Concentration Of Hydrogen Sulfide Gas Research Articles

GSH-Triggered/Photothermal-Enhanced H2S Signaling Molecule Release for Gas Therapy.

Traditional treatment methods for tumors are inefficient and have severe side effects. At present, new therapeutic methods such as phototherapy, chemodynamic therapy, and gasodynamic therapy have been innovatively developed. High concentrations of hydrogen sulfide (H2S) gas exhibit cancer-suppressive effects. Herein, a Prussian blue-loaded tetra-sulfide modified dendritic mesoporous organosilica (PB@DMOS) was rationally constructed with glutathione (GSH)-triggered/photothermal-enhanced H2S signaling molecule release properties for gas therapy. The as-synthesized nanoplatform confined PB nanoparticles in the mesoporous structure of organosilica silica due to electrostatic adsorption. In the case of a GSH overexpressed tumor microenvironment, H2S gas was controllably released. And the temperature increases due to the photothermal effects of PB nanoparticles, further enhancing H2S release. At the same time, PB nanoparticles with excellent hydrogen peroxide catalytic performance also amplified the efficiency of tumor therapy. Thus, a collective nanoplatform with gas therapy/photothermal therapy/catalytic therapy functionalities shows potential promise in terms of efficient tumor therapy.

Evaluation of the determination of hydrogen sulfide in the air of workplace by the detection tube method

Objective: To evaluate the accuracy and applicability of detection tube method for quantitative detection of hydrogen sulfide in workplace air. Methods: In September 2021, the lower limit of quantification, accuracy, precision, environmental factors, interfering gases and other performance indicators of the method for determining hydrogen sulfide in the air of workplace were verified by the detection tube, and the results were compared with those of GB 11742-89 "Standard method for hygienic examination of hydrogen sulfide in air of residential areas-methylene blue spectrophotometric method" to evaluate the application effect of the detection tube method for quantitative detection of hydrogen sulfide in workplace air. Results: There was no significant difference in the results of 2.83 mg/m(3), 4.25 mg/m(3) and 17.00 mg/m(3) hydrogen sulfide concentration between the two methods (P>0.05) , but there was significant difference in the results of 8.50 mg/m(3) concentration (P<0.05) . The lower limit of quantification of hydrogen sulfide in workplace air was 2.83 mg/m(3), the accuracy was 96.0%-111.0%, and the precision was 0.70%-6.64%. Under the condition of 4 ℃, the measured results decreased by 3.39%-13.10%. When the humidity was 50%-80%, the relative error of the average measured value was -1.67%-4.44%. Interference gases that may exist in the workplace (including carbon dioxide, carbon monoxide, mercaptans, nitrogen oxides, sulfur dioxide, etc.) did not interfere with the results of the test tube. Conclusion: The accuracy and precision of the detection tube method meet the detection requirements. The method is simple, rapid and easy to be popularized, and can be used for the rapid detection of hydrogen sulfide gas concentration in the workplace.

Anatomical Study of Nerium oleander L. Leaves Found in Places Contaminated with H2S

The research study the effect of H2S on Nerium oleander leaves, the leaves were collected from the pollution places in the crowded streets with cars and factory areas from five different regions of Basrah city, The results showed that the average of highest concentration of hydrogen sulfide gas was 4. ppm in the Al-Amin Aldakhli area, while the lowest value of gas was recorded in Karmat Ali, it was 0.4 ppm of date palm plants and 0.8 ppm. Anatomy study of N. oleanderleaves showed that the different changes in plant internal tissues with H2S pollution which presented by difference in the thickness of epidermal cell walls of N. oleander leaves in the areas of Al-Dair, Manawi Pasha and Andal’s, while the thickness of the cells was less in the area of Karmat Ali. Highest average length of cells of the upper epidermis was recorded in the Al-Dier and Karmat Ali region was 40 μm and 37.5 μm respectively, while the lower epidermis was 35.82 μmin Al-Dier. Stomata dimension found the lowest average was recorded in the Al-Amin Aldakhli area was 24 μm while in the upper epidermis have highest value, it was in Karmat ali was 30 μm. The number of stomata different between the stations, it was found that the highest average of stomata was found in the lower epidermis in Al-Amin Aldakhli station was 215.98, while the lowest average in Karmat Ali was 98. The upper epidermis had the highest average number of stomata in the Minawi Pasha station was 183.96 on lower epidermis and the lowest average in Andal’s area was 66. Also, the highest average number of cells was in the Lower epidermis in Andal’s region was 3159.96, and the lowest average was 919.98 in the Al-Dair.

Karakterisasi Kadar Air Dan Penyerapan Iodin Karbon Dari Tempurung Buah Nipah Sebagai Adsorben Gas H2S

Air pollution requires proper handling so that the impact can be reduced. Nipah fruit shell contains high cellulose and lignin so that carbon from nipah fruit shell needs to be implemented as an adsorbent to reduce the concentration of Hydrogen sulfide (H 2 S) gas produced from fish waste. The purpose of this study was to determine the characterization of carbon from nipah fruit shells as H 2 S gas absorbers with the effect of time variations of 10 minutes, 15 minutes and 20 minutes. The method of absorption of H 2 S absorption using iodine absorption with iodometric titration. The sampling process went through several stages, such as the carbonization process, carbon characterization process, and H 2 S gas adsorption using carbon that had been characterized by water content and iodine absorption. This research resulted in the production of carbon from nipa palm shell as an H 2 S gas absorber which has a water content characterization of 1.0651% and an iodine absorption capacity of 615.6105 mg/g so that it can adsorb H 2 S gas with an initial concentration of 64 ppm until it reaches the lowest concentration of 5.538 ppm.

CH3SH and H2S Sensing Properties of V2O5/WO3/TiO2 Gas Sensor

Resistive-type semiconductor-based gas sensors were fabricated for the detection of methyl mercaptan and hydrogen sulfide. To fabricate these sensors, V2O5/WO3/TiO2 (VWT) particles were deposited on interdigitated Pt electrodes. The vanadium oxide content of the utilized VWT was 1.5, 3, or 10 wt.%. The structural properties of the VWT particles were investigated by X-ray diffraction and scanning electron microscopy analyses. The resistance of the VWT gas sensor decreased with increasing methyl mercaptan and hydrogen sulfide gas concentrations in the range of 50 to 500 ppb. The VWT gas sensor with 3 wt.% vanadium oxide showed high methyl mercaptan and hydrogen sulfide responses and good gas selectivity against hydrogen at 300 °C.

Influence of hydrogen sulfide gas concentrations on LOD and LOQ of thermal spray coated hybrid-bacterial cellulose film for intelligent meat label

Hybrid nanocomposite thin film for hydrogen sulfide (H2S) gas sensor based on bacterial cellulose nanocrystals (BCNCs) has resulted in high demand of environmentally friendly nanomaterials. Films were prepared using thermal spray coating that sprayed hybrid nanocomposite suspension based on silver nanoparticles (AgNPs)-loaded BCNCs’s surface and alginate-molybdenum trioxide (MoO3NPs) onto PET substratum. In this study, a novel food package label characterized as H2S gas sensor for meat spoilage is based on an optically transparent coated film with thickness ranging from 0.73 to 2.18 μm. Sensor characteristics with different suspension concentrations and various H2S gas concentrations were evaluated. The highest sensitivity to H2S with the limit of detection (LOD) (3.27 ppm) and the limit of quantification (LOQ) (10.94 ppm) was exhibited in 1%w/v suspension. Label prototypes which respond as visible color changes through naked-eye to H2S gas released during meat spoilage, monitored at 4 °C and varying storage times were conducted.

Design of a hydrogen sulfide gas sensor based on a photonic crystal cavity using graphene

Abstract We report the design and simulation of a high sensitivity H2S gas sensor using a combination of graphene properties as a hydrogen sulfide-sensitive nanomaterial and features of photonic crystal cavity. The shoulder-coupled resonant cavity is introduced in the photonic crystal that consists of a triangular array of air holes on the silicon-on-insulator substrate. To adsorb H2S gas, a graphene layer is deposited on the inner wall of the two cavity air holes. Changes in the concentration of hydrogen sulfide gas alter the refractive index of graphene, thereby resulting in wavelength shift in the sensor transmittance spectrum. We achieved a sensitivity of 1.2 × 104 nm/RIU and a detection limit of 1.87 × 10−6 RIU. To the best of our knowledge, the sensitivity of our sensor is much higher than other sensors previously reported in the literature.

Influence of Intermittence and Pressure Differentials in Hydrogen Sulfide Concentration in a Gravity Sewer

The work presented herein was carried out to assess the effect of intermittent pumping events in sewer headspace pressure differentials, as well as their relationship with hydrogen sulfide gas concentration. A full scale gravity sewer in Portugal, located downstream of several pumping stations, was used as the guiding case study. Under normal system operation, pressure difference between the outside atmosphere and the sewer headspace seemed to influence the in and out-gassing of gas pollutants emitted through the venting stack. Wastewater pumping cycles generated maximum pressure differentials of roughly 100 Pa, which in turn originated maximum air velocities of 1.76 m s−1 exiting the venting stack. Each pumping event was followed by a pressure drop of about 50 Pa, quickly attaining null concentrations of H2S at the venting stack. A statistically significant relationship between pressure differentials and air exit velocity was observed, which allowed obtaining an empirical equation for expedite prediction of airflows emitted to the outside atmosphere (R2 = 0.77). Conversely, the same effect was not observed along the length of the sewer pipe, unlike the findings of other studies. The effect of a full flowing pipe at the downstream end of the gravity trunk sewer was also noticeable in downstream sewer pressurization and gas build-up. It was concluded that the magnitude of the gas pollutant emissions may heavily depend on the impacts of hydraulic flows and pumping characteristics in headspace pressure differences, denoting the need for better approaches when designing and installing venting stacks.

224 Impact of bunk management strategy on animal performance, carcass characteristics, and hydrogen sulfide gas concentrations in steers fed modified distillers grains with solubles

Abstract The objective of this study was to evaluate the impacts of bunk management on animal performance, carcass characteristic, and hydrogen sulfide gas concentrations in beef steers fed modified distillers grains with solubles (MDGS; DM basis). One hundred and thirty-nine steers (initial BW = 240 ± 5.17 kg) were allocated into 16 pens and assigned to one of two treatments: 1) Control-managed bunks: bunks devoid of feed prior to feeding; and 2) Long-managed bunks: bunks with approximately 2.54cm of feed remaining at the time feeding. Treatments were applied during a 28-d adaptation period, during which time, steers were adapted to a common finishing ration containing 25% MDGS (DM basis). Ruminal hydrogen sulfide gas was collected by rumenocentesis from two steers from each of three pens per treatment on d 0, 7, 14, and 28, which correspond to days of diet transition. Animal performance data were collected throughout the study and carcass characteristic data were collected when steers reached market weight. There were no differences (P &lt; 0.13) in BW, ADG, or F:G between treatments during the adaptation period or throughout the entire study. Steers managed with long bunks had greater (P = 0.001) intake during adaptation; however, overall DMI was not different (P = 0.14) between treatments. Hydrogen sulfide gas concentrations were not affected by the day x treatment interaction (P = 0.30) but were affected by day (P = 0.003) with hydrogen sulfide concentrations increasing throughout adaptation. Hydrogen sulfide concentrations tended (P = 0.07) to be greater in steers with long-managed bunks vs. control-managed bunks. There were no differences (P &gt; 0.53) in carcass characteristics. In summary, bunk management had no effect on performance or carcass characteristics and only tended to impact hydrogen sulfide gas concentrations.

Release of hydrogen sulfide under intermittent flow conditions - the potential of simulation models.

For engineering purposes it is especially useful to be able to predict and control sewer corrosion rates and odor impacts as well as to design effective measures aiming to reduce effects related to hydrogen sulfide formation and release. Doing so, it is important to use modeling tools that are capable of assessing variations of dissolved oxygen, dissolved sulfide and hydrogen sulfide gas concentrations for a wide range of environmental scenarios. Two such models were assessed: AEROSEPT, an empirical formulation, and WATS, a conceptual and more complex approach. The models were applied to evaluate the effects of transitions between pressure mains and gravity sewers in the air-liquid mass transfer of hydrogen sulfide at the Ericeira sewer system in Portugal. This network is known to have odor and corrosion problems, especially during summer. Despite the unavoidable uncertainties due to the unsteady flow rate and the quantification of air velocity and turbulence, the simulation results obtained with both models have been shown to adequately predict the overall behavior of the system.

Optical fiber evanescent-wave sensing technology of hydrogen sulfide gas concentration in oil and gas fields

For the problems of light source fluctuation noises, zero drift and other problems of H2S gas concentration sensor in optic-fiber evanescent-wave absorption spectroscopy, double-light-path absorption system was designed to theoretically analyze the relationship between evanescent-wave power and gas concentration as well as detection sensitivity. Moreover, the relationship between evanescent-wave power and optical-fiber residual diameter in the optic fiber corrosion process was also studied. The sensing probes with different evanescent-wave power ratios were used to detect experiments of H2S gas concentration. The experimental results show that the sensitivity is up to 0.169μw/ppm when the evanescent-wave power ratio of sensing probe is 10%, detected minimum H2S gas concentration is 5.1ppm, the detection repeatability is good and the response time is only 2.03s. Due to low production cost, high sensitivity and short response time, the optic-fiber evanescent-wave sensor can be used for real-time on-line measurement of H2S gas in the area of the hydrocarbon exploration and development.

Effects of dried distiller's grains and lasalocid inclusion on feedlot lamb growth, carcass traits, nutrient digestibility, ruminal fluid volatile fatty acid concentrations, and ruminal hydrogen sulfide concentration.

Our hypothesis was that increasing the inclusion level of dried distiller's grains with solubles (DDGS) to feedlot lambs would increase growth and the inclusion of lasalocid (LAS; Bovatec, Alpharma, LLC, Bridgewater, NJ) would increase ADG and G:F, while not affecting digestibility, ruminal VFA concentration, and ruminal pH. Furthermore, we hypothesized that rations containing LAS and higher levels of DDGS would cause increased ruminal hydrogen sulfide gas (HS) concentrations. Two hundred forty crossbred (Suffolk × Rambouillet) lambs (31.9 ± 5.87 kg BW; approximately 90 d of age) were allocated to 6 treatments in a completely randomized design with a 3 × 2 factorial arrangement of treatments. Lambs were placed into 24 feedlot pens (4 pens/treatment; 10 lambs/pen) for a 111 d finishing study. Main effects included concentration of DDGS (0, 15, or 30% DM basis) and inclusion of LAS (0 or 22.05 g/metric ton LAS) resulting in treatments of: 1) 0% DDGS without LAS (0DDGS-NL), 2) 0% DDGS with LAS (0DDGS-L), 3) 15% DDGS without LAS (15DDGS-NL), 4) 15% DDGS with LAS (15DDGS-L), 5) 30% DDGS without LAS (30DDGS-NL), and 6) 30% DDGS with LAS (30DDGS-L). Two-day weights were taken at the beginning and end of the experiment. Two-hundred-eighteen lambs (64.8 ± 7.99 kg BW) were slaughtered on d 112 at a commercial abattoir and carcass data collected. The inclusion of LAS increased ( ≤ 0.02) final BW, ADG, G:F, and HCW. As DDGS in the ration increased to 30%, DMI decreased linearly ( = 0.03) while G:F increased linearly ( = 0.03). A second study was conducted utilizing the same treatments to evaluate N and S balance, ruminal VFA and H2S concentration, and ruminal pH in 24 crossbred wethers (Suffolk × Rambouillet; 41.2 ± 12.23 kg BW). Daily urinary sulfur excretion and ruminal H2S concentration were linearly increased ( < 0.001) as DDGS increased in the ration. Total ruminal VFA concentration linearly decreased ( = 0.002) as DDGS increased in the ration. The inclusion of LAS increased ( = 0.02) ruminal pH. The results confirm our hypothesis that LAS increased overall growth and increasing DDGS increased ruminal HS concentration but did not influence growth. We reject the hypothesis that the combined effects of LAS and DDGS would have no effect on rumen pH and VFA concentrations.

Release of hydrogen sulfide in a sewer system under intermittent flow conditions: the Eiceira case study, in Portugal.

The presence and fate of hydrogen sulfide in wastewater systems were studied in two stretches of an intercepting sewer system located in a coastal village, in Portugal. A range of hydraulic parameters were obtained and liquid and gas phase measurements were carried out, both continuously and through intensive sampling campaigns. Upstream, where flow rates were relatively low, dissolved sulfide concentrations around 12 mg S L-1 and hydrogen sulfide gas concentrations above 250 ppm were observed, along with limited corrosion damage. It is believed this is due to the low relative humidity detected along the atmosphere of the studied sewer system. Downstream, gas concentrations were always below 40 ppm. Despite that, high signs of corrosion were detected, particularly in manholes with drop structures. It is thought that condensation of spray produced by the fall is the main cause of the phenomenon. Another relevant observation was the rapid decline in dissolved sulfide contents along gravity trunk sewers following the discharge of rising mains, with loss rates as high as 40 mg S L-1 h-1. Air-flow velocities corresponded to 15-50% of wastewater flows, an observation which agrees with other authors' publications addressing relatively small pipes and moderate water flows.

Novel proximal fish freshness monitoring using batteryless smart sensor tag

Fish is the most perishable of fresh foods, but it is held in high regard for its flavor, taste and nutrition for the human body. Until now, most studies on monitoring the freshness of fish have used semiconducting metal oxide sensors that consume much power in sensing operation. To supply the operational sensing power and the power for wireless communication, any wireless sensor module needs a battery attached, and this entails extra effort for a regular battery change. Therefore, we developed a novel fish monitoring system in which no battery is needed for the sensing module. This study proposes a novel proximal fish freshness monitoring system. The novel smart sensing tag module has been developed as a self-powered device by using an additional energy harvesting circuit that operates at a frequency of 13.56MHz. The harvester can collect sufficient radio frequency (RF) energy from the reader by using RF energy coupling within a maximum distance of 30cm; then, the received power is stored in a single energy chip for supplying to the sensing circuit. The fish freshness is monitored by sensor modules for temperature and either hydrogen sulfide (H2S) or ammonia (NH3) gas concentration measurement in the fish packaging. The sensing module is designed using ultra-low-power sensors that consume less than ∼10mW, enabling us to extend the distance between the RF reader and the smart sensor tag for effective RF energy coupling and sensing data transmission. The results of freshness monitoring of a seafish package are classified into four grades to indicate the food quality: good, normal, caution, and bad. The proposed sensor tag can be used to predict the quality of packaged fish by accurate monitoring of temperature and the concentration of H2S or NH3 in range of −40 to 105°C, 0–200ppm, and 0–100ppm, respectively.

Effects of dietary roughage and sulfur in diets containing corn dried distillers grains with solubles on hydrogen sulfide production and fermentation by rumen microbes in vitro.

Dried distillers grains with solubles (DDGS) have been used in production animal diets; however, overuse of DDGS can cause toxic concentrations of ruminal hydrogen sulfide gas (HS), resulting in polioencephalomalacia, a deleterious brain disease. Because HS gas requires an acidic rumen environment and diet can influence ruminal pH, it has been postulated that dietary manipulation could help mitigate HS production. The objective of this study was to assess the effect of dietary roughage and sulfur concentrations on HS production and rumen fermentation. In Exp. 1, 7 dual-flow continuous culture fermenters were used in 4 consecutive 9-d periods consisting of 6 d of adaptation followed by 3 d of sampling. At the conclusion of each 9-d continuous culture period, adapted rumen fluid was used for inoculation of 24-h batch culture incubations for Exp. 2. For both experiments, 6 dietary treatments were formulated to consist of 0.3%, 0.4%, or 0.5% dietary sulfur (LS, MS, and HS, respectively) and 3% or 9% dietary roughage (LR and MR, respectively), using grass hay as the roughage source. A corn-based diet without DDGS was used as a control diet. Headspace gas was sampled to determine HS production and concentration. In Exp. 1, greater dietary roughage had no effect ( = 0.14) on HS production but did create a less acidic environment because of an increase ( < 0.01) in the in vitro pH. In Exp. 2, an increase in dietary sulfur caused an increase ( = 0.04) in ruminal HS production, but there was no direct effect ( = 0.25) of dietary roughage on HS production. Greater dietary roughage resulted in a less ( = 0.01) acidic final batch culture pH but a lower ( < 0.01) total VFA concentration. Further investigation is needed to determine a more effective way to mitigate ruminal HS production using dietary manipulation, which could include greater inclusion of dietary roughage or the use of different roughage sources.

Development of a hydrogen sulfide end-of-service-life indicator for respirator cartridges using cobinamide

An inexpensive paper-based sensor was developed for detecting low ppm concentrations of hydrogen sulfide gas. A piece of filter paper containing aquohydroxocobinamide [OH(H2O)Cbi] was placed on the end of a bifurcated optical fiber, and the reflectance spectrum of the OH(H2O)Cbi was monitored during exposure to 10.0ppm hydrogen sulfide gas (NIOSH recommended exposure limit). Reaction of sulfide (HS-) yielded an increase in reflectance from 400–450nm, and decrease from 470–550nm. Spectral changes were monitored as a function of time at 25, 50, and 85% relative humidity. Spectral shifts at high-er humidity suggested reduction of the Cbi(III) compound. The sensor was used to detect hydrogen sulfide breakthrough from respirator carbon beds and results correlated well with a standard electrochemical detector. The simple paper-based sensor could provide a real-time end-of-service-life alert for hydrogen sulfide gas.

High-resolution microbial community succession of microbially induced concrete corrosion in working sanitary manholes.

Microbially-induced concrete corrosion in headspaces threatens wastewater infrastructure worldwide. Models for predicting corrosion rates in sewer pipe networks rely largely on information from culture-based investigations. In this study, the succession of microbes associated with corroding concrete was characterized over a one-year monitoring campaign using rRNA sequence-based phylogenetic methods. New concrete specimens were exposed in two highly corrosive manholes (high concentrations of hydrogen sulfide and carbon dioxide gas) on the Colorado Front Range for up to a year. Community succession on corroding surfaces was assessed using Illumina MiSeq sequencing of 16S bacterial rRNA amplicons and Sanger sequencing of 16S universal rRNA clones. Microbial communities associated with corrosion fronts presented distinct succession patterns which converged to markedly low α-diversity levels (< 10 taxa) in conjunction with decreasing pH. The microbial community succession pattern observed in this study agreed with culture-based models that implicate acidophilic sulfur-oxidizer Acidithiobacillus spp. in advanced communities, with two notable exceptions. Early communities exposed to alkaline surface pH presented relatively high α-diversity, including heterotrophic, nitrogen-fixing, and sulfur-oxidizing genera, and one community exposed to neutral surface pH presented a diverse transition community comprised of less than 20% sulfur-oxidizers.

Identifying Production Sources and Quantifying H2S Gas from Underground Storage and Facilities of Masjid Suleiman Oil and Gas Exploitation Company

Hydrogen sulfide gas is one of the most dangerous gases in the workplaces of oil and gas industry and is considered as a contrary combination in gas reservoirs which not only reduces the economic contribution of hydrocarbon of gas reservoirs, but also is toxic and causes corrosion of equipment exploiting the reservoirs. In this study, due to high levels of hydrogen sulfide gases in Masjid Suleiman oil and gas Exploitation Company And risks associated with it, it was attempted to identify the sources of producing and detector hydrogen sulfide gas in the area. For this purpose, after identifying the sources of hydrogen sulfide gases emissions in the area of the study, finally 8 points (including 5 units of Masjid Suleiman oil and gas Exploitation Company such as unit 9 Bibayan, Talbezan, Anbar, Nargesi, and Zilaeai and 3 urban regions of Kuye Naftkhiz, Siberenj, and Pansium e Khayam) as the major points of leaks have been identified and evaluated in 4 months of May, July, September and November by the use of gas detector device. The results showed that the concentration of hydrogen sulfide gas in urban areas ranged from 15 to 17 ppm. While the amount of gas emissions in Masjid Suleiman oil and gas Exploitation Company was anticipated from 2 to 5 ppm respectively. It was also found that the differences of concentration of hydrogen sulfide gases are not significant in various months there. Comparison of the results with national and international standards confirmed that in urban areas, the concentration of hydrogen sulfide gases is beyond the scope of the standard but in the installations the amount of the gas is only beyond OEL-TWA standard values.

Effects of dietary sulfur source on rumen pH and hydrogen sulfide gas concentration

A variety of sources of S have been utilized to study S toxicity in cattle; however, it is unknown if these S sources have similar potential to produce ruminal hydrogen sulfide (H2S). The objective of this study was to evaluate the effects of different sources of dietary S commonly used in ruminant S toxicity research on ruminal pH and gas-cap H2S. Five cannulated steers were used in a 5×5 Latin square and fed 1 of 5 diets containing 0.49% S once daily at 1.3% of body weight (DM basis). Dietary S sources included ethanol co-products: dried distillers grains plus solubles (DDGS), condensed corn distillers solubles (CCDS), or inorganic sources: sulfuric acid (SA), sodium sulfate (SS), and calcium sulfate (CS). All diets contained 45% corn and 10% grass hay (DM basis). In the DDGS treatment, DDGS was included at 42% diet DM and contributed 0.40% S. In the non-DDGS treatments, DDGS was included at 21% diet DM and contributed 0.19% S to these diets. In the CCDS treatment, CCDS was included at 7% diet DM and contributed 0.19% S to the diet. For the inorganic treatments (SA, SS and CS) S sources contributed 0.17% S to the diet. In the non-DDGS diets, soyhulls were included to make up the balance of diet DM (15% diet DM for CCDS diet and 21% diet DM for the inorganic S source diets). Sampling of ruminal pH and H2S gas concentration occurred at 6h post-feeding. Diet pH (P<0.01; SEM±0.032) differed due to S source, with SA (3.93) having the lowest pH (P<0.01) whereas SS (4.79) and CS (4.79) were greatest (P<0.01), but did not differ (P=0.97). The co-product diets were intermediate, with DDGS (4.08) having a lower (P<0.01) pH than CCDS (4.18). However, ruminal pH at 6h post-feeding (SEM±0.076) was least (P<0.01) for CS (5.03), followed by SA (5.28) which was lesser (P≤0.05) than DDGS (5.40), SS (5.43), and CCDS (5.50) which did not differ (P≥0.09). There was no difference in S intake (P=0.31) or ruminal H2S concentration (P=0.62) among treatments. Even though dietary pH varied among treatments ruminal pH differences were minimal and no differences in ruminal H2S were observed, suggesting that results of experiments utilizing these different S sources to research S toxicity may be comparable.

Preparation of Sorbent Loaded with Nano-CuO for Room Temperature to Remove of Hydrogen Sulfide

In this paper, an efficient metal oxide sorbents for the deep removal of H2S were synthesized using equal volume impregnation (EVIM) method. Modified coconut shell charcoal was selected as support to deposite the particles of copper oxide onto the surface. And copper nitrate were selected as the active component precursors in the preparation process of sorbents. Sorption experiments were carried out at room temperature in fixed-bed reactor. The grain size and crystal form of loading metals were characterized by X-ray diffraction (XRD). We investigated the effects of modifier onto coconut shell charcoal, load rate of metal oxide and calcination temperature on the desulfurization activity of the sorbent. Results show that the best modifier for coconut shell charcoal is KOH, which is significantly better than the other modifiers. And the optimum load rate is 20%(wt), the optimum calcination temperature is 300°C. Copper oxide onto the surface of modified coconut shell charcoal proved to be monoclinic nanoparticles with grain size of 18.7nm. Sulfidation test was carried out on the condition of i) the concentration of hydrogen sulfide gas (mixed with nitrogen ) is 1024.2ppm and ii) gas velocity is 20ml/min, iii) 0.1g sample in the middle of the fixed-bed reactor (length: 450 mm, interior diameter: 5 mm) to test. The sample show excellent sulfur removal efficiency and its breakthrough time is up to 287 min on this condition.