Stéphane P. Lemay

Greenhouse Gas and Odor Emissions from Liquid Swine Manure Storage and Manure Treatment Facilities in Quebec

Greenhouse gas (GHG) and odor emissions were measured over a two-year period from a swine manure storage tank and from two swine manure treatment facilities (an aerobic-anoxic and a biofilter manure treatment system). Floating open chambers were used to collect air samples on top of the stored manure. GHG concentrations were either measured continuously, by gas chromatography, or determined from air samples collected using syringes and stored in evacuated glass containers. Air bag samples were collected and odor concentrations (in OU m-3) were measured using a dynamic dilution olfactometer. Odor intensities (in ppb eq of 1-butanol) were measured on site using a suprathreshold dynamic dilution olfactometer. Total GHG emissions (including CO2) from the farm under liquid manure management (manure tank and land application) were equal to 5.3 kg CO2 eq year-1 kgpigs -1. From the aerobic-anoxic treatment system and the biofilter treatment system, total GHG emissions were equal to 1.9 and 3.5 kg CO2 eq year-1 kgpigs -1, respectively. Odor emissions from the manure tank were 12 OU s-1 m-2. From the aerobic-anoxic treatment system and the biofilter treatment system, odor emissions were 1.5 OU s-1 m-3 and 6.7 OU s-1 m-3, respectively.

Biotrickling filter for the treatment of swine exhaust air.

The piggery industry is important both worldwide and in Canada, but swine production sites can emit substantial amounts of aerial contaminants. Biological treatment systems, such as biotrickling filters (BTF), have the potential to treat these emissions which are generally characterised by low concentrations and very high flow rates. The main objective of this study was to test the effect of certain operating parameters on the performance of BTFs treating swine exhaust air.

Size Distribution of Particulate and Associated Endotoxin and Bacteria in Traditional Swine Barn Rooms and Rooms Sprinkled With Oil

ABSTRACT The objective of this pilot study was to investigate if a once-a-day sprinkling of canola oil in a swine confinement facility alters the airborne concentration and distribution of particulate matter and associated compounds (endotoxin and culturable microbes). Particulate was collected using an eight-stage cascade impactor in four identical swine grower/finisher rooms of a swine barn. Particulate (mg/m3) and endotoxin (EU/m3 and EU/mg) distribution was determined. A six-stage viable cascade impactor was used to quantify total bacteria, enteric bacteria, and fungi. Microbes were characterized from subcultures prepared from the 10 most predominant colony types on each stage 3 (aerodynamic size 3.3–4.7μm) of the collection plates. Results indicated that oil sprinkling reduced total dust by 86% and total endotoxin concentration by 82.5%. However, the distribution patterns indicate that reduction is observed predominantly on large dust particles. In addition, the proportion of endotoxin associated with smaller particulate sizes (i.e., particles <4.7 μm) was higher in the oil-sprinkled rooms. Oil sprinkling does not markedly alter distribution of total bacteria, enteric bacteria, or fungi. The most frequently identified species were gram-positive genera. Oil sprinkling in swine confinement grower/finisher rooms can significantly reduce airborne total dust and endotoxin; however, smaller particles and associated endotoxin appear to remain in suspension, suggesting the overall improvement in air quality is uncertain. Further distribution studies and exposure outcome studies would need to be undertaken to determine the impacts of oil sprinkling.

Development of an innovative in-barn manure handling system for grower-finisher pigs to separate feces from urine: assessment of impact on odor and gaseous emissions

In this work, a new housing system for grower-finisher pigs that incorporates a belt conveyor (BC) system to separate feces from the urine at the pen level was developed. This innovative manure handling system was evaluated for its effectiveness in partitioning nutrients (i.e., phosphorus and nitrogen) in the separated solid and liquid manure components as well as its impact on pig well-being, and on odor and gaseous emissions. Experiments conducted at two collaborating research facilities allowed for the comparative evaluation of two small-scale rooms – one that simulated a conventional swine production room with partially slatted floor pen and a shallow pit and a second room that featured the new pen design concept with the BC replacing the concrete pen floor slats. Four trials were completed at each facility. Results of the trials showed that the performance and well-being of the animals were not adversely affected by the use of the BC pen design. The BC system was effective in isolating most of the phosphorus in a low mass solid phase; 76 to 81% of the phosphorus excreted by the pigs in the BC room was isolated within the solid phase of excreta representing 20% of the total manure mass. Various opportunities exist to refine the BC pen concept to reduce the total water usage and consequently, to reduce the total manure production as well. The overall trends in gas concentration levels (i.e., NH3 and CO2) observed in trials conducted at the two locations indicated that the BC pen design contributed to the reduction in the levels of these gases. The odor concentration values for the samples taken from the conventional and BC rooms were highly variable, thus statistical comparison of the odor values from the two chambers showed no significant difference (p>0.05). The overall trends in gas emission rates showed that the BC pen design concept can help reduce the emission rate of carbon dioxide compared to the conventional room. No significant impact of the system was observed for ammonia and odor emissions. Further work to better assess the technology is recommended, particularly with respect to improved control of inlet air contaminant levels and more accurate assessment of odor and hydrogen sulfide concentrations.

Evaluation of Greenhouse Gas Emissions from Five Swine Production Systems Based on Life Cycle Assessment

The goal of this paper was to compare greenhouse gas (GHG) emissions produced by different manure management strategies and using different nutrient to establish the farm manure management plan for a typical pig farm. Five scenarios were tested and the method used to compare GHG emissions was based on life cycle assessment. In scenarios #1 to #4, pigs were raised in a conventional building under liquid manure management. In scenario #5, pigs were raised in a building equipped with a V-shaped scraper installed underneath the slats. In scenario #1, the nutrient balance was based on nitrogen while, in scenarios #2 to #5, it was based on phosphorus. Results were expressed in terms of total GHG emissions and by two functional units: per kg of pig produced and per ha of land used. Total GHG emissions, in t CO2e per year, were 300.4 t CO2e for scenario #1, 448.4 t CO2e for scenario #2, 177.9 t CO2e for scenario #3, 278.7 t CO2e for scenario #4 and 200.5 t CO2e for scenario #5. The impact of the functional unit chosen to express the emissions and to compare scenarios had an influence on how the results were interpreted. If the pig produced were considered more representative, scenario #2 did not represent and interesting option in terms of GHG reduction while scenario #5 was the most interesting. Considering the area of land used, scenario #5 produced more GHG than scenario #2.

A New Housing System for Grower-Finisher Pigs to Separate Feces from Urine and to Reduce Odor and Ammonia Emissions

A new housing concept including a belt conveyor (BC) system to separate feces from the urine at the pen level has been successfully developed at IRDA and the main objectives of this part of the project were to measure the separation efficiency of the new pen configuration including the BC system and to evaluate its effect on pig behavior. The pen concept integrates an inclined BC covering the pen dunging area to separate feces from the urine. Pigs walk on the BC, the urine drains out in the middle portion of the pen and the BC activation removes feces from the pen and collects them into a container. Two rooms have been built at IRDA to conduct the experiment. The control room simulates a partially slatted floor pen with a conventional shallow pit configuration and the second room has a custom built BC activated during 3 min every 30 min. Four trials of four weeks each have been completed, providing four replicates for each treatment. In both rooms, pigs performed really well both in terms of growth and feed efficiency and there was no indication of any detrimental effect of the BC system on animal performance or comfort. The BC system has been very effective at isolating most of the phosphorus in a low mass solid phase as 76 to 81% of the phosphorus excreted by the pigs in the BC room has been isolated within the solid phase of excreta representing 20% of the total manure mass. In its current configuration, wash water used to clean the belt would increase water storage requirements by 34% and further investigations are necessary to decrease the amount of water required for cleaning.

Measuring the Social Acceptability of Participants for Two Manure Spreading Techniques, With and Without an Information Session: A Case Study

Relationships between farmers and rural residents are sometime problematic, especially during manure spreading periods. To improve the social acceptability of spreading activities, newer technologies can be used. However, there is limited information on the impact of those technologies compared to a social intervention on the social acceptability. A first project was carried out in 2007 using two spreading techniques and an information session. The participants who took part of this first project were neutral regarding swine production. The goal of this new study was thus to measure the impact of two manure spreading techniques and of an information session on the social acceptability of participants in an area where relationships were problematic. Two groups of similar subjects were formed; one group who received an information session about the swine production and another kept as a control group. Both groups were then exposed to the same two spreading techniques; a surface application technique and an incorporation technique. The social acceptability of all participants was measured using a questionnaire. The odor concentrations at the participant’s level and near the spreading operation were measured using dynamic olfactometry. The social acceptability results show that the impact of an information session alone was negligible. However, the use of a manure incorporation technique increased the acceptability. In fact, the use of a surface application technique increased the risk that participants had a low acceptability by 64% compared with an incorporation technique. A spreading technique releasing less airborne contaminants should contribute at enhancing community relationships.

Modeling Ammonia Emission from Urine Puddles

Urine puddles have been identified as one of the main sources of ammonia in swine barns. In this project, the ammonia emission and puddle characteristics for 36 simulated urine puddles under a variety of temperature, air velocity and initial urea concentration conditions were measured. The measurements were used to calibrate and validate a dynamic, mechanistic, urine puddle emission model that considers the processes of evaporation, urea conversion, change in liquid concentration and puddle pH in order to simulate the amount of ammonia emitted from a puddle. Based on the correlation coefficients (r) between measured and simulated values for water volume (r=0.99), total ammoniacal nitrogen concentration (r=0.90), and total emission (r=1.00), along with five other statistical tests for each simulated variable, the model was deemed accurate. The measurements and simulations in this experiment show the impact of puddle pH and changing environmental conditions on the average puddle emission rate, and that puddle emission will continue to occur as long as there is still water.

Would separating feces and urine under pigs be a key to minimize odors and gas emissions

Would it be possible to minimize odors and gas emissions from swine buildings just by changing the way the manure is handled? According to Koger et al. (2002) and Arogo et al. (2001), to minimize odor and gas emissions, urine should be separated from the manure as soon as possible. In fact, by restricting the retention time of urine under the slats, the ammonia production would be minimized. Since 1990, some experiments were conducted in order to separate urine from feces directly under slats in piggeries. On average, for separating manure management systems, about 50% reduction in ammonia as well as malodorous emissions can be reached. In this present experiment, three different separation systems are evaluated (conveyor rubber belt, conveyor screen, V-shaped scraper). The scraping frequency (1, 2 or 3 days) is also studied on the latest method. Moreover, an ordinary flat scraper is studied in order to evaluate the effectiveness of the separation process. A pull plug system is used as a control. The experiment took place in 12 bench scale rooms, each one containing four grower-finisher pigs. Every room had its own manure management system. Preliminary results for trial 1 show an odors emission reduction up to 48%. Regarding scraping frequency, it seems that emptying the channel every 2 to 3 days vs once a week result in a reduction of odor emissions. The second trial was only completed on July 15th, 2004 and no conclusion can be drawn at this point. Once the overall data analysis is complete, the most promising manure handling system to reduce ammonia and odor emissions will be selected and tested in full-scale building.

Improving Air Quality in Swine Buildings by Using a Combination of Technologies - Pilot-Scale Tests

Abstract. The environmental impact of swine production is still a great concern for the industry as well as for rural populations. Substantial amounts of aerial contaminants such as odors, gases and dust can be emitted by livestock buildings and affect both pig and worker health as well as the nearby environment. Different strategies have successfully reduced some of these airborne contaminants over the years, but few studies looked at their combined effect. Thus, the main objective of this study is to evaluate the reduction of airborne contaminants by using a combination of best practices as compared to conventional management in swine industry at a pilot-scale. Previously in the project, a series of experiments was conducted at a laboratory-scale (4-5 grower-finisher pigs per room) to evaluate the performance of some strategies alone or combined. Results have shown that in order to protect both worker health and reduce environmental emissions, all three tested technologies should be used together: manure separation with a v-shaped scraper, oil sprinkling and an air treatment unit. Following the laboratory-scale results, it was necessary to validate the performance of the technologies at a pilot-scale using two rooms with 16 pigs each. Ammonia emissions for both rooms were quite similar. Unfortunately, the v-shaped scraper didn‘t provide the expected reduction in ammonia emissions. The air treatment unit removed up to 66% of the ammonia on average with peaks up to 80%. For dust, oil sprinkling reduced the dust load by 70% on average.