Long-term immunity alterations in the employees of the high hydrogen sulfide content gas condensate processing facility

The current measures for protection of the gas processing plant employees cannot fully prevent the impact of pollutants. Evaluation of the immune system is one of the methods for monitoring of the employees' health, and testing the system of measures used to improve the working conditions. The study was aimed to identify alterations in the immune status of the employees at the gas processing and high hydrogen sulfide content condensate processing facility depending on their working experience. The working environment and the employees' immune system were evaluated by standard methods. Pollutants were detected with the Bruel & Kjaer 1302 Multi-Gas Monitor, and the Tsvet-550 gas chromatographer. A total of 160 employees and 81 controls (blood donors of the regional blood transfusion station) were surveyed. The immune system was evaluated using the System 9000 Plus hematological analyser, Cyto FLEX LX flow cytometer, UNICO 2100UV specrophotometer, and KFK-3-03-ZОМЗ photometer. It was concluded that the existing complex of occupational and industrial hazards affects the immune status of the main production unit employees, which is reflected in the decreased CD20 levels and increased CD8 levels along with the constant levels of CD4. Correlations were revealed between the immuniglobuline level alterations, decrease in the phagocytic index and phagocytic number, as well in lysozyme activity, and the working experience. Pollutant exposure results in altered immunity of the employees, which could be considered the adaptation mechanism.

Exploring the Potential for Utilization of Medium and Highly Sulfidic Mine Tailings in Construction Materials: A Review

Medium and highly sulfidic tailings are high-volume wastes that can lead to severe environmental damage if not properly managed. Due to the high content of sulfide minerals, these tailings can undergo weathering if put in contact with oxygen and water, generating acid mine drainage (AMD). The moderate-to-high sulfide content is also an important technical limitation for their implementation in the production of construction materials. This paper reviews the use of sulfidic tailings as raw material in construction products, with a focus on cement, concrete, and ceramics. When used as aggregates in concrete, this can lead to concrete degradation by internal sulfate attack. In building ceramics, their implementation without prior treatment is undesirable due to the formation of black reduction core, efflorescence, SOx emissions, and their associated costs. Moreover, their intrinsic low reactivity represents a barrier for their use as supplementary cementitious materials (SCMs) and as precursors for alkali-activated materials (AAMs). Nevertheless, the production of calcium sulfoaluminate (CSA) cement can be a suitable path for the valorization of medium and highly sulfidic tailings. Otherwise difficult to upcycle, sulfidic tailings could be used in the clinker raw meal as an alternative raw material. Not only the SO3 and SiO2-rich bulk material is incorporated into reactive clinker phases, but also some minor constituents in the tailings may contribute to the production of such low-CO2 cements at lower temperatures. Nevertheless, this valorization route remains poorly explored and demands further research.

Influence of Selected Substrate Dosage on the Process of Biogas Installation Start-Up in Real Conditions

This paper presents an analysis of selected parameters of biogas, formed as a result of methane fermentation, during the start-up of a biogas installation, using water, liquid manure, corn silage and inoculated sludge as substrates. Moreover, the dependencies between the type and amount of the supplied substrate and the obtained parameters of biogas and fermentation mass are presented and explained. During 59 days after the start of the biogas plant operation, the methane content increased to a maximum of about 62%. Finally, after about 80 days, the methane content stabilized at a constant level of about 55%. CO2 content increased from about 6% (day 32) to about 46% (day 84), with a clear linear correlation between carbon dioxide and methane content. Oxygen content decreased from about 18% (day 32) to about 0.3% (day 84) as the resulting gases displaced air from the reactor, and there was also a linear correlation between oxygen and methane content. The hydrogen sulfide content decreased from about 76 ppm (day 32) to about 0 ppm (day 47), after which, in a clear power correlation to the methane content, it maximally increased to 890 ppm (day 61). However, for the sake of safe engine operation, the desulfurization plant was started on day 63, which resulted in a H2S concentration below 50 ppm on day 74 of the experiment. The final hydrogen sulfide content was 9 ppm on day 84 of the biogas plant start-up.

Sulfur-Based Denitrification in Streambank Subsoils in a Headwater Catchment Underlain by Marine Sedimentary Rocks in Akita, Japan

Sulfur-based denitrification may be a key biogeochemical nitrate (NO3−) removal process in sulfide-rich regions, but it is still poorly understood in natural terrestrial ecosystems. We examined sulfur-driven NO3− reduction using streambank soils in a headwater catchment underlain by marine sedimentary rock in Akita, Japan. In a catchment exhibiting higher sulfide content in streambed sediment, we sampled two adjacent streambank soils of streambank I (two layers) and of streambank II (eight layers). Anaerobic long-term incubation experiments (40 days, using soils of streambank I) and short-term incubation experiments (5 days, using soils of streambank II) were conducted to evaluate variations of N solutes (NO3−, NO2−, and NH4+), N gases (NO, N2O), and the bacterial flora. In both experiments, two treatment solutions containing NO3− (N treatment), and NO3− and S2O32− (N + S treatment) were prepared. In the N + S treatment of the long-term experiment, NO3− concentrations gradually decreased by 98%, with increases in the SO42−, NO2−, NO, and N2O concentrations and with not increase in the NH4+, indicating denitrification had occurred with a high probability. Temporal accumulation of NO2− was observed in the N + S treatment. The stoichiometric ratio of SO42− production and NO3− depletion rates indicated that denitrification using reduced sulfur occurred even without additional S, indicating inherent S also served as an electron donor for denitrification. In the short-term incubation experiment, S addition was significantly decreased NO3− concentrations and increased NO2−, NO, and N2O concentrations, especially in some subsoils with higher sulfide contents. Many denitrifying sulfur-oxidizing bacteria (Thiobacillus denitrificans and Sulfuricella denitrificans) were detected in both streambank I and II, which dominated up to 5% of the entire microbial population, suggesting that these bacteria are widespread in sulfide-rich soil layers in the catchment. We concluded that the catchment with abundant sulfides in the subsoil possessed the potential for sulfur-driven NO3− reduction, which could widely influence N cycling in and NO3− export from the headwater catchment.

Hydrogen sulfide content in pregnant women with preeclampsia in late gestation and their newborns

We examined 70 women who were 22-40 weeks pregnant and their newborns. Of these, 15 women with moderate PE made up group 1, 22 women with severe PE-group 2, and 55 women with uncomplicated pregnancy without hypertensive disorders - the control group. Blood was collected from women when they were admitted to the clinic, and blood was taken from newborns for 3-5 days of life. The concentration of hydrogen sulfide was determined by the method of K. Qu et al [17]. There was a decrease in the level of hydrogen sulfide in the blood serum of women whose pregnancy was complicated by severe preeclampsia. In newborns born to mothers with preeclampsia, an increase in the concentration of hydrogen sulfide was detected in the blood, which is probably a compensatory reaction aimed at restoring vascular homeostasis during early postnatal adaptation.

Development of A Polymer Material for A Chemical Sensor Gas Sensitive Element that Determines Hydrogen Sulfide Based on Pan

Recently, in chemical sensors of gases operating at low temperatures, polymeric materials with semiconducting properties are used as a gas sensitive element. One of these materials is polyacrylonitrile (PAN). The use of PAN based film as a gas sensitive material has great potential for creating sensors that operate at room temperature without heating. Development of a technology for the production of metal-containing films based on polyacrylonitrile to create unheated sensors for detecting hydrogen sulfide and studying their properties [1]. A semiconductor sensor for detecting hydrogen sulfide, made using fuels and lubricants based on polyacrylonitrile (PAN), received the symbol "P.SS-H2S". It was investigated that the analytical signal of a hydrogen sulfide sensor (σgas/σweather) based on tungsten and copper oxides depends on the amount of the detected component (SH2S ) in the mixture. The developed sensors: S.S-H2S WO3-5% CuO, S.S-H2S WO3-10% CuO and P. S.S-H2S can be used for analytical control of hydrogen sulfide content in objects of various nature.

The geophysical response of the Goldrush-Fourmile orebody and implications for camp-scale Carlin-type deposit exploration, Cortez District, Nevada

Since discovery of the Goldrush and Fourmile deposits, numerous geophysical surveys have been acquired over the footprint of mineralization and surrounding areas to focus exploration. The Goldrush-Fourmile system extends more than 7 km in strike length and averages approximately 300 m wide. Most of the orebody lies more than 300 m below ground surface and continues to depths of more than 900 m. Direct detection of the ore system using geophysical tools is impeded by several factors. The system is relatively flat lying and sits in the hinge of a doubly plunging anticline. This gives the shallowest zones a very small lateral footprint. The ore consists of thin strata-bound zones of silica-sulfide mineralization with a tight alteration selvage. Structural controls along faults are limited, with only small displacements. Strong petrophysical contrasts exist between unaltered rock units. Finally, the terrain is rugged. Resistivity inversions of airborne electromagnetic data show that mineralization sits within a complex zone of resistivity responses. Close to intrusions, the host stratigraphy is resistive. Away from intrusions, the same stratigraphic units show highly variable but commonly very low resistivities. This suggests the possibility of redistribution of carbon around intrusions during premineralization metasomatism. Within the orebody, sulfide content increases conductivity within individual formations related to the distribution of fine-grained sooty pyrite. The geometry of the Red Hill Anticline is imaged as a positive density contrast in the observed gravity and geologically constrained gravity inversions. The positive density contrast represents the gross geophysical signature of denser carbonates within the Paleozoic stratigraphy. Magnetic surveys are crucial for mapping the distribution of igneous rocks and potentially hornfelsed sedimentary rocks. The challenges associated with exploring for deeply buried Carlin mineralization notwithstanding, the application of innovative geophysical tools tuned to assess specific geologic questions, combined with best-practice geologic and geochemical modeling, is helping drive exploration for additional Carlin-type mineralization across the Cortez District.

Comparative assessment of biological activity of peloids of Ukraine of different genesis

The article presents the results of comprehensive studies of the influence of peloids from different geographic regions of Ukraine and different genesis on the course of experimental pathology. Methods:At the first stage of research we have determined the type of peloids these are medium-mineralized weakly sulfide magnesium-sodium silt peloids, low-ash organic sapropels, and peat low-mineralized high-ash sulfide-free peloids. Physicochemical parameters have been established: mass fraction of moisture, volumetric weight, hydrogen sulfide content, contamination with particles with a diameter greater than 0.25 × 10-3 m, shear stress, stickiness, specific heat capacity, the content of organic substances, colloidal complex, the concentration of water conduit ions (pH) , redox potential (Eh). In the second stage of the study, 55 white rats were examined for the state of the liverʹs detoxification function (by carrying out a metabolic test using sodium thiopental) and the morphological form of the liver in normal conditions and toxic alcoholic hepatosis. The toxic alcoholic hepatosis model was induced by daily (30 days) intragastric watering of animals with a 25% solution of ethyl alcohol. From the 15th day, the rats received a course of applications: a cake with the corresponding peloids was applied to the bare part of the back. Results: It was determined that the peloids used had a positive effect on animalsʹ condition, which was expressed in the restoration of the detoxification function of the liver and its structural and functional organization. The most substantial positive effect is observed when using silt-sulfide peloids, which, according to the authors, is due to the peculiarities of their physicochemical composition (increased content of magnesium, chlorides, sodium, as well as hydrogen sulfide). Conclusion: Based on the results obtained, it was concluded that the studied peloids meet the criteria for the quality of therapeutic peloids in terms of physicochemical parameters, biological activity, and expands the possibilities of their application in balneology. Keywords: liver, toxic alcoholic hepatosis, rats, peloids,