Project Background
Dust and odor emissions from tunnel ventilated poultry houses have been identified as a significant environmental issue for the US poultry industry, especially when poultry operations are located close to residential, commercial or recreational areas. The recent expansion of the poultry industry in Texas along with the increasing trend of people moving out into rural areas has led to the increased number of odor related complaints. In order to mitigate these complaints, new methods or technologies for abating environmental pollutants are needed. Numerous technologies are available on the market, but are expensive and lack sound pollutant reduction data that would allow producers to make an informed decision about purchasing such equipment. Odor, particulate matter (PM) and gas (ammonia, hydrogen sulfide, volatile organic compounds etc.) emissions can have potentially harmful effects on the environment and/or human and bird health and are the primary pollutants of concern. Poultry producers are under increasing pressure to reduce those impacts and need cost-effective solutions.
A patented Electrostatic Particle Ionization (EPI) system used in conjunction with a BioCurtain have shown promise for reducing ammonia and PM emissions from poultry facilities; however, there is little scientifically supported evidence to validate the claims associated with the EPI or BioCurtain systems. Moreover, information on the performance, costs, operational requirement, benefits, and limitations of these technologies in different climatic condition are yet to be determined. The EPI technology utilizes an array of sharp-pointed stainless steel electrodes charged to -30kV (DC) to induce an electric field that negatively charges air ions, which are then attracted to grounded surfaces. The system is current-limited to no more than 2 mA to ensure worker and animal safety. The BioCurtain technology for reducing dust and odor consists of a metal frame structure covered with a woven geotextile fabric and functions by settling airborne dust particles on the ground after they are exhausted from the barn.
Project Work Plan
This project has been designed as the first in a two-phase project that will design, install and verify the ability of two air pollution abatement BMPs. The second phase will be performed at a later date and will demonstrate the ability of the installed and verified air pollution abatement BMPs to mitigate emissions from an individual house at a commercial scale broiler operation as compared to air emissions from a separate, yet co-located individual house not equipped with the demonstrated BMPs. The paired-plot scenario will utilize two identically designed (500' X 46') and ventilated poultry barns at the same operation that are interior houses on the farm but not adjacent to each other, are populated with similar numbers of birds and utilize the same climate control strategy. One barn will be utilized as a control while the other barn will be the treatment. The barns will be bedded with new litter if possible to exclude the effect of bedding material age on gas emissions; this will also help to investigate the effect of litter aging on gas emissions from the control barn. Cleaning frequency and treatment method/processes will also be similar for both treatment and control barns. The management of both barns will be identical and will be congruent with the cooperating producer's typical management strategies. The total number of birds will be the only potential difference as a result of bird mortality throughout the flock's progression.
- Phase I
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The first phase of this project will focus on identifying a cooperating producer, conducting on-site an evaluation of the operation and selecting the treatment and control houses. Houses that are located in the interior on the farm but not adjacent to each other will be selected for the installation of the BMPs. Two individual BMPs will be installed on the treated house. The first will be the EPI system that utilizes a series of negatively charged electrodes to charge air particles and cause them to be attracted to grounded surfaces. The second BMP is a BioCurtain consists of a metal frame covered with a woven geotextile fabric. Air is forced through this fabric and restricts dust particles causing them to fall to the ground.
Following BMP installation, trial tests of the BMPs will be conducted to verify that each system is functioning properly. Initial effectiveness measurements will also be taken to verify that the monitoring plan to be used in Phase 2 of the project is sufficient. Additionally, an interim report will be developed that provides a brief, yet all inclusive summary of the costs that a producer would realize if they chose to implement this dust and odor BMP mitigation system. This report will include initial capital costs, shipping, installation, any retrofitting costs incurred during the installation process. This interim report will not include operation and maintenance costs.
To test the effectiveness of EPI and BioCurtain systems, a monitoring system that quantifies a wide variety of air quality constituents will be employed. Ammonia (NH3) and hydrogen sulfide (H2S), odor causing volatile organic compounds (VOCs), and total suspended particulate matter (TSP) will be measured in both treatment and control barns simultaneously. Air samplers for measuring NH3 (continuous measurements) and H2S concentrations (continuous and periodic measurements with handheld monitors) and), VOCs (sorbent tubes and a GC-MS olfactometer), and TSP (TEOM continuous samplers and low volume TSP samplers) will be collocated inside and outside the treatment and control barns at 4-6 feet above the barn floor, 3-4 fan diameters upwind of all exhaust fans, at the BioCurtain openings outside the barn, and 4-5 diameters downwind of all fans.
Barn temperatures, relative humidity and static pressure changes with and without treatments will be measured. Litter samples will be taken during the course of each experiment to analyze for nitrogen, moisture and organic matter. In addition, a weather station at the poultry farm will be deployed to measure wind speed, direction, relative humidity, temperature and solar radiation on a continuous basis.
A Fan Assessment Numeration System (FANS; Gates et al., 2004) will be used to determine the ventilation rate for each exhaust fan in all barns being investigated. Emissions from the barns will then be calculated by multiplying the average pollutant concentrations in the barn at a given time by the corresponding ventilation rate.
Sensors and analyzers monitoring climate parameters, NH3 concentrations inside and outside the barns will be interfaced to CR1000X data loggers (Campbell Scientific, Logan, Utah) and will be programmed to scan each sensor for short durations (30 seconds) and to record the average values every five minutes.
During this first phase of the project, this monitoring system will merely be tested to ensure that it is working as planned.
- Phase 2
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The second phase of the project will consist of extended BMP demonstrations and extensive air quality monitoring that compare air quality emissions from the treated and control house under the operation of the installed BMPs.
Two treatments will be tested to investigate the effectiveness of EPI and BioCurtain (BC) systems for emissions (gas, odor and dust) reductions in this demonstration. The EPI and BC will be installed concurrently; however, the BC systems will initially be tested independently and then in conjunction with the EPI to evaluate the effectiveness of the various system components.
Treatment-1, BC system installed inside a 46' X 500' broiler barn will be tested independently. No EPI will be deployed during this demonstration. This treatment will be tested for two weeks during summer and winter seasons when the birds inside the barns will be five-week old and the full tunnel ventilation system is in frequent use.
Treatment-2, EPI and BC will be deployed simultaneously and tested for emission reductions. This treatment will be tested for one full flock (7 weeks) during summer. While litter analysis, gaseous concentrations, and odor causing volatile organic compounds (VOCs) will be measured for seven weeks, intensive PM concentration measurements will be conducted from week 6 to 7. The entire experiment will be replicated again in winter to determine the efficacy of each system using lower ventilation schemes.
The monitoring system described in Phase 1 will be employed as described earlier in Phase 2 as well. Data collected throughout the course of the demonstrations will be processed to evaluate the influences of the BMPs on air quality constituent levels. Emissions (gas and PM) datasets will be arranged for daily and monthly analysis using MS Access. The effects of EPI and BioCurtain systems on emissions reduction will also be investigated using Analysis of Variance (ANOVA) procedures to determine differences in ammonia, hydrogen sulfide, VOCs, and particulate matter (PM) concentrations and other parameters, between broiler barns equipped with the EPI and BioCurtain systems and the control barn. Correlations among gas concentrations and PM concentrations as well as ventilation rates will also be investigated.
Concentrations inside the barn and emissions outside the barn (in the exhaust air) will be compared with concentrations and emissions inside and outside of the control barn. Results will be translated into educational materials that highlight the independent performance of each technology as well as their performance when operated together. These materials will be distributed to poultry producers during a field day held at the cooperating poultry farm and at other poultry producer meetings.
With the help of the cooperating producer, costs to operate and maintain the EPI and BioCurtain systems will be tracked during the demonstrations. Identified operation and maintenance costs will be paired with initial installation costs presented in Phase 1's interim report to produce an overall anticipated cost to purchase, install and operate this dust and odor mitigation system thus allowing producers to make well informed decisions about the costs of the system versus its benefits.