Ion Concentration In Solution Research Articles

Role of seed layer in van der Waals growth of vanadium dioxide film on mica prepared by chemical solution deposition

Vanadium dioxide (VO2) has unique electrical and optical properties, which have practical applications in many devices. However, preparing high-quality VO2 films and transferring them to flexible substrates by an economic and simple way are still challenging. Functional thin films can be grown on van der Waals (vdW) substrates and then transferred to flexible substrates due to the weak interaction between films and their substrates. Herein, VO2 thin films were grown on mica substrates by using the polymer-assisted deposition technique. By controlling the ion concentration in the polymer precursor solution, a flat seed layer was prepared at the initial growth stage. It was found that the introduction of the seed layer can improve the crystallinity, increase the grain size and reduce the defects of the VO2 thin films. It is believed that less nucleation density and layered growth at the initial growth stage are critical to the formation of large size grains. Our results confirmed that chemical solution deposition can prepared high-quality VO2 films on vdW substrates.

Acidity, fluoride and silver ion concentrations in silver diamine fluoride solutions: a pilot study.

There has been renewed interest in the use of silver diamine fluoride (SDF) for the management of carious lesions in high-risk groups. Previous studies have found a difference in clinical efficacy among different concentrations of SDF and discrepancies between ionic concentrations of fluoride (F) and silver (Ag) in SDF preparations. The aim of this study was to measure the free F, Ag ion concentrations and pH of a variety of commercially available SDF preparations. Seven SDF products used globally were evaluated for F and Ag ion concentrations using a calibrated ion-selective electrode and optical emission spectrometry respectively. Acidity was determined with a pH electrode. The 30% SDF solution contained almost half the F concentration and a much higher Ag concentration than expected (16343ppmF and 246000ppmAg). Comparatively, the mean F concentration of the remaining six 38% solutions was 74802ppm (expected mean 44800ppm) ranging from 36457ppm to 120760ppm. The mean Ag concentration was 326000ppm (expected mean 253870ppm) and ranged from 246000ppm to 425451ppm. All solutions were found to be neutral or mildly alkaline in nature (pH 7-10.3). Wide variations between claimed and measured F and Ag ion concentrations exist among the different brands of commercially available SDF products.

Investigation on the removal of bivalent cadmium ions from aqueous solution and treatment of industrial wastewater using new alumina interfaced biocarbon

The presence of heavy metals in water and wastewater is becoming a severe environmental and public health concern. It may contribute variety of adverse environmental and human health effects due to their acute and chronic exposure through air, water and food chain. They are released into the aquatic environment from many industrial activities. The present research paper deals with the adsorption capacity of the biocarbon material produced from the leaves of Lawsonia inermis plant. The biocarbon was prepared by the H2SO4 activation process. The adsorption capacity of the biocarbon was evaluated by considering the effect of various parameters such as pH of the solution, biocarbon dose, contact time, and initial metal ions concentration and to optimize the conditions for maximum adsorption. The metal ion uptake capacity of the biocarbon was tested in the stimulated wastewater containing bivalent cadmium ions. The maximum uptake of 97.85% of the Cd (II) metal ions was observed at the equilibrium time of 3.0 hours at a dose of 3.0 g and at the pH of 4.5 in the stimulated wastewater. In the real sample analysis, electroplating industry wastewater is used for the removal of cadmium (II) ions. The results indicate that 95.16% of ions were effectively removed at the same experimental conditions. It is also further noted that the metal sorption capability of the adsorbent is higher with rising concentration of metal ions in the solution. The percentage of adsorption of the metal ions was also significantly increased with rise of temperature of the wastewater.

FUNCTIONALIZED HALLOYSITE NANOTUBES FOR ENHANCED REMOVAL OF Hg2+ IONS FROM AQUEOUS SOLUTIONS

Water is essential for humans, animals, and plants; pollutants, usually derived from anthropogenic activities, can have a serious effect on its quality. Heavy metals are significant pollutants and are often highly toxic to living organisms, even at very low concentrations. Among the numerous removal techniques proposed, adsorption onto suitable adsorbent materials is considered to be one of the most promising. The objective of the current study was to determine the effectiveness of halloysite nanotubes (HNT) functionalized with organic amino or thiol groups as adsorbent materials to decontaminate polluted waters, using the removal of Hg2+ ions, one of the most dangerous heavy metals, as the test case. The effects of pH, ionic strength (I), and temperature of the metal ion solution on the adsorption ability and affinity of both materials were evaluated. To this end, adsorption experiments were carried out with no ionic medium and in NaNO3 and NaCl at I = 0.1 mol L−1, in the pH range 3–5 and in the temperature range 283.15–313.15 K. Kinetic and thermodynamic aspects of adsorption were considered by measuring the metal ion concentrations in aqueous solution. Various equations were used to fit experimental data, and the results obtained were explained on the basis of both the adsorbent’s characterization and the Hg2+ speciation under the given experimental conditions. Thiol and amino groups enhanced the adsorption capability of halloysite for Hg2+ ions in the pH range 3–5. The pH, the ionic medium, and the ionic strength of aqueous solution all play an important role in the adsorption process. A physical adsorption mechanism enhanced by ion exchange is proposed for both functionalized materials.

Immobilization persistence of Cu, Cr, Pb, Zn ions by the addition of steel slag in acidic contaminated mine soil

Adding steel slag to the acidic contaminated mine soil can immobilize heavy metal ions, but immobilization persistence of the metal ions needs to be determined. In this study, dynamic column simulation experiments were set up to compare the immobilization persistence of Cu, Cr, Pb and Zn ions in original soil and with the addition of slag, lime or fly ash to the soil during a simulated 36-month of acid rain leaching. After adding slag and lime, the pH, organic matter content and cation exchange capacity of soil were significantly increased. Compared with the original soil, additions of slag and lime to the soil were able to persistently immobilize the metal ions, whereas fly ash additions had little effect. During simulation, the metal ion concentrations in the slag group leaching solution were essentially consistent with Standard IV for groundwater. The metal ions were immobilized to form instable hydroxides and stable fractions following adding slag to soil. The hydroxide could rerelease metal ions by acid rain leaching, part of which were re-immobilized into stable fractions by entering slag lattice and complexing with soil organic matter. Therefore, adding slag to soil can persistently immobilize metal ions for heavy metal-contaminated acidic mine soil.

Adsorption of Heavy Metal ions and Antibiotics from Aqueous Solution on Activated Carbons Prepared from Agricultural Waste

The contamination of water by heavy metal ions and antibiotics is presently a serious environmental challenge of the world. This work intends to use activated carbons made out of agricultural waste to alleviate the problem of water pollution. Commercialized coconut shell activated carbon was used for the experiment. Cadmium ions and chloramphenicol were selected as the model compounds for heavy metal and antibiotics in water solution. TOC analyzer and the atomic absorption spectrophotometry were used to determine the concentration of antibiotics and metal ions in solution, respectively. The coconut shell activated carbon turned out to be efficient in the adsorption of metal ions (removal efficiency up to 90% when concentration is 1mg/L) and chloramphenicol (removal efficiency up to 40% when concentration is 1ml/L). The rates of adsorption of both cadmium ions and chloramphenicol were high at first but declined as the contact time increases. The competitive adsorption was investigated in this study by using a mixed solution of cadmium nitrate and chloramphenicol. It was found that the adsorption capacity of chloramphenicol of activated carbon remains the same while the adsorption capacity of metal ions sharply dropped by 44%, indicating that Cadmium ions have no obvious effect on the adsorption of chloramphenicol, whereas chloramphenicol hinders the adsorption of cadmium ions.

Six fruit and vegetable peel beads for the simultaneous removal of heavy metals by biosorption

ABSTRACT In this study, a comparison between the biosorption performance of six fruit and vegetable peels, namely kiwifruit (KP), apple, banana, cucumber, orange and potato immobilized on sodium alginate beads has been made. Inductively coupled plasma coupled with mass spectroscopy was used for measuring the concentration of metal ions in solution before and after biosorption. A range of kinetic models were also applied to the biosorption batch data. The results showed that biosorption percentage of the ions were different on the various beads. For example, the decreasing order of biosorption by one KP bead at equilibrium was Cd > Cu > Hg > Ni > Pb > Cr > As, with approximately 92%, 84%, 80%, 75%, 67%, 34%, and 17% simultaneous removal of ions, respectively. The fastest biosorption was seen with Cd and Pb, as both reached equilibrium by 24 h. Equilibrium time of all other ions occurred by 48 h. While all beads in their unmodified form were suitable for the removal of divalent cations, KP bead showed significantly higher removal of the anion hexavalent Cr. Biosorption of Cd, Hg and Ni was limited by both pseudo-first order and pseudo-second order reaction rates. For Cr and Cu, the reaction was controlled by film diffusion and pseudo-first order rates. At a higher solution concentration, the preference of ions biosorbed as well as their percentage removed changed. Overall, the results indicated that KP beads show promise as a cost-effective method for removing toxic ions by biosorption, especially hexavalent chromium from drinking water.

Elastic compliance and adsorption profiles of Bovine serum albumin at fluid/solid interface in the presence of electrolytes

Non-trivial topology of proteins under shear suggests that even small structural changes in proteins result in dramatic variations in the mechanical properties and stability. In this study, we have analysed the elastic compliance of solvated bovine serum albumin (BSA) with NaCl,MgCl2, FeCl3 of concentration-ranging from 50 mM to 250 mM using Quartz crystal microbalance with dissipation. The compliance shows a reverse Hofmeister trend (Na + <Mg 2+ < Fe 3+) for high salt concentrations with a fine balance, between intra and intermolecular interactions for the cations. Radius of gyration of BSA with the electrolytes from small angle X-ray scattering (SAXS) is in agreement with this reverse Hofmeister trend. Depending on the valency and concentration of metal ion, the repulsive double layer screening provides sufficient energy to overcome the interactions between hydrophobic domains in the protein molecule resulting in protein assemblies. The long-range effect of high concentrations of divalent and trivalent ions in solution studied using UV–visible and fluorescence spectroscopy, zeta potential and circular dichroism, demonstrates spontaneous aggregated assemblies of BSA. These assemblies are dominated by the long-range distribution of the ions around the proteins, as described by Debye–Hückel theory, with the local salt structure near the protein surface playing a minor role.

Effect of Ion Corrosion on 517 Phase Stability

The main hydration product and source of strength of magnesium oxysulfate cement is 5Mg(OH)2·MgSO4·7H2O (known as the 517 phase). Hardened pastes containing 92.38% of the 517 phase were synthesized in this study, and the influence of different types of chloride solutions on the stability and compressive strength of the 517 phase was investigated. X-ray diffraction and the Rietveld method were used to investigate the 517 phase transition in chloride solutions. Ion chromatography and inductively coupled plasma spectrometry were used to analyze the ion concentrations of the chloride solutions. Scanning electron microscopy and mercury injection porosimetry were used to investigate the effect of ion erosion on the microstructure and pore size distribution. The results showed that the crystal structure of 517 phase remained stable upon immersion in chloride solutions (except for the CaCl2 solution) up to 28 days, and there was no discernible attenuation in the compressive strength of the hardened pastes. Immersion of the 517 phase in CaCl2 solution for 28 days caused Ca2+ ions to combine with SO42− groups to generate CaSO4·2H2O, thereby decomposing the 517 phase. An increase in the concentration of magnesium and sulfate ions in the immersion solutions confirmed the decomposition of the 517 phase. Gel-like Mg(OH)2 was observed in the microstructure of the decomposed 517 phase, and the decomposition of the 517 phase increased the porosity of the hardened pastes.

Characterisation of a Bioactive SiO2-CaO-CaF2-Na2O Glass Used in Composites

ObjectivesTo characterise the ion release, pH changes and apatite formation of a phosphate free bioactive glass. MethodsA SiO2-CaO-CaF2-Na2O glass was synthesized by a melt route with a composition close to the reactive glass in the commercial Cention N® composite. The glass was characterized after immersion in three media: Artificial Saliva pH4 (AS4) Artificial Saliva pH7 (AS7) and in a high phosphate artificial saliva at pH6.5 (AS6.5). The pH and fluoride release were measured using a pH meter and an ion selective electrode. The concentration of Ca, P, Na and Si were measured by ICP-OES. The glass powders after immersion were characterized by FTIR, X-ray powder diffraction and 19F MAS-NMR. ResultsThe glass increased the pH in all three media. Fluoride was detected in all three media but was much higher in AS 6.5. Calcium fluoride formed in AS4 with a small amount of fluorapatite at long immersion times. Fluorapatite and calcium fluoride formed in AS7, whilst in AS6.5 fluorapatite formed.The ion concentrations in solution after immersion reflected the glass composition and the immersion media with fluorapatite being favoured by higher pHs and phosphate contents in the media. SignificanceThe results demonstrated the ability of the glass to increase the pH and to form fluorapatite in phosphate containing media. This may explain the low incidence of secondary caries found in the commercial composite. Unlike the commercial composite evidence was found for the precipitation of fluorite, which will act to reduce the release of fluoride for preventing secondary caries.

Effect of Pt Solution Concentration during Direct Preparation of Core–Shell Pt Cathode in MEA Catalyst Layer for PEFC

Core-shell catalyst, which consists of thin Pt shell on non-Pt metal core, has been attracting attention as a low-Pt catalyst for polymer electrolyte fuel cell (PEFC). Typically, it is synthesized by using Cu-underpotential deposition (Cu-UPD) followed by surface limited redox replacement (SLRR). However, since this method is normally performed on a rotating disk electrode, it can only be prepared on a microgram scale. We have been developing a novel method to overcome this problem by directly performing Cu-UPD and SLRR to the catalyst layer made from the core material. Using this method, the reaction area is increased since the reaction occurs on particles in the three-dimensional network. In our previous study, we have reported that a Pd@Pt/C catalyst layer prepared by this method shows higher mass activity than conventional Pt/C. However, deposition at the surface of the catalyst layer appeared to be larger than in the interior of the layer. In this study, the effect of Pt ion solution concentration on the Pt deposition behavior was studied to develop highly active low-Pt catalyst layer by this novel method.Pd/C was used to fabricate a catalyst layer made of core material. Cu-UPD and SLRR was performed twice on this catalyst layer. In the SLRR process, Pt ion solution with various concentration was used. When a high concentration solution was used, large deposition at the surface was apparent. On the other hand, when a low concentration solution was used, the deposition at the surface was suppressed but the amount of Pt deposition was insufficient. By using both the low and high concentration solution, metallic luster caused by the large depositon of Pt was not observed, and a sufficient amount of Pt was deposited. The performance of a MEA prepared by this catalyst layer showed higher performance than that prepared by the previously reported method.

Removal of Fluoride Ions from the Mine Water

Murmansk Region is home to some major mining and mineral sites. One of the most challenging environmental problems in themining industry is mine water treatment. For example, the rocks of the deposit operated by Lovozero Mining and Mineral ProcessingCompany contain villiomite (NaF). It is highly soluble in water, and the mine waters at the site have a high content of fluoride ions –significantly above the maximum permissible values.Lab-scale experiments were conducted to test various reagents and different initial concentrations of fluoride ions in the treatment ofmodel solutions and mine water. Depending on the initial concentrations, magnesium and calcium-containing sorbents are proposedfor the defluorization of water. Using scanning electron microscopy and microprobe analysis, it was found that fluorine can be boundin poorly soluble compounds, such as, for example, fluorite.Pilot trials are planned.

Effect of ionic strength on methylene blue sorption onto macroporous resins: a comprehensive study

In the current study, adsorption behaviors of amberlite XAD-7 and XAD-16 for the removal of methylene blue from its aqueous solutions have been reported with several respects. First, response surface approach (RSA) has been used to identify the optimum conditions (0.21 g resin/10 mL MTB solution under 149 rpm mixing speed of shaking bath) for the best adsorption process of methylene blue (MTB) removal (≈99%). The most significant process parameter was found to be solution volume, followed by resin amount and speed. Effects of fluoride and chloride on the MTB removal have been also investigated. Elevated concentration of ions in MTB solutions gave rise to decline the adsorption capacity regularly, while the adsorption yield enhanced by increase in pH. On the other hand, the concerned adsorption system was a chemisorption process based on the kinetic (pseudo-first order, pseudo-second order, intraparticle diffusion models) and equilibrium (Langmuir, Freundlich, Temkin, Dubinin–Radushkevich isotherm equations) parameters.

Wet regeneration of waste artificial sand used in sand casting using chemical solutions

Natural sand and organic binders have been the main materials used in sand casting. However, inorganic binders are used in novel casting technologies, and research on artificial sand as a substitute of natural sand has been conducted. Herein, the wet regeneration of waste artificial sand was performed using a sodium silicate binder. Acidic, neutral, and basic solutions were used for wet regeneration. The effects of binder removal and reusability of the regenerated sand were investigated by comparing the characteristics and strengths of the artificial and regenerated sand. It was demonstrated that the basic solution effectively removed the binder from the surface of the waste artificial sand. The Si-O-Si bond cleavage in the binder occurred due to the high concentration of hydroxide ions in the basic solution. The strength of the regenerated sand treated with the basic solution and that of the artificial sand were similar. Moreover, the strengths of regenerated sands treated with the acidic or neutral solutions were lower than that of artificial sand due to the presence of residual binder. These results indicated that the basic solution was suitable for removing the sodium silicate binder. The quality of the regenerated sand was similar to that of artificial sand.

THE SORPTION CAPACITY OF MOSSES AND LICHENS OF ZAURALIE IN RELATION TO LEAD IONS

The purpose of the study is mosses and lichens of the Kurgan region for use as sorbents of heavy metals.&#x0D; The sorption of lead ions (II) is studied on the native and mechanochemically activated samples of true moss (Pleurozium schreberi), white moss (Sphagnum fuscum), lichen genus cladonia: cladoniaforest (Cladonia sylvatica) and cladonia horned (Cladonia cornuta), growing in the ecologically clean districts of Zauralie.&#x0D; The concentration of lead ions in model solutions has been measured ionometrically (ion-selective electrode – XC-Pb-001). The specific surface area of natural sorbents has been determined using the classical dynamic method of low-temperature adsorption of inert gases (Sorbi®-MS device).&#x0D; Sorption isotherms have been obtained. The sorption kinetics has been studied. Equilibration time varies from 30 to 45 min. It is shown that the maximum sorption of lead ions (is) on white moss (a=0.25 mmol/g). The mathematical treatment of sorption isotherms has been fulfilled, actual values of empirical constants of Freundlich’s and Langmuir’s equations and correlation coefficients have been calculated. Langmuir’s model is most suitable to describe the sorption processes.&#x0D; All the used sorbents are macroporous. The mechanochemical activation of moss and lichen with solid sodium hydrogen carbonate leads to an increase in the sorption of lead ions (II) by 2–3 times, which is an indirect confirmation of the ion-exchange mechanism of sorption.

Characterization and physicochemical aspects of novel cellulose-based layered double hydroxide nanocomposite for removal of antimony and fluoride from aqueous solution

A series of novel adsorbents composed of cellulose (CL) with Ca/Al layered double hydroxide (CCxA; where x represent the Ca/Al molar ratio) were prepared for the adsorption of antimony (Sb(V)) and fluoride (F−) ions from aqueous solutions. The CCxA was characterized by Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), elemental analysis (CHNS/O), thermogravimetric analysis (TGA-DTA), zeta potential, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) analysis. The effects of varying parameters such as dose, pH, contact time, temperature and initial concentration on the adsorption process were investigated. According to the obtained results, the adsorption processes were described by a pseudo-second-order kinetic model. Langmuir adsorption isotherm model provided the best fit for the experimental data and was used to describe isotherm constants. The maximum adsorption capacity was found to be 77.2 and 63.1 mg/g for Sb(V) and F−, respectively by CC3A (experimental conditions: pH 5.5, time 60 min, dose 15 mg/10 mL, temperature 298 K). The CC3A nanocomposite was able to reduce the Sb(V) and F− ions concentration in synthetic solution to lower than 6 μg/L and 1.5 mg/L, respectively, which are maximum contaminant levels of these elements in drinking water according to WHO guidelines.

Microbial potentiometric sensor technology for real-time detecting and monitoring of toxic metals in aquatic matrices

Considering that toxic metals can affect metabolic processes in microorganisms adversely, it can be hypothesized that these metals in water matrices would induce a decrease in metabolic activity of the biofilm microorganisms populating the surface of a sensing electrode, which could be registered as a change in the open-circuit potential (OCP) generated by the biofilm microorganisms. The goal of this study was to test this hypothesis and demonstrate the underlying principle that microbial potentiometric sensor (MPS) technology could be used for long-term and real-time monitoring and detection of rapid changes in metal concentrations in realistic aquatic environments. To address the goal, four objective were addressed: (1) a batch reactor with three graphite-based MPS electrodes was fabricated; (2) a set of single-ion solutions and one multiple ion solution were prepared reflecting realistic concentrations of metals found in electroplating wastewaters; (3) the responses of the MPS to the simultaneous presence of multiple toxic metal ions in a single solution were measured; and (4) the changes of the MPS signals to the presence of individual metal ion solutions were examined. While the hypothesis was validated, the study also revealed that the MPS was sufficiently sensitive to not only detect, but also quantify, toxic metal ion concentrations in aqueous solutions. The coefficients of determination, which were R2&gt;0.995, and responsiveness of &lt;1 μmol/L for some toxic metal cations, strongly support the performance of MPS technology in the echelons of expensive analytical tools capable detecting and measuring trace elements.The magnitude of the MPS response was toxic metal specific. When the molar concertation normalizes the inhibition portion of the signal area, the assessed sensitivity order was: Se&gt;Cd&gt;Pb&gt;Ag&gt;Ni&gt; Zn. The study provides valuable information for enforcement agents, environmental professionals, and wastewater treatment operators, so toxic metal pollution and its detrimental impacts can be prevented and mitigated.

Effect of Different Kinds of Zinc (II) on Early Hydration of Calcium Aluminate Cement

The early hydration of calcium aluminate cement (CAC) with different kinds of zinc (II), such as ZnSO4·7H2O, ZnO, Zn(NO3)2·6H2O and ZnCl2, was analyzed. Changes in consistency, setting time, hydration heat flow, hydration heat amount, ion concentration in solution, and hydration products were found upon the addition of different Zn2+. The water consumption of standard consistency of CAC is decreased with different Zn2+. Zn2+ can delay the initial hydration of CAC. The induction period of cement with Zn2+ is longer than that of CAC, especially the reaction time of the acceleration period is extended. Zn2+ can promote hydration hydrate of CAC at 24 h. The characteristic diffraction peaks of CA and CA2 in CAC with different Zn2+ are significantly reduced. It can inhibit the formation of CAH10 and promote the formation C3AH6 and AH3 in hydration products at 24 h.

Оценка возможности переработки техногенного сырья с применением ультранизких концентраций цианистого натрия

The purpose of the study is to conduct experiments in order to determine the possibility of technogenic gold-bearing raw material cyanidation using ultra-low concentrations of NaCN. Experiments are carried out on the cyanidation of three samples of technogenic raw materials of different composition. The first sample consists of pyrite cinders (Au - 1.8-2.3 g/t, Ag - 13-22 g/t, Fe - 48.52%, Cu - 0.15-0.30%, Zn - 0.3-0.6%). The second sample is represented by the aged tailings of copper-zinc flotation (sample I) with the content of Au - 0.8 g/t, Ag - 7.0 g/t, Fe - 17.2%, Cu - 0.212%, Zn - 0.207%. The next object is the copper-zinc flotation tailings of a concentration plant (sample II), with the following content of Au - 1.22 g/t, Ag - 15.2 g/t, Cu - 0.13%, Zn - 0.23%. It is recommended to use an aqueous wash from non-ferrous metals with subsequent lime treatment as a preliminary processing of pyrite cinders. Cyanidation is carried out at different consumptions of reagent: from 0.075 to 3 kg/t. The experiments have shown that gold recovery in this range of NaCN consumption varies from 42.9 to 44.2%; moreover, a decrease in the reagent consumption allows to reduce the concentration of non-ferrous metal ions in cyanidation solutions. Before cyanidation sample I has also been subjected to aqueous wash to remove acid and non-ferrous metals. NaCN consumption varies from 0.25 to 2.2 kg/t. In this case the extraction of gold amounts to 36.6-46.4%. Cyanidation of tailings (sample II) is carried out in the range of 0.15-1.2 kg/t of NaCN. Gold recovery varies from 24.1 to 30.9%. The cyanidation technology of technogenic raw materials in the field of ultra-low concentrations of sodium cyanide is promising, since it provides acceptable gold recovery under low reagent consumption. For further research in the field of development of an extraction technology of valuable components, the flotation tailings of copper-zinc production (sample II) are chosen as a promising object. It is planned to carry out semi-industrial tests, calculate technical and economic indicators and develop process regulations.

Genetic diversity of VIR Raphanus sativus L. collections on aluminum tolerance.

Radish and small radish (Raphanus sativus L.) are popular and widely cultivated root vegetables in the world, which occupy an important place in human nutrition. Edaphic stressors have a significant impact on their productivity and quality. The main factor determining the phytotoxicity of acidic soils is the increased concentration of mobile aluminum ions in the soil solution. The accumulation of aluminum in root tissues disrupts the processes of cell division, initiation and growth of the lateral roots, the supply of plants with minerals and water. The study of intraspecific variation in aluminum resistance of R. sativus is an important stage for the breeding of these crops. The purpose of this work was to study the genetic diversity of R. sativus crops including 109 accessions of small radish and radish of various ecological and geographical origin, belonging to 23 types, 14 varieties of European, Chinese and Japanese subspecies on aluminum tolerance. In the absence of a rapid assessment methodology specialized for the species studied, a method is used to assess the aluminum resistance of cereals using an eriochrome cyanine R dye, which is based on the recovery or absence of restoration of mitotic activity of the seedlings roots subjected to shock exposure to aluminum. The effect of various concentrations on the vital activity of plants was revealed: a 66-mM concentration of AlCl3 · 6Н2О had a weak toxic effect on R. sativus accessions slowing down root growth; 83 mM contributed to a large differentiation of the small radish accessions and to a lesser extent for radish; 99 mM inhibited further root growth in 13.0 % of small radish accessions and in 7.3 % of radish and had a highly damaging effect. AlCl3 · 6Н2О at a concentration of 99 mM allowed us to identify the most tolerant small radish and radish accessions that originate from countries with a wide distribution of acidic soils. In a result, it was possible to determine the intraspecific variability of small radish and radish plants in the early stages of vegetation and to identify genotypes that are contrasting in their resistance to aluminum. We recommend the AlCl3 · 6Н2О concentration of 83 mM for screening the aluminum resistance of small radish and 99 mM for radish. The modified method that we developed is proposed as a rapid diagnosis of aluminum tolerance for the screening of a wide range of R. sativus genotypes and a subsequent study of contrasting forms during a longer cultivation of plants in hydroponic culture (including elemental analysis of roots and shoots, contrasting in resistance of accessions) as well as reactions of plants in soil conditions.