Hongwei Xin

Reduction of Ammonia Emission from Stored Poultry Manure Using Additives: Zeolite, Al+clear, Ferix-3 and PLT

Manure storage can be a significant source of ammonia emission that impacts the environment. Ammonia emission from manure storage can be controlled by using physical, chemical and/or biological methods. Five treatment agents, including zeolite, liquid Al+Clear (aluminum sulfate), granular Al+Clear (aluminum sulfate), and granular Ferix-3 (ferric sulfate), and PLT (sodium hydrogen sulfate) were topically applied to stored fresh layer manure. Each agent was tested at three application rates, i.e., low, medium and high. Manure was stored in 19-litter Teflon-lined vessels under a constant ambient temperature of 23 oC with a constant airflow of 3 liter per minute. The ammonia concentrations and emissions from the vessels were measured and ammonia emission reductions by the treatment regimens were evaluated as compared to the control. Reduction of ammonia emission as a result of topical application of the tested manure treatment agents, when compared to the control, over a 7-day manure storage period was as following: A) 68%, 81% or 96%, respectively, for zeolite applied at 2.5%, 5% or 10% of the manure weight; B) 63%, 89%, or 94%, respectively, for liquid Al+Clear applied at 1, 2, or 4 kg m-2 of manure surface area; C) 81%, 93%, or 94%, respectively, for dry granular Al+Clear applied at 0.5, 1.0, or 1.5 kg m-2; D) 82%, 86%, or 87%, respectively, for Ferix-3 applied at 0.5, 1.0, or 1.5 kg m-2; and E) 74%, 90%, or 92%, respectively, for PLT applied at 0.5, 1.0, or 1.5 kg m-2.

Development and Testing of a Fan Monitoring System Using Induction Operated Current Switches

Emissions of gaseous compounds and particulate matter are the product of the pollutant concentrations and air exhausted from the fans of mechanically ventilated animal confinement buildings. Direct methods of monitoring exhaust fan operation (i.e., mercury tilt, limit or whisker, and vibration switches) have been reported to have limitations due to mechanical failure and/or the effect of the environment (dust, wind, moisture). Another method involves monitoring the control relay status at the fan system control box. A problem could occur at the fan but not in the signal at the control box, thereby giving a false operational signal. The objective of this project was to find a more reliable method of monitoring fan operation status. This paper describes the development, lab testing, and use of a fan monitoring system based on induction operated current switches (ICS). ICSs are unaffected by the environment and can provide direct measurement of real-time fan operational status by sensing AC current. A laboratory test of the ICS was performed to simulate a fan off/on duty cycle in a two-year emissions study; no ICS failure was recorded. The Southeastern Broiler Gaseous and Particulate Matter Emission study led by Iowa State University has been using 28 ICSs for over 190 days without a failure. At a unit cost as low as

Evaluation of a Flux Chamber for Assessing Gaseous Emissions and Treatment Effects of Poultry Manure

19.50 this method offers a reliable, accurate, and economical way of measuring the real-time operational status of ventilation fans – a critical component of any air emissions monitoring in a mechanically ventilated confinement system.

Use of CO2 Concentrations or CO2 Balance to Estimate Ventilation Rate of Modern Commercial Broiler Houses

The need to quantify air emissions from animal feeding operations (AFOs) with relative ease and reasonable certainty continues to rise. Exploration of practical means to reduce air emissions also calls for less sophisticated but reasonably dependable methods to quantify the treatment effect. Although mobile air emissions monitoring units (MAEMUs) capable of precise and real-time emission measurement is the norm for continuous, intensive monitoring of emissions from mechanically ventilated animal facilities, their relative immobility and high cost are limiting the widespread use. Several other methods, such as gas-washing, micro-meteorological, wind tunnel, flux chamber, and mass-balance methods, have been employed to accommodate different measurement needs. Flux chambers have the advantages of being portable, small size, low cost, and less labor requirement. The objectives of this study were: (1) to develop a portable emission flux chamber system (EFC) for in-situ measurement of ammonia (NH3) and carbon dioxide (CO2) emissions from manure; (2) to assess gaseous (NH3 and CO2) emissions of high-rise layer houses with the EFC vs. MAEMU; and (3) to evaluate the adequacy of using the EFC to determine the effects of dietary regimens on ammonia emissions from the layer manure. The preliminary data showed that NH3 emission from the manure surface measured with the EFC was 8% to 16% that of the whole barn measured with the MAEMU, while CO2 emission from the manure surface was 1% to 4% of the barn emission. The preliminary results obtained with EFC concerning the dietary efficacy of ammonia emission reduction were mixed as compared to those obtained with the MAEMU. More evaluation is continuing.

Effects of dietary modification on laying hens in high-rise houses: Part I - Emissions of ammonia, hydrogen sulfide and carbon dioxide.

Ventilation rate (VR) is one of the two key elements for quantifying aerial emissions from animal production facilities. Direct measurement of building VR can be challenging and impractical under certain circumstances, e.g., naturally ventilated animal housing. This study delineates VR of broiler houses with build-up litter as estimated via CO2 balance or building CO2 concentration. The indirectly derived VR compared favorably with the directly measured VR. Specifically, integration time of 30 min or longer leads to non-significant differences in VR between the indirect and the direct methods (P>0.2). Omission of CO2 generation by the litter from total house CO2 production results in an overall 7% underestimation of the building VR. The indirect method provides a possible, viable alternative for quantifying VR of naturally ventilated broiler confinement.

Ammonia, Hydrogen Sulfide, and Greenhouse Gas Emissions from Wean-to-Finish Swine Barns Fed Diets with or without DDGS

Dietary manipulation can substantially lower ammonia (NH3) emissions from laying-hen houses or manure storage. Recent lab studies showed a reduction of 40–60% in ammonia emissions for an experimental (EcoCalTM) diet as compared the standard or control diet. However, adoption of a mitigation technology at commercial production level should be preceded by substantial field verification tests to document not only NH3 emission reduction, but also impact of the strategy on production performance of the hens and cash returns. A study to assess the effects of feeding diets containing EcoCal on NH3, hydrogen sulfide (H2S), and carbon dioxide (CO2) emissions, laying-hen production performance, and economic returns was conducted at a commercial laying-hen farm in central Iowa. Two houses (256,000 or 262,000 hens per house) were used for the study. Hens in one house were fed the EcoCal diet while hens in the other house were fed a standard or control diet containing no EcoCal. A state-of-the-art mobile air emissions monitoring unit (MAEMU) and the associated sampling system were used to continuously monitor the gaseous concentrations, ventilation rate and environmental conditions. Comparative data collected from December 2006 to May 2007 are presented in this paper. Data from this period showed that the EcoCal diet led to NH3 emission reduction by up to 23.2% (0.86±0.04 and 1.12±0.03 g/d·hen for EcoCal and Control diet, respectively), at the same time, H2S emission increased by up to 134% (4.38±0.20 and 1.82±0.07 mg/d·hen for EcoCal and Control diet, respectively), although the magnitude of H2S emission is rather small for both dietary regimens. Data on the hen production performance are reported in a companion paper (Roberts et al., 2008).

Particulate Matter Emissions from a High-rise Layer House in Iowa

In recent years the corn grain ethanol industry has expanded and led to increased availability of dried distillers grains with solubles (DDGS). As a result, feeding DDGS to swine is becoming more common in pork production. With feed being the primary cost in pork production and increasing interest in air emissions from animal feeding operations, it is important to understand the impacts of non-traditional dietary formulations on aerial emissions. The purpose of this study was to evaluate the impacts of feeding DDGS on ammonia (NH3), hydrogen sulfide (H2S) and greenhouse gas (GHG) emissions from deep-pit swine wean-to-finish (5.5 – 118 kg) facilities in Iowa, the leading swine producing state in the USA. To attain the study objectives, two commercial, co-located wean-to-finish barns were monitored: one barn received a traditional corn-soybean meal diet (designated as Non-DDGS regimen), while the other received a diet that included 22% DDGS (designated as DDGS regimen). Gaseous concentrations and barn ventilation rate (VR) were monitored or determined semi-continuously, and the corresponding emission rates (ER) were derived from the concentration and VR data. Two turns of production were monitored for this study, covering the period of December 2009 to January 2011. The daily and cumulative emissions are expressed on the basis of per barn, per pig, and per animal unit (AU, 500 kg live body weight). Results from this project indicate that feeding 22% DDGS does not significantly affect aerial emissions of NH3, H2S, CO2, N2O or CH4 when compared to the Non-DDGS regimen in a deep-pit wean-to-finish swine facility (p-value = 0.10 for NH3, 0.13 for H2S, 0.55 for CO2, 0.58 for N2O, and 0.18 for CH4). ER for the Non-DDGS regimen, in g/d-pig, averaged 7.5 NH3, 0.37 H2S, 2127 CO2 and 72 CH4. In comparison, ER for the DDGS regimen, in g/d-pig, averaged 8.1 NH3, 0.4 H2S, 1849 CO2, and 48 CH4. On the basis of kg gas emission per AU marketed, the values were 8.7 NH3, 0.724 H2S, 2350 CO2 and 84 CH4 for the Non-DDGS regimen; and 12 NH3, 0.777 H2S, 2095 CO2, and 60 CH4 for the DDGS regimen. Results of this extended field-scale study help filling the knowledge gap of GHG emissions and impact of DDGS on gaseous emissions from modern swine production systems.

Downstream Placement of FANS to Determine Fan Performance in Situ

Particulate matter (PM) in animal feeding operations is a concern for the occupants and the surrounding community. Baseline measurements of the concentration and emission rate of PM are the first step toward assessing the environmental impact of animal feeding operation and evaluating the effectiveness of dust control strategies. This study presents the results of the PM measurement at a high-rise layer house in central Iowa. The average PM10 emission rate over the 9-month measurement period was 21.6 (±10 S.D.) mg/bird/day. Comparing with the emission rates reported literature, the mean and range of PM10 emission from high-rise layer hen barns using cage systems were 33.5 and 19-48 mg/bird/day. The average PM2.5 emission rate over the measurement period was 2 (± 1.5 S.D.) mg/bird/day, which is less than literature values of 3.52-14.2 mg/bird/day.

Development and Testing of a Hydrogen Sulfide Detection System for Use in Swine Housing

Accurate ventilation rate data are essential to maximizing the quality of aerial emission measurements. The fan assessment numeration system (FANS) devices have been widely used by U.S. researchers in measuring aerial emissions from mechanically ventilated livestock and poultry confinement. It is used to conduct in-situ calibration of building ventilation fans and thus development of the fan performance curve under the field operation conditions. The FANS device was originally intended to be placed in the upstream of the fan under in-situ calibration. However, certain field situations make it impractical to apply the FANS device as such. This study assessed the possible use of the FANS in the downstream of a ventilation fan, with the gaps between the FANS device and the discharge cone of the exhaust fan sealed by non-permeable fabric. Nine exhaust fans (1.22 - 1.32 m diameter) in laying-hen and turkey houses were tested with the FANS placed in upstream or downstream for a building static pressure range of 10 to 40 Pa. The results revealed that downstream placement of FANS device yielded 0.44 to 3.1% higher ventilation rate when compared to its upstream placement. This discrepancy is considered acceptable for in-situ fan calibration.

Electricity and fuel usage of aviary laying-hen houses in the Midwestern United States.

Transient hazards to human and animal health can occur in swine barns due to sudden bursts of high concentration hydrogen sulfide (H2S) gas released when manure slurry is agitated during removal from sub-floor pits. Studies have shown that H2S levels can go from harmless to deadly in a matter of minutes during pit agitation (Patni and Clarke, 2003). From 1983 to 1990, H2S poisoning was responsible for the death of 24 swine workers in the Midwest alone and at least 15 more deaths since 1994 (Walinga, 2004). Swine slurry removal workers and producers report swine deaths every year from slurry agitation in sub-floor storage, or pits. Hence, a system that can reliably and promptly report H2S concentrations in swine housing without direct exposure of the operator(s) to the potentially hazardous environment is of socioeconomic importance to the swine producers. This paper describes the development and testing of a wireless, portable H2S detection system, followed by the use of the system under field conditions by slurry removal workers to monitor H2S levels during slurry agitation and removal in deep-pit swine housing systems in Iowa. The system developed in this study has a component cost of