Extraction of Valuable Components from Man-made Waters

2020 ◽  
Vol 24 (12) ◽  
pp. 4-10
Author(s):  
A.S. Chugunov ◽  
V.A. Vinnitskii ◽  
G.F. Nafikova
Keyword(s):  
Solid Solutions ◽  
Surface Waters ◽  
Experimental Studies ◽  
Membrane Reactors ◽  
Ore Body ◽  
Energy Consuming ◽  
Membrane Methods ◽  
Additional Dosage ◽  
Hydrographic Network ◽  
Purification Of Water

The results of experimental studies on isolation of poly-charged metals cations from man-made waters, which are valuable components, are presented. For their isolation and concentration, the method of homogenous sedimentation was used, which provides self-purification of water bodies in natural conditions and is responsible for the formation of bottom sediments. To implement these processes, energy-consuming low-pressure membrane methods were used- nanofiltration and dialysis, which creates conditions for the formation of solid solutions inside the composite membrane and do not require additional dosage of reagents. With the help of such combination, it was possible to obtain conditionally clean water for technical and household use, to divert environmentally friendly waste waters to the hydrographic network of the region. In addition, the shape of resulting original “ore body” simplifies its processing into individual components. It is noted the use of membrane reactors makes it possible to implement the homogenous deposition regime, which ensures the isolation of transition metals in the form of solid solutions with natural components of surface waters.

scholarly journals Температурные зависимости электропроводности и магнитной восприимчивости кристаллов твердых растворов Sb-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=--Bi-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=-

2021 ◽  
Vol 55 (12) ◽  
pp. 1162
Author(s):  
Н.П. Степанов ◽  
В.Ю. Наливкин ◽  
А.К. Гильфанов ◽  
А.А. Калашников ◽  
Е.Н. Трубицына
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Susceptibility ◽  
Solid Solutions ◽  
Thermoelectric Materials ◽  
Materials Science ◽  
Practical Importance ◽  
Experimental Studies ◽  
Electronic System ◽  
Temperature Dependences ◽  
The Subject

Solid solutions Bi2Te3-Sb2Te3 continue to be the subject of numerous and versatile experimental studies due to their practical importance for thermoelectric materials science. In this regard, the problem of studying the regularities of changes in the state of the electronic system of these semiconductors from composition and temperature remains urgent. This paper presents the results of studying the temperature dependences of the magnetic susceptibility of Bi2Te3-Sb2Te3 crystals containing 10, 25, 40, 50, 60 mol. % Sb2Te3. The correlation of the behavior of the temperature dependences of the magnetic susceptibility and electrical conductivity is analyzed.

scholarly journals Carbides and Nitrides of Zirconium and Hafnium

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2728 ◽  
Author(s):  
Sergey V. Ushakov ◽  
Alexandra Navrotsky ◽  
Qi-Jun Hong ◽  
Axel van de Walle
Keyword(s):  
Experimental Data ◽  
Phase Equilibria ◽  
Ab Initio ◽  
Solid Solutions ◽  
Binary Systems ◽  
Experimental Studies ◽  
Published Data ◽  
Oxygen Solubility ◽  
Melting Temperatures ◽  
Ab Initio Computations

Among transition metal carbides and nitrides, zirconium, and hafnium compounds are the most stable and have the highest melting temperatures. Here we review published data on phases and phase equilibria in Hf-Zr-C-N-O system, from experiment and ab initio computations with focus on rocksalt Zr and Hf carbides and nitrides, their solid solutions and oxygen solubility limits. The systematic experimental studies on phase equilibria and thermodynamics were performed mainly 40–60 years ago, mostly for binary systems of Zr and Hf with C and N. Since then, synthesis of several oxynitrides was reported in the fluorite-derivative type of structures, of orthorhombic and cubic higher nitrides Zr3N4 and Hf3N4. An ever-increasing stream of data is provided by ab initio computations, and one of the testable predictions is that the rocksalt HfC0.75N0.22 phase would have the highest known melting temperature. Experimental data on melting temperatures of hafnium carbonitrides are absent, but minimum in heat capacity and maximum in hardness were reported for Hf(C,N) solid solutions. New methods, such as electrical pulse heating and laser melting, can fill the gaps in experimental data and validate ab initio predictions.

scholarly journals Eco-chemical mechanisms govern phytoplankton emissions of dimethylsulfide in global surface waters

2020 ◽  
Author(s):  
Xuwei Deng ◽  
Jun Chen ◽  
Lars-Anders Hansson ◽  
Xia Zhao ◽  
Ping Xie
Keyword(s):  
Surface Waters ◽  
Experimental Studies ◽  
Feedback Regulation ◽  
Global Ocean ◽  
Negative Feedback Regulation ◽  
Chemical Mechanisms ◽  
Global Patterns ◽  
Gaseous Sulfur ◽  
The Relationship ◽  
Global Surface

Abstract The anti-greenhouse gas dimethylsulfide (DMS) is mainly emitted by algae and accounts for more than half of the total natural flux of gaseous sulfur to the atmosphere, strongly reducing the solar radiation and thereby the temperature on Earth. However, the relationship between phytoplankton biomass and DMS emissions is debated and inconclusive. Our study presents field observations from 100 freshwater lakes, in concert with data of global ocean DMS emissions, showing that DMS and algal biomass show a hump-shaped relationship, i.e. DMS emissions to the atmosphere increase up to a pH of about 8.1 but, at higher pH, DMS concentrations decline, likely mainly due to decomposition. Our findings from lake and ocean ecosystems worldwide were corroborated in experimental studies. This novel finding allows assessments of more accurate global patterns of DMS emissions and advances our knowledge on the negative feedback regulation of phytoplankton-driven DMS emissions on climate.

scholarly journals The biological action of solid solutions (on the example of cadmium-mercury-tellurium alloy)

2020 ◽  
Vol 64 (3) ◽  
pp. 158-162
Author(s):  
Natalia I. Nikolayeva ◽  
Andrey S. Filin ◽  
Ekaterina A. Guseva ◽  
Lubov’ G. Ivanova
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Biological Effect ◽  
Prolonged Exposure ◽  
Biological Effects ◽  
Experimental Studies ◽  
Mercury Vapor ◽  
The Body ◽  
Hazard Class ◽  
Statistical Research

Solid solutions are widely used in various industries. Experimental studies have been conducted to study the biological effects of warm-blooded animals (rat, mouse) solid solution based on cadmium (7%) mercury (52%) and tellurium (41%) (CMT). The purpose of the study: To investigate the biological effect of the solid solution (CMT) on the body of experimental animals. Material and methods. On the models of acute and subchronic exposure, the biological effect of CMT on the organism of warm-blooded animals (rats, mice) was evaluated. Studies have been carried out to establish toxicometry parameters (acute toxicity, the threshold for acute inhalation and intragastric effects, cumulative properties). In subchronic experiments, local and general toxic effects were investigated. The work used biochemical, physiological, toxicological, pathomorphological, statistical research methods. Results. According to acute experiments, the investigated substance belongs to the 4th hazard class (low-hazard compound). The threshold of acute inhalation action for rats is 46.20 mg/m3, and the intragastric effect for rats is 5000 mg/kg. CMT has moderate cumulation (Kcum = 4.79), does not irritate the skin. The compound was found to have a general toxic effect, which is based on functional disorders of the nervous system, liver, and kidneys. Discussion. The results of the study indicate that solid CMT solution has a polytropic effect on the warm-blooded organism. Conclusion. With prolonged exposure, the CMT aerosol can harm the body of workers, it is necessary to provide general preventive measures that prevent the aerosol of solid solutions from entering the body: automation, mechanization, sealing of production, adequate ventilation of production rooms, the use of personal protective equipment, the passage of mandatory periodic medical examinations by workers, and monitoring the concentration of CMT in the air of the working area should be carried out according to the MPC - 1.0 mg / m3 (mercury vapor).

scholarly journals Evaluation of Economic Consequences of Anthropogenic Pollution of Water Objects (On the Example of Vyalivsky Reservoir

2019 ◽  
Keyword(s):  
Bottom Sediments ◽  
Surface Waters ◽  
Experimental Studies ◽  
Anthropogenic Pollution ◽  
Economic Consequences ◽  
Test Facility ◽  
Insect Larvae ◽  
Toxicological Assessment ◽  
Toxicological Studies

Purpose. Eco-toxicological assessment of surface water and bottom sediments of Vyalivsky reservoir and based on the results of experimental studies on the influence of anthropogenic pollution on the livelihoods of fodder organisms, to calculate the damage caused to water bodies by the indicator of decrease of bio-productivity on the example of Vyalivsky reservoir. Methods. Biotesting of water samples was carried out using zooplankton (Ceriodaphnia affinis Lilljeborg) and zoobenthos - insect larvae (Chironomus dorsalis Meig.) as a test facility for fodder organisms for fish. For estimation of losses caused for Vyalivsky reservoir we used methodology for calculating the amount of compensation for damage caused to the fishery as a result of violations of legislation on the protection, use and reproduction of aquatic biological resources. Results According to the results of determination of the toxicity of surface waters and bottom sediments, damages caused to Vyalivsky reservoir were calculated on the indicator of decrease in fish productivity as a result of the death of fodder organisms for fish. Conclusions The toxicological studies of surface waters and bottom sediments of Vyalivsky reservoir have revealed the presence of toxic properties of the investigated objects, which may result in the reduction of biomass of fodder organisms of aboriginal species of fish in a given reservoir.

The activities of components in clinopyroxene and garnet solid solutions and their application to rocks

1977 ◽  
Vol 286 (1336) ◽  
pp. 331-342 ◽  
Keyword(s):  
Equilibrium Constant ◽  
Excellent Agreement ◽  
Solid Solutions ◽  
Thermodynamic Data ◽  
Experimental Studies ◽  
Thermodynamic Approach ◽  
Equilibrium Conditions ◽  
Mineral Assemblages ◽  
Mineral Compositions ◽  
Simple Systems

Experimental studies of equilibria in chemically simple systems may be quantitatively extrapolated to rocks provided the activities of components in the appropriate complex phases are known. For each solid-solid equilibrium extrapolated in this way a curve of fixed K i (equilibrium constant) for the rock may be defined in pressure-temperature space. Provided crystallization of the rock takes place under equilibrium conditions, use of two such solid-solid equilibria fixes the pressure and temperature uniquely. The relations between activities of components and mineral compositions have been determined for CaAl 2 SiO 6 -CaMgSi 2 O 6 -CaFeSi 2 O 6 clinopyroxene and Ca 3 Al 2 Si 3 O 12 - Mg 3 Al 2 Si 3 O 12 - Fe 3 Al 2 Si 3 O 12 garnet solid solutions. These activity-composition relations, combined with thermodynamic data on simple equilibria, were then applied to the granulites of South Harris. The equilibria used were: CaAl 2 Si 2 O 8 ^ CaAl 2 SiO 6 + SiO 2 , plagioclase clinopyroxene quartz CaFeSi 2 O 6 + |Mg 3 Al 2 Si 3 O 12 ^ clinopyroxene garnet JFe 3 Al 2 Si 3 O 12 + CaMgSi 2 O 6 , garnet clinopyroxene 3CaAl 2 Si 2 O 8 ^ Ca 3 Al 2 Si 3 O 12 + plagioclase garnet 2Al 2 SiO 5 + SiO 2 . kyanite quartz The intersection of K i curves for appropriate mineral assemblages of the South Harris granulites yield estimated metamorphic conditions of 825 °C and 13 kbar. The calculated pressure is in excellent agreement with independent estimates (10- 13 kbar) based on the presence or absence of garnet in orthogneisses. It is concluded that, for many equilibria, the thermodynamic approach should yield pressure estimates which are accurate to within ± 1-2 kbar. Temperature uncertainties, being dependent on the slopes of K i curves in pressure-temperature space, are related to these quoted pressure uncertainties.

The Impact of Exploiting Lignite in Lupoaia Open Pit on Environmental Water

Mining Revue ◽  
2021 ◽  
Vol 27 (2) ◽  
pp. 76-83
Author(s):  
Corina Maria Iladie
Keyword(s):  
Surface Waters ◽  
Wastewater Treatment Plants ◽  
Morphological Changes ◽  
Environmental Water ◽  
Environmental Risks ◽  
Open Pit ◽  
Industrial Wastewaters ◽  
The Impact ◽  
Hydrographic Network

Abstract The impact of extracting lignite in Lupoaia open pit over waters is local and regional, and temporary. The hydrographic network in Lupoaia open pit depends on River Motru, with its afluents, Ploștina and Lupoița Valley Rivers. The aquifers are to be found in the coal layers V-XII, mainly of sands formation. The impact over water in Lupoaia consists of water pollution and of changes in both the quality and the quantity of ground and surface waters. The surface waters are polluted resulting in industrial wastewaters, household wastewaters and waste rainwater. The wastewater is polluted within maximum admitted limits. The quality of groundwaters is influenced and modified by extracting coal resulting in the extinction of some aquifers. Environmental risks that can occur when extracting lignite are water floods, landslides, disasters which can be prevented by building guard channels around the open pit. The actions for reducing the impact are, in general, accomplished through monitoring both the water pollutants and the morphological changes caused by extracting lignite. That is why wastewater treatment plants must function. The impact of the activity in Lupoaia open pit over the hydrographic net of the area is to be observed during the entire extracting period, and monitoring this activity is highly demanded by the European environmental protection laws.

scholarly journals Study on the Assessment of the Oxygen Regime and the Nutrients Content of Some Water Streams in Gorj County

2020 ◽  
Vol 71 (2) ◽  
pp. 315-323
Author(s):  
Daniela Cirtina ◽  
Maria Nicoleta Mihut
Keyword(s):  
Water Quality ◽  
Surface Waters ◽  
Oxygen Demand ◽  
Organic Pollution ◽  
Environmental Legislation ◽  
Oxygen Regime ◽  
Ammonium N ◽  
Nitrite Content ◽  
Hydrographic Network

The study aims to characterize the quality of some representative surface waters of Gorj county�s hydrographic network by assessing the oxygen regime, namely the dissolved oxygen content (DO), the chemical oxygen demand (COD-Cr), the biochemical consumption of oxygen BOD5) and nutrients measured by ammonium (N-NH4+), nitrites (N-NO2-), nitrates (N-NO3-), total nitrogen, soluble orthophosphates (P-PO43-) and total phosphorus during 2016-2018. In order to carry out the study, representative sections of the Jiu, Motru and Jilt rivers were monitored in areas considered vulnerable to nutrient and organic pollution. The results regarding water quality from the monitored natural receptors generally showed an evolution within the limits allowed by the environmental legislation, except for the nitrite content that was exceeded for all three monitored rivers. Also, the values of the COD-Cr and BOD5 indicators have been exceeded in some Jiu and Jilt river monitoring sections. Consequently, there is a need to monitor the mentioned parameters.

Ammonia decomposition in catalytic membrane reactors: Simulation and experimental studies

AIChE Journal ◽  
2012 ◽  
Vol 59 (1) ◽  
pp. 168-179 ◽  
Author(s):  
Gang Li ◽  
Masakoto Kanezashi ◽  
Tomohisa Yoshioka ◽  
Toshinori Tsuru
Keyword(s):  
Experimental Studies ◽  
Ammonia Decomposition ◽  
Membrane Reactors ◽  
Catalytic Membrane ◽  
Catalytic Membrane Reactors

scholarly journals Analysis of experimental studies of the tractor equipped with an elastic-damping mechanism in the transmission when moving as part of a transport tractor unit

2020 ◽  
Vol 1 (6) ◽  
pp. 59-66
Author(s):  
S.E. Senkevich ◽  
◽  
N.S. Kryukovskaya ◽  
Keyword(s):  
Agricultural Production ◽  
Experimental Studies ◽  
Statistical Processing ◽  
Energy Performance ◽  
Traction Forces ◽  
Dirt Road ◽  
Speed Range ◽  
Lower Load ◽  
Energy Consuming ◽  
Cargo Transportation

The cargo transportation is an integral and energy-consuming part of agricultural production. To improve the energy performance of transport tractor units (TTU), an elastic-damping mechanism (EDM) installed in the tractor transmission was developed. An experimental study was conducted to identify the influence of the EDM on the operation of the tractor as part of the TTU, when it is moving on a dirt road in the 9th gear of the main speed range of the gearbox (GB) of the tractor. A tractor of traction class 1.4 was used. Energy sensors were installed on the main elements of the tractor. The energy performance of the tractor with a transmission equipped with the EDM and the tractor with a factory transmission are determined. A decrease in fuel consumption by 7.3%, a decrease in traction forces from an aggregated trailer by 19.9%, a decrease in the amplitude of fluctuations in traction forces by 28.3% and a decrease in skidding of the driving units by an average of 9.7% were revealed. A graph describing the dynamics of changes in the skidding of the driving units of a serial tractor and a tractor with the EDM in time is constructed. The statistical processing of the skidding indicators is performed. A decrease in the amplitude of fluctuations in the coefficient of skidding by 16.3% was revealed. The obtained results of experimental studies indicate that the tractor as part of the TTU with the EDM in the transmission has better performance compared to a serial tractor and has a lower load on the engine, gearbox elements and driving wheels of the tractor.

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