Hydrogen Sulfide Concentrations Research Articles

207 Effect of Sodium Sulfate in Water and Dietary Bismuth Subsalicylate on Feed and Water Intake, Ruminal Hydrogen Sulfide Concentration, and Trace Mineral Status of Growing Beef Heifers

Abstract Cattle consuming increased concentrations of sulfur (S) are at an increased risk for depletion of copper (Cu) and or S-induced polioencephalomalacia and there are limited mitigation strategies to alleviate risk for cattle consuming high sulfate water. This study evaluated the effects of feeding growing beef heifers bismuth subsalicylate (BSS; 0.0 vs. 0.4% DM basis) when provided water with a low (LS; 346 ± 13) or high (HS; 4,778 ± 263 mg/L) sulfate concentration on dry matter intake (DMI), water intake, ruminal hydrogen sulfide (H2S) concentration, and trace mineral status. Twenty-four beef heifers (221 ± 41 kg) were stratified based on initial liver copper concentrations collected 13 d before the start of the study, into a completely randomized block design using a high forage diet fed for 98 d. Feed and water intake (weekly), ruminal H2S concentration (d 42 and 91), and liver (pre-study and d 91) and serum trace mineral concentrations (d 1, 28, 56, and 91) were evaluated. Initial liver trace-mineral concentration was used as a covariate in the statistical model. Water intake tended to be reduced with the inclusion of BSS (P = 0.10) but was not affected by water sulfate (P = 0.40). Water sulfate and BSS did not affect DMI (P ≥ 0.89), but total S intake increased (P < 0.01) from LS to HS (17.6 to 51.0 g/d) resulting in diets that contained 0.28 and 0.78% S (DM basis). Heifers consuming HS had 1.58 µg/mL more (P < 0.01) ruminal H2S than LS. The inclusion of BSS reduced (P = 0.04) ruminal H2S concentration by 46%. Regardless of water sulfate concentration, heifers fed BSS had lesser liver Cu (average of 4.08 mg/kg) than heifers not provided BSS, and when not provided BSS, HS had lesser Cu than LS (42.2 vs. 58.3; sulfate × BSS, P = 0.02). Serum concentration of Cu did not differ over time for heifers not provided BSS; whereas heifers provided BSS had less serum Cu on d 91 than d 28 and 55 (BSS × time, P < 0.01). The liver concentration of selenium (Se) was reduced (P < 0.01) with BSS inclusion. The Se concentration in serum was not affected by sulfate, BSS, or time (P ≥ 0.16). Bismuth subsalicylate reduces ruminal H2S concentration, but depletes liver Cu and Se. Moreover, sulfate concentration in water does not appear to affect DMI or water intake but reduces liver Cu concentration.

PSVIII-A-1 Effect of Source of Trace Mineral and Bismuth Subsalicylate on Growth, Ruminal H2s, and Trace Mineral Status of Growing Heifers

Abstract This study evaluated the effects of providing inorganic, chelated, and inorganic plus injectable trace mineral supplementation strategies with or without the inclusion of bismuth subsalicylate (BSS) on dry matter intake (DMI), water intake, ruminal hydrogen sulfide (H2S) concentration, and trace mineral status of growing beef heifers provided high sulfate (5,055 ± 228 mg/L) water. This study consisted of an 84-d feeding period with a 2×2 + 1 factorial treatment arrangement conducted using 2 blocks. Beef heifers (n = 15/block; 367 ± 33 kg BW) in each block were stratified according to their initial liver copper concentration. Mineral treatments included inorganic [added CuSO4 (7.76 mg/kg), ZnSO4 (22.92 mg/kg), MnSO4 (15.28 mg/kg)], chelated (100% of the Cu-methionine (7.68 mg/kg ), Zn-methionine (22.89 mg/kg), and Mn-methionine (15.27 mg/kg), and injectable trace mineral (15 mg/mL Cu, 10 mg/mL Mn, 60 mg/mL Zn) provided in combination with the inorganic mineral treatment. The BSS treatments were 0.0 (CON) or 0.2% (BSS) on a DM basis. Feed and water intake (weekly), ruminal H2S concentration (d 42 and 84), and liver (pre-study, d 42 and 84) and serum trace mineral concentrations (d 1, 28, 56, and 84) were evaluated. Initial liver trace mineral concentration was used as a covariate. Dry matter intake tended to be greater (mineral × BSS, P = 0.05) for heifers provided chelated minerals and fed CON, compared with BSS, and tended to be less for heifers fed inorganic and CON than BSS. Heifers fed chelated minerals drank 6.1 L/d more (P < 0.05) water than those provided inorganic minerals. Injectable trace-mineral provision did not affect DMI or water intake. Ruminal H2S was not affected by mineral type or BSS (P ≥ 0.33). The inclusion of BSS reduced (P < 0.01) liver Cu concentration from 60.5 to 31.3 ppm. Heifers provided the injectable minerals had greater (P < 0.01) liver Cu concentration than the inorganic without BSS treatment. Serum copper was not affected by BSS or mineral treatment (P ≥ 0.44). The liver concentration of Se was reduced (P < 0.01) by the inclusion of BSS. The serum Se concentration was not affected by mineral type, BSS, time, or any two- or three-way interactions (P ≥ 0.24). Bismuth subsalicylate did not affect ruminal H2S, and negatively affected liver Cu concentration. The use of organic trace mineral supplementation strategies did not affect the trace mineral status of beef heifers drinking high sulfate water, but use of an injectable trace mineral supplement increased liver Cu.

The effect of anaerobic remineralization of the seagrass Halophila stipulacea on porewater biogeochemistry in the Gulf of Aqaba

IntroductionSeagrasses form oxidizing microenvironments around their roots, creating complex and strong redox gradients, thus affecting the rates of microbial carbon mineralization in their surrounding sediments. Since seagrasses are continuously being lost worldwide, a deeper understanding of the changes that occur within different seagrass sediments following the disappearance of the plants is of ecological and global importance.MethodsWe conducted a slurry experiment with sediments that have different characteristics from the northern tip of Gulf of Aqaba; the different sediments included different compartments of the tropical seagrass Halophila stipulacea (old and young leaves, rhizomes, or roots). We measured the changes over time in dissolved inorganic carbon (DIC), alkalinity, ferrous iron (Fe2+), hydrogen sulfide (H2S), sulfate (SO42-), and sulphur isotope ratios in sulfate within water. These measurements were used to calculate the rate of remineralization of each seagrass compartment, allowing us to predict the potential effects of the disappearance of different H. stipulacea compartments on key microbial processes in the surrounding environment.ResultsWe show that H. stipulacea’s rhizomes had the fastest decomposition rates, followed by the young leaves, roots, and old leaves (which also indicates the preservation potential of old leaves).DiscussionHigh concentrations of hydrogen sulfide were detected only in the slurries containing rhizomes and young leaves. High sulfide concentrations can lead to seagrass mortality and cause a positive feedback loop where the loss of seagrass due to sulfide generates further sulfide accumulation. This positive feedback loop can also be further reinforced by the loss of burrowing fauna in the sediment. This emphasizes the importance of understanding the extent of different pathways of seagrass disappearance on the surrounding environment and other geochemical feedbacks.

Environmental influence on summer survival of Manila Clam Ruditapes philippinarum: A case study in an aquaculture bay

The aquaculture of Manila clam (Ruditapes philippinarum) is under threat due to its high mortality in summer. To investigate the environmental influence on mortality of the species, we have conducted field surveys in the aquaculture area in Laizhou Bay, during the summers of 2019 and 2020. Environmental and biological data were collected. The results of data analysis have shown that in 2020, large-scale mortality events were not recorded and spatial variations of environmental variables were no significant within the survey area. However, in August 2019, significant variations of environmental variables were detected in the middle tidal area. This area was charactered with relatively high-water temperature (with maximum temperature of 31.49 °C and mean value of 26.17 ± 1.62 °C), elevated hydrogen sulfide concentrations (with a maximum concentration of 24.72 μmol/L and a mean concentration of 7.89 ± 4.14 μmol/L), and low dissolved oxygen concentrations (with a minimum concentration of 3.35 mg/L and a mean concentration of 6.27 ± 0.42 mg/L). Correspondingly, high mortality of the clam was recorded in the area, the abundance of live Manila clams has decreased by 80%. No significant abnormalities of environmental variables and clam growth were observed in other regions in 2019. Glycogen content and condition index of the clam were analyzed to investigate the relationship between environmental stress and the health of the clam. Compared to the condition index, glycogen content is a more sensitive indicator of the health status of the clam because changes in glycogen content appeared earlier than changes in condition index and mortality. A principal component analysis further indicated that the high mortality of the clam corresponds with a few environmental variables, including elevated temperature, hypoxia and the concentration of hydrogen sulfide. The simultaneous presence of these multiple environmental stressors could have triggered alterations in the physiological responses of the clam.

Fusobacterium nucleatum and its metabolite hydrogen sulfide alter gut microbiota composition and autophagy process and promote colorectal cancer progression.

Fusobacterium nucleatum is a harmful bacterium that produces hydrogen sulfide by metabolizing sulfur-containing amino acids, both of which have been shown to promote/initiate the development of various cancers, such as colorectal cancer, liver cancer, as well as lung cancer. However, few studies have reported how F. nucleatum acts on gut microbiota, influences the autophagy process, and promotes the development of colorectal cancer through the metabolite hydrogen sulfide. It was found that HCT116 cells secreted more inflammatory factors and showed higher survival as well as migration rate when given a pathological concentration of hydrogen sulfide. Using cellular transcriptome sequencing, it could be seen that after giving HCT116 cells F. nucleatum or F. nucleatum with L-cysteine, many inflammation-related signaling pathways, including autophagic pathways, were elevated compared to the control group. In vivo, the mice in the model groups displayed cancer progression, and the expression of some of the autophagy-related genes, DRAM1, NBR1, ATG7, MAP1LC3A were also increased in mice given F. nucleatum or F. nucleatum with L-cysteine when compared to the untreated control mice. The number of certain probiotic bacteria and fungi in the mice given F. nucleatum or F. nucleatum and L-cysteine decreased significantly; in contrast, the number of potentially pathogenic bacteria and fungi increased. These findings suggest that F. nucleatum and its metabolite hydrogen sulfide can modulate intestinal microbiota and autophagy as well as promote the development and progression of colorectal cancer.IMPORTANCEColorectal cancer (CRC) is the second most common cancer in the world; the main treatment for CRC is immunosuppressive therapy, but this therapy is only effective for a small percentage of CRC patients, so there is an urgent need for a treatment with fewer side effects and higher efficacy. This study demonstrated that Fusobacterium nucleatum with increased abundance in CRC can regulate the autophagy process and disrupt normal intestinal microbiota by producing hydrogen sulfide, factors that may be involved in the development and progression of CRC. This study may provide a reference for future CRC treatment options that are efficient and have fewer side effects.

Enhancing Ecological Efficiency in Biological Wastewater Treatment: A Case Study on Quality Control Information System

This study aimed to improve the control system of the biological stage of wastewater treatment using the quality control information system to support the concept of environmental efficiency management. In this case, the object of the study was the treatment facilities of Sumy city (Ukraine). For automatic control of wastewater quality, pH, oxidation reduction potential (ORP), electrical conductivity, and temperature indicators were taken, as well as hydrobiological analysis of activated sludge and mathematical modelling. The pH of wastewater at the input system has systematically unacceptable values (above 8.5 were recorded). Unacceptable concentrations of sulphur-containing toxicants arrive at the entrance of treatment facilities (0.22–1.3 mg/L). The response of activated sludge biocenosis to increasing concentrations of hydrogen sulphide in wastewater was analysed. Furthermore, a mathematical model of monoculture population growth, with two factors that affect population growth (nutrient concentration and monoculture production concentration), was implemented for the initial assessment of possible negative effects on wastewater treatment. The differential equation of the population dynamics of the i-th species of microorganisms in activated sludge was described. The applied system of automated monitoring of wastewater parameters with expert assessment of activated sludge and a unified mathematical model of approaches allows for a complex system of decision-making support to be realised. However, this requires the construction of mathematical models that would take into account the cause–effect relations that operate under conditions of incomplete technological information and the potential presence of emergencies due to natural disasters and military activities.

Simulation of the Modes of Medium Flow Movement through a Gas Pipeline during Corrosion Tests

Elevated concentrations of corrosive carbon dioxide or hydrogen sulfide in gas and gas condensate both produced and transported through pipelines lead to serious corrosion damage to the internal surfaces of steel infrastructure facilities. The paper presents the results of studying the corrosive effect of the medium flow along the lower component of the gas pipeline, which can exhibit a dynamic, intermittent or static character. During testing, the effect of both dynamic conditions of the medium flow on the U-shaped cell and static conditions of the permanent impact of the aqueous phase on the pipeline wall during the bubble test was evaluated. Modeling of variable wetting conditions inside the gas pipeline showed that such conditions are typical and occur upon production and transportation of raw gas to the places of gas processing and purification. We have simulated dangerous operational factors that occur inside the gas pipeline: the composition of the aquatic environment, temperature, and the content of corrosive gases. When determining the resistance of steels to local forms of corrosion (pitting, wide and shallow corrosion pits), we revealed that the rate of developing local and general corrosion of steel in aggressive carbon dioxide and hydrogen sulfide conditions can reach 2 – 3 mm/year. In addition, it has been shown that the use of corrosion inhibitors for protecting the equipment and pipelines of gas facilities can effectively prevent the occurrence of internal corrosion processes. The results obtained can be used in assessing the corrosion activity of operating media and selecting the most proven corrosion inhibitors for pilot testing at gas fields.

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.

Simulation Of Acidic Water Purification Process In Refinery Based On Determining Appropriate Operating Conditions

Acidic process water produced by refineries contains some hazardous pollutants such as (H2S and NH3). Acid water extraction units remove both compounds from the water. The removed contaminants are sent to a sulphur recovery unit to produce sulphur and avoid any acid emissions contrary to environmental regulations. Water pollution is a problem that concerns all people in the world. In view of the importance of preserving the environment and water resources, in this research, the simulation of the acid water treatment unit in the refinery was studied using the Aspen Hysys software based on determining the appropriate operating conditions. The NRTL electrolyte activity coefficient model was used to predict the system's thermodynamic behaviour. The simulation results showed that the suitable temperature for the feed entering the tower is about 38°C and the convenient distance for the trays in the disposal tower is 0.54 mm. Under these conditions, the concentration of hydrogen sulphide 0.1694 and 0.2418 of ammonia in the acid gas exiting the tower reaches its maximum at a molar flow rate of the mixture of about 39.86 kgmol/h, according to the economic considerations of the operating tower.

Гидрохимические особенности озёр Большое и Малое Турали по результатам исследований в 2018 и 2021 годах

In the summer months of 2018 and 2021, concentrations of major ions, dry residue, pH and temperature were determined in the water of the Maloe and Bolshoe Turali lakes; in various horizons (up to 20 cm) of bottom sediments, in addition to concentrations of methane and total hydrogen sulfide, Eh and pH values, humidity and density were determined. The mineralization of the waters of the Bolshoe and Maloe Turali lakes in 2018 was 275.8 and 19.1 g/dm3, respectively. According to the chemical composition, the class of waters in lakes is chloride, the sodium group, the second type. In 2021, the mineralization of lakes decreased, especially strongly in the lake Bolshoe Turali. It is shown that the significant salinization of its waters is not associated with precipitation, but is caused by artificial flooding of the feeding channel with water. Lake sediments are characterized by a neutral or slightly alkaline environment (pH from 7.01 to 7.88) and strong variability of redox conditions (Eh from -213.8 to 177.1 mV). The concentrations of CH4 in the sediments of the Maloe and Bolshoe Turali lakes varied in the range of 0.006–0.070 μg/g of wet sediment and 0.011–0.12 μg/g, respectively. The concentrations of ΣH2S varied from <0.005 to 0.241 mg/g in the lake of Maloe Turali and from <0.005 to 1.47 mg/g in the lake of Bolshoe Turali. The relationship between CH4 and ΣH2S is weakly manifested, which is due to their insignificant concentrations associated with Eh not low enough for intensive anaerobic processes in most sediment horizons.

Концентрация и эмиссия метана и сероводорода в озере Баскунчак, ручье балки Улан-Благ и дегазирующих источниках подземных вод в весенний период

For the first time, the distribution of methane in the brine and bottom sediments of Lake Baskunchak, as well as its tributary, the Ulan-Blag stream, in the beam of which the discharge of ascending degassing groundwater sources takes place, was studied. In addition to CH4, concentrations of total hydrogen sulfide (ΣH2S), Eh and pH values, humidity and density were determined in various horizons (up to 35 cm) of stream sediments. Concentrations of CH4, major ions and pH values were determined in the brine of the lake and stream; experimental measurements of CH4 emission by the chamber method were carried out on one of the debit fields where degassing sources are discharged. Brine mineralization in Lake Baskunchak is 312 g/dm3, which is 2.1 times more than in the Ulan-Blag stream; the water class in the stream and lake is chloride, the sodium group, type II and III, respectively. The fluxes of CH4 into the atmosphere from the surface of the studied degassing source vary in the range of 1.97–2.07 mg/(m2 h). In the brine of degassing sources, a high concentration of CH4 (up to 215 μl/dm3) is recorded, which is 1-2 orders of magnitude higher than in the brine of the lake. Low concentrations of CH4 in the brine of the lake are due to its insignificant flow from bottom sediments into the water due to the presence of a salt crust that prevents gas emission, as well as due to its small concentrations in the upper layers of sediments (0.01 μg/g). Low concentrations of CH4, despite the reducing conditions, are also characteristic of the sediments of the mouth of the Ulan-Blag creek (0.04–0.32 μg/g), which, at high concentrations of ΣH2S in them (0.06–1.32 mg/g), is probably caused by the suppression of methanogenesis in the sediments by sulfate reduction. In general, the distribution of CH4 and ΣH2S along the vertical of deposits is quite synchronous (r = 0.64) and correlates with the distribution of Eh values.

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.

Sour-Rated 10,000-psi System High-Temperature Gas Development Wells: Sustaining the Malaysian National Gas Supply Through a Journey of Optimization in North Malay Basin

Summary High temperature (HT), high carbon dioxide (CO2) coupled with hydrogen sulfide (H2S) contents, and rapid pore pressure fracture gradient (PPFG) pressure ramp increase in gas development wells can lead to significant capital expenditures for operators. Such wells typically need high corrosion resistance alloy material with at least a 10,000-psi (10-ksi)-rated system to complete. The deep reservoirs of the North Malay Basin, offshore peninsular Malaysia, also fall into the described category. In this paper, we aim to share the optimization journey, applications, and learnings of the company’s HT sour-rated 10-ksi gas development wells through several phases, besides fulfilling the gas delivery need for the country. In addition, we identify engineering and operational optimizations to reduce the well’s time and cost while upholding the safety of the crew as a top priority. The sour-rated HT gas development campaign for the company began in the year 2017, followed by a second campaign in the year 2018. Our focus centers on the third campaign, which concluded in the year 2022. A total of four, three, and four wells were drilled and completed in the first, second, and third campaigns respectively. The company’s wells engineering team applied Lean methodologies that covered the entire Plan-Do-Check-Adjust cycle to achieve optimization. Using well data, learning from experiences, working together, maintaining consistency, and pursuing ongoing enhancements are the main factors that ensure positive optimization outcomes. Fit-for-purpose drilling and completions equipment design and application, rig offline capabilities planning, wellhead dummy hanger plug design for offline cementing, intervention-less production packer setting device, offline annulus nitrogen cushion fluids displacement, and other applications will be explained in the paper. In this paper, we describe the operational challenges faced and outline the applied optimizations that led to significant improvements in the well performance compared with targets and previous campaigns. The optimization efforts by the wells team extended from the engineering phase to the execution stage, including the use of in-house digital capabilities to monitor well performance, in alignment with industry practice. The recent campaign post-optimization concluded with no safety incidents, average per well more than 48 days ahead with 39% lower cost than previous campaigns, average of 5.6% overall well nonproductive time (NPT), and achieved first gas to meet the country’s power generation demand. Furthermore, the motivating optimization results also coupled with 25% more production results compared with the prognosed. The positive results of this optimization journey were significantly influenced by transparent, collaborative, and proactive communication across different departments.

Role of garbage classification in air pollution improvement of a municipal solid waste disposal base

Assessing the impact of garbage classification on air pollution in rapidly developing economic regions is particularly necessary in light of the current policy trends. We evaluated the resulting changes in air pollution levels before and after garbage classification based on a three-year field observation using high-resolution online instruments in a municipal solid waste comprehensive disposal base. A targeted scheme is proposed to analyze the variation characteristics of major sources in a complex multi-source environment (Environments with multiple sources of pollution). We found that the concentrations of hydrogen sulfide (H2S) and volatile organic compounds (VOCs) in ambient air decreased by 48% and 43% respectively after garbage classification, and their spike frequency was controlled at approximately 0.01. The average H2S and VOC concentrations were generally low during the daytime, but relatively high during the nighttime because of meteorology and photochemistry. The ozone formation potential of the base decreased by 56%. Alternatively, emissions from transportation and combustion sources increased, while landfill pollution decreased owing to changes in the method of waste disposal. This finding suggests that garbage classification is an effective means of improving the air quality. This new scheme has a good potential in actual research scenarios.

Comparative Study of Air Quality Assessment in Bonny, Bille And Degema Communities in The Niger Delta Region, Nigeria

Purpose: This study was undertaken to ascertain the air quality in the oil-producing towns for the purpose of making recommendations that address the health challenges of the inhabitants Gas flaring has a negative impact on air quality in oil-producing towns. &#x0D; Methodology: This paper adopted Robert King's Exposure Risk Theory from the late 1970s, this research employs an experimental design to analyze air quality in Bonny, Degema, and Bille towns located in Rivers State. Data was collected from these towns, followed by rigorous laboratory analysis to evaluate air quality. A comparison of these findings with the air quality guidelines established by the World Health Organization (WHO) was made to facilitate an understanding of potential health implications associated with air quality issues in the study area.&#x0D; Findings: The study reveals that nitrogen (IV) oxide (NO2) concentrations spanned from 0.006 to 0.085 ppm in Station 3 and 0.018 to 0.006 ppm in Station 1. Notably, statistically significant differences (P &lt; 0.05) in NO2 levels were observed across the diverse towns of the Niger Delta investigated in this study. The high recorded levels of nitrogen (IV) oxide (NO2) can potentially be attributed to heightened vehicular emissions in Bonny relative to Degema and Bille. Furthermore, the study identifies hydrogen sulphide (H2S) concentrations ranging from 0.001 ppm to 0.123 ppm, with the highest levels in Bonny. Carbon (II) oxide (CO) levels varied between 0.032 and 3.355 ppm in Degema and Bonny, respectivelyy. No statistically significant difference (P &gt; 0.05) was found. The study also identifies ammonia (NH3) levels ranging from 0.001 to 0.008 ppm in Degema, Bille, and Bonny communities. Notably, no significant variance in ammonia concentration was observed among the study's locations. In conclusion, the study underscores the detrimental impact of oil-related activities, including gas flaring, on air quality within the examined areas, consequently endangering residents' well-being.&#x0D; Unique Contribution to Theory, Practice and Policy (Recommendations): This study offers a forward stride in the Exposure Risk Theory's application by contextualizing it within the study area. Through this lens, we uncover the ramifications of prevalent practices such as gas flaring on air quality. Practical implications emerge as valuable guidance for stakeholders including industries and regulatory bodies to sculpt targeted pollution control strategies addressing specific pollutants. Moreover, local communities and health agencies stand to harness these insights to champion cleaner air and enhanced living conditions.

Exploring the link between sulphur-containing compounds and noxious odours at waste management facilities: implications for odour monitoring and mitigation strategies.

With this study we challenge the widely held assumption that sulphur-containing compounds in ambient air are good indicators of the presence noxious odours near waste management facilities. We analysed an extensive set of olfactometric data and data on the concentrations of hydrogen sulphide and trace sulphur compounds (TSCs) near a waste management facility in Croatia in 2021. The results show that the presence of noxious odours significantly correlates only with the concentrations of hydrogen sulphide and methyl mercaptan in ambient air but not with other measured TSCs. Thus, in addition to the measurement of pollutants in ambient air, Integrated Pollution and Prevention Control (IPPC) permits should mandate olfactometric measurements to detect and mitigate noxious odours near waste management facilities.

Alleviation of Adverse Effects of Drought Stress on Growth and Nitrogen Metabolism in Mungbean (Vigna radiata) by Sulphur and Nitric Oxide Involves Up-Regulation of Antioxidant and Osmolyte Metabolism and Gene Expression.

The influence of drought induced by polyethylene glycol (PEG) and the alleviatory effect of nitric oxide (50 µM) and sulphur (S, 1 mM K2SO4) were studied in Vigna radiata. Drought stress reduced plant height, dry weight, total chlorophylls, carotenoids and the content of nitrogen, phosphorous, potassium and sulphur. The foliar applications of NO and sulphur each individually alleviated the decline, with a greater alleviation observed in seedlings treated with both NO and sulphur. The reduction in intermediates of chlorophyll synthesis pathways and photosynthesis were alleviated by NO and sulphur. Oxidative stress was evident through the increased hydrogen peroxide, superoxide and activity of lipoxygenase and protease which were significantly assuaged by NO, sulphur and NO + sulphur treatments. A reduction in the activity of nitrate reductase, glutamine synthetase and glutamate synthase was mitigated due to the application of NO and the supplementation of sulphur. The endogenous concentration of NO and hydrogen sulphide (HS) was increased due to PEG; however, the PEG-induced increase in NO and HS was lowered due to NO and sulphur. Furthermore, NO and sulphur treatments to PEG-stressed seedlings further enhanced the functioning of the antioxidant system, osmolytes and secondary metabolite accumulation. Activities of γ-glutamyl kinase and phenylalanine ammonia lyase were up-regulated due to NO and S treatments. The treatment of NO and S regulated the expression of the Cu/ZnSOD, POD, CAT, RLP, HSP70 and LEA genes significantly under normal and drought stress. The present study advocates for the beneficial use of NO and sulphur in the mitigation of drought-induced alterations in the metabolism of Vigna radiata.

Contrasting Intermediate-Temperature La0.7Sr0.3VO3.86-⸹ (LSV) Porous Catalyst Elevated Sulfur Tolerance Using Gaseous and Liquid Fuel Explored through Experimental and Modeling Characterization Over Time

The U.S. Army is investigating Solid Oxide Fuel Cells (SOFCs), which can produce clean, secure, and sustainable energy to replace existing power sources. Today SOFCs are known to provide high density, high efficiency power with long term stability at low cost and environmental impact, utilizing a variety of naturally sourced fuels such as hydrogen, hydrocarbons, and alcohols. This fuel flexibility makes SOFCs attractive for use with multiple applications and helps bridge the gap between current hydrogen-fueled SOFC technologies and future hydrocarbon-fueled based use. Despite this potential, many technical hurdles remain, such as thermal stress cracking and coarsening, delamination, and catalyst contamination. Catalyst contamination is of particular concern for the U.S. Army, which operates on JP-8 kerosene-based fuel via AR-70 single fuel policy, as sulfur impurities commonly found in naturally sourced hydrocarbon-based fuels, can poison the catalyst, permanently degrading SOFC system performance, even at low concentrations. As the U.S. Army begins to investigate SOFCs to enable additional capabilities like silent watch, advanced radios, and exportable power in their fleet, catalyst poisoning from sulfur presents a concerning technology gap that must be addressed, especially since it is also possible that sulfur contaminated fuel, scavenged in theater, may be used, and could contain elevated levels (>300ppm) of sulfur.While lower temperature SOFC operation is also actively being pursued to help alleviate physical material degradation issues, with the introduction of hydrocarbon-based fuels, catalyst development to reduce sulfur poisoning degradation also needs further exploration. This study continues to experimentally and theoretically investigate the response of sulfur tolerant anode catalyst La0.7Sr0.3VO3.86-⸹ (LSV) at currently targeted SOFC intermediate operating temperatures (400-600°C). We have previously investigated low and moderate hydrogen sulfide (H2S) concentrations (30ppm, 300ppm) in balance hydrogen and methane gas environments for up to 100 hours. In this work, LSV showed significant sulfur tolerance in hydrogen and methane balance gases when compared to the industry standard Ni-YSZ anode, where sulfur adsorption rates were 278-287x lower in some cases. The lowest rates occurred between 600-700°C, which is attributed to the cubic structure the material presents in this temperature range. Higher adsorption rates were observed in the monoclinic/tetragonal structure the material presents at temperatures between 400-500°C. Average adsorption rates were overall higher in methane. When compared against Ni-YSZ, which is known to accumulate sulfur from hydrogen sulfide via two-step dissociative adsorption, LSV was observed to accumulate sulfur through weak chemisorption (H2S*, 0.43 eV max) of molecular hydrogen sulfide on oxygen deficient surfaces and one-step dissociative adsorption (H2S*, 0.34 eV, max, HS*+H*, 8.34 eV, max) on oxygen sufficient surfaces. The weak chemisorption behavior on oxygen deficient surfaces is attributed to the reduced oxygen stoichiometry of the material, in which only vanadium V2+/3+ couples exist. Overall, molecular adsorption/dissociation was observed to occur near strontium defects on LaO/SrO terminations. The propensity of H2S adsorption on LSV surfaces was observed to be significantly less for oxygen deficient LSV, and significantly higher for oxygen sufficient LSV, when compared to H2S adsorption calculations on Ni (100) surfaces, which follow a two-step dissociative adsorption reaction (H2S* → HS*+H* → H*+S*), resulting in a strongly adsorbed S* species (5.96 eV, max).Under the Army’s single fuel policy, it is more likely SOFCs would be fueled using hydrogen and/or methane, which are both gases, however SOFCs in the future could also be directly fueled using liquid alcohol fuels, or as scavenged from theater. Typical small alcohol molecules (methanol or ethanol) do not contain high concentrations of sulfur; however, alcohols can be contaminated with sulfur-containing hydrocarbons. This work will investigate sulfur adsorption using methanol contaminated with 300ppm thiophene using the same operating temperature and heating duration conditions with hydrogen and methane. These results will be contrasted against the 300ppm H2S hydrogen and methane results previously reported. Figure 1

L-Aminoguanidine Induces Imbalance of ROS/RNS Homeostasis and Polyamine Catabolism of Tomato Roots after Short-Term Salt Exposure.

Polyamine (PA) catabolism mediated by amine oxidases is an important process involved in fine-tuning PA homeostasis and related mechanisms during salt stress. The significance of these amine oxidases in short-term responses to salt stress is, however, not well understood. In the present study, the effects of L-aminoguanidine (AG) on tomato roots treated with short-term salt stress induced by NaCl were studied. AG is usually used as a copper amine oxidase (CuAO or DAO) inhibitor. In our study, other alterations of PA catabolism, such as reduced polyamine oxidase (PAO), were also observed in AG-treated plants. Salt stress led to an increase in the reactive oxygen and nitrogen species in tomato root apices, evidenced by in situ fluorescent staining and an increase in free PA levels. Such alterations were alleviated by AG treatment, showing the possible antioxidant effect of AG in tomato roots exposed to salt stress. PA catabolic enzyme activities decreased, while the imbalance of hydrogen peroxide (H2O2), nitric oxide (NO), and hydrogen sulfide (H2S) concentrations displayed a dependence on stress intensity. These changes suggest that AG-mediated inhibition could dramatically rearrange PA catabolism and related reactive species backgrounds, especially the NO-related mechanisms. More studies are, however, needed to decipher the precise mode of action of AG in plants exposed to stress treatments.

Methane Emission from Flooded Soils of Rice Paddies in Rostov Oblast

The methane fluxes to the atmosphere from the rice fields in the Rostov oblast (south of the European Russia) are analyzed using the results of field chamber measurements. In addition to the measurements of methane fluxes at the stages of rice seedlings and full ripeness, the concentrations of methane and hydrogen sulfide, Eh, pH, density, and moisture content are determined in water and different horizons of flooded paddy soils. The methane flux to the atmosphere from a rice paddy varies in the range of 0.195–0.531 mg CH4/(m2 h) and is on the average 2.1-fold higher at the stage of full ripeness as compared with the stage of seedlings. The rate of the methane flux to the atmosphere from the surface of dry soils separating rice paddies is on the average 4.9–12.1-fold lower as compared with the flux from the paddies, varying from 0.034 to 0.045 mg CH4/(m2 h). After flooding the rice paddies, the Eh values decrease in the soils isolated by a water layer and, as a consequence, the methane concentration in soils increases as well as its fluxes to the atmosphere. According to our assessment, the total methane emission from the rice fields in the Rostov oblast approximately reaches 1.253 t/day of 150 t/year, which accounts for 0.4–1.5% of the total methane emission from the soils of the Rostov oblast.