High Concentrations Of Trace Elements Research Articles

Association between serum mineral levels and reproductive performance in primiparous dairy cows during the peripartum period.

To the best of the authors' knowledge, no study has previously investigated whether the concentration of minerals is related to reproductive outcomes in primiparous cows. For this reason, two objectives were set in the present study: (i) to assess serum mineral levels, macrominerals, and trace elements during the transition period (period of high nutritional requirements) in primiparous cows, considering reproductive efficiency, and (ii) to address if the serum mineral levels of primiparous cows are related to reproductive efficiency. Blood samples were taken (i) one month before calving, (ii) one week before calving, (iii) one week postpartum, and (iv) one month postpartum. At the beginning and the end of the study, a body condition score (BCS) was assigned to each lactating cow with no clinical signs of disease. The difference between one month before and one month after calving was the body condition loss (ΔBCS). Optimal prepartum concentrations of K and Cl were associated with fewer days open and a shorter interval calving. Furthermore, macrominerals in the serum decreased immediately after calving (one week) but recovered at one month postpartum. In contrast, the highest concentration of trace elements was found at one week postpartum. Primiparous cows with higher postpartum Se, Mn, Co, and Mo concentrations exhibited better reproductive efficiency, and the concentrations of trace elements in serum were correlated with interval calving and the number of inseminations. Finally, primiparous cows with a greater ΔBCS (at least one point) in period 4 exhibited both a longer calving interval and a greater number of days open. In summary, this study showed, for the first time in primiparous cows, that the concentration of some serum minerals not only plays a crucial role during the transition period but is also related to crucial reproductive parameters, such as interval calving and days open.

Young KREEP-like mare volcanism from Oceanus Procellarum

The Moon’s mare volcanism predominantly occurs within the Procellarum KREEP Terrane (PKT), which is widely thought to be associated with KREEP components within the lunar interior. The Chang’e-5 (CE-5) mission sampled a young (2 Ga) mare basalt Em4/P58 unit of northern Oceanus Procellarum. The geochemistry of the CE-5 mare basalt enables assessment of mantle source compositions which are essential to understand the thermo-chemical mechanism for prolonged volcanism during secular cooling of the Moon. Geochemical compositions of the CE-5 bulk soil, breccias, and basalt clasts from various depths within the drill core consistently display high concentrations of incompatible trace elements (ITE: ∼ 0.3 × high-K KREEP; ∼ 5 μg/g Th) with KREEP-like inter-element ratios, for example for La/Sm, Nb/Ta, and Zr/Y. Exotic impact ejecta, extensive magma differentiation (<70 % fractional crystallization) and significant assimilation of KREEP materials during magma transit and eruption cannot account for the ITE contents and ratios or radiogenic isotope compositions (e.g., εNdinitial of + 8 to + 9 and εHfinitial of + 40 to + 46) of the CE-5 basalts; instead, partial melting of their mantle source played a dominant role. The Chang’e-5 basalt is a chemically evolved low-Ti mare basalt (Mg# of ∼ 34) with enriched KREEP-like ITE compositions but high long-term time-integrated Sm/Nd and Lu/Hf ratios, which represent a hitherto unsampled type of mare basalt. It formed by melting of an augite-rich mantle source (late-stage magma ocean cumulates containing > 30–60 % augite, and little or no ilmenite), with a small amount of late-stage interstitial melt that resembles KREEP (∼1–1.5 modal %, equivalent to 0.2–0.3 μg/g Th in the mantle source). The voluminous mare basalts making up the Em4/P58 unit (>1500 km3) provide compelling evidence for large-scale, ITE enriched young mare magmatism within Oceanus Procellarum. In combination with remote sensing data and with the unique Th-rich Apollo 12 basalt fragment 12032,366–18 (impact ejecta likely from Oceanus Procellarum), this implies that significant portions of the FeO- and Th-rich mare regions of the western PKT may also have formed in a similar way.

Alterations of High-Carbon (Shungite) Rocks by the Lake Onega Waters: Mineralogy and Geochemistry of the Process

Abstract ––Carbonaceous (shungite) rocks have high contents of trace elements, which can get to the environment through natural weathering. Shungite rocks are a group of Precambrian carbonaceous rocks of volcanic and sedimentary genesis in Karelia. In this work we present results of studying the mineral and geochemical compositions of shungite rocks at their outcrops on the shoreline of Lake Onega. The interaction of the Onega waters with shungite rocks led to: (1) the removal of most elements, except for K, Mn, Ba, and Mg, whose contents in the rocks increased; (2) the formation of an assemblage of secondary minerals, such as hematite, jarosite, goethite, chalcocite, anglesite, brookite, and Mn hydroxides. Based on the results obtained, we propose a model of the transformation of high-carbon (shungite) rocks by the Onega waters.

Evaluating health risks from the release of trace elements to groundwater by rock-water interaction in a weathered gneissic aquifer.

High concentration of trace elements in groundwater poses more health risks to humans by drinking groundwater and dermal contact. This work aimed to assess the trace element concentrationin groundwater, water quality for drinking purposes, and its effect on human health upon prolonged consumption. The study was carried out in the gneissic terrain of Perambalur District, Tamil Nadu, India, where groundwater is used mainly for drinking, agricultural, and domestic purposes. Hydrochemistry, water quality, and health risk assessments of trace elements from 44 groundwater samples for pre- and post-monsoon were determined by drinking water quality, hazard quotient, hazard index, and carcinogenic risk. The dominance of trace elements in groundwater was in the order of Zn > Fe > Cu > Ni > Te > Pb > Co. Ni and Co are released more during the post-monsoon, and Zn, Fe, Cu, and Pb concentration during the pre-monsoon. The dominant type of groundwater was Ca-HCO3 and mixed Ca-Mg-Cl type. The dissolution of fissile hornblende biotite gneissic rock dissolves more trace elements to groundwater than charnockite rock. The correlation matrix indicates that major ion and trace elements were positively good in groundwater during the pre-monsoon and post-monsoon 2018. The principal component analysis suggests that the weathering of rocks, rainwater recharge, and evaporation processes controlled the hydrochemistry of trace and major ions. The concentration of Pb, Ni, and Cd elements exceeded the permissible limit of BIS and WHO; these elements are unsuitable for drinking. The trace element concentration in groundwater was good for drinking and irrigation in the study area, except in a few wells. The hazard quotient and hazard index were computed, which revealed that non-carcinogenic risk to human health by drinking groundwater was more of a problem for children than adults. This study will help prevent children from health risks of trace elements.

Tracing Detrital Epidote Derived from Alteration Halos to Porphyry Cu Deposits in Glaciated Terrains: The Search for Covered Mineralization

Abstract Distal alteration related to porphyry Cu mineralization is typically characterized by an abundance of green minerals, such as epidote, tremolite, and chlorite, within the propylitic and sodic-calcic alteration zones and extends far outside (&amp;gt;1 km) the mineralized zone(s). Glacial erosion and dispersal derived from rocks affected by propylitic and sodic-calcic alteration have resulted in the development of extensive dispersal trains of epidote in till (glacial sediment) that can reach 8 to 330 km2 as observed at four porphyry Cu study sites in the Quesnel terrane of south-central British Columbia: Highland Valley Copper, Gibraltar, Mount Polley, and Woodjam deposits. At each of these sites, epidote is more abundant in heavy mineral concentrates of till collected directly over and down-ice from mineralization and associated alteration. Epidote grains in till with &amp;gt;0.6 ppm Sb and &amp;gt;8 ppm As (as determined by laser ablation-inductively coupled plasma-mass spectrometry) are attributed to a porphyry alteration provenance. There is a greater abundance of epidote grains with high concentrations of trace elements (&amp;gt;12 ppm Cu, &amp;gt;2,700 ppm Mn, &amp;gt;7 ppm Zn, and &amp;gt;37 ppm Pb) in each porphyry district compared to background regions. This trace element signature recorded in till epidote grains is heterogeneously distributed in these districts and is interpreted to reflect varying degrees of metal enrichment from a porphyry fluid source. Tracing the source of the epidote in the till (i.e., geochemically tying it to porphyry-related propylitic and/or sodic-calcic alteration), coupled with porphyry vectoring tools in bedrock, will aid in the detection of concealed porphyry Cu mineralization in glaciated terrains.

Association and textural-compositional evolution of pyrite-organic matter in coals of the Tarakan, Barito, and Pasir Basins, Kalimantan, Indonesia

The Barito, Pasir, and Tarakan Basins in Kalimantan Island is the most extensive coal-bearing sedimentary basin in Indonesia, mined since 1989. The coal is notable in having high sulfur coal content, exceeding >10% in some cases, contributed by the presence of pyrite. The latter issue contributed to interest in the coal, forming economic mineral deposits hosted by the sedimentary pyrite and organic matter. Novel findings of this research providing valuable information of trace element behavior during the diagenetic conditions. This paper documents the textural and compositional evolution of pyrite-organic matter of coals using coal petrographic, proximate, ultimate, total sulfur content, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), electron probe micro analyser (EPMA), and Raman spectroscopy. Coals from Kalimantan are mainly characterized by medium-high sulfur content (>3%) and the maximum temperatures reached by organic matter during diagenesis are 166 ± 10 °C for the Pasir Basin, 136 ± 11 °C for the Barito Basin, and 132 ± 12 °C for the Tarakan Basin. Pyrite is mainly found as large size framboids (mostly >5 μm), indicating formation in the sedimentary layer with dysoxic bottom water conditions during early–late diagenetic stages. The framboidal pyrite was likely formed in detrovitrinite and gelovitrinite under topogenous mire conditions, due to the degradation of macerals and biochemical gelification, which provided the organic templates. High concentrations of trace elements (TE) of framboidal pyrite, such as 1) Cu, Ni, and Co in the Pasir Basin and 2) As in the Barito Basin, likely reflect the local sedimentary provenance and underlying basement rocks. Pyrite texture evolved with increasing diagenetic temperatures from 1) framboidal pyrite, 2) recrystallized framboidal pyrite rims, and 3) anhedral, anhedral-euhedral pyrite transition, and euhedral massive pyrite. This study shows a similar average TE concentrations of various pyrite texture, suggesting that the TEs are not remobilized during the evolution of pyrite at the diagenetic stages.

Ecological features of trace elements tolerant microbes isolated from sewage sludge of urban wastewater treatment plant

Worldwide wastewater treatment plants generate enormous amounts of sewage sludge, and their further disposal depends on the treatment technologies applied and spontaneously occurring microbiological processes. From different ages urban sewage sludge, 12 strains of bacteria with simultaneous tolerance to two or more trace elements: Co, Ni, Cu, Zn, Cd and Pb at concentration of 3-5 mmol were isolated and identified by PCR of target genes and Sanger sequencing methods. The isloated metal(loids) tolerant strains belong to the species, i.e., Serratia fonticola, Rhodococcus qingshengii, Pseudomonas fragi, Pseudomonas extremaustralis, Pseudomonas cedrina, Stenotrophomonas maltophilia, Serratia liquefaciens and Citrobacter freundii. The ecological features of the isolated strains were studied. The optimal growth temperatures for most strains was 15–30°C at pH range of 5–9, although some strains grew at 7°C (Pseudomonas fragi SS0-4, Serratia fonticola SS0-9 and Serratia fonticola SS12-11). Satisfactory growth of two strains (Serratia fonticola SS0-1and Citrobacter freundii SS60-12) was noted in an acidic medium at pH 4. Most of the strains grew in the NaCl concentration range of 1–5%. The isolated bacteria resistant to high concentrations of trace elements can be used for the effective mineralization of sewage sludge and for the decontamination of wastewater.

Study of composite mixtures based on durum wheat semolina and white beans flour for pasta production as specialized food products

Increasing the number of chronic non-communicable diseases around the world is a critical social problem in many countries. In this regard, the creation of specialized foods that correct dysfunctions of the human body is a priority direction in science and food industry. Legumes are characterized by a high content of protein, minerals and trace elements, which determines their possible use as the main raw materials for creating specialized foods. The aim of this research was to present a medical, biological and technological justification for the possibility of producing pasta based on composite mixtures of durum wheat semolina and white bean flour as specialized foods with increased protein content and optimal mineral ratio. Material and methods. The objects of the study were grains of durum wheat (grade Krasnokutka-13), whole meal flour from white beans, composite mixtures in various percentages, and pasta from them. The nutritional and biological value of durum wheat semolina and bean flour was determined experimentally, the nutrient profile of the developed composite mixtures - by calculation. The rheological properties of dough from composite mixtures and the cooking properties of pasta made from them were assessed. Results. It has been established that increase in the proportion of white bean flour in composite mixes elevated calcium and protein content, optimized an amino acid profile, the ratio of calcium to phosphorus, significantly reduced the glycemic load. Bean flour introduction into composite mixtures positively affected the rheological properties of the dough and products from it, in particular, on the speed and energy intensity of dough kneading and aging processes of starched polysaccharides, however, lead to a decrease in dry pasta strength. The pasta made from composite mixtures meets the technological requirements for pasta in terms of a number of basic indicators, namely: the volume of dry pasta, the volume of pasta after cooking and the boilability coefficient. Conclusion. The rheological and technological properties of composite mixtures and their nutrient profile make it possible to recommend them for the production of pasta, as specialized foods.

Tetrad Effect of Rare Earth Element Fractionation in Zircon from the Pegmatite of the Adui Massif, Middle Urals

The zircon from the pegmatite of the Adui granitic massif displays the unique the rare earth element (REE) distribution spectrum with the tetrad effect in REE fractionation. The tetrad effect often occurs in granitoid rocks, but it is rarely encountered in minerals, e.g., zircon. Fluid saturated with volatiles, water and trace elements is a factor responsible for the tetrad effect in the zircon. The detailed isotopic-geochemical study of the zircon has revealed several zones differing in internal structure (in the back-scattered electron (BSE) image), composition and REE distribution. The zones indicate changes in the crystallization environment provoked by the evolution of the pegmatite-forming melt. They occur as the gradually growing changes in composition from the unaltered zones that are light-colored in BSE to the altered zones that are dark-colored in BSE. The unaltered zones are consistent in composition and geochemical features with magmatic zircons. The high content of trace (U, Th, REE) and volatile elements (F, Cl) in water suggests its crystallization from the fluid-saturated magmatic melt. The altered zircon zones occur as recrystallized zones with high content of non-formula elements (Y, Ca, Sr, Nb, P), a non-differentiated REE distribution spectrum and an absent Ce anomaly. These features are consistent with those of hydrothermal-metasomatic zircon.

Chemical composition аnd morphology of pyrite and marcasite in blue clay from the Maritsa East lignite basin, Bulgaria

Pyrite and marcasite aggregates were found in a sample of blue silty clay from an exploration drill core at the northern edge of the Troyanovo North mine, Maritsa East lignite basin, Bulgaria. The aggregates have various sizes – from 50 µm (single crystal twins) to 0.5 cm (large twinned aggregates). Pyrite occurs as single cubic and cuboctahedral crystals, penetrative twins forming oval-shaped aggregates with visible cubic to truncated octahedral habits. Marcasite occurs as single tabular, pyramidal crystals, but often as twinned (penetrative, parallel, contact) composite oval-shaped aggregates. Marcasite has higher trace element contents than pyrite. In both minerals are detected Mn, Co, Ni, Cu, Zn, Mo, As, Sb, Hg, Tl and Pb with varying contents. The crystal aggregate growth is slow in varied supersaturation and pH due to the occurrence of both octahedral and cubic faces in pyrite and marcasite presence.

Evidence of a distal axis inactive high-temperature hydrothermal field on the ultraslow spreading Southwest Indian Ridge: Insights from mineralogy and geochemistry studies

The development of hydrothermal activities on mid-ocean ridges is primarily influenced by magmatic and tectonic activities close to the ridge axis. On slow and ultraslow spreading ridges featured by limited magma supply, prolonged hydrothermal activity can also occur in non-transform offsets (NTO), where sustained ultramafic-related hydrothermal circulation happens due to prolonged hydrothermal processes associated with the expose of ultramafic rocks. In contrast, basalt-hosted hydrothermal fields are barely developed in NTOs, especially in off-axis area, due to insufficient magma supply. In this study, we reported the occurrence of a distal axis (∼9.5 km) basalt-hosted hydrothermal field (50.63°E) on the NTO of segment 27 of the ultraslow spreading Southwest Indian ridge. The hydrothermal products are characterized by layered crusts mainly composed of oxides, such as limonite and goethite, rich in Fe and depleted in Si. These crusts contain high contents of trace elements derived from seawater, such as P, As, Mo, U, and Sb and show REE pattens with negative Eu and mostly positive Ce anomalies. However, the high Cu content (1.82 ± 0.89 wt%, N = 27), low absorption ratio of Cu (18.39 ± 12.71%, N = 9), and residual chalcopyrite altered by goethite suggest prior high-temperature hydrothermal activity. Lead isotopic composition with basaltic rocks signatures that distinct from those of low-temperature crusts of seawater origin also support this conclusion. The Fe-rich crusts appears to be the result of high-temperature sulfides altered by late-stage low-temperature diffuse flow. This field is currently the furthest known distal axis basalt-hosted hydrothermal field located in NTOs of ultraslow spreading ridges. The hydrothermal circulation is likely due to a combination of off-axis normal fault and gabbro diking. Our results emphasize the occurrence of distal axis basalt-hosted high-temperature hydrothermal activities on NTOs of ultraslow spreading ridges, and may lead to an increased estimation of hydrothermal heat and chemical influx to the ocean.

Mo isotopes record recycling of anoxic sediment in a Paleo-oceanic subduction zone

Mafic arc igneous rocks with oceanic crust-derived fluids in their mantle sources generally show heavy Mo isotope compositions. However, these rocks may exhibit variable Mo isotope compositions due to involvement of seafloor sediments under different redox conditions. Thus, it is intriguing how Mo isotope recycles with sediment subduction and how Mo isotope fractionation occurs during this process. Here we report Mo isotope data for Paleozoic mafic arc igneous rocks from the Qinling-Tongbai orogenic belt in Central China. The Qinling mafic rocks have δ98Mo values of −0.03 to 0.40‰, and the Tongbai mafic rocks have δ98Mo values of −0.26 to 0.17‰. These values are considerably higher than the normal mantle values of −0.20 ± 0.01‰. In combination with low Mo/Ce ratios, enriched SrNd isotope compositions, and high melt-mobile incompatible trace element contents for these rocks, the high δ98Mo values suggest that anoxic sediment-derived melts with heavy Mo isotopes were incorporated by oceanic subduction into the mantle sources. The high δ98Mo values of the mafic rocks indicate the limited Mo isotope fractionation during subduction of the anoxic sediment. This inference is further verified by modeling of Mo isotope fractionation under reducing conditions in the subduction zone. In this regard, Mo isotopes can be used to identify the recycling of sediments in different types and thus provide geochemical constraints on the redox conditions of oceanic subduction zones.

FORMATION OF THE COMPOSITION OF TRACE ELEMENTS OF SNOW DUST IN TYUMEN AND TOBOLSK USING HIERARCHICAL CLUSTER ANALYSIS

Link for citation: Zakharchenko A.V., Pasko O.A., Tigeev A.A. Formation of the composition of trace elements of snow dust in Tyumen and Tobolsk using hierarchical cluster analysis. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 8, рр. 110-120. In Rus. The relevance: search for new methodological approaches and techniques for assessing the aerosol migration of substances and characterizing air pollution. The purpose of the work is a comparative analysis of clusters of the content of microelements of the solid phase of snow in the closely located cities of Tyumen and Tobolsk with respect to clean background and areas subject to technogenic impact. The materials: the trace elements of solid phase of the snow cover. The methods: chemical-analytical for determining the content of trace elements, hierarchical cluster in the analysis of geochemical spectra, probabilistic-statistical. Results. The background dust load in Tobolsk is less, and the inner city load is higher compared to Tyumen. A cluster data structure of 8 clusters has been established with the allocation of two large groups that combine the Tobolsk and Tyumen sites, which are divided into clusters with low and high content of trace elements. Conclusions. The conditionally background cluster C6 is present in Tobolsk (22,6 %) and Tyumen (11,7 %), and C5 – 13 % in Tobolsk and 8 % in Tyumen. A specific Tobolsk cluster C8 with a predominance of scattered elements (48 %) was found at 2 sites in Tyumen, which may indicate a possible transfer of aerosols between these cities. Some technogenic clusters contained heavy metals, while others were dominated by Sc, Cr, Ni, Zn, and Cd. Technogenic clusters (C7, C1) differ in the shape of the geochemical spectrum: heavy metals predominate in some, trace elements (C8) predominate in others; the same applies to conditionally background samples. The specific technogenic Tyumen cluster C4 is distinguished by high values of Cu and Mo. Conditionally isolated background clusters had a low content of microelements. To identify environmental conditions, we moved from the standardized values of cluster analysis to their material content. It is shown that some clusters contain heavy metals, while others contain Sc, Cr, Ni, Zn, and Cd. Conditionally isolated background clusters had a low content of microelements. Using the content of microelements of the C5 cluster as a background, the environmental index of pollution Zc was calculated, which in Tobolsk reaches a high and dangerous level of pollution 60,8–83,7, in Tyumen – an average, moderately dangerous level Zc (32–64). The use of cluster analysis makes it possible to determine the trace elements pollution of snow dust and the territory as a whole.

Elemental Characterization of Indonesian Coral Skeleton Using Underwater Laser-Induced Breakdown Spectroscopy (LIBS), X-Ray Fluorescence Spectroscopy (XRF), and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES)

The identification and determination of elements from the Indonesian coral skeleton are required to characterize anthropogenic activities. To this end, various spectroscopy methods were used for elemental analysis including underwater laser-induced breakdown spectroscopy (LIBS), x-ray fluorescence spectroscopy (XRF), and inductively coupled plasma – optical emission spectroscopy (ICP-OES). The results show that the LIBS was able identify the major elements Ca, Mg, and Sr. Using ICP-OES, all elements including major, minor, and trace elements were quantitatively determined. The results show that coral skeletons from Karimunjawa contain the highest concentrations of trace elements, which may be due to expanded human activities.

On the question of the mechanism of the general toxic action of lead nitrate

The leading unfavorable factor in the working environment that affects the health of miners is polymetallic dust, which contains a large number of toxic chemical elements. The study of the chemical composition of the floating dust in the air environment of the quarries of the East Kazakhstan copper-chemical plant and processing plant (Mamyrbaev, Konakbaev, 1992) showed a high content of lead, selenium, antimony, arsenic, and other trace elements.

Evolution of an ancient VMS ore-forming system recorded by pyrite and sphalerite mineral texture, trace elements, and sulfur isotope: A case study from the Huangtupo Cu-Zn (-Au) deposit, Eastern Tianshan, NW China

The Huangtupo Cu-Zn (-Au) volcanogenic massive sulfide deposit is hosted in a suite of Early Paleozoic basic to acidic volcanic, volcaniclastic rocks in the Eastern Tianshan orogen, northwest China. The Cu-Zn orebodies are characterized by the zoning of metallogenic elements upward from a deep stockwork mineralized zone (Cu > Zn) to a shallow massive mineralized zone (Zn > Cu). Detailed petrographic and LA-ICP-MS analyses have identified five types of pyrite and three types of sphalerite. These sulfides can be distinguished in a paragenesis with four stages of sulfide mineralization. The preore stage (SⅠ) from the deep volcanic rock contains subhedral-euhedral pyrite (Py1) with high trace element contents (e.g., Co, Ni, and Ti; Average value of total trace elements: 16764 ppm), except for Sb, and Tl, indicating a euxinic and high-temperature environment. Both the disseminated and veined pyrite (Py2) from the early ore stage (SⅡ; stockwork zone) and the euhedral pyrite (Py3) from the main ore stage-1 (SIII-1) have a similar chemical signature, suggesting that they precipitated under similar physicochemical conditions. These two paragentic stages of pyrite contributed only minimally to the trace elements endowment, except for higher Se contents. The continuous convection of hydrothermal fluids caused a large accumulation of copper and zinc, forming massive orebodies. Pyrite within the Zn(Cu)-rich zone of the main ore stage-2 (SIII-2) comprises three sub-generations (Py4a ∼ c) which are characterized by enrichment in most trace elements such as Au, As, Cu, and Sb. Pyrite 4a ∼ c formed in a fluctuating sedimentary environment and recorded the injection of a short-term, gold-rich fluid, which dissolved and reprecipitated trace elements from earlier ores and surrounding rocks. Orebody deformation and local metamorphism played a key role in this gold enrichment event. Pyrite (Py5) from the late ore stage (SⅣ) is deficient in most elements but relatively enriched in Co, Ni, and Se. Three stages of sphalerite associated with the Py3 ∼ 4 have been distinguished in the SIII. From Sp1 to Sp3, the content of Fe, Ge, Mo, and Cd decreased gradually, but the Sp2 is relatively depleted in Ag, As, Au, Pb, and Sb compared to Sp1 and Sp3. The sensitive variation of As, Co, Ni, Se, Pb in pyrite and Fe, Cu, Mn, Sb, Cd in sphalerite provide significant information for reconstructing the hydrothermal evolution process. The sulfur isotopes of these pyrites determined by in situ LA-multicollector (MC)-ICP-MS analyses are concentrated around 0‰, but vary significantly from −2.3 to 5.8‰. The δ34S values of the sphalerite range from −3.5 to 4.0 ‰ and tends to decrease from Sp1 to Sp3. These results show that the metals of the SIII were most likely derived from the deep-seated Early Paleozoic subvolcanic intrusion and Daliugou Formation during the evolution of regional island arcs.Combining the chemical, and isotopic data and geological features, the ore-forming process of an ancient VMS deposit was deduced. These results constrain the texture, composition and sulfur isotopic signatures of sulfides in veins and deformed ore bodies, as well as the gold enrichment mechanism, and also reflect the vertical variation of trace elements at the scale of VMS deposits, supporting the existence of multiple depositional mechanisms.

In situ characterization of pyrite from multiple microenvironments in middle Jurassic strata, northeastern Ordos Basin, China: Evaluation of synsedimentary/diagenetic fluid evolution

The sulfur isotopic composition and trace element content recorded in sedimentary pyrite have been widely used as a proxy to establish the geochemistry of pyrite-forming fluids. However, a continuous and complete evolution process of these fluids from the sedimentary period to diagenetic period remains not well constrained. The middle Jurassic strata (the Yan'an Formation containing coal seams and its overlying Zhiluo Formation hosting U deposits in the sandstone) in the northeastern Ordos Basin contain four kinds of microenvironments favorable for pyrite formation, namely coal, carbonaceous debris in barren gray sandstone, barren gray sandstone without carbonaceous debris and U mineralized gray sandstone from bottom to top, providing a good opportunity to decode pyrite formation in response to synsedimentary/diagenetic fluid evolution. In these microenvironments, pyrite named as PC, PD, PB and PM respectively, displays a variety of micro morphologies (framboidal, euhedral, infilling, irregular and cement) formed during sedimentary and diagenetic stages. PC has δ34S values ranging from −36.1 to +26.5 ‰ and low contents of total trace elements (from 6.7 to 58 ppm of Co + Ni + As + Se + Mo). PD and PB present δ34S signatures from −33.6 to +14.4 ‰ and from +9.7 to +22.2 ‰, respectively, with moderate trace element contents (from 21 to 111 ppm and from 23 to 80 ppm, respectively). PM resulting from the oxidation of PD and PB shows negative δ34S values (from −16.9 to −11.1 ‰ for framboidal pyrite and from −56.7 to −34.8 ‰ for euhedral pyrite + pyrite cement) and high trace element contents varying from 350 to 931 ppm. Detailed sulfur isotope and trace element microanalyses indicate that S involved in the formation of pyrite is derived from the fractionation process of organic sulfur in the coal, while Fe and trace elements originate from the surface-derived meteoric water. A paragenetic sequence from early PC, to PD and PB, and finally PM implies an evolution trend of δ34S values increasing first and then decreasing (bacterial sulfate reduction for framboids and Ostwald ripening for euhedral pyrite and pyrite cement of PM) and gradual enrichment of trace elements from synsedimentary to diagenetic fluids. The quantitative results can contribute to a better understanding of synsedimentary/diagenetic fluid evolution both locally and regionally for sedimentary strata in the low-temperature system.

STUDY OF THE INFLUENCE OF ENVIRONMENTAL FACTORS ON THE GROWTH AND DEVELOPMENT OF THE INSECT SPECIES HERMETIA ILLUCENS (BLACK SOLDIER FLY)

Background. The problem of agricultural waste disposal is currently very relevant. In the Russian Federation, the agro-industrial complex annually produces hundreds of millions of tons of waste that must be disposed of and used rationally. Organic waste from agricultural production and farm animal manure can be effectively disposed of using directed microbiological fermentation and larvae of the insect Hermetia illucens (black soldier fly). As a result of the activity of the enzyme system of black lion larvae and specific microflora, agricultural waste turns into zoohumus with a high content of nitrogen, phosphorus, potassium and trace elements, which can be used as an organic fertilizer that improves the quality of the soil, and the biomass of larvae for animal feed and for obtaining protein concentrate and fat.&#x0D; Purpose. To determine the optimal temperature conditions for the cultivation of the insect species Hermetia illucens (black soldier fly) on various types of substrates, to study the effect of the substrate composition on the production of larval biomass, protein concentrate and fat.&#x0D; Materials and Methods. The research work was carried out in the microbiological laboratory of the Center for Technological Excellence “Advanced Chemical and Biotechnology”, laboratories of the Department of Biology and Technologies of Living Systems, Faculty of Natural Sciences of the Tula State Pedagogical University named after L. N. Tolstoy and insectaria LLC “Lvinka”.&#x0D; To study the effect of the feed composition on the growth and development of the larvae of the insect species Hermetia illucens, substrates from various agricultural, food and animal waste were used. To determine the influence of temperature and humidity on the development of larvae, thermostats and insectarium rooms were used.&#x0D; Results. The study of the effect of various solid organic waste on the biomass of live and dried larvae showed that the larvae of the insect H. illucens grew and developed better on food waste consisting of meat and fish waste, as well as plant food waste. Larvae developed worse on plant residues. This is due to the fact that these wastes contain a large amount of cellulose and much less nutrients in their composition, therefore, on a substrate of this composition, the larvae gained biomass worse. The optimal temperature for the cultivation of insect larvae of the species H. illucens is t-22°C. The ratio of protein and fat in the larvae of the insect H. illucens depends on the composition of the feed. In those types of feed where protein predominates, the content of this component in the larvae is high. For example, when using food meat waste, the content of protein concentrate reaches 595 g/kg, fat only 323 g/ kg, and when using vegetable waste containing a large amount of carbohydrates, more fat and less protein are produced.&#x0D; Concisions. As a result of the research work carried out, it was possible to study the influence of environmental factors on the growth and development of the insect species H. illucens (black soldier fly), and to select favorable conditions for the development of larval biomass. Optimal substrates were selected for the cultivation of larvae of the insect species H. illucens. The most suitable substrates for the production of protein concentrate and fat were also determined.

Trace elements in aquatic products from Shenzhen, China and their implications for human exposure

Aquatic organisms in industrially polluted areas can accumulate large quantities of heavy metals. To assess the resulting health risks, 11 trace elements in 184 aquatic products representing 14 species of fish, crustaceans, and bivalves collected from Shenzhen, China were determined. Aluminum (Al), chromium (Cr), nickel (Ni), selenium (Se), antimony (Sb), manganese (Mn), copper (Cu), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) were determined by inductively coupled plasma mass spectrometry. The pollution levels of each product and the human health risk resulting from their consumption were then assessed. The concentrations of As in 57 % of samples and Cd in 11 % of samples exceeded the upper limits stipulated by the Chinese National Food Safety Standards (GB 2762-2017), which was mainly due to high concentrations of trace elements in crustaceans and bivalves. The Nemerow integrated pollution index indicated that the aquatic products accumulated high levels of As and Cd. Health risk assessments using the target hazard quotient (THQ) and hazard index (HI) suggested that As and Cd exposure due to consumption of aquatic products presents a potential health risk for residents of Shenzhen.

Distribution, Risk Assessment and Source Identification of Potentially Toxic Elements in Coal Mining Contaminated Soils of Makarwal, Pakistan: Environmental and Human Health Outcomes

The present research was carried out to examine the health and environmental impacts associated with coal mining activities in the Makarwal coal mining area in Pakistan. To achieve the objectives, 41 soil samples were collected from the coalmine-affected areas and analyzed for major and toxic trace elements (TTEs) using atomic absorption spectroscopy. Most of the soil samples have extremely high concentrations of toxic metals such as Ni, Cd, Cr, Cu, Zn, and Pb. The positive correlations and high concentration of trace elements in the Makarwal coalmine-affected region suggest an analogous origin of soil contamination. The factor analysis (FA) showed two components, i.e., F1 (53.4%) and F (74.21%), of total variability for soil. The F2 was loaded with Pb, Zn, Ni, and Cr, which was similar to cluster 2, while the F1 was loaded with Cu and Cr, having a similar pattern to cluster 1. This proves that the contamination in the surrounding area is mostly associated with geological ore strata existing in the Makarwal coalfield. Based on geoaccumulation (Igeo), the elemental concentration in the studied soil sample could be categorized as follows: (1) Pb, Ni, and Zn are moderate to severely polluted and (2) Cr and Cu are in the moderately polluted category. The ecological risk indices (ERIs) of the single trace element contamination index highlighted that Cd, Pb, Ni, and Cr pose a high risk to humans and the ecosystem. Based on different statistical tools performed for the source identification and distribution of metal contamination, it seems that the exposed sedimentary rocks, including limestone, dolomite, sandstone, and coal, are responsible for the toxic metal contamination in the study area.