Hydrogen Sulfide Emissions Research Articles

Control sulfide and methane production in sewers based on free ammonia inactivation

Emissions of hydrogen sulfide and methane are two of the major concerns in sewers, causing corrosion, odour and health problems. This study proposed a new free ammonia (FA)-based approach for controlling the biological production of sulfide and methane in sewers. This is based on the discovery that the FA contained in urine wastewater is strongly biocidal to anaerobic sewer biofilms. Long-term operation of two laboratory sewer reactors, with one being dosed with urine wastewater and the other being dosed with raw sewage as a control, revealed the effectiveness of the proposed FA approach. The results showed that dosing of real urine wastewater at FA concentration of 154 mg NH3-N/L with exposure for 24 h immediately reduced over 80% sulfide and methane in the experimental sewer reactor, while the time for recovering 50% sulfide and methane production were 6 days and 28 days, respectively. It also showed that intermittent dosing with an interval time of 5–15 days reduced around 60% sulfide on average. As suggested by community analysis, the remaining sulfide might be produced by a sulfate-reducing bacterial genus Desulfobulbus. Collectively, urine is a part of municipal sewage, and thus separation and re-dosing of the urine wastewater into the sewer for sulfide and methane control should enable the minimization of operational costs and environmental impacts, compared with the previous dosing of chemicals.

Effects of Treated Manure Conditions on Ammonia and Hydrogen Sulfide Emissions from a Swine Finishing Barn Equipped with Semicontinuous Pit Recharge System in Summer

Gaseous emissions from animal production systems affect the local and regional air quality. Proven farm-scale mitigation technologies are needed to lower these emissions and to provide management practices that are feasible and sustainable. In this research, we evaluate the performance of a unique approach that simultaneously mitigates emissions and improves air quality inside a barn equipped with a manure pit recharge system. Specifically, we tested the effects of summertime feeding rations (used by farmers to cope with animal heat stress) and manure management. To date, the pit recharge system has been proven to be effective in mitigating both ammonia (NH3; approximately 53%) and hydrogen sulfide (H2S; approximately 84%) emissions during mild climate conditions. However, its performance during the hot season with a high crude protein diet and high nitrogen loading into the pit manure recharge system is unknown. Therefore, we compared the emissions and indoor air quality of the rooms (240 pigs, ~80 kg each) equipped with a conventional slurry and pit recharge system. The main findings highlight the importance and impact of seasonal variation and diet and manure management practices. We observed 31% greater NH3 emissions from the pit recharge system (33.7 ± 1.4 g·head−1·day−1) compared with a conventional slurry system (25.9 ± 2.4 g·head−1·day−1). Additionally, the NH3 concentration inside the barn was higher (by 24%) in the pit recharge system compared with the control. On the other hand, H2S emissions were 55% lower in the pit recharge system (628 ± 47 mg·head−1·day−1) compared with a conventional slurry pit (1400 ± 132 mg·head−1·day−1). Additionally, the H2S concentration inside the barn was lower (by 54%) in the pit recharge system compared with the control. The characteristics of the pit recharge liquid (i.e., aerobically treated manure), such as the total nitrogen (TN) and ammonium N (NH4-N) contents, contributed to the higher NH3 emissions from the pit recharge system in summer. However, their influence on H2S emissions had a relatively low impact, i.e., emissions were still reduced, similarly as they were in mild climate conditions. Overall, it is necessary to consider a seasonal diet and manure management practices when evaluating emissions and indoor air quality. Further research on minimizing the seasonal nitrogen loading and optimizing pit recharge manure characteristics is warranted.

Determination of ammonia and hydrogen sulfide emissions from a commercial dairy farm with an exercise yard and the health-related impact for residents

Airborne emissions from concentrated animal feeding operations (CAFOs) have the potential to pose a risk to human health and the environment. Here, we present an assessment of the emission, dispersion, and health-related impact of ammonia and hydrogen sulfide emitted from a 300-head, full-scale dairy farm with an exercise yard in Beijing, China. By monitoring the referred gas emissions with a dynamic flux chamber for seven consecutive days, we examined their emission rates. An annual hourly emission time series was constructed on the basis of the measured emission rates and a release modification model. The health risk of ammonia and hydrogen sulfide emissions around the dairy farm was then determined using atmospheric dispersion modeling and exposure risk assessment. The body mass-related mean emission factors of ammonia and hydrogen sulfide were 2.13 kg a−1 AU−1 and 24.9 g a−1 AU−1, respectively (one animal unit (AU) is equivalent to 500 kg body mass). A log-normal distribution fitted well to ammonia emission rates. Contour lines of predicted hourly mean concentrations of ammonia and hydrogen sulfide were mainly driven by the meteorological conditions. The concentrations of ammonia and hydrogen sulfide at the fence line were below 10 μg m−3 and 0.04 μg m−3, respectively, and were 2–3 orders of magnitude lower than the current Chinese air quality standards for such pollutants. Moreover, the cumulative non-carcinogenic risks (HI) of ammonia and hydrogen sulfide were 4 orders of magnitudes lower than the acceptable risk levels (HI = 1). Considering a health risk criterion of 1E-4, the maximum distance from the farm fence line to meet this criterion was nearly 1000 m towards north-northeast. The encompassed area of the contour lines of the ambient concentration of ammonia is much larger than that of hydrogen sulfide. However, the contour lines of the ammonia health risk are analogous to those of hydrogen sulfide. In general, the ammonia and hydrogen sulfide emissions from the dairy farm are unlikely to cause any health risks for the population living in the neighborhood.

Geothermal energy resources: potential environmental impact and land reclamation

With increasing costs, finite sources, and adverse environmental impacts of fossil fuels, global attention has focused on developing renewable and clean sources of energy. Although geothermal energy is considered one of the most promising sources of renewable and clean energy, it may not be as benign as widely believed. In this paper, we evaluate the environmental challenges for geothermal resource extraction and describe potential reclamation strategies for disturbed ecosystems. Generally, the environmental impacts of geothermal power generation and direct use are minor and in most cases controllable. Geothermal plants have low emissions of carbon dioxide, hydrogen sulfide, and ammonia, and low land and water usage; these impacts can be minimized through appropriate mitigation measures. Other potential emissions such as mercury, boron, and arsenic may result in local and regional environmental consequences, although their impacts are poorly understood on a global scale. Geothermal plants can alter vegetation and wildlife habitat by reducing species diversity and community composition. There are small risks of subsidence, induced seismicity, and landslides, with potential serious consequences. Integration of timely reclamation during and after plant operation can significantly contribute to reducing long term reclamation costs while enhancing ecosystem recovery. This paper is expected to contribute to understanding environmental impacts associated with geothermal energy production and to determining appropriate mitigation and land reclamation strategies.

Process optimization and energy analysis of vacuum degasifier systems for the simultaneous removal of dissolved methane and hydrogen sulfide from anaerobically treated wastewater

The control of dissolved methane (CH4) and hydrogen sulfide (H2S) emissions in anaerobic effluents is essential for minimizing the environmental implications of greenhouse gases, odor, and carbon footprint, as well as for preventing energy loss in the form of unrecovered dissolved methane. This study assessed the feasibility of a vacuum degasifier for the removal of CH4 and H2S from staged anaerobic fluidized membrane bioreactor (SAF-MBR) effluent. The optimization results showed that the efficiency of the nozzle fitted degasifiers were superior to the media packed ones. In three-stage vacuum degasifiers at a −0.8 bar vacuum pressure, H2S removal was mostly pH dependent and 88% removal efficiency was achieved with an initial concentration of 13.6 mg/L. Methane removal was dependent primarily on the number of degasifier units, and approximately 94% efficiency was achieved in a three-stage degasifier. Energy balance analysis showed that energy production exceeded the system energy requirements with 0.05–0.07 kWh/m3 of surplus energy. These results provide deep insights into this new technology for simultaneous removal of dissolved CH4 and H2S, which can be referred for potential future applications.

Can dried mealworm (Tenebrio molitor) larvae replace fish meal in weaned pigs?

ABSTRACT This study was conducted to determine the influence of substitution of fish meal with dried mealworm (Tenebrio molitor) larvae on growth performance, nutrient digestibility, blood profiles and fecal noxious gas emission in weaned pigs. A total of 240 crossbred weaned pigs [(Yorkshire × Landrace) × Duroc] at 22 d of age with an average body weight (BW) of 6.90 ± 0.03 kg were randomly allocated into 3 treatments with 8 replicates per treatment and 10 pigs per replicate (pen) according to BW. Dietary treatments included: 1) CON, basal diet with 2% fish meal; 2) T1, basal diet with 1% fish meal and 1% dried mealworm (Tenebrio molitor); T2, basal diet with 2% dried mealworm (Tenebrio molitor). During d 0-7, weaned pigs fed T2 diet had higher (P 0.05) red blood cells, white blood cells, lymphocyte, total protein, blood urea nitrogen, insulin-like growth factor or immunoglobulin G and fecal ammonia, hydrogen sulfide or total mercaptans emission. Taken together, the dried mealworm (Tenebrio molitor) larvae did not outperform the fish meal in this study.

Landfill GHG Reduction through Different Microbial Methane Oxidation Biocovers

Emissions from daily and final covers of municipal solid waste (MSW) landfills can produce significant impacts on local and global environments. Simplifying, landfills can cause local impacts with odor emissions and global impacts with GHGs. This work focuses on hydrogen sulfide (H2S) and methane (CH4) emissions, with the aim of studying how it is possible to reduce their impacts by means of biofiltration systems. Both field and laboratory investigations have been carried out in Casa Rota Landfill (Tuscany, Italy). In the field trials, four pilot-scale biocovers made of compost from a source-selected organic fraction (SS compost), compost from a mechanical biological treatment plant—the residual fractions of the MSW, a mixed compost (SS-MSW compost) and sand were monitored in the daily cover area of the landfill, where high emissions were detected. Results showed that high CH4 and H2S emissions reductions occurred in the mixed SS-MSW compost plot, given a maximum methane oxidation efficiency of greater than 98% and an average oxidation efficiency of about 75%. To assess the specific oxidation rate, laboratory tests using SS-MSW compost sampled from the biocovers were done.

Effects of calcium magnesium phosphate fertilizer, biochar and spent mushroom substrate on compost maturity and gaseous emissions during pig manure composting

This study used a laboratory-scale system to investigate the effects of calcium magnesium phosphate fertilizer (CaMgP), biochar, and spent mushroom substrate (SMS) on compost maturity and gasous emissions during pig manure composting. The results showed that the addition of CaMgP, Biochar or SMS had no negative effect on the quality and maturity of compost, and all three additives could reduce the emissions of ammonia (NH3), hydrogen sulfide (H2S), dimethyl sulfide (Me2S) and dimethyl disulfide (Me2SS). Among them, the effect of adding CaMgP on NH3 emission reduction was the most obvious, reduced 42.90%. The emission reduction of CaMgP to H2S was similar to that of SMS, which decreased by 34.91% and 32.88% respectively. The emission reduction effects of the three additives on Me2S and Me2SS were obvious, all of which were over 50%. However, only adding SMS reduced the N2O emission by 37.08%.

Toxic gas and respirable dust concentrations and emissions from broiler and cage-layer barns in the Canadian Prairies.

This study monitored concentrations and emissions of ammonia (NH3), hydrogen sulfide (H2S), and respirable dust for a commercial broiler and a cage-layer barn in the Canadian Prairies over a year between March 2015 and February 2016. Seasonal concentration and emission profiles were acquired by monthly measurements, while diurnal profiles were generated in different seasons. The indoor air quality was evaluated considering both the individual and the additive health effect (respiratory irritation) of the three air pollutants. In winter, both 8-h and 15-min exposure limits (threshold concentrations) of NH3 were exceeded in the broiler barn; the highest additive level was more than two times of the limit. Seasonal average emissions of NH3, H2S, and respirable dust were 57gd-1AU-1, 1.35gd-1AU-1, and 1.99gd-1AU-1, respectively, for the layer barn, all with higher levels in the mild and warm seasons than in the cold season. The emission data were only obtained for the worst-case scenarios (last week of the production cycle) of the broiler barn, with annual averages of 92gd-1AU-1 for NH3, 1.19gd-1AU-1 for H2S, and 4.32gd-1AU-1 for respirable dust, with obvious higher NH3 levels in winter. Additionally, manure removal once every 3-4days for the layer barn reduced NH3 emissions by 62% and 90% in the cold and mild seasons, respectively. This study also found significant negative influence of outdoor T (Tout) on NH3 emissions for the broiler barn but positive impact of Tout on NH3 emissions for the layer barn.

Gases emissions estimation and analysis by using carbon dioxide balance method in natural-ventilated dairy cow barns

Contaminated gases emissions from livestock industry are becoming one of the most significant contributors to the increasingly serious environmental pollution. To find a way to reduce gases emissions, it is essential to reveal the factors that can affect the gases emissions. In this study, the concentrations of typical gases (including ammonia (NH3), carbon dioxide (CO2), hydrogen sulfide (H2S), and sulfur dioxide (SO2)) generated from naturally-ventilated dairy cow barns were detected through the sample-data method in Tianjin, northern China. Indoor environmental conditions, such as temperature (T) and relative humidity (RH), were measured simultaneously. After applying the carbon dioxide mass balance method, ammonia, hydrogen sulfide and sulfur dioxide emissions were determined. The correlation analysis and regression analysis between the climate condition and gas emissions were conducted to assess the data collected in dairy cow barns during the whole study period. There was a significant relationship between environmental conditions and gas emissions. NH3, H2S and SO2 emissions from the building are in the range of 0.98-2.36 g/LU·h, 0-0.034 g/LU·h, and 0-0.069 g/LU·h, respectively. The numerical analysis shows that the NH3 emission is highly correlated with the temperature and relative humidity. The ventilation rate shows a positive correlation with all the three gases. Keywords: gas emissions, environmental conditions, correlation analysis, regression analysis, carbon dioxide, H2S emission, NH3 emission, SO2 emission DOI: 10.25165/j.ijabe.20201302.4802 Citation: Zou B, Shi Z X, Du S H. Gases emissions estimation and analysis by using carbon dioxide balance method in natural-ventilated dairy cow barns. Int J Agric & Biol Eng, 2020; 13(2): 41–47.

A novel strategy for gas mitigation during swine manure odour treatment using seaweed and a microbial consortium

Gas emissions from swine farms have an impact on air quality in the Republic of Korea. Swine manure stored in deep pits for a long time is a major source of harmful gas emissions. Therefore, we evaluated the mitigation of emissions of ammonia (NH3), hydrogen sulfide (H2S) and amine gases from swine manure with biological products such as seaweed (Sargassum horneri) and a microbial consortium (Bacillus subtilis (1.2 × 109 CFU/mL), Thiobacillus sp. (1.0 × 1010 CFU/mL) and Saccharomyces cerevisiae (2.0 × 109 CFU/mL)) used as additives due to their promising benefits for nutrient cycling. Overall, seaweed powder masking over two days provided notable control of over 98%–100% of the gas emissions. Furthermore, significant control of gas emissions was especially pronounced when seaweed powder masking along with a microbial consortium was applied, resulting in a gas reduction rate of 100% for NH3, amines and H2S over 10 days of treatment. The results also suggested that seaweed powder masking and a microbial consortium used in combination to reduce the gas emissions from swine manure reduced odour compared with that observed when the two additives were used alone. Without the consortium, seaweed decreased total volatile fatty acid (VFA) production. The proposed novel method of masking with a microbial consortium is promising for mitigating hazardous gases, simple, and environmentally beneficial. More research is warranted to determine the mechanisms underlying the seaweed and substrate interactions.

Effects of UV-A Light Treatment on Ammonia, Hydrogen Sulfide, Greenhouse Gases, and Ozone in Simulated Poultry Barn Conditions

Gaseous emissions, a side effect of livestock and poultry production, need to be mitigated to improve sustainability. Emissions of ammonia (NH3), hydrogen sulfide (H2S), greenhouse gases (GHGs), and odorous volatile organic compounds (VOCs) have a detrimental effect on the environment, climate, and quality of life in rural communities. We are building on previous research to bring advanced oxidation technologies from the lab to the farm. To date, we have shown that ultraviolet A (UV-A) has the potential to mitigate selected odorous gases and GHGs in the context of swine production. Much less research on emissions mitigation has been conducted in the context of poultry production. Thus, the study objective was to investigate whether the UV-A can mitigate NH3, H2S, GHGs, and O3 in the simulated poultry barn environment. The effects of several variables were tested: the presence of photocatalyst, relative humidity, treatment time, and dust accumulation under two different light intensities (facilitated with fluorescent and light-emitting diode, LED, lamps). The results provide evidence that photocatalysis with TiO2 coating and UV-A light can reduce gas concentrations of NH3, CO2, N2O, and O3, without a significant effect on H2S and CH4. The particular % reduction depends on the presence of photocatalysts, relative humidity (RH), light type (intensity), treatment time, and dust accumulation on the photocatalyst surface. In the case of NH3, the reduction varied from 2.6–18.7% and was affected by RH and light intensity. The % reduction of NH3 was the highest at 12% RH and increased with treatment time and light intensity. The % reduction of NH3 decreased with the accumulation of poultry dust. The % reduction for H2S had no statistical difference under any experimental conditions. The proposed treatment of NH3 and H2S was evaluated for a potential impact on important ambient air quality parameters, the possibility of simultaneously mitigating or generating GHGs. There was no statistically significant change in CH4 concentrations under any experimental conditions. CO2 was reduced at 3.8%–4.4%. N2O and O3 concentrations were reduced by both direct photolysis and photocatalysis, with the latter having greater % reductions. As much as 6.9–12.2% of the statistically-significant mitigation of N2O was observed. The % reduction for O3 ranged from 12.4–48.4%. The results warrant scaling up to a pilot-scale where the technology could be evaluated with economic analyses.

Use of Alternative Cover Materials to Control Surface Emissions (H2S and VOCs) at an Engineered Landfill

Between 2010 and 2015, the Bellechasse Regional County Municipality (Bellechasse RCM) was affected by particularly noxious odors issuing from its Municipal Solid Waste Landfill (Bellechasse RCM MSWL) in Armagh, Canada. A study carried out in 2015-2016 by Centre de recherche industrielle du Québec (CRIQ) confirmed that it was still possible for hydrogen sulfide (H2S) emissions to cause odor issues in and around the site. The experimental project carried out by CRIQ in cooperation with Bellechasse RCM, Englobe, Quebec City and the Regroupement des récupérateurs et des recycleurs de matériaux de construction et de démolition du Québec (represented by AIM Éco-centre) made it possible to test three (3) different industrial residue as an alternative cover materials on site and study how they controlled H2S emissions, volatile organic compounds (VOCs) and odors at the Bellechasse RCM’s landfill. The site was monitored from November 2016 to September 2017 to confirm the effectiveness of alternative biofiltration cover materials (soil + compost), domestic waste incineration bottom ash and 0 to 2.5-inch concrete residues and to compare the results with the sand cover currently used as the cover material. Effectiveness was determined by measuring the Area Source Emission Rate (ASER) with a 3 m x 3 m static flux chamber developed for the project. Methane measurements were concomitantly taken to confirm that the biogas could escape through the cover materials. The monitoring results made it possible to demonstrate that domestic waste incineration bottom ash as well as 0-2.5 in. concrete received the highest load of H2S and showed an H2S capture performance of greater than 83ϿFor volatile organic compounds, materials such as 0-2.5 in. concrete and the alternative biofiltration cover materials were most effective for capture (greater than 73Ͽfor the highest loads. The lowest content of CH4 after covering was measured for the alternative cover materials. The site where the incineration bottom ash was used managed to decrease odors by ±200 odor units. Overall, we have demonstrated in this project, the capacity of different alternative cover materials under real condition for the control of gas emissions from landfill.

Protected Organic Acids Improved Growth Performance, Nutrient Digestibility, and Decreased Gas Emission in Broilers.

Simple SummaryRecently, the development of antimicrobial resistance of bacteria has become a global health problem. Such a situation has compelled nutritionists and researchers to explore other potential alternatives. Among a variety of candidates for the replacement of antibiotic growth promoters, organic acids (OAs), both individual and as a blend of several acids are the most promising ones as feed additives in animal production. Organic acids maintain cellular integrity of the gut lining and improve the digestive process by maintaining normal gut flora. Addition of OAs to the diet can improve the absorption rate of proteins, amino acids, and minerals. This may contribute not only in improving performance but also reducing nitrogen and phosphorus excretion. Besides, medium-chain fatty acids (MCFAs) constitute another type of acid and have been shown to be potential alternatives for in-feed antibiotics in farm animals as they have strong antibacterial activity against Gram-positive cocci and Escherichia coli. The combination of OAs and MCFAs has been reported to improve the nutrient digestibility, growth performance, proliferation of Lactobacillus, and immunity of the animal. The present study investigated the effect of a blend of dietary protected OAs and MCFAs on broiler chickens. The results of this study showed that the blend of OA and MCFA supplementation positively influenced growth performance, DM digestibility, excreta Lactobacillus counts, as well as NH3 gas emission in broiler chickens.We investigated the effects of a blend of organic acids (OAs) and medium-chain fatty acids (MCFAs) supplementation in 800 1-d-old male Ross 308 broiler chickens (42 ± 0.90 g) in a 7-week study. Broiler chicks were randomly allocated into one of the five dietary treatments (16 birds per pen with 10 pens per treatment). Dietary treatments consisted of corn-soybean meal based basal diet and the basal diet supplemented with blend of OAs and MCFAs at 0.25, 0.5, 0.75 g, and 1 g per kg of feed. In the current study, during the whole experimental period, the inclusion of the blend of OAs and MCFAs in the basal diet linearly improved (p < 0.05) body weight gain (BWG), feed conversion ratio (FCR), and dry matter digestibility. The increasing inclusion of the blend of OA and MCFA levels in the diets linearly decreased (p = 0.002) feed intake during d 1 to 7. Broilers fed diets containing different levels of the blend of OAs and MCFAs showed a linear increase (p = 0.006) in Lactobacillus concentrations and decrease (p = 0.014) in ammonia (NH3) at the end of the experiment. However, the blend of OAs and MCFAs did not affect carcass quality, E. coli, and Salmonella counts, as well as hydrogen sulfide and total mercaptans gas emission (p > 0.05). In conclusion, the blend of OA and MCFA supplementation positively influenced growth performance, DM digestibility, excreta Lactobacillus counts, as well as NH3 gas emission in broiler chickens.

Hydrogen sulphide emissions and dispersion modelling from a wastewater reservoir using flux chamber measurements and AERMOD® simulations

Odours associated with hydrogen sulphide (H2S) have been a concern in the municipality of Sibaté (Colombia) over the last decades. With the aim of determining the odour impact of Muña's reservoir, different H2S emission sources were evaluated and simulated. H2S surface emission rates from Muña's reservoir were estimated using the Flux Chamber experimental method. Meteorological conditions and emission rates were then fed to the AERMOD® model to identify the contribution of Muña's reservoir on H2S concentration in Sibaté’s urban area. These results were compared and calibrated with real time H2S atmospheric concentration data. The average H2S emission rate was 1,886 μg/(min·m2), which primarily affects the municipality when wind direction is towards the south. The results of this study demonstrated the applicability of the AERMOD® model and flux chamber measurements in predicting H2S behaviour in the Sibaté region.

Hydrogen sulfide production assessment based on sewage physicochemical properties using artificial neural network

In sewers, the emission of hydrogen sulfide is of great danger to the environment. The aim of this work is two folds, firstly to explore sewage water characteristics as key element of sulfide estimation in water phase. Secondly, to quantify the influence of each parameter on sulfide concentration, applying statistic method of artificial neural network. The obtained data is collected from Morocco, Casablanca city. The sulfide concentration is correlated to physicochemical parameters using artificial neural network (ANN). The reliability of the ANN model has been successfully tested with a correlation coefficient equal to 95% and a mean squared error of 5%. Hence, the model is used to calculate the importance of the parameters that affects sulfide production using Garson’s algorithm. Results show that the water quality meets multiple required conditions for sulfide buildup. Also, temperature has the most significant impact on sulfide production, followed by BOD5.

Gases emissions estimation and analysis by using carbon dioxide balance method in natural-ventilated dairy cow barns

Contaminated gases emissions from livestock industry are becoming one of the most significant contributors to the increasingly serious environmental pollution. To find a way to reduce gases emissions, it is essential to reveal the factors that can affect the gases emissions. In this study, the concentrations of typical gases (including ammonia (NH3), carbon dioxide (CO2), hydrogen sulfide (H2S), and sulfur dioxide (SO2)) generated from naturally-ventilated dairy cow barns were detected through the sample-data method in Tianjin, northern China. Indoor environmental conditions, such as temperature (T) and relative humidity (RH), were measured simultaneously. After applying the carbon dioxide mass balance method, ammonia, hydrogen sulfide and sulfur dioxide emissions were determined. The correlation analysis and regression analysis between the climate condition and gas emissions were conducted to assess the data collected in dairy cow barns during the whole study period. There was a significant relationship between environmental conditions and gas emissions. NH3, H2S and SO2 emissions from the building are in the range of 0.98-2.36 g/LU·h, 0-0.034 g/LU·h, and 0-0.069 g/LU·h, respectively. The numerical analysis shows that the NH3 emission is highly correlated with the temperature and relative humidity. The ventilation rate shows a positive correlation with all the three gases. Keywords: gas emissions, environmental conditions, correlation analysis, regression analysis, carbon dioxide, H2S emission, NH3 emission, SO2 emission DOI: 10.25165/j.ijabe.20201302.4802 Citation: Zou B, Shi Z X, Du S H. Gases emissions estimation and analysis by using carbon dioxide balance method in natural-ventilated dairy cow barns. Int J Agric & Biol Eng, 2020; 13(2): 41–47.

Feeding a diet with corn distillers grain with solubles to dairy cows alters manure characteristics and ammonia and hydrogen sulfide emissions from manure

The objective of the experiment was to examine effects of a diet containing a high concentration (28.8% dry matter basis) of corn distillers grain with solubles on manure characteristics and NH3 and H2S emissions from dairy cow manure. Eighteen cows were blocked by parity and days in milk, and cows in each block were assigned to the following treatments: the control diet (CON) or CON with distillers grains with solubles at 28.8% (dry matter basis) replacing mainly soybean meal (DG). The experiment was conducted for 11 wk, and feces and urine from individual cows were collected over 3 d in wk 11 (a total of 8 spot samples per cow). Fecal or urine samples were composited by cow, and the composite feces and urine were analyzed for indigestible neutral detergent fiber and creatinine concentration, respectively, for individual cows to estimate total fecal and urine outputs. Immediately before the manure incubation, composited feces and urine were sampled to determine manure characteristics. Manure was reconstituted according to daily fecal and urine excretion estimated for individual cows. Individual manures were incubated using a continuous air flux multichamber system over 10 d to measure NH3 and H2S emissions. All data from 18 manures were analyzed using the Mixed procedure of SAS (SAS Institute Inc., Cary, NC). The ratio of feces to urine and the contents of manure total and volatile solids were not different among treatments. Urine from DG had lower pH and DG manure had lower N content and greater S content compared with CON. During the 10-d incubation, NH3 emission was considerably less for DG versus CON. The emission of H2S over 10 d for DG was greater compared with that for CON. After the incubation, manure pH and N and S concentrations were greater for DG versus CON. In conclusion, manure from cows fed a high-DG diet decreased urinary N contribution to manure N and lowered urine pH, which were the factors that caused the decrease in NH3 emission from DG manure. However, the DG diet increased dietary S concentration and increased S excretion in urine and feces. This increased H2S emission from DG manure during the 10-d manure incubation.

PSXI-3 Impact of carbohydrate source on manure and air emissions from swine diets

Abstract Dietary fiber is known to reduce ammonia emissions, but little is known about its effect on emissions of major odorants. An experiment was conducted to determine the effect fiber and fiber source has on manure composition and gas emissions. Two groups of 44 gilts averaging 128 kg BW were fed standard corn soybean meal diets that contained 9.6% NDF or 17% NDF with the following fiber sources: beet pulp (BP); dried distillers grain with solubles (DDGS); soybean hulls (SB); and wheat bran (WB). Animals were fed twice daily, and feces and urine were collected after each feeding and added to manure storage containers. At the end of the experiment, stored manures were monitored for gas emissions and chemical properties. Animals on average gained 724 g/d and consumed 2.74 kg feed/d over 42-d trial ANOVA showed that dietary fiber in swine diets significantly increased the animals manure acidity, dry matter (DM), organic N, total N, total C, and volatile fatty acids contents, while the source of the fiber material in the diet significantly impacted the animals manure DM, total N, total C, and total S. Manures of animals fed lower fiber diets had significantly higher ammonia (NH3) and hydrogen sulfide emissions, while manure emissions of NH3 and total phenols was impacted by the fiber source in the animal diet. In conclusion, dietary fiber and the source of fiber have a dramatic impact on manure composition and gas emissions.

Calculation of an electrochemical reactor for cleaning the air of the city from hydrogen sulfide emissions

The environmental safety of the urban economy requires the creation of new environmentally friendly technologies that ensure human protection from the negative impact of water management systems, in particular the urban sewer system, which is a potentially dangerous source of decomposition products of biological waste. Hydrogen sulfide is a gas that has a significant danger for both the city population and the high corrosivity of metal and concrete structures. At the Department of General and Applied Chemistry (VSTU), we developed an electrochemical method for purifying air from hydrogen sulfide, which allows to neutralize it locally, in the zone of hydrogen sulfide emission, with the release of environmentally friendly products: chemically pure sulfur and water.