Geobiological features of storage hydrogen-methane mixtures in underground reservoirs

Taking into account the world and domestic experience of studying the ontogenesis of lithospheric hydrogen a combination of coupled hydrochemical, geochemical and microbiological factors of the accumulation of this natural gas together with methane in the terrigenous formations of the sedimentary cover is justified. It is predicted that various hydrochemical and microbiological processes that cause the development of carbon dioxide and sulfate corrosion of engineering structures, as well as cement of reservoir rocks and tires, can occur together with methane at industrial facilities of underground storage of hydrogen. The risks of reducing the volume of injected hydrogen in underground storage in addition to diffusion losses can be associated with geobiological factors, including the conversion of hydrogen into CH4 and H2S due to microbial activity, chemical interaction of hydrogen with minerals of reservoirs and tires, accompanied by changes in filtration-capacity and geomechanical properties, hydrogen embrittlement of metal structures of ground and underground well equipment. Keywords: geobiology; hydrogen; methane; underground storage; methanogenesis; acetogenesis; sulfate reduction.

Approximate Models of Microbiological Processes in a Biofilm Formed on Fine Spherical Particles

This paper concerns the dynamical modeling of the microbiological processes that occur in the biofilms that are formed on fine inert particles. Such biofilm forms e.g. in fluidized-bed bio-reactors, expanded bed biofilm reactors and biofilm air-lift suspension reactors. An approximate model that is based on the Laplace–Carson transform and a family of approximate models that are based on the concept of the pseudo-stationary substrate concentration profile in the biofilm were proposed. The applicability of the models to the microbiological processes was evaluated following Monod or Haldane kinetics in the conditions of dynamical biofilm growth. The use of approximate models significantly simplifies the computations compared to the exact one. Moreover, the stiffness that was present in the exact model, which was solved numerically by the method of lines, was eliminated. Good accuracy was obtained even for large internal mass transfer resistances in the biofilm. It was shown that significantly higher accuracy was obtained using one of the proposed models than that which was obtained using the previously published approximate model that was derived using the homotopy analysis method.

Analysis of Bacillus thuringiensis treatment impact on microflora and cellulosolytic processes in southern chernozem

When using insecticides based on B. thuringiensis in biocenoses, the issues of their influence directly on plants and soil fertility are particularly relevant. The aim of the research was to study the direction of microbiological processes in the soil after processing potato plants with liquid spore cultures of entomopathogenic B. thuringiensis 792, 800, 810, 815, 857, 888, 902, 989, 994 and 0371 strains. The nature and extent of insecticide exposure were assessed by the quantity of microorganisms in the main ecological and trophic groups. It has been shown that soil treatment with B. thuringiensis strains 792, 854 and 989 influences the intensity of southern chernozem CO2 emission most actively, by 5.7-6.0 times. The studies made it possible to establish that B. thuringiensis strains 810, 854, 888 and 902 are able to exert the most active effect on the decomposition of cellulolose, increasing its activity by 93.7; 85.6; 82.0-93.7% to control. The statistically significant relationships study of correlation dependences made it possible to conclude that the treatment of southern chernozem with strains of B. thuringiensis 792, 800, 810, 854, 888 and 0371 does not have a destructive effect on soil microbocenosis.

Microbiological activity in the soils of pingos and thermokarst depressions in the south of the Vitim Plateau (Transbaikalia, Eastern Siberia)

The intensity of microbiological processes in soils of pingos and thermokarst depressions in the south of the Vitim Plateau was studied. The number of dominant groups of microorganisms (Fungi; Bacteria, and Actinomycetes as a separate group) in Haplic Chernozems (Stagnic, Turbic) and Calcaric Gleyic Phaeozems were identified. Carbon accumulation in microbial biomass in soils of pingos and thermokarst depressions varies considerably in comparison with background soils. Bacterial microflora has been proven to prevail in soils under the study. The maximum indicators of actinomycete and fungal mycelium were found in the soils of thermokarst depressions. Microbiological activity for all studied parameters is higher in Calcaric Gleyic Phaeozems.

Study of the efficiency of the inhibitory effect of antimicrobial preparations in the production of sugar substances

This article presents the relevance of the issue of inhibition of microbiological processes at different stages of processing of sugar-containing raw materials, in particular ensuring the microbiological purity of juices and syrups in the production of sugar substances. Information on the composition of microbiota contaminating raw materials in the production of beet sugar, raw cane sugar, food syrups from sugar sorghum is analyzed. Experimental data on the evaluation of the effectiveness of a number of antimicrobial preparations in terms of growth retardation of pure cultures of microorganisms and the effect of disinfection during the introduction of preparations are presented. The greatest danger in production is caused by the development of spore-forming and mucus-forming bacteria, which led to the choice of research objects. Thus, the effect of antimicrobial preparations on microorganisms: mesophilic bacteria Bacillus subtilis, B. megatherium, thermophilic bacteria B. stearothermophilus, mucus-forming bacteria of the genus Leuconostos, was investigated. In addition, the effect of antimicrobials on mycelial fungi of the genus Aspergillus was studied. Based on the conducted experimental studies, the range of costs of the studied antimicrobial preparation for the suppression of contaminating microflora in the production of sugar and food syrups from vegetable raw materials was determined

Bioindication of soil of unauthorized landfills in the Carpathian region

The article presents the results of monitoring the area adjacent to the Carpathian Biosphere Reserve for the detection of unauthorized landfills and examines the ecological status of these soils. Four unauthorized landfills of solid waste in Pidhirna, Stanislav, Steryshora, and Feresok tracts with an area of 0.15 to 1.5 ha with a waste accumulation period of 12–22 years and different morphological composition which had a significant impact on the ecological status of the soil have been identified. Bioindication methods have shown changes in the soil microbial cenoses under the direct influence of unauthorized landfills of solid waste, namely increased the number of organotrophic bacteria and micromycetes and decreased number of nitrogen-fixing microorganisms. The highest number of bacteria using nitrogen of organic compounds (25.36–28.61 million CFU/g soil) and micromycetes (51.8–76.8 thousand CFU/g soil) was fixed in the soils in the tract PidhirnaandFeresok with advantage of 1.5–1.7 times and 2.5–3.8 times compared to the soil of the protected area. Increasing the number of pedotrophic and oligotrophic microorganisms and microorganisms that assimilate organic forms of nitrogen, on average, 2.70, 2.84 and 1.48 times has been affected the direction of the main soil-microbiological processes. The coefficient of oligotrophicity varied in the range of 0.21–0.30, mineralization-immobilization one — 1.22–1.38, pedotrophic one — 0.55–0.96 with a maximum in the soil of the landfill in the tracts of Feresok and Pidhirna, which indicates the strengthening of microbiological processes of mineralization and decomposition of soil organic matter, including humus compounds. A close relationship was established between the duration of solid waste storage in a certain area and the level of soil phytotoxicity (r = 0.92). In the soil of landfills in Pidhirna, Steryshora and Feresok tracts, the phytotoxicity index is significant (over 50%), which indicates a high level of soil ecosystem pollution and increased environmental risks in the area of unauthorized accumulation of solid waste.

INFLUENCE OF REGIMES OF USE AND FERTILIZATION OF SPONTANEOUSLY RENEWABLE SWARD ON THE COURSE OF SOIL MICROBIOLOGICAL PROCESSES

Objective. To study the state of the soil microbiocenosis of spontaneously renewable phytocoenosis of the 21st year of self-growth after the application of mineral fertilizers at the dose of N90P40K70 and the two-mow regime. Methods. Experimental-field, laboratory-analytical, microbiological, statistical. Results. Optimization of mineral nutrition of renewable phytocoenosis contributes to an increase in the number of microorganisms: ammonifiers 2.24 times, mineral nitrogen immobilizers — 1.39, denitrifiers — 3.19, nitrifiers — 1.71, cellulose-destructive — 1.64, actinomycetes — 1.17, micromycetes — 1.20, organophosphate mobilizers — 1.33 times. As a result of twomow regime of the use grass cenoses, the number of microorganisms in most of the studied groups does not change, except for denitrifiers, cellulose-destroying bacteria, micromycetes and organophosphate mobilizers. The use of mineral fertilizers leads to a slowdown of mineralization processes in the soil: pedotrophicity index decreases by 2.28 times, the coefficient of mineralization of nitrogen compounds — by 1.60 time, oligotrophicity — by 2.25 times, the activity of humus mineralization — by 1.65 times. Alienation of plant biomass has a negligible effect on the course of microbiological processes in the soil: pedotrophicity index increases by 18.2 %, oligotrophicity coefficient — by 3.63 %, nitrogen mineralization coefficient decreases by 6.6 %, humus mineralization activity — by 6.2 %. Conclusion. Lack of mineral elements in the soil of the fallow provokes the intensification of mineralization processes, and the optimization of mineral nutrition of phytocoenosis plants contributes to their slowing down. The decrease in the total biological activity and the increase in the phytotoxicity of the soil with the two-mow use of sward indicate the beginning of the processes of soil depletion.

Composition and amount of nutrients entering the soil with cotton biomass and green manure

The experience of developed countries in the field of agriculture and research results show that high efficiency from mineral fertilizers can be obtained on fertile soils. That is, the soil should contain a large amount of organic substances, microelements, beneficial microorganisms, various enzymes that activate microbiological processes, normalize and optimize the nutritional, thermal and water-physical properties of the soil. This can be achieved by regularly applying crop residues and organic fertilizers to the soil. Siderata - green fertilizers - are of great importance for increasing soil fertility.

Prediction of hydrogeochemical effects in clayey cap rocks during underground storage of hydrogen with methane

Theoretical issues of joint underground storage of hydrogen with methane are poorly studied, and practical examples are rare. Therefore, it is extremely important to analyze the mutual influence of hydrogen-methane mixtures and the host geological environment. This article presents material that makes it possible to substantiate the most significant hydrochemical processes that affect the transformation of cap rocks. For this purpose, the results of our own experiments, as well as published data on the study of the influence of hydrochemical conditions on the diffusion loss of hydrogen, its interaction with rock-forming minerals, organic matter, and pore waters were used. A quantitative assessment of the decrease in the moisture saturation of clay-rocks samples and, as a consequence, the loss of the mass content of mineral and organic substances is given. It was found that the cyclic change of thermobaric effects leads to a change in the redox conditions in the system “rock ↔ pore water” and is accompanied by an increase in the reactivity of calcium, magnesium, sulfur, iron. The saturation indices of pore water with carbonate and sulfate calcium salts were calculated under the conditions of their precipitation, dissolution, and removal from solution. The interpretation of the experimental data made it possible to substantiate the most probable transformations in clayey cap rocks, which affect their screening capabilities. It is recommended to take into account, when designing and operating storage facilities for hydrogen-methane mixtures, the variety of accompanying hydrochemical and microbiological processes that affect the change in the filtration properties of cap rocks.