Claude A. Diehl

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).

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.

Characteristics of ammonia and carbon dioxide releases from layer hen manure

1. Ammonia (NH3) is an important gaseous pollutant generated from manure in commercial poultry farms and has been an environmental, ecological, and health concern. Poultry manure also releases carbon dioxide (CO2), which is a greenhouse gas and is often used as a tracer gas to calculate building ventilation. 2. A 38-d laboratory study was conducted to evaluate the characteristics of NH3 and CO2 releases from layer hen manure using 4 manure reactors (122 cm tall, 38 cm internal diameter), which were initially filled with 66 cm deep manure followed by weekly additions of 5 cm to simulate manure accumulation in commercial layer houses. 3. The average daily mean (ADM) NH3 and CO2 release fluxes for the 4 reactors during the entire study were 161⋅5 ± 21⋅1 µg/s.m2 (ADM ± 95% confidence interval) and 10⋅0 ± 0⋅3 mg/s.m2, respectively. The daily mean NH3 and CO2 releases in individual reactors varied from 35⋅2 to 679⋅1 µg/s.m2 and from 6⋅6 to 20⋅5 mg/s.m2, respectively. 4. The ADM NH3 release flux was within the range of those obtained in 4 high-rise layer houses by Liang et al. (2005, Transactions of the ASAE, 48). However, the CO2 release flux in this study was about 10 to 13 times as high as the data reported by Liang et al. (2005). Fresh manure had greater NH3 release potential than the manure in the reactors under continuous ventilation. Manure with higher contents of moisture, total nitrogen, and ammonium in the 4th weekly addition induced 11 times higher NH3 and 75% higher CO2 releases immediately after manure addition compared with pre-addition releases.

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

Surfactant-assisted UV-photolysis of nitroarenes.

Photochemical transformations (lambda-254 nm) of 2,4-dinitrotoluene (2,4-DNT) in aqueous solutions containing the cationic surfactant cetyltrimethylammonium (CTA) and the anionic nucleophile borohydride (BH4-) were investigated. The overall decay rate was enhanced at CTA concentrations above the critical micelle concentration (cmc) when stoichiometric excess BH4- was present in solution. A kinetic model that separates the overall reaction rate into micellar and aqueous pseudo-phase components indicates transformation in micelles is 17 times faster that in the homogeneous water phase under those conditions investigated. Intermediate products were identified by comparing the HPLC retention times and ultraviolet-visible absorption spectra of product peaks to those of analytical standards. 2-Methyl-5-nitroaniline, 4-nitrotoluene, 2-nitrotoluene, 4-methyl-3-nitroaniline, 2,4-diaminotoluene, o-toluidine, 1,3-dinitrobenzene, 3-nitroaniline, p-cresol, and 2,4-diaminophenol were identified as photo-transformation intermediates or products.

Ventilation rates in large commercial layer hen houses with two-year continuous monitoring.

1. Ventilation controls the indoor environment and is critical for poultry production and welfare. Ventilation is also crucial for assessing aerial pollutant emissions from the poultry industry. Published ventilation data for commercial layer houses have been limited, and are mostly based on short-term studies, mainly because monitoring airflow from large numbers of fans is technically challenging. 2. A two-year continuous ventilation monitoring trial was conducted at two commercial manure belt houses (A and B), each with 250 000 layers and 88 130-cm exhaust fans. All the fans were individually monitored with fan rotational speed sensors or vibration sensors. Differential static pressures across the house walls were also measured. Three fan performance assessment methods were applied periodically to determine fan degradations. Fan models were developed to calculate house ventilations. 3. A total of 693 and 678 complete data days, each containing >16 h of valid ventilation data, were obtained in houses A and B, respectively. The two-year mean ventilation rates of houses A and B were 2·08 and 2·10 m3 h−1 hen−1, corresponding to static pressures of −36·5 and −48·9 Pa, respectively. For monthly mean ventilation, the maximum rates were 4·87 and 5·01 m3 h−1 hen−1 in July 2008, and the minimum were 0·59 and 0·81 m3 h−1 hen−1 in February 2008, for houses A and B, respectively. 4. The two-year mean ventilation rates were similar to those from a survey in Germany and a 6-month study in Indiana, USA, but were much lower than the 8·4 and 6·2 m3 h−1 hen−1 from a study in Italy. The minimum monthly mean ventilation rates were similar to the data obtained in winter in Canada, but were lower than the minimum ventilation suggested in the literature. The lower static pressure in house B required more ventilation energy input. The two houses, although identical, demonstrated differences in indoor environment controls that represented potential to increase ventilation energy efficiency, and reduce carbon footprints and operational costs.

Large scale application of vibration sensors for fan monitoring at commercial layer hen houses.

Continuously monitoring the operation of each individual fan can significantly improve the measurement quality of aerial pollutant emissions from animal buildings that have a large number of fans. To monitor the fan operation by detecting the fan vibration is a relatively new technique. A low-cost electronic vibration sensor was developed and commercialized. However, its large scale application has not yet been evaluated. This paper presents long-term performance results of this vibration sensor at two large commercial layer houses. Vibration sensors were installed on 164 fans of 130 cm diameter to continuously monitor the fan on/off status for two years. The performance of the vibration sensors was compared with fan rotational speed (FRS) sensors. The vibration sensors exhibited quick response and high sensitivity to fan operations and therefore satisfied the general requirements of air quality research. The study proved that detecting fan vibration was an effective method to monitor the on/off status of a large number of single-speed fans. The vibration sensor itself was

Assessment of Long-Term Gas Sampling Design at Two Commercial Manure-Belt Layer Barns

2 more expensive than a magnetic proximity FRS sensor but the overall cost including installation and data acquisition hardware was