Bernardo Predicala

Diurnal Odor, Ammonia, Hydrogen Sulfide, and Carbon Dioxide Emission Profiles of Confined Swine Grower/Finisher Rooms

Abstract The objective of this study was to obtain diurnal variation profiles of odor and gas (ammonia [NH3], hydrogen sulfide [H2S], carbon dioxide [CO2]) concentrations and emission rate (OGCER) from confined swine grower/finisher rooms under three typical weather conditions (warm, mild, and cold weather) in a year. Two grower/finisher rooms, one with a fully slatted floor and the other with partially slatted floors, were measured for 2 consecutive days under each weather condition. The results revealed that the diurnal OGCER in the room with a fully slatted floor was 9.2–39.4% higher than that with a partially slatted floor; however, no significant differences in the diurnal OGCER were found between these two rooms, except for the NH3 concentrations in August, the NH3 and H2S concentrations and emissions in October, and odor concentrations and emissions in February (p > 0.05). The OGCER variations presented different diurnal patterns as affected by time of day, season, type of floor, ventilation rate, animal growth cycles, in-house manure storage, and weather conditions. Significant diurnal fluctuations in the OGCER (except for the odor concentrations and H2S emissions) were observed in August (p < 0.05); all of the gas emissions in October and the CO2 concentrations and emissions in February also showed significant diurnal variations (p < 0.05). These significant diurnal variations indicated that the OGCER during different periods of a day should be monitored when quantifying OGCER concentrations and emissions; for example, source emission data used in air dispersion modeling to decrease the great incertitude of setback determination using randomly measured data.

Laboratory, semi-pilot and room scale study of nitrite and molybdate mediated control of H2S emission from swine manure.

The effects of manure age on emission of H(2)S and required level of nitrite or molybdate to control these emissions were investigated in the present work. Molybdate mediated control of H(2)S emission was also studied in semi-pilot scale open systems, and in specifically designed chambers which simulated swine production rooms. With fresh 1-, 3- and 6-month old manures average H(2)S concentration in the headspace gas of the closed systems were 4856+/-460, 3431+/-208, 1037+/-98 ppm and non-detectable, respectively. Moreover, the level of nitrite or molybdate required to control the emission of H(2)S decreased as manure age increased. In the semi-pilot scale open system and chambers, average H(2)S concentration at the surface of agitated fresh manure were 831+/-26 and 88.4+/-5.7 ppm, respectively. Furthermore, 0.1-0.25 mM molybdate was sufficient to control the emission of H(2)S. A cost study for an average size swine operation showed that the cost of treatment with molybdate was less than 1% of the overall production cost for each market hog.

ZnO Nanoparticles Impose a Panmetabolic Toxic Effect Along with Strong Necrosis, Inducing Activation of the Envelope Stress Response in Salmonella enterica Serovar Enteritidis

ABSTRACT In this study, we tested the antimicrobial activity of three metal nanoparticles (NPs), ZnO, MgO, and CaO NPs, against Salmonella enterica serovar Enteritidis in liquid medium and on solid surfaces. Out of the three tested metal NPs, ZnO NPs exhibited the most significant antimicrobial effect both in liquid medium and when embedded on solid surfaces. Therefore, we focused on revealing the mechanisms of surface-associated ZnO biocidal activity. Using the global proteome approach, we report that a great majority (79%) of the altered proteins in biofilms formed by Salmonella enterica serovar Enteritidis were downregulated, whereas a much smaller fraction (21%) of proteins were upregulated. Intriguingly, all downregulated proteins were enzymes involved in a wide range of the central metabolic pathways, including translation; amino acid biosynthetic pathways; nucleobase, nucleoside, and nucleotide biosynthetic processes; ATP synthesis-coupled proton transport; the pentose phosphate shunt; and carboxylic acid metabolic processes, indicating that ZnO NPs exert a panmetabolic toxic effect on this prokaryotic organism. In addition to their panmetabolic toxicity, ZnO NPs induced profound changes in cell envelope morphology, imposing additional necrotic effects and triggering the envelope stress response of Salmonella serovar Enteritidis. The envelope stress response effect activated periplasmic chaperones and proteases, transenvelope complexes, and regulators, thereby facilitating protection of this prokaryotic organism against ZnO NPs.

Effectiveness of a Manure Scraper System for Reducing Concentrations of Hydrogen Sulfide and Ammonia in a Swine Grower-Finisher Room

The effectiveness of a manure scraper system for reducing the risk of barn worker and animal exposure to hydrogen sulfide (H2S) was evaluated by comparing gas levels in two swine production rooms, one with a manure scraper system installed (scraper) and the other with a conventional manure pit-plug system (control). Measurements were done over four production cycles; during each 12-week cycle, gas concentrations were measured 4 to 5 times during weeks that conventional manure removal activities were performed in the control room, while the scraper system was operated daily in the scraper room. Daily removal of manure from the scraper room resulted in measured maximum H2S concentrations that were significantly lower (by 90%) compared to the control room. The type of manure removal system had no significant effect on ammonia (NH3) concentration and emission; during each trial, NH3 emission increased in both rooms over the 4 to 5 monitored weeks. The scraper system was also operated in two different modes. These tests revealed that NH3 production was reduced when all the manure was removed from the room compared to leaving the liquid portion on the pit floor surface, although the differences were not significant (p > 0.10). The estimated cost of including the scraper system in the construction and operation of a new barn is CDN

Biodegradation of phenol in batch and continuous flow microbial fuel cells with rod and granular graphite electrodes

1.89 per pig sold, which is 35% less (on a per pig basis) than the cost of retrofitting an existing facility. The manure removal system tested was effective in reducing exposure of workers and animals to H2S, without significant adverse impact on NH3 production. However, given the highly variable nature of H2S production and dispersion within a room, care should always be taken when handling manure inside swine barns.

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

ABSTRACT Phenol biodegradation was evaluated in batch and continuous flow microbial fuel cells (MFCs). In batch-operated MFCs, biodegradation of 100–1000 mg L−1 phenol was four to six times faster when graphite granules were used instead of rods (3.5–4.8 mg L−1 h−1 vs 0.5–0.9 mg L−1 h−1). Similarly maximum phenol biodegradation rates in continuous MFCs with granular and single-rod electrodes were 11.5 and 0.8 mg L−1 h−1, respectively. This superior performance was also evident in terms of electrochemical outputs, whereby continuous flow MFCs with granular graphite electrodes achieved maximum current and power densities (3444.4 mA m−3 and 777.8 mW m−3) that were markedly higher than those with single-rod electrodes (37.3 mA m−3 and 0.8 mW m−3). Addition of neutral red enhanced the electrochemical outputs to 5714.3 mA m−3 and 1428.6 mW m−3. Using the data generated in the continuous flow MFC, biokinetic parameters including μm, KS, Y and Ke were determined as 0.03 h−1, 24.2 mg L−1, 0.25 mg cell (mg phenol)−1 and 3.7 × 10−4 h−1, respectively. Access to detailed kinetic information generated in MFC environmental conditions is critical in the design, operation and control of large-scale treatment systems utilizing MFC technology.

Assessing the Performance of Hydrogen Sulfide Monitoring Devices and a Water Spray Method to Reduce Worker Exposure in Swine Buildings

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.

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

A spray treatment method was evaluated for reducing worker exposure to hydrogen sulfide (H2S). Additionally, the performance of commercial H2S monitoring devices was verified by comparing readings with a reference analytical method using a gas chromatograph. Results showed that the H2S monitors yielded readings that were in close agreement with those from the reference method. Additionally, spraying with water was effective in reducing the levels of H2S released from agitated manure, although an initial increase in H2S levels was observed at the start of spray application. An additive mixed with spray water did not help in reducing H2S levels.

Evaluation of Energy Saving Measures in Swine Barns Using Numerical Simulation

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.

Use of zinc oxide nanoparticles to control hydrogen sulphide, ammonia and odour emissions from pig barns.

The economic challenges faced by the pork industry as well as the continuous rising trend in energy prices made the investigation of various ways to reduce energy use in pork production imperative. This study aims to develop and evaluate various energy saving measures to reduce energy consumption in swine barns using TRNSYS energy simulation software and Excel spreadsheet. Different energy conservation strategies pertaining to building materials and insulation, equipment, and barn management were examined to determine their impact on overall annual room energy use. Results of the evaluation showed that lighting modifications and the use of heat exchanger and geothermal heating have greater impact on the energy requirement of a swine room than the use of additional insulation materials, decreasing the temperature set points, and using energy efficient fans.