Accumulation Coefficient Research Articles

Clinical significance of PET/CT in the diagnosis of primary adrenal malignancies

Background. According to the literature, the role of combined positron-emission and X-ray computed tomography (PET/CT) in diagnosing primary adrenal tumors (AT) remains limited due to both the frequency of these neoplasms and the availability of the method. Various research is required to assess the diagnostic resources of PET/CT with 18-fluorodeoxyglucose (18F-FDG). Aim. To evaluate the clinical role of PET/CT with 18F-FDG in the diagnosis of primary adrenal malignancies (PAM). Materials and methods. The study included 9 patients, 5 males and 4 females aged 44–76, with a median age of 59.3 years, with a morphologically confirmed diagnosis of the PAM. All patients underwent PET/CT with 18F-FDG. Visual and quantitative analysis of the obtained images was performed, including determination of the standardized maximum accumulation coefficient (SUVmax) in the tumor, liver, and spleen, the ratio of SUVmax of the primary tumor to SUVmax in the liver and spleen. Tumors were more often localized on the right (5/55.6%), and one case was bilateral. The maximum size of the adrenal mass averaged 6.8 cm (3.2–11.2) and the minimum size was 6.0 cm (2.3–9.0). The median SUVmax in AT was 10.0 (3.54–22.29), while in liver and spleen, it was 3.16 and 2.34, respectively, and the ratio of tumor SUVmax to liver and spleen SUVmax was 3.33 and 4.48, respectively. Conclusion. Hybrid PET/CT with 18F-FDG is a medical imaging method with a high diagnostic accuracy of PAM. PET/CT showed significant 18F-FDG tumor uptake, with a median SUVmax of 10.0 and a ratio of tumor SUVmax to liver and spleen SUVmax of 3.33 and 4.48, respectively. PET/CT with 18F-FDG may be a method of choice for diagnosing primary ATs.

Migration of Plutonium, Micro- and Macroelements in the “Soil–Plant” System at Different Soil Moisture

In the vegetation experiment, the plutonium, micro- and macroelements migration in the “soil–agricultural plant” system depending on soil moisture in the range from 15 to 40٪ of absolute soil moisture were studied. The content of 239Pu was analyzed by α-spectrometry with preliminary radiochemical isolation. The elemental composition was analyzed by the ICP-MS and ICP-AES methods. Beans (Fabaceae) variety “Amber” were used as a test culture. The plutonium transfer factor obtained in the vegetation experiments are in the range of of 5.3×10–4–1.5×10–2, with an average value of 5.4×10–3 for the aboveground part of bean and range of 4.5×10–2–2.7×10–1, with an average of 1.6×10–1 for bean roots. It was determined that the distribution of plutonium, micro and macro elements in the vegetative organs of plants is not equally, the transfer factor of plutonium for the aboveground part of plants is lower than for the root part. It has been established that the accumulation of plutonium, micro- and macroelements, depending on soil moisture, is different for the organs of beans. The dependence of plutonium accumulation by plants on soil moisture is significantly higher than for other considered elements. A decrease in the coefficient of accumulation of plutonium in the aerial part of the beans is recorded with an increase in soil moisture up to two orders of magnitude. There is a trend towards a slight decrease in the accumulation coefficients of Fe, Mg, Mn, Cr, Mo, Ni, Co, Cu. For the root system of beans, a clear dependence of the accumulation of the considered elements on soil moisture is not observed.

Influencing factors of bentonite for the directional electric repair of landfill HDPE membrane leakage in calcium ion solution

The timely repair of high-density polyethylene (HDPE) membrane leakage in landfills is an important means of environmental risk control, which is critical for preventing leachate from polluting groundwater and soil. Electric repair technology is expected to become a hot spot in the leakage repair of HDPE films, because it can solve the issues of complex operation, high costs, and security risks during the operation and closure of landfills. To explore the influence law of various technical factors on the electric repair process, we carried out single factor experiments on the main influencing factors such as the operation time, bentonite concentration and dispersant/bentonite dosage ratio, leakage size, and calcium concentration. We then explored the best technological conditions. The results showed that accumulation at the leakage site possessed a good repair effect with a permeability coefficient of 4.22 × 10−6 cm/s. Furthermore, we observed that the Zeta potential played an important role in the electric repair technology, where the higher the absolute value of the Zeta potential, the faster the electrophoretic migration rate of the bentonite particles, and the lower the permeability coefficient of accumulation. This study may serve as a theoretical basis and offer scientific guidance for the directional electric repair of HDPE membrane leakage during the operating period and after the closure of landfills.

Assessment of environmental and health risks of potentially toxic elements associated with desert dust particles affected by industrial activities in Isfahan metropolitan

Dust particles and their associated compounds can adversely affect human health and ecosystems. The aim of this study was to investigate the concentration, health, and ecological risks of selected potentially toxic elements (e.g. Pb, Cd, Cr, Co, Cu, Zn, V, Ni, and As) bound to air particles generated by dust storms in the Sejzi plain desert area within the industrial district of Isfahan metropolitan, Iran. The enrichment factor revealed the highest values for Zn, Pb, and Cd which among them Zn showed the highest value (8.1) with the potential source of industrial activities confirmed by the integrated pollution index, accumulation coefficient, and ecological risk index. Regarding health risk analysis (non-cancer and cancer risks) the elements including Co, As, and Cr showed a significant risk for adults and children across all seasons. It’s concluded that mitigation of air particles originated from both natural and industrial activities is necessary to reduce their relevant risks to human being and ecosystems in the region.

Content and Distribution of Radionuclides in the Profile of Light Gray Forest Soil and Agrocenosis Plants

The results of long-term radiation monitoring of light gray forest soil and cultivated plants of the reference area are presented. Correlation analysis has determined the relationship between the distribution of artificial and natural radionuclides in the soil profile with its agrochemical properties. The distribution of radionuclides in the soil profile is determined by the intensity of the podzolic process. The profile shows the eluvial-illuvial differentiation of radionuclides, when an increase in their accumulation occurred in the illuvial horizon. According to the density of contamination of the surface soil layer with cesium-137 and strontium-90, a satisfactory level of the environmental situation was determined, according to which the soil of the site is classified as uncontaminated. Rows of cultivated plants with an increasing ability to accumulate caesium-137 and strontium-90 from the soil have been constructed. The grain of all grain crops accumulated less cesium-137 and strontium-90 compared to straw. All grown plant products of all types of crops fully met veterinary and hygienic standards for the content of caesium-137 and strontium-90 in feed (green mass, straw and feed grain) and food grains. The coefficients of accumulation and transfer of caesium-137 and strontium-90 from soil to plants were calculated.

Determination of the coefficient of thermal effusivity ε for a semi-confined rod

The article provides methods and formulas for calculating the coefficient of thermal effusivity ε (coefficient of heat accumulation) of solid bodies using known solutions of direct heat conduction problem. The work describes a method by which the final formulas are simplified to algebraic equations using the relative temperature θM of heating semi-confined rod from the end. The temperature Tc at the beginning of the rod is measured — x0 and time — τ0 from the start of heating. For calculation, the amount of heat Q accumulated during heating by a heater with a constant temperature at the end of the rod is used for the entire heating time. The technique is physically implemented during the experiment by bringing the ends of two semi-confined rods into contact. A flat, low-inertia electric heater is placed between the rods. The amount of heat ∆Q used in the calculations is half of the total heat of the heater for the entire heating time.

Accumulation Radiocesium (137cs) By Plants of the Dnipro River’s Floodplain Ecosystems after Chernobyl Contamination

The analysis of radiocesium (137Cs) accumulation by plants of forest, marsh, meadow, psamophytic, and ruderal communities in the Dnipro River floodplain (Ukraine) was carried out. The species specificity of radiocesium accumulation by plants of specific biotopes and the direct dependence of the plant accumulation coefficient on the density of biotope contamination with radionuclides were confirmed. Differences in different radiocesium accumulation by plants of different ecosystems are probably related to the fact that the bioavailability of radiocesium strongly depends on soil properties. In the analyzed statistical model, the processes of accumulation and dissipation of 137Cs are significant.

Precision Remediation of Mining Soils through On-Site Investigation and Large-Scale Synthesized Ferrosilicate

To seek a restoration plan for the safe use of agricultural land around mining areas, this study focuses on the regions around a mining plant in Huidong County, western Sichuan Province, affected by lead–zinc mining, and the precise remediation of heavy metal pollution through large-scale synthesis of iron silicate. In this study, we investigated heavy metal pollution in the vicinity of the mining area and proposed a treatment strategy using large-scale synthesis of iron silicate to mitigate this pollution. According to field investigation and sampling analysis, the collected soil samples contained excessive Cd, Pb, and Zn. Cd is a heavy metal related to lead–zinc mining. The planting of crops such as loquats and garlic with a high accumulation coefficient for Cd was found inappropriate for the research area. Instead, it was recommended to plant economically important crops like mangoes and peaches which had lower heavy metal accumulation. On the basis of field investigation, the study area was seriously polluted by heavy metals, among which Cd was 4.0 times higher than the standard of agricultural land. In order to accurately passivate excessive Cd, Zn, and Pb, iron silicate material was put into mass production. In situ passivation experiments showed that when the soil water content was between 25% and 20%, adding 4% silicate material could rapidly reduce the content of effective heavy metals in the soil and the heavy metal content of garlic and other cash crops in the research area by about 8%. After conducting a field investigation, it has been determined that the large-scale preparation of iron silicate can accurately repair soil contaminated by heavy metals in the vicinity of mining areas. In conclusion, iron silicate is capable of effectively reducing the pollution of heavy metals on agricultural land and facilitating the safe utilization of such land.

ДИНАМИКА АКТИВНОСТИ ФЕРМЕНТОВ УГЛЕРОДНОГО ЦИКЛА В УСЛОВИЯХ ПЕРЕХОДА НА МИНИМАЛЬНЫЕ ТЕХНОЛОГИИ ОБРАБОТКИ

The purpose of research is to study the dynamics of the activity of enzymes in the carbon cycle of agrochernozems and its effect on the transformation of easily mineralizable organic compounds when using waste and surface treatment methods. Field observations were carried out on the basis of the production experience of OOO OPH Dary Malinovki in the Sukhobuzimo District in the Krasnoyarsk forest-steppe (56°10′ N and 91°47′ E). The impact of dump and minimal processing technologies on the seaso¬nal dynamics of the activity of carbon cycle enzymes in the layers of agrochernozem is considered. The field experiment scheme is represented by the following options: moldboard plowing (standard), minimal tillage (surface disking), flat-cut tillage (cultivation). The level of polyphenol oxidase activity in the soil of the experimental variants was estimated to be weak. The intraseasonal dynamics of the studied enzymes was significant and correlated with the transformation of the humus accumulation coefficient. On non-dumping backgrounds, the variability of polyphenol oxidase was less variable. The minimum va¬lues of the humus accumulation coefficient were found at the initial stage of introducing the technologies under study during the fallow period of agrochernozems, as well as during the barley growing season. The maximum is in the soil under spring wheat crops. The use of flat-cut cultivators led to a strong relationship between the activity of polyphenol oxidase and the coefficient of humus accumulation. In the soil of all variants, an inverse relationship was observed between peroxidase activity and the coefficient of humus accumulation. The participation of peroxidase in the biochemical processes of mineralization was carried out mainly under the conditions of dump processing of agrochernozems. The activity of oxidoreductase enzymes indicated favorable conditions for the humification of organic compounds and the accumulation of newly formed humic substances in the soil when spring wheat was placed in fallow under conditions of using no-moldboard technologies.

Enhancing heavy metal phytoremediation in landfill soil by Chrysopogon zizanioides (L.) roberty through the application of bacterial-biochar pellets

This work investigated the performance of bacterial-biochar pellets (BBP) on promoting heavy metal phytoremediation by Chrysopogon zizanioides (L.) Roberty planted in landfill soil. Micrococcus sp. MU1, an indole-3-acetic acid (IAA)-producing bacterium, was incorporated into biochar pellets (MU1-BBP). MU1-BBP contained a high number of viable bacterial cells with 90 % viability after storage at 4°C for two months. In addition, it had a greater survival capability in heavy metals-contaminated landfill soil than MU1-free cells. The application of MU1-BBP significantly promoted the growth performance and chlorophyll synthesis of C. zizanioides planted in landfill soil. Cd, Cu, Pb and Zn were mostly retained in the roots relative to the shoots of C. zizanioides. The accumulation of Cd, Cu, Pb, and Zn in the roots of C. zizanioides were significantly boosted by MU1-BBP inoculation. Plants with MU1-BBP inoculation enhanced the accumulation coefficient (AC) of all four heavy metals. The values of AC values of Cd, Cu, and Zn in C. zizanioides with MU1-BBP inoculation were greater than 1.0. However, translocation factors of all four metals were low. The findings suggest C. zizanioides may be a good heavy metal phytostabilizer. The findings support the potential of bacterial-biochar pellets to enhance the efficiency of heavy metal phytostabilization of C. zizanioides in landfill sites.

Native plant species growing on the abandoned Zaida lead/zinc mine site in Morocco: Phytoremediation potential for biomonitoring perspective.

This study aims to assess the level of metal contamination and the ecological risk index at the abandoned Zaida Pb/Zn mining site in eastern Morocco and identify native plant species found on the site that can be used in site rehabilitation through phytoremediation strategies. Samples from seven native and abundant plant species at the site, along with their rhizospheric soils, were collected and analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to determine the concentrations of various metal(loid)s, including As, Cu, Ni, Cd, Sb, Zn, and Pb. Indicators of soil pollution and ecological risks were also assessed, including the enrichment factor (EF), pollution index (PI), and ecological risk index (ERI). The Biological Accumulation Coefficient (BAC), Translocation Factor (TF), and Biological Concentration Factor (BCF) of plant samples were calculated. The results reveal polymetallic soil contamination, with notably higher concentrations of Pb, Cu and Zn, reaching respectively 5568 mg kg-1 DW, 152 mg kg-1 DW, and 148 mg kg-1 DW, indicating a significant potential ecological risk. The enrichment factor (EF) was also assessed for each metal(loid)s, and the results indicated that the metal contamination was of anthropogenic origin and linked to intensive mining activities in Zaida. These findings are supported by the pollution index (PI) ranging from 1.6 to 10.01, which reveals an extremely high metal(loid)s pollution level. None of the plant species exhibited a hyperaccumulation of metal(loid)s. However, Artemisia herba alba demonstrated a strong capacity to accumulate Pb in its aboveground parts, with a concentration of 468 mg kg-1 DW. Stipa tenacissima, Retama spherocarpa, and Astragalus armatus, showed a significant Pb accumulation in their roots reaching 280, 260, and 256 mg kg-1 DW.respectively. Based on BAC, TF, and BCF, Stipa tenacissima exhibited potential for Ni and Cd phytostabilization, as well as the ability for Zn phytoextraction. Additionally, Artemisia herba alba displayed the capability to phytoextract Cd and had a high propensity to translocate all the studied metal(loid)s. Astragalus armatus has the potential to be used in the phytostabilization of Zn and Ni, as well as for the phytoextraction of As and Sb. These native species from the Zaida site, although not hyperaccumulators, have the potential to contribute significantly to the phytoextraction or phytostabilization of potentially toxic elements (PTEs). Moreover, they can serve as vegetative cover to mitigate the erosion and dispersion of metal(loid)s.

Simulation of rice grain breakage process based on Tavares UFRJ model

Understanding the breakage characteristics of rice grains is an important means to reduce rice breakage rate. However, the dynamic breakage mechanism of rice grain is unclear due to the lack of a reasonable breakage model. In this study, the uniaxial compression test and drop weight test of single rice were carried out, the breakage model of rice grain was constructed, the reliability of rice model was verified by the experiment and simulation results. The results showed that the fracture energy distribution of rice can be obtained by uniaxial compression test, the specific fracture energy of rice accords with a lognormal distribution, and the median specific fracture energy of rice is 479.75 J/kg. The damage accumulation coefficient and fragment size distribution of rice can be acquired by drop test, the result of damage accumulation coefficient of rice was 4.3. Rice grain breakage mainly occurs in the milling section of the vertical circulation rice mill.

SCIENTIFIC BASIS OF MONITORING THE BOTTOM SEDIMENTS STATE AS AN INDICATOR OF THE ENVIRONMENTAL DANGER LEVEL OF HYDROECOSYSTEMS

The work proposes a method of monitoring the condition of surface water bodies that were subject to the influence of aviation industry enterprises, by studying the contamination of bottom sediments.Using the example of petroleum hydrocarbons - specific pollutants of aviation enterprises, the author proved that bottom sediments are an integral indicator of the level of manmade pollution, an indicator of the ecological safety level of hydroecosystems. The calculated coefficients of bottom accumulation indicate the progressive pollution of the reservoir and the accumulation of the main mass of pollutants in the bottom sediments. The results of studies of the small river, that flows along the airline, show that the bottom sediments belong to the category of “extremely polluted”. The structural and functional properties of bottom sediments enable us to state that, on the one hand, they contribute to the process of self-purification of the water environment by accumulating oil products, but on the other hand, bottom sediments represent a danger to the water column secondary pollution, since when physical and chemical conditions change, pollutants from the bottom sediments can pass into the water masses of the reservoir.

Asymmetry in Body Composition Variables of Youth Athletes

Assessing bilateral differences in paired anthropometric features is an important methodological problem in sports anthropology. The present study included 128 adolescent female athletes (59 rhythmic gymnasts, 58 tennis players, and 11 swimmers). Body composition components were determined using multi-frequency bioelectrical impedance measurements (analyzer InBody 170). Asymmetry coefficients of muscle and fat mass accumulation in the upper (AA) and lower (AL) limbs were calculated using the Nacheva` equation (1986). The percentiles method was applied to distribute the bilaterally studied anthropometric features according to the mean values of the units of asymmetry (UA). Wilkoxon-test was used to assess the statistically significant differences in paired variables. Kruskal-Wallis test was applied to determine the differences in UA between three assessed athlete groups, depending on their age. The differences in body composition components between rhythmic gymnasts (RG), tennis players (TP), and swimmers (SW) were well expressed in all assessed age groups. The most considerable inter-group differences were observed in terms of the asymmetry coefficient in the lean body mass (LBM) with a right direction and body fat mass with a left direction for upper limb fat mass (%, kg), which have signed the highest values in the tennis players group, followed by the RG on the same age. Swimmers had significantly the lowest values of UA for all body segments. A close relation was found between asymmetry in body composition variables and the type of sports activity. Tennis was found as a sport with more pronounced inter-limbs asymmetry.

Prediction models for building thermal mass of intermittently heated rooms for balancing energy consumption and indoor thermal comfort

Building thermal mass (BTM) plays an essential role in maintaining a comfortable indoor environment for intermittently heated rooms (IHR). However, how to properly determine the BTM in IHR is unclear for the comprehensive consideration of the opposite effects on the reduction of heating energy consumption (HEC) as well as the improvement of indoor thermal comfort (ITC). This study aims to investigate the comprehensive impact of BTM on the HEC and ITC of IHR in the hot summer and cold winter (HSCW) zone of China using the validated EnergyPlus model. The results indicate that BTM can significantly improve the ITC of IHR, whereas increase HEC. The degree of impact is mainly related to the internal wall heat accumulation coefficient, external wall insulation layer thermal resistance, and outdoor air mean temperature during non-heating periods. Response surface methodology is further employed to quantify the effects of BTM on HEC and ITC of IHR. Based on the predictive models, the range of parameter variations for BTM that simultaneously meet HEC and ITC requirements is obtained. The predictive models can provide a theoretical basis for balancing HEC and ITC in intermittently heated buildings in the HSCW zone of China.

Microbial metabolic capacity regulates the accrual of mineral-associated organic carbon in subtropical paddy soils

In general, the accrual of mineral-associated organic C (MAOC) level is limited by the finite area of reactive minerals. However, microbial metabolism probably affects MAOC accumulation and saturation because microbial necromass C constitutes the primary component of MAOC. To address this gap in current understanding, we used 18O–H2O incubation and biomarker analyses to quantify microbial C metabolism and necromass accumulation respectively, and quantify their relationship with MAOC and saturation levels across gradients of soil organic C (SOC) that ranged from 4.0 to 40.1 g kg−1 in subtropical paddy soils. Results showed that particulate organic C (POC) increased linearly as SOC increased whilst MAOC tended to saturation. Notably, MAOC accumulation showed a significant positive relationship to increases in microbial necromass C indicating that MAOC accumulation prior to saturation was closely linked to the activity of microbial C metabolism. Compared with low C soils, lower microbial growth efficiencies (qgrowth) and slower biomass turnover rates were observed in high C soils. Moreover, the necromass accumulation coefficient (i.e. necromass produced per unit of microbial biomass) was also lower in high C soils than in low C soils. The lower microbial growth efficiency in the high C soils was attributed to greater C/P and higher clay proportion, which decreased microbial biosynthesis and substrate accessibility. Microbial communities showed adaptive shifts in composition to modulate bacterial metabolic activity, with increases in the relative abundance of r-strategists and decreases in the K-strategists. Management strategies for actively increasing the size of the MAOC pool, by bolstering microbial anabolism and necromass accumulation, are essential for increasing the MAOC content in paddy soils where the MAOC is unsaturated. For high C soils, where the MAOC is already saturated, the use of structural and recalcitrant organic materials to increase the size of the POC pool is needed to enhance carbon sequestration efforts.

The capacity of Plectranthus sp. to perform phytoremediation on heavy metal mercury (Hg) in the tailing of gold processing industries

Sludge (tailing), a waste product of the amalgamation process used in the mining of gold, contains a high concentration of the heavy metal mercury (Hg). It is well known that mercury builds up in large quantities in Plectranthus sp. herbaceous plants in the Pancurendang Village Small-Scale Gold Mining area. The study intends to: 1) quantify the amounts of mercury present in plant organs and media tailing during phytoremediation treatment; 2) examine the mechanisms and capacities of plant phytoremediation using values of the Biological Accumulation Coefficient (BAC), Biological Concentration Factor (BCF), and Translocation Factor (TF); and 3) determine the impact of percentage variations in tailing and time on Plectranthus sp.’s capacity to accumulate mercury. On a lab scale, phytoremediation of tailings is done with concentrations of 0%, 30%, 50%, and 100%. Planting medium is combined with dried tailings. Pots are used for phytoremediation, and the residence times are 10, 20, and 30 days. With the use of a mercury analyzer, the amount of mercury present in plant media, roots, and shoots is determined. Using the BAC, BCF, and TF values, the mathematical calculation of phytoremediation ability is performed. Hg content ranged from 1.82 to 16.23 ppm in shoots and 5.15 to 37.19 ppm in roots. Throughout the course of treatment, the tailings Hg concentration varied between 13.18 and 220.05 ppm. Plectranthus sp. is categorized as a medium accumulator with a phytoextraction mechanism, according to the analysis’s findings. Hg phytomining is possible with Plectranthus sp., the TF value is 2.38. Within 10 days, Plectranthus sp. most effectively accumulates 50% Hg in tailings.

Assessment of two non-invasive techniques for measuring turbulent benthic fluxes in a shallow lake

Benthic fluxes refer to the exchange rates of nutrients and other compounds between the water column and the sediment bed in aquatic ecosystems. Their quantification contributes to our understanding of aquatic ecosystem functioning. Near-bed hydrodynamics plays an important role at the sediment-water interface, especially in shallow lakes, but it is poorly considered by traditional measuring techniques of flux quantification, such as sediment incubations. Thus, alternative sampling techniques are needed to characterize key benthic fluxes under in-situ hydrodynamic conditions. This study aimed to evaluate the performance of two promising methods: relaxed eddy accumulation (REA) and mass transfer coefficient (MTC). We applied them in a hyper-eutrophic shallow lake to measure the fluxes of ammonium, phosphate, iron, and manganese ions. For the first time, REA revealed hourly nutrient flux variations, indicating a strong lake biogeochemical dynamics at short time-scales. Daily average fluxes are of similar orders of magnitude for REA and MTC for ammonium (24 and 42 mmol m2 d−1), manganese (1.0 and 0.8), and iron (0.8 and 0.7) ions. They are one order of magnitude higher than fluxes estimated from sediment incubations, due to the difficulty in reproducing in-situ oxygen and hydrodynamic conditions in the laboratory. Although the accuracy of both techniques needs to be improved, the results revealed their potential: REA follows the short-term biogeochemical dynamics of sediments, while MTC could be widely used for lake monitoring because of its simpler implementation.

Геохимическая оценка системы «поверхностная вода – донные отложения» в зоне горнопромышленного техногенеза

Introduction. Tailings dumps are the most common by-product of the process of extracting valuable minerals and metals from mined ore. Their placement is accompanied by a violation of the natural properties of natural landscapes, changes in the geochemistry of soils and the hydrochemistry of the aquatic environment, the accumulation of heavy metals and toxicants in depositing media. The issues of geochemistry and stability of landscapes, the safety of natural and technical systems, the identification, study, assessment and forecast of their development in the conditions of increasing techno genesis is an urgent global problem. One of the most important directions in the geochemistry of mountain landscapes and mining and industrial ecology is the purposeful study of the relationship and interdependence of the processes of technogenic geochemical migration of the main and associated ore-forming elements into the environment with the technological processes of ore extraction and processing. The development of scientifically-based principles for the organization of control and monitoring of disturbed geo-systems in the conditions of techno genesis is not only an important fundamental research task, but has practical significance in order to preserve natural landscapes and mountain geo-systems. Purpose of research. Geochemical assessment of the “surface water-bottom sediments” system in the area of a copper-molybdenum deposit. Materials and methods. The research methodology is based on the theoretical foundations of landscape geochemistry. The object of the study is the system “surface water-bottom sediments” in the zone of technogenic influence of the tailings dump of a copper-molybdenum deposit. Field and standard physical-chemical methods, Excel graphics, geo-information analysis, 3D modeling Statistica were used. Discussion. Geochemical testing of the surface river in the tailings storage area revealed a significant enrichment of the aquatic environment with salt ions, which enter the surface water in the form of dam filtrate. The violation of the ratio of alkali metal ions, as well as the ratio of alkali-earth metal ions to alkali metal ions, which is a geochemical anomaly for fresh surface natural waters, is shown. As a result of constant filtration through the body of the tailings dam, heavy metals also enter the river water, primarily Cu, Mo, Fe, which, under conditions of an alkaline water environment, accumulate mainly at the bottom of the watercourse in the form of insoluble deposits. The coefficients of accumulation of metals in bottom sediments relative to clerks are obtained. The spatial dynamics of their distribution and variability along the riverbed are revealed, which makes it possible to predict the development of the situation in the zone of mining and industrial techno genesis. 3D models of the distribution of the analyzed metals from the properties of the pH medium, the main regulating factor of the formation of various forms of heavy metals, are obtained. Conclusion. It is shown that the hydro-geochemical features in the “surface water – bottom sediments” system of the river in the area of the tailings dam inherit chemical ore occurrence during Cu, Mo, Fe extraction. This indicates a technogenic transformation of the hydrosphere in a zone with a predominance of mining and industrial specialization of the deposit. The results obtained are of scientific interest as an empirical model for studying the process of formation of sedimentary ores, which, in turn, represents a fundamental aspect for the development of the theory of subsoil development design and studying the processes of formation of technogenic deposits.

The contribution of microbial necromass to soil organic carbon and influencing factors along a variation of habitats in alpine ecosystems

A growing consensus is reached that microbes contributes to regulating the formation and accumulation of soil organic carbon (SOC). Nevertheless, less is known about the role of soil microbes (necromass, biomass) in SOC accumulation in different habitat conditions in alpine ecosystems. To address this knowledge gap, the composition and distribution of amino sugars (ASs) and phospholipid fatty acids (PLFAs) as biomarkers of microbial necromass and biomass were investigated in forest, meadow and wetland soil profile (0–40 cm) of Mount Segrila, Tibet, China, as well the contribution of bacterial and fungal necromass to SOC. The results revealed that microbial necromass carbon contributed 45.15 %, 72.51 % and 78.08 % on average to SOC in 0–40 cm forest, meadow and wetland soils, respectively, and decreased with microbial biomass. Fungal necromass contributed more to SOC in these habitats than bacterial necromass. Microbial necromass increased with microbial biomass and both of them decreased with soil depth in all habitats. The necromass accumulation coefficient was significantly correlated with microbial necromass and biomass, affected by habitat and soil moisture. Structural equation model indicated that soil abiotic factors indirectly mediated the accumulation of SOC through microbial necromass and biomass. This study revealed that different habitats and soil depths control considerably soil physicochemical properties and microbial community, finally influencing SOC accumulation in alpine ecosystems, which emphasized the influence of abiotic factors on microbial necromass and biomass for SOC accumulation in alpine ecosystems.