently required by olfactometry standards in the U.S.

EFFECT OF A MANURE ADDITIVE ON AMMONIA EMISSION FROM SWINE FINISHING BUILDINGS

The effect of a commercial manure additive (Alliance®) on ammonia (NH 3 ) emissions was evaluated in commercial 1000-head grow-finish swine buildings over a six-month period. The test was conducted in two treated and two control buildings at a modern swine-finishing site consisting of nine identical buildings. Automatic spray application systems in the treated buildings intermittently sprayed the additive onto the surfaces of the below-floor manure storages. Ammonia concentrations were measured with a chemiluminescence analyzer at three location groups in each building over 7 or 12 min periods every 1.0 to 1.5 h. Pit fan airflow rates were measured continuously with impeller anemometers. Wall fan airflow rates were calculated from fan pressure/airflow curves and measured static differential pressure between indoor and outdoor air. Nearly 7,000 data subsets from 332 building-days of testing were obtained for comparing NH 3 emission rates between control and treated buildings. The mean NH 3 emission rate per AU (animal unit or 500 kg live weight) from the treated buildings (96.4 g/day·AU) was 24% (P < 0.05) lower than the control buildings. The volume of additive solution was sufficient to dilute the fresh manure by 20%, but the effect of dilution only on NH 3 emission was not measured.

Air Quality Monitoring and On-Site Computer System for Livestock and Poultry Environment Studies

This article reviews the development of agricultural air quality (AAQ) research on livestock and poultry environments, summarizes various measurement and control devices and the requirements of data acquisition and control (DAC) for comprehensive AAQ studies, and introduces a new system to meet DAC and other requirements. The first experimental AAQ study was reported in 1953. Remarkable progress has been achieved in this research field during the past decades. Studies on livestock and poultry environment expanded from indoor air quality to include pollutant emissions and the subsequent health, environmental, and ecological impacts beyond the farm boundaries. The pollutants of interest included gases, particulate matter (PM), odor, volatile organic compounds (VOC), endotoxins, and microorganisms. During this period the research projects, scales, and boundaries continued to expand significantly. Studies ranged from surveys and short-term measurements to national and international collaborative projects. While much research is still conducted in laboratories and experimental facilities, a growing number of investigations have been carried out in commercial livestock and poultry farms. The development of analytical instruments and computer technologies has facilitated significant changes in the methodologies used in this field. The quantity of data obtained in a single project during AAQ research has increased exponentially, from several gas concentration samples to 2.4 billion data points. The number of measurement variables has also increased from a few to more than 300 at a single monitoring site. A variety of instruments and sensors have been used for on-line, real-time, continuous, and year-round measurements to determine baseline pollutant emissions and test mitigation technologies. New measurement strategies have been developed for multi-point sampling. These advancements in AAQ research have necessitated up-to-date systems to not only acquire data and control sampling locations, but also monitor experimental operation, communicate with researchers, and process post-acquisition signals and post-measurement data. An on-site computer system (OSCS), consisting of DAC hardware, a personal computer, and on-site AAQ research software, is needed to meet these requirements. While various AAQ studies involved similar objectives, implementation of OSCS was often quite variable among projects. Individually developed OSCSs were usually project-specific, and their development was expensive and time-consuming. A new OSCS, with custom-developed software AirDAC, written in LabVIEW, was developed with novel and user-friendly features for wide ranging AAQ research projects. It reduced system development and operational cost, increased measurement reliability and work efficiency, and enhanced quality assurance and quality control in AAQ studies.

The National Air Emissions Monitoring Study: Overview of Barn Sources

The National Air Emissions Monitoring Study (NAEMS) is required by a U.S. EPA air consent agreement, in which livestock producers agreed to collect air emission data in exchange for more time to report their emissions and apply for any necessary permits. Field measurement of livestock air emissions is a major part of the study. Compared with most previous field studies of barn air quality, the NAEMS was designed to have 1) several pollutants measured simultaneously including particulate matter (PM), ammonia (NH3), hydrogen sulfide (H2S), and non-methane volatile organic compounds (NMVOC), 2) a long duration of two years, 3) a large number of measured barns (38) using the same protocol, 4) careful selection of farms to enhance their representativeness, and 5) a high level of quality assurance and quality control as required by the U.S. EPA, which is supervising the study. The NAEMS is collecting continuous air emission data from 38 barns at five dairies, five pork production sites, three egg layer operations, one layer manure shed, and one broiler facility for a period of 2 years starting in 2007. At each barn monitoring site, an on-farm instrumentation shelter houses equipment for measuring pollutant concentrations at representative barn air inlets and outlets, barn airflows, operational processes, and environmental variables. A multipoint gas sampling system delivers selected air streams to gas analyzers. Mass PM concentrations are measured at one representative exhaust location per barn using real-time monitors. Motion sensors monitor activity of animals, workers and vehicles. Building ventilation rate is assessed by monitoring fan operation and building static pressure in mechanically ventilated barns, and air velocities through ventilation openings in naturally-ventilated buildings. Data is logged every 15 and 60 s and retrieved with network-connected PCs, formatted, validated, processed, and delivered to the U.S. Environmental Protection Agency (EPA).

AIR QUALITY MEASUREMENTS AT A LAYING HEN HOUSE: PARTICULATE MATTER CONCENTRATIONS AND EMISSIONS

Particulate matter (PM) was measured in the ventilation exhaust air of a caged layer house using three tapered element oscillating microbalances (TEOMs). Diurnal patterns of PM concentration and emission were observed during 6 days in June 2002. The average daily mean (±95% c.i.) concentrations and emissions were 39±8.0, 518±74, and 1887±563 .g/m3 and 1.1±0.3, 16±3.4, and 63±15 g/d-AU for PM2.5, PM10, and total suspended particulates (TSP), respectively. Daytime (lights on) PM2.5, PM10, and TSP concentrations were 151, 108, and 136% higher (P<0.05) than at night. Emissions peaked during the day when birds were most active and ventilation rates were the highest. Wide diurnal variations in PM concentration and ventilation were observed. PM emission was correlated to ventilation, ambient and exhaust temperatures, and relative humidity (P<0.05).

Field Tests of a Particulate Impaction Curtain on Emissions from a High-Rise Layer Barn

Particulate matter (PM) emission rates from two high-rise layer barns (barns 1 and 2) were measured from 1 August 2004 to 31 January 2005. A commercial particulate impaction curtain (PIC) was installed parallel to the first floor sidewalls and upstream of the exhaust fans of barn 2 for PM reduction by impaction. Tapered element oscillating microbalance (TEOM) monitors were used to measure PM10 (PM <10 µm) concentrations of barn 1 exhaust air and before and after the PIC in barn 2. Concentrations of total suspended particulate (TSP) were monitored at each location two to three times per week with a gravimetric sampler. Prior to the six-month full-scale test, a preliminary test of the PIC was conducted at a single continuous sidewall fan of barn 2 for 10 d. Results of the preliminary test indicated that the PIC reduced PM10 emission by 33% to 49% and TSP emission by 62% to 72%. In the full-scale test, average untreated daily mean PM10 emissions were 30 ±13 and 35 ±33 mg d-1 hen-1 (mean ±standard deviation) from barns 1 and 2, respectively. The mean treated PM10 emission rate was 22 ±23 mg d-1 hen-1 and was decreased by 41% based on measurements before and after the PIC. However, some dilution occurred due to backflow through non-operating fans. The TSP emission rate of barn 2 was 27 ±23 g d-1 AU-1, 39% lower than barn 1, which was 44 ±29 g d-1 AU-1. However, some important practical issues currently hinder the use of PIC in high-rise layer barns.

Hydrogen sulphide emission from two large pig-finishing buildings with long-term high-frequency measurements

SUMMARYHydrogensulphide(HS)isacommontoxicairpollutantandisemittedfromdecomposingmanureatanimalfacilities.However,therehavebeenonlyafewstudiesofHSemissionsfromanimalbuildings,especiallythoseinvolvinglong-term,high-frequencymeasurements.Inthecurrentstudy,HSemissionsfromtwo,1000-headpig-finishingbuildingsinIllinois,USA,weremonitoredwithahigh-frequencymeasurementsystemfor6monthsin1997duringtwo,partial,pig-growthcycles.Airsamplestreamswerecontinuouslytakenfromthepitheadspace,andthepitandwallfanexhaustair.HydrogensulphideconcentrationwasmeasuredateachlocationwithHSconvertersandsulphurdioxide(SO)analysersduring16or24samplingcyclesperday,resultingin4544samplingcyclesand219daysofreliabledata.Buildingventilationratewasthesummationofpitfanandwallfanairflowrates.Airflowratesoftheunderfloormanurepitfansweremeasureddirectlywithfull-sizeimpelleranemometersorcalculatedfromairflow voltagerelationshipsofthefans.Airflowratesofthewallfanswerecalculatedfromfanoperationanddifferentialstaticpressuredataandfanperformancecurves.MeanHSemissionwas059kg dayperbuilding,074g dayperm ofpitsurfacearea,or63g dayperanimalunit(AU 500kganimalweight).ThedeterminationofHSemissionperAUwasrestrictedto193dayswhenbuildingoccupancywasatleast700pigsperbuilding.HighertemperaturesandbuildingventilationratesresultedinsignificantlyhigherHSemissionsperAU.INTRODUCTIONHydrogensulphide(HS)isoneofseveralnoxiousgasesemittedbylivestockconfinementfacilities.Itisgeneratedfromanaerobicfermentationofmanure.Usually, the concentration of HS is very low inanimalhousescomparedwithothergaseouspollu-tantslikecarbondioxide(CO)andammonia(NH).ThemeanHSconcentrationwasabout127µg m inatypicallyventilatedpigbuildingandabout396µg mafter the ventilation was shut off for 6 hours(Muehling 1970) (Cited volumetric concentrationsfromoriginalpublicationswereconvertedtomassconcentrations assuming 20 C and 1013 10 Paatmosphericpressure.)ThemeanHSconcentrationin

CONTROL OF AIR EMISSIONS FROM SWINE FINISHING BUILDINGS FLUSHED WITH RECYCLED LAGOON EFFLUENT

The goal of this study was to evaluate the effects of 1) soybean oil sprinkling (SOS), 2) misting of essential oils (MEO), and 3) misting of essential oils and water (MEOW) on ammonia (NH3), hydrogen sulfide (H2S), non-methane hydrocarbons (NHC), total suspended particulate (TSP), particulate matter less than ten microns diameter (PM10), and odor. Baseline emissions of each variable are also presented. Measurements recorded at 1-min intervals were taken from 8/27/02 to 7/21/03 at two fan-ventilated swine finishing barns that were flushed daily with lagoon effluent. TSP and PM10 were monitored with real-time PM monitors. Gas concentrations were measured with one set of analyzers by time-sharing between both barns and ambient air. The tests consisted of four trials over three pig groups or cycles: SOS in the first and second cycles, MEO in the second cycle, and MEOW in the third cycle. The treated barn with SOS resulted in 40% less NH3, 60-63% less TSP, 68-70% less PM10, and in one trial, 30% less odor than the control barn. MEO and MEOW slightly improved hedonic tone of barn air. The mean concentration and emissions were: 1) 18 ppm (n=132) and 55 g/d-AU (n=125, AU=animal unit=500 kg) for NH3, 2) 98 ppb (n=153) and 0.72 g/d-AU (n=129) for H2S, 3) 259 ppb (n=98) and 3.3 g/d-AU (n=92) for NHC, 4) 1424 µg/m3 (n=73) and 6.07 g/d-AU (n=70) for TSP, 5) 334µg/m3 (n=83) and 1.6 g/d-AU (n=75) for PM10. The mean odor concentration and emission were 519 OU/m3 (508 OUE/m3) and 23.5 OU/s-AU (n=21). Odor, H2S and NH3 increased when flushing pits with effluent.

Real-Time Ventilation Measurements from Mechanically Ventilated Livestock Buildings for Emission Rate Estimations

A six-state USDA-IFAFS funded research project (Aerial Pollutant Emissions from Confined Animal Buildings, APECAB) was conducted with the purpose of determining hydrogen sulfide, ammonia, PM10, and odor emission rates from selected swine and poultry housing systems. An important aspect of emission studies is to be able to measure the mass flow rate of air through the housing system. For this research project, the decision was made to study only fan ventilated buildings due to the difficulty in estimated mass flow rates through naturally ventilated buildings. This paper highlights the various techniques used throughout the study to determine mass flow rate through fan ventilated swine and poultry housing systems.