scholarly journals Characteristics of diatomite-alginate-Fe3O4 composite as a phosphate adsorbent

2021 ◽  
pp. 61-65
Author(s):  
Olexander Pasenko ◽  
Liliya Frolova ◽  
Ihnat Shunkin
Keyword(s):  
Diatomaceous Earth ◽  
Solid Phase ◽  
Experimental Studies ◽  
Static Strength ◽  
Raw Material ◽  
Adsorption Activity ◽  
Composite Adsorbent ◽  
Composite Adsorbents ◽  
Developed Surface ◽  
Granular Adsorbent

Technological approaches to the use of diatomaceous earth as a raw material for the creation of composite adsorbents for wastewater treatment from phosphate ions are analysed. It is shown that the developed surface of diatomite can be used to create a granular adsorbent, and iron (III) oxides (magnetite, goethite, lepidocrocite, ferrihydrite, hematite and goethite) are environmentally safe, cheap, economically feasible modifiers. Emphasis is placed on the possibility of obtaining magnetic granules due to the formation of magnetite. The use of the deposition method for the formation of the applied granular adsorbent is proposed.  The influence of diatomite concentration on the static strength of granules was established. It is determined that the diameter of the nozzle is also an important factor. The selected technical solutions are aimed at solving the problems of granule hardening and ensuring high adsorption activity. Experimental studies of the synthesis and granulation of the composite adsorbent alginate - diatomaceous earth - magnetite have shown that an increase in the content of diatomaceous earth leads to a natural increase in the size of the granules. When increasing the diameter of the nozzle from 1.5 mm to 3.5 mm, for example, the size of the granules 1.5-4.0 (dc = 1.5 mm), 2.0-5.0 mm (dc = 3.0 mm) and 2.5-5.0 mm (dc = 3.5 mm). The diatomaceous earth content of more than 20% does not allow to carry out high-quality granulation on the experimental installation due to the increase in the viscosity of the suspension. The relationship between the size of gel granules and dried.  The process of application of the active magnetic phase of the adsorbent is investigated. The dependence of the quality of the granulation process on the solid phase content is established. The measured static strength of the adsorbent granules is in the range of 17 - 25 kPa. It is established that the composite adsorbent with the applied layer of magnetite has magnetic properties. The adsorption of PO43- anions from aqueous solutions was studied. For the adsorbent alginate - diatomite and alginate - diatomite - Fe3O4 - the adsorption capacity is 4 and 9 mg PO43- / g, respectively. The obtained composite adsorbents have a set of functional properties that are promising for use in modern water purification and purification systems.

scholarly journals Innovation of Energy Technologies of Food Raw Material Dehydration and Extraction

2021 ◽  
Author(s):  
Oleg Burdo ◽  
◽  
Ilya Sirotyuk ◽  
Maxim Shcherbich ◽  
Aleksandr Akimov ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Liquid Phase ◽  
Solid Phase ◽  
Experimental Studies ◽  
Electromagnetic Energy ◽  
Raw Material ◽  
Practical Significance ◽  
Industry Waste ◽  
Energy Technologies ◽  
Reduction Of Energy Consumption

The researchings of raw material dehydration and extraction are analyzed. The energy problems of product dehydration processes are analyzed. It is shown that recent trends in the development of heat and mass transfer technology are associated with the use of electromagnetic energy generators. The aim of the work is reduction of energy consumption during liquid phase removing from solid plant raw material and reduction of product losses from oil-containing food-industry waste. Achievement of this aim lies with a hypothesis that the use of electromagnetic energy sources in the process of removing moisture from food raw material containing a solid phase will allow to form an additional flow of the liquid phase, in addition to the traditional outlet of the vapor phase. The driving force of such a flow is the effect resulting from the local dissipation of electromagnetic energy in the solid phase volume. A mathematical model of the dehydration process is presented and a set of experimental studies was carried out, which confirmed the validity of the hypothesis. The most significant result of the work is proof of the possibility to organize modes when the juice yield is 4 times higher than the steam yield and, accordingly, to reduce energy consumption for product dehydration. The scientific significance of the obtained results is that a new effect was obtained in the work, which the authors called parodynamic. The practical significance of the work consists of proposing of the technological line for processing oilcontaining waste: coffee sludge, coffee beans husk, reagents (clay and perlite).

scholarly journals Peculiarities of Portland Cement Clinker Synthesis in the Presence of a Significant Amount of SO3 in a Raw Mix

2021 ◽  
Author(s):  
Oleg Sheshukov ◽  
Michael Mikheenkov
Keyword(s):  
Portland Cement ◽  
Solid Phase ◽  
Experimental Studies ◽  
Total Content ◽  
Raw Material ◽  
Cement Clinker ◽  
Material Base ◽  
Free Lime ◽  
Portland Cement Clinker ◽  
Negative Effect

Due to the depletion of the raw material base and a technogenic materials addition into a raw mix for the Portland cement clinker synthesis, sulfur and its oxides amount in a raw mix increases. According to literature the Portland cement clinker synthesis in the presence of a sulfur oxides significant amount is difficult. As the content of SO3 in the raw mix increases the amount of C2S increases while C3S and C3A amount decrease. With an equal total content of C2S and C3S in the clinker their ratio C3S/C2S decreases with an increased content of SO3. These factors lead to a deterioration in the Portland cement clinker quality. The clinker formation reactions thermodynamic analysis and some experimental studies allow determining reasons for the Portland cement clinker quality deterioration. It was found that the presence significant amount of a SO3 in the raw mix the synthesis in solid phase of low-basic C4A3 S¯ (ye’elimite) is the thermodynamically preferred rather than high-basic C3A and C4AF. As a result, excess and crystallized free lime inhibits the C3S synthesis through the liquid phase. The experimental studies result helped to develop a methodology for calculating the composition of a raw mix from materials with significant amount of SO3. It allows to reduce the SO3 negative effect on the Portland cement clinker synthesis and to obtain high-quality Portland cement.

SYNTHESIS OF HYDROGEN IN ACOUSTOPLASMA DISCHARGE IN A LIQUID-PHASE STREAM

2019 ◽  
pp. 42-48 ◽  
Author(s):  
N. A. Bulychev
Keyword(s):  
Liquid Phase ◽  
Organic Compounds ◽  
Electrode Materials ◽  
Solid Phase ◽  
Plasma Discharge ◽  
Raw Material ◽  
Two Phase ◽  
Reduced Pressure ◽  
External Power Source ◽  
Phase Medium

In this paper, the plasma discharge in a high-pressure fluid stream in order to produce gaseous hydrogen was studied. Methods and equipment have been developed for the excitation of a plasma discharge in a stream of liquid medium. The fluid flow under excessive pressure is directed to a hydrodynamic emitter located at the reactor inlet where a supersonic two-phase vapor-liquid flow under reduced pressure is formed in the liquid due to the pressure drop and decrease in the flow enthalpy. Electrodes are located in the reactor where an electric field is created using an external power source (the strength of the field exceeds the breakdown threshold of this two-phase medium) leading to theinitiation of a low-temperature glow quasi-stationary plasma discharge.A theoretical estimation of the parameters of this type of discharge has been carried out. It is shown that the lowtemperature plasma initiated under the flow conditions of a liquid-phase medium in the discharge gap between the electrodes can effectively decompose the hydrogen-containing molecules of organic compounds in a liquid with the formation of gaseous products where the content of hydrogen is more than 90%. In the process simulation, theoretical calculations of the voltage and discharge current were also made which are in good agreement with the experimental data. The reaction unit used in the experiments was of a volume of 50 ml and reaction capacity appeared to be about 1.5 liters of hydrogen per minute when using a mixture of oxygen-containing organic compounds as a raw material. During their decomposition in plasma, solid-phase products are also formed in insignificant amounts: carbon nanoparticles and oxide nanoparticles of discharge electrode materials.

Applications of Bentonite to Soil Decontamination

2018 ◽  
Vol 69 (7) ◽  
pp. 1695-1698
Author(s):  
Marin Rusanescu ◽  
Carmen Otilia Rusanescu ◽  
Gheorghe Voicu ◽  
Mihaela Begea
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Laboratory Experiments ◽  
Experimental Studies ◽  
Heavy Metal Concentration ◽  
Polluted Soil ◽  
Raw Material ◽  
Soil Decontamination ◽  
Metal Retention ◽  
Removal Of Heavy Metals

A calcium bentonite from Orasu Nou deposit (Satu Mare Romania) was used as raw material. We have conducted laboratory experiments to determine the influence of bentonite on the degree of heavy metal retention. It has been observed that the rate of retention increases as the heavy metal concentration decreases. Experimental studies have been carried out on metal retention ( Zn) in bentonite. In this paper, we realized laboratory experiments for determining the influence of metal (Zn) on the growth and development of two types of plants (Pelargonium domesticum and Kalanchoe) and the effect of bentonite on the absorption of pollutants. These flowers were planted in unpolluted soil, in heavy metal polluted soil and in heavy metal polluted soil to which bentonite was added to observe the positive effect of bentonite. It has been noticed that the flowers planted in unpolluted soil and polluted with heavy metals to which bentonite has been added, the flowers have flourished, the leaves are still green and the plants whose soils have been polluted with heavy metals began to dry after 6 days, three weeks have yellowish leaves and flowers have dried. Experiments have demonstrated the essential role of bentonite for the removal of heavy metals polluted soil.

Perspective Biomass Carrier for Anaerobic Processing Systems of Organic Waste AIC

2020 ◽  
Vol 67 (1) ◽  
pp. 148-155
Author(s):  
Anatoliy V. Fedotov ◽  
Viktor S. Grigoriev ◽  
Dmitriy A. Kovalev ◽  
Andrey A. Kovalev
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Specific Surface ◽  
Organic Waste ◽  
Porous Ceramic ◽  
Experimental Studies ◽  
Ceramic Materials ◽  
Porous Ceramics ◽  
Developed Surface ◽  
Highly Porous

To speed up the wastewater treatment under aerobic conditions and to optimize the processes of anaerobic wastewater treatment in digesters, immobilization technologies of microorganisms and enzymes on solid carriers are used. Ceramic carriers based on aluminosilicates and alumina are one of the promising inorganic biomass carriers. (Research purpose) To study the structure of porous ceramic biomass carriers for anaerobic processing of organic waste and evaluate the prospects for their use. (Materials and methods) The substrate for anaerobic digestion was a mixture of sediments of the primary and secondary sewage sumps of the Lyubertsy treatment facilities. K-65 cattle feed was used to ensure the constancy of the composition of organic substances in substrates as a cosubstrate. The authors used the method of low-temperature nitrogen adsorption of Bruner-Emmett-Teller to study the pore structure and specific surface of solid carriers on a specific surface analyzer Quntachrome Autosorb-1. (Results and discussion) The main characteristics (specific surface, volume of micro- and mesopores, predominant pore radius, water absorption and others) of chamotte foam lightweight and highly porous corundum ceramics were determined. It was revealed that ceramic materials with a developed surface and electrically conductive material provided an increase in biogas yield by 3.8-3.9 percent with an increase in methane content by an average of 5 percent. (Conclusions) The results of anaerobic digestion showed a positive effect of both a conductive carrier and highly porous ceramic materials on the process of anaerobic bioconversion of organic waste into biogas. It is advisable to expand experimental studies on the use of a conductive carrier with a developed surface based on highly porous ceramics.

scholarly journals Effect of Fertilisation on the Quality of Dried Coriander (Coriandrum sativum L.) and Lovage (Levisticum officinale)

Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 386
Author(s):  
Natalia Matłok ◽  
Józef Gorzelany ◽  
Adam Figiel ◽  
Maciej Balawejder
Keyword(s):  
Bioactive Compounds ◽  
Crop Production ◽  
Solid Phase ◽  
Quality Parameters ◽  
Raw Material ◽  
Vacuum Microwave ◽  
Dpph Method ◽  
Total Antioxidant ◽  
Total Antioxidant Potential

The study presents the effects of fertilisation on selected quality parameters of the dried material obtained from plants of lovage and coriander. During the crop production process, the plants were treated with two fertilisers containing substances potentially acting as elicitors. The dried material was obtained in course of a drying process carried out in optimum conditions and based on the CD-VMFD method which combines convective pre-drying (CD) at a low temperature (40 °C) with vacuum-microwave finish drying with the use of 240 W microwaves (VMFD). The quality of the dried material was evaluated through measurement of the total contents of polyphenols, total antioxidant potential (ABTS and DPPH method), and the profile of volatile compounds (headspace-solid phase microextractio-HS-SPME) as well as assessment of the colour. It was found that by applying first fertilisation (with organic components) it is possible to significantly increase the contents of both bioactive compounds and volatile substances responsible for the aroma. It was determined that the higher content of bioactive compounds was related to the composition of the first fertiliser, presumably the extract from common nettle. The study showed that the application of the first fertiliser contributed to enhanced quality parameters of the raw material obtained.

Nanostructured Doped Silica Films Application as Sensitive Layers for Chemical Sensors

2013 ◽  
Vol 684 ◽  
pp. 7-11
Author(s):  
Sergey Krutovertsev ◽  
Alla Tarasova ◽  
Olga Ivanova ◽  
Larisa Krutovertseva
Keyword(s):  
Initial Conditions ◽  
Sol Gel ◽  
Silica Films ◽  
Adsorption Activity ◽  
Developed Surface ◽  
Sol Gel Process ◽  
Sensitive Characteristics ◽  
The Right ◽  
Kinetics Of ◽  
Matrix Factors

The sensor behavior of nanostructured doped silica films produced by sol-gel way were examined. Hygroscopic substances and polyoxometalates were used as additives to make more significant sensitive characteristics of initial matrix. Factors that have effect on sol preparation and films forming were investigated. Adsorption activity of the sensitive films was studied and it was shown that the films had a highly developed surface with nano-size pores. Change of initial conditions of sol-gel process gives opportunity to influence on kinetics of gel formation and consequently, on structure and properties of final materials. The study showed that the conditions of the environment affected the sensors characteristics markedly, which can be improved by choosing of the right procedure of forming and treatment. Influence of type and additive substances quantity into doped films was discussed in the paper

Planar structures of nano-voids in volume of a crystal

2021 ◽  
Author(s):  
E.A. Stepantsov
Keyword(s):  
Plastic Deformation ◽  
High Precision ◽  
Solid Phase ◽  
Crystal Surface ◽  
Ion Beam ◽  
Photonic Devices ◽  
Planar Structure ◽  
Compression Pressure ◽  
Planar Structures ◽  
Developed Surface

It was studied the possibility of solid phase intergrowth of optical Y-ZrO2 crystals with preliminarily developed one of their two contacting surfaces. The developing included creation of determined relief by argon ion beam milling through a mask with determined layout. The process of solid phase intergrowth of crystals with such developed surfaces was fulfilled in the same conditions, which were used at the similar procedure for crystals with undeveloped surfaces. During the process crystal samples were put together in contact in parallel crystallographic orientation along preliminary polished and etched surfaces. Then they were heated in vacuum up to temperature 1600°С. After that they were pressed to each other up to pressure 1.4 kN/mm2 for 4 hours with further cooling with rate 10°С/min down to room temperature. Decreasing of effective square of contacting surfaces on a value of total square of etched relief picture was taken into account at calculating of compression pressure. It was found out that solid phase intergrowth on undeveloped parts of the surfaces was realized with the same result, as it was in case of solid phase intergrowth of Y-ZrO2 crystals, the contacting surfaces of which had not been developed by Ar beam milling. It was shown that nano-voids is formed at the rest parts of the contacting surfaces of crystalline specimens during their solid phase intergrowth. As a result a planar structure of nano-voids is created in a volume of a crystal, fabricated by solid phase intergrowth of two crystalline samples with preliminarily developed surface of one of them by argon beam milling through special mask. It was demonstrated that a configuration of nano-voids planar structure corresponds to a picture of the relief of the developed crystal surface with precision not worse than +/- 1 µ. By chemical etching for dislocation holes of the crystal side surfaces, which are perpendicular to a plane of a planar structure of nano-voids, it was demonstrated that during of solid phase intergrowth process plastic deformation of the material did not have place even on micro-level, corresponding to thickness of etched relief. Full absence of even weak traces of plastic deformation in the zone of crystal specimen intergrowth is an explanation of so high precision correspondance of etched relief to configuration of planar structure of nono-voids. The shown results demonstrate the possibility of creation a planar structure of nano-voids inside of a crystal, corresponding to in advance determined picture with so high precision, that it gives new possibilities in designing of photonic devices.

Ca isotope fractionation upon synthesis of carbonated apatite

2021 ◽  
Author(s):  
Michael E. Böttcher ◽  
Nikolaus Gussone ◽  
Anika C. Conrad ◽  
Iris Schmiedinger ◽  
Jens Fiebig ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Isotope Fractionation ◽  
Solid Phase ◽  
Experimental Studies ◽  
Apatite Formation ◽  
Calcium Isotope ◽  
Hydroxy Apatite ◽  
Carbonated Apatite ◽  
Batch Type ◽  
Synthetic Calcite

<p>Carbonated hydroxy-apatite (CHAP) was experimentally synthesized in batch-type set-ups by mixing of calcium (Ca)- and phosphate-bearing aqueous solutions and the transformation of calcite powder in aqueous solution between 11° and 65°C (Gussone et al., 2020). Compositional changes of the experimental solution and solid phase products were followed by elemental analysis, Raman spectroscopy, scanning-electron microscopy, and powder XRD. In the mixing experiments, crystallization of CHAP took place following the precipitation of metastable brushite as precursor that was then transformed into CHAP. In the transformation experiments using synthetic calcite as a precursor phase it was found that the reaction at pH values between 7.5 and 7.9 occurs via the direct replacement of calcium carbonate by CHAP.</p><p>Calcium isotope fractionation led to an enrichment of the light isotope in the solid CHAP compared to the aqueous solution by about -0.5 to -1.1 ‰, independent from the experimental approach, and the magnitude was essentially independent of temperature. The metastable brushite formed prior to transformation to CHAP showed a reduced fractionation compared to the CHAP. The observed Ca isotope fractionation into the CHAP lattice resembles that of natural phosphorites and lies within the range of the view existing theoretical and experimental studies.</p><p> </p><p>Reference: Gussone N., Böttcher M.E., Conrad A.C., Fiebig J., Pelz M., Grathoff G., Schmidt B.C. (2020) Calcium isotope fractionation upon experimental apatite formation. Chem. Geol., 551, 119737</p><p>The study was supported by German Science Foundation (DFG) to M.E.B and J.F. within the EXCALIBOR project (BO1548/8 and FI 948/7), and to N.G. (GU1035/10), and by Leibniz IOW.</p>

Studying the Effect of some Factors on the Stress-Strain Behavior of the Rostov Region Limestones in the Course of their Production and Use

2021 ◽  
Vol 1022 ◽  
pp. 80-86
Author(s):  
Mikhail G. Kholodnyak ◽  
Sergey A. Stelmakh ◽  
Evgeniy M. Shcherban ◽  
Mukhuma P. Nazhuev
Keyword(s):  
Construction Material ◽  
Experimental Studies ◽  
Raw Material ◽  
Material Base ◽  
Strain Behavior ◽  
Current State ◽  
Rostov Region ◽  
Literary Sources ◽  
Crushed Granite ◽  
Strain Stress

The paper considers the current state of the mineral raw material base and the construction material market of the Rostov Region. The effect of various factors on the strain-stress behavior of local limestones has been investigated. The scientific and technical literary sources devoted to the processes of rock failure under various loads have been analyzed. The experimental studies have shown that the tested samples of limestone with a high content of cuboidal grains have characteristics comparable to those of the crushed granite stone. It has been concluded that the use of the Rostov Region limestones in the construction industry is competitive and feasible, provided the proper implementation of the engineering measures proposed in their production.

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