Concentrations Of Metal Cations Research Articles

Development of a Mechanism for Copper Corrosion Under Gamma Radiation

Copper is an important candidate material considered as corrosion barrier for used nuclear fuel containers (UFC) (1). The current Canadian UFC design involves a Cu-coated carbon steel vessel. In the Deep Geological Repository (DGR), the Cu coating will be exposed to a continuous flux of g-radiation emitted from the fission products trapped in the spent fuel matrix and also to water trapped in the gap between a clay buffer material and the UFC. The water volume per unit surface area will be small and under stagnant condition (2). In the presence of g-radiation, condensed water on copper surface decomposes and forms redox active species such as H2O2 (3). Predicting the corrosion rate of copper in DGR environments, and at timescales, that are well beyond those that can be easily tested in a laboratory is very challenging. Existing copper corrosion models ignore the interfacial solution reactions and cannot explain many of the observed relationships between corrosion results and solution parameters. This makes it very difficult to apply them to the Cu corrosion in the DGR environments that can vary as corrosion progresses. The work presented here was performed to develop a high-fidelity model that can predict the long-term evolution of the Cu corrosion rate as a function of solution parameters.In this work systematic studies are being performed to decouple the effect of solution parameters on copper corrosion. We focus on establishing the relation between the overall corrosion rate and the rate of dissolution and oxide formation by monitoring the solution and surface changes. Corrosion in solutions containing different anions was investigated but only the results from the tests performed in 5 mM sulphuric solution is presented here. The effect of water volume to surface area ratio, and solution pH were studied by exposing Cu coupons to the test solution in the presence and absence of g-radiation and monitoring the surface and solution as a function of time.The changes in pH and the amount of copper dissolved in the solution was measured during corrosion time. Surface and cross section analyses were performed to investigate the morphology and the composition of oxide formed on the surface of coupons corroded for different times. This work focuses on establishing the relation between the overall corrosion rate and the rate of dissolution and oxide formation.Our study shows that copper corrosion progresses through different stages in which different elementary processes determine the overall corrosion rate. At all tested conditions, the time-dependent behaviour of the corrosion shows three characteristic kinetic stages. During each stage, the same trend of copper dissolution, pH changes, and oxide evolution is followed. The result from one of studied solution depths (2.5 cm) in the absence of g-radiation is presented in figure 1. The rate of corrosion in stage I, has a linear trend and is limited by the dissolution of copper cations and is independent of solution depth. The second stage starts when quasi-equilibrium is established near the surface and this condition assist Ostwald ripening of oxides formed on the surface. In stage III, the dissolved copper species precipitate from saturated bulk solution and form Cu(I) and/or Cu(II) oxides depending on the stability of different oxides. Any solution paramter including the initial and evolving parameters may affect the duration of each kintetic stage. The results of radiation experiments are in a good agreement with our purposed mechanism. The radiation products may affect the equilibrium reactions in the second stage of corrosion.This study clearly demonstrates that in a small stagnant water volume, the concentration of metal cations released due to corrosion can be high even for a corrosion resistant material like Cu. The solution reactions and transport of dissolved metal cations occur at rates that can strongly couple with electrochemical metal oxidation and precipitation of oxide deposits. In the presence of such strong systemic feedback, the effects of different solution parameters on the overall corrosion rate cannot be evaluated based on linear chemical dynamics.

Qualitative and quantitative 1 H NMR spectroscopy for determination of divalent metal cation concentration in model salt solutions, food supplements, and pharmaceutical products by using EDTA as chelating agent.

This paper introduces an 1 H NMR method to identify individual divalent metal cations Be2+ , Mg2+ , Ca2+ , Sr2+ , Zn2+ , Cd2+ , Hg2+ , Sn2+ , and Pb2+ in aqueous salt solutions through their unique signal shift and coupling after complexation with the salt of ethylenediaminetetraacetic acid (EDTA). Furthermore, quantitative determination applied for the divalent metal cations Ca2+ , Mg2+ , Hg2+ , Sn2+ , Pb2+ , and Zn2+ (limit of quantification: 5-22 μg/ml) can be achieved using an excess of EDTA with aqueous model salt solutions. An internal standard is not required because a known excess of EDTA is added and the remaining free EDTA can be used to recalculate the quantity of chelated metal cations. The utility of the method is demonstrated for the analysis of divalent cations in some food supplements and in pharmaceutical products.

Quantification of Metal Leaching in Immobilized Metal Affinity Chromatography.

Contamination of enzymes with metals leached from immobilized metal affinity chromatography (IMAC) columns poses a major concern for enzymologists, as many of the common di-and trivalent cations used in IMAC resins have an inhibitory effect on enzymes. However, the extent of metal leaching and the impact of various eluting and reducing reagents are poorly understood in large part due to the absence of simple and practical transition metal quantification protocols that use equipment typically available in biochemistry labs. To address this problem, we have developed a protocol to quickly quantify the amount of metal contamination in samples prepared using IMAC as a purification step. The method uses hydroxynaphthol blue (HNB) as a colorimetric indicator for metal cation content in a sample solution and UV-Vis spectroscopy as a means to quantify the amount of metal present, into the nanomolar range, based on the change in the HNB spectrum at 647 nm. While metal content in a solution has historically been determined using atomic absorption spectroscopy or inductively coupled plasma techniques, these methods require specialized equipment and training outside the scope of a typical biochemistry laboratory. The method proposed here provides a simple and fast way for biochemists to determine the metal content of samples using existing equipment and knowledge without sacrificing accuracy.

Sodium cationization can disrupt the intramolecular hydrogen bond that mediates the sunscreen activity of oxybenzone.

A key decay pathway by which organic sunscreen molecules dissipate harmful UV energy involves excited-state hydrogen atom transfer between proximal enol and keto functional groups. Structural modifications of this molecular architecture have the potential to block ultrafast decay processes, and hence promote direct excited-state molecular dissociation, profoundly affecting the efficiency of an organic sunscreen. Herein, we investigate the binding of alkali metal cations to a prototype organic sunscreen molecule, oxybenzone, using IR characterization. Mass-selective IR action spectroscopy was conducted at the free electron laser for infrared experiments, FELIX (600-1800 cm-1), on complexes of Na+, K+ and Rb+ bound to oxybenzone. The IR spectra reveal that K+ and Rb+ adopt binding positions away from the key OH intermolecular hydrogen bond, while the smaller Na+ cation binds directly between the keto and enol oxygens, thus breaking the intramolecular hydrogen bond. UV laser photodissociation spectroscopy was also performed on the series of complexes, with the Na+ complex displaying a distinctive electronic spectrum compared to those of K+ and Rb+, in line with the IR spectroscopy results. TD-DFT calculations reveal that the origin of the changes in the electronic spectra can be linked to rupture of the intramolecular bond in the sodium cationized complex. The implications of our results for the performance of sunscreens in mixtures and environments with high concentrations of metal cations are discussed.

Nanoplastics display strong stability in aqueous environments: Insights from aggregation behaviour and theoretical calculations

Nanoplastics are inevitably released into aquatic environments due to their extensive use and the continuous fragmentation of plastics. Therefore, it is imperative to understand the aggregation behaviours that determine the transport and fate of nanoplastics in aquatic environments. In this study, the effects of various metal cations, pH, aging and extracellular polymeric substances (EPS) on the aggregation of polystyrene nanoplastics (nano-PS) in aqueous solutions were systematically evaluated based on aggregation kinetics experiments and Derjaguin–Landau–Verwey–Overbeek (DLVO) theoretical calculation. The concentration, valence and hydration ability of metal cations jointly affected the aggregation of nano-PS. The critical coagulation concentration (CCC) of nano-PS was significantly higher than the ionic strengths in aquatic environments, indicating that the aggregation rate of nano-PS is relatively low in aquatic environments. The results of the aggregation kinetics experiments were consistent with DLVO theory, which showed that the energy barrier of nano-PS was dependent on electrostatic repulsion forces and van der Waals forces, and increased with pH. Nano-PS was artificially aged by UV-H2O2, which reduced the hydrophobic nature of the particle surfaces, consequently enhancing the stability of the nanoplastics. EPS (excreted from Chlorella pyrenoidosa) decreased the aggregation rates of nano-PS due to steric effects, which was confirmed by the extend DLVO model. Our results highlight the high stability of nano-PS in aquatic environments, which could help facilitate the evaluation of their environmental impact.

Prediction of Metal Ion Toxicity Using Ion Characteristics

Mathematical models have been proposed to relate median lethal concentrations of metal cations with respect to daphnia and nematodes to their physicochemical characteristics (descriptors). The most informative descriptors quantitatively related to the toxicity of metal cations for Daphnia magna and Caenorhabditis elegans have been found to be the negative logarithm of the first hydrolysis constant, negative logarithm of the solubility product of the corresponding sulfides, and stability constant of the metal complex with ethylenediamine. The linear regression equations for the median lethal concentrations of metal ions for Daphnia magna and Caenorhabditis elegans can be used as predictive correlations due to their significant predictive ability.

Toxicity of Metal Cations for Daphnia

A statistically significant relationship was established between the median lethal concentrations of metal cations for daphnia and the maximum permissible concentrations of metals for fishery water bodies. A new eco-toxicological approach to the integrated assessment of the surface water contamination by metals, based on the combined risk concept, was developed. This approach can be used for assessment of the metal contamination of water bodies in various climatic zones and for analysis of the inter- and intra-annual trends of water body contamination.

Molecular dynamics simulations of the removal of lead(II) from water using the UiO-66 metal-organic framework

In this work, we use molecular dynamics simulations to investigate the viability of using the UiO-66 MOF for the removal of lead ions, Pb2+, from water. We study the concentration of Pb(II) in water in the presence of this MOF under varying conditions of number density of particles in the system (500, 300, 74 and 20 particles), metal cation concentration (1.5 M, 3.7 M, 6 M and 55.6 M) and presence of NO3− ions. Pb(II) ions are observed to adsorb onto the UiO-66 framework under favorable conditions, corresponding to: low number density of particles, high metal cation concentration and absence of NO3− ions in the vicinity of the MOF. According to the radial distribution functions, preferential adsorption sites for the Pb2+ in UiO-66 correspond to the oxygen atoms forming the Zr–O–Zr bridge. This study indicates that UiO-66 could be a successful candidate for the removal of Pb(II) from water.

Application of the Langmuir Technique to Study the Response of C-dec-9-en-1-ylcalix[4]resorcinarene and C-undecylcalix[4]resorcinarene Ultra-thin Films' Interactions with Cd2+, Hg2+, Pb2+, and Cu2+ Cations Present in the Subphase

The calix[4]resorcinarene macrocycles are excellent oligomers for the design of amphiphilic derivatives; they can form self-assemblies and stable sensing networks. Owing to their favorable properties, they are the focus of many exploitations and studies ranging from biological controls to heavy metal ion sensing. In this perspective, two calix[4]resorcinarene derivatives, namely: C-dec-9-en-1-ylcalix[4]resorcinarene (ionophore I) and C-undecylcalix[4]resorcinarene (ionophore II) were used to form stable ultra-thin Langmuir monolayer films at the air/water interface; their interactions with different harmful metal cations (Cd2+, Pb2+, Hg2+, and Cu2+) were studied and highlighted via the pressure-area (Π-A) isotherms. The obtained results in the current investigation showed a dependence of both macrocycle interactions on the metal cation concentration in the subphase, confirming their complexation. In addition, the ionophore (I) exhibited high selectivity towards Pb2+ and Cu2+ cations, whereas the ionophore (II) showed tendency to bind with Cu2+ cations over others, approving the potential applicability of these macrocycles as ion selective chemical sensors.

Effect of polymerized sewage on viscosity of polymer solution and countermeasures

In order to better analyze the influence of sewage on the viscosity of polymer solution, this paper uses BROOKFIELD viscometer to determine the viscosity value of solution. The results show that the viscosity decreases rapidly with the increase of the of polymer solution concentration of metal cations. Especially, the concentration of Mg2+ and Ca2+ have a great influence on the viscosity and the small increase of the concentration of Mg2+ and Ca2+ can lead to the decrease of the viscosity of HPAM solution. Na2CO4 was chosen as the complexing agent to improve the viscosity of HPAM solution, and the viscosity increasing rate of HPAM solution with the concentration of 1500 mg/L reached 33.2%.

A chemo-thermo-mechanically constitutive theory for thermal barrier coatings under CMAS infiltration and corrosion

High temperature ceramic corroded by calcium-magnesium-alumino-silicates (CMAS) deposits is an inevitable part of severe degradation of thermal barrier coatings (TBCs). Based on thermodynamic laws, a mechanism-based constitutive theory is proposed for describing CMAS corrosion process at high temperature in TBCs. Concentration of metal cations in CMAS and degree of corrosion dissolution of TBCs are defined respectively. The constitute of free energy which decides the driving force for governing equation of field variables includes energy contribution from the infiltration of CMAS, the subsequent corrosion dissolution of TBCs by CMAS and elastic strain energy. Also, some coupling terms are added to the expression of free energy to describe coupled effects between field variables. We further establish two 3D plate models for TBCs with and without constraint by substrate to predict the chemo-mechanical response of corroded TBCs. A corrosion experiment is conducted to confirm deformational behavior of corroded TBCs and transient distribution of CMAS mass density. In addition, coupled kinetics capture that out-plane tensile stress piles up near the bottom of corroded coating with constraint by substrate, and disastrous delamination can occur from the interface under the CMAS covered region. The constitutive theory presented here provides a great potential for modeling chemo-thermo-mechanical corrosion process in TBCs at high temperature.

Synthesis of ZSM‐5 by hydrothermal method with pre‐mixing in a stirred‐tank reactor

This work proposed a synthesis route of ZSM‐5 via the hydrothermal method with premixing in a stirred tank reactor (STR). Effects of various operating conditions, including pre‐mixing time, molar ratio of SiO2/Al2O3, TPAOH (organic template agents) concentration, NaCl (alkali metal cations) concentration, crystallization temperature, and crystallization reaction time, on the average particle size (PS) and particle size distribution (PSD) were investigated. It was found that the pre‐mixing time in the STR significantly affect the formation of proto‐nuclei in premixing process and crystal growth in hydrothermal reaction process, and consequently influence the PS and PSD of the prepared ZSM‐5. ZSM‐5 with good thermal stability, a PS of 380 nm, PSD of 0.17–0.9 µm, pore diameter of 2.31 nm, pore volume of 0.19 cm3 · g−1 and specific surface area of 337.25 m2 · g−1 were obtained under the optimal conditions of a crystallization reaction time of 24 h, a crystallization temperature of 130 °C, a molar ratio of SiO2/Al2O3 of 200, a TPAOH concentration of 3.5 mol · L−1, NaCl concentration of 0.3 mol · L−1, and a pre‐mixing time of 5 h. This work indicated that the operating conditions including premixing time have a significant effect on its PS and PSD.

Betacyanins in dragon fruit peels: the kinetic models of their degradation under different treatment conditions

SummaryIn this study, after purification, the content of betacyanins in dragon fruit peels was 9.22 mg g−1 dry sample. The stability of betacyanins under the effect of different concentration of metal cation (K+, Na+, Cu2+, Fe2+, Fe3+, Mg2+, Al3+) solutions and sugars (glucose, sucrose, fructose, maltose and lactose) solutions was observed. The results showed that 10% lactose and 0.08 mol L−1 potassium chloride solution increased the stability of betacyanins and could be used as stabiliser agents. The degradation reaction under different temperatures (20, 30, 40, 50, 60, 70, 80 °C), pH (2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0) and light conditions (light and dark) of mixed solution (betacyanins and stabiliser), including aqueous pigments solution (APS), lactose pigments solution (LPS) and potassium chloride pigments solution (PCPS), accorded with the first‐order reaction kinetics. The t1/2 values (the hours needed for 50.0% degradation of betacyanins) of LPS even up to 330.0 h at 20 °C and dark condition.

Competitive biosorption of Cu2+ and Ag+ ions on brown macro-algae waste: kinetic and ion-exchange studies.

The application of biosorption operation has gained attention in the removal and retrieval of toxic metal ions from water bodies. Wastewater from industrial activity generally presents great complexity due to the coadsorption of cations to the inactive biomass binding sites. In this work, the competitive biosorption of Cu(II) and Ag(I) ions was studied in batch systems. A kinetic study applying a non-acidified and acidified waste of Sargassum filipendula in equimolar and non-equimolar metal samples was carried out and the acidified biosorbent was selected due to higher removal rates and selectivity of silver ions. The assays were performed with 2 g L-1 of biosorbent concentration at 25 °C for 12 h and pH was controlled at around 5.0. Copper presented higher affinity for the biosorbent and a fast biosorption kinetic profile, while silver equilibrium times exhibited dependence on the copper concentration. External diffusion is the rate-limiting step in Cu(II) ion removal and it might also limit the kinetic rates of Ag(I) ions with intraparticle diffusion, depending on the initial concentration of metal cations. The ion-exchange mechanism is evidenced and complexation and electrostatic attraction mechanisms might be suggested, explained by simultaneous chemisorption and physisorption processes during the operation. Calcium and sodium were released in considerable amounts by the ion-exchange mechanism. Characterization analyses confirmed the role of several functional groups in the competitive biosorption accompanied by a homogenous covering of both metal ions on the surface of the particles. Particle porosity analyses revealed that the material is macroporous and an appreciable amount of macropores are filled with metal cations after biosorption.

Structural and pyrolysis behaviors analysis of coal pretreated with a weak acid

ABSTRACT Mineral matters are essential components of coal and significantly affect its thermal conversion process. To investigate the effects of the minerals on the structures and pyrolysis behaviors, three middle/low-rank Xinjiang coals were mildly pretreated with a weak organic acid with low concentration. We evaluated the physicochemical properties and mineral matters of raw and acid-pretreated coals and analyzed their pyrolysis behaviors. The results indicated that the chemical structure of coals changed slightly; their physical pore structure enlarged; the content of metal cations decreased obviously. The minerals are adverse to conducting the depolymerization and decomposition reaction at the temperature lower than 300 °C. With the temperature increasing, the minerals exhibit excellent catalytic performance and reduce the release of gaseous products (H2O, CO2, H2, C1~C3) mainly from the polycondensation and secondary reaction. The coal rank and the content of coal ash could affect the catalytic performance.

(Invited) The Cation Effects on the Alkaline HER/HOR Kinetics

The sluggish kinetics of the hydrogen evolution and oxidation reactions (HER/HOR) in base remains unclear despite the fundamental importance of these reactions. Herein, we show that increasing the alkali metal cation (AM+) concentration promotes the HER while varying the identity of AM+ affects both HER/HOR. On the basis of these observations, we conclude that the presence of solvated AM+ anchored by OHad (OHad-(H2O)x-AM+) have two effects: (1) facilitating the OHad removal into the bulk forming OH--(H2O)x-AM+ as per the hard-soft acid-base (HSAB) theory, which selectively promotes the HER and makes the sharp HUPD peaks associated with the exchange of H/OH less reversible; (2) weakening the OHad binding energy to the surface, which hinders the HOR and the CO oxidation as per the bifunctional mechanism.

RHEOLOGICAL PROPERTIES OF MICELLAR SOLUTIONS OF A MIXTURE OF COCAMIDOPROPYLBETAINE AND SULFOSUCCINATES OF ETOXYLATED FATTY ALCOHOLS

Restoring and improving the filtration characteristics of the bottomhole zone of carbonate reservoirs using acidic compositions is the most com- monly used geological and technical measure. One of the main recent trends to increase the effectiveness of acidic compositions is the modifi- cation of their compositions, which is associated with the addition of various organic and inorganic components in order to give the reagent the required technological properties. An example of the acidic composi- tions modification is the use of viscoelastic viscoelastic surfactants, which give acidic reagents «self-diverting» properties. When hydrochlo- ric acid interacts with carbonate rock, a change in the pH of the medium changes and divalent metal cations concentration increase, which leads to a thickening of the system and the deviation of a fresh acid portion, moreover viscoelastic properties are not manifested in the presence of hydrocarbons. Thus, it is a continuous diverting process during the acid composition injection. The change in the rheological properties of the composition is explained by the aggregation of surfactants with the for- mation of a three-dimensional micellar structure with viscoelastic char- acteristics. This paper presents the results of laboratory experiments of the rheo- logical properties of aqueous and hydrochloric acid solutions of the mixture of cocamidopropylbetaine and sulfosuccinates etoxylated fatty alcohol sulfosuccinates. The rheological properties study results of mixed micellar aqueous and hydrochloric acid solutions based on the optimal ratio of surfactant, the dependence of the viscosity of mixed zwitterionic-anionic surfactant solutions on the total concentration and the viscosity dependence of the composition on reactions with carbonate rock, also the temperature and hydrocarbons effect on the rheological properties of a viscoelastic surfactant system indicate that the proposed surfactants combination enables to develop acid composition which has viscoelastic gel properties.

Adsorption and On-Site Transformation of Transition Metal Cations on Ni-Doped AlOOH Nanoflowers for OER Electrocatalysis

AlOOH has long been used as excellent adsorbent for removal of heavy metal cations from wastewater. Herein we report one-pot synthesis of carboxylic-functionalized Ni-doped AlOOH nanoflowers (AlOOH NFs) with high adsorptive capability toward various transition metal cations, and more importantly, the AlOOH NFs adsorbed with various transition metal cations were for the first time directly used as electrocatalyst for oxygen evolution reaction (OER). By simply manipulating the initial metal cation concentration and their molar ratio, the OER catalytic performance of the resulting catalysts could be modulated. The lowest overpotential at a current density of 10 mA cm–2 prepared from AlOOH NFs adsorbed with FeIII and NiII is 0.32 V in 0.1 M KOH and 0.275 V in 1.0 M KOH. Such AlOOH-supported electrocatalyst demonstrates remarkable stability, which shows no evident increase of the overpotential at 10 mA cm–2 after 2 h of steady electrolysis at an overpotential of 0.42 V. The excellent OER electrocatalytic activ...

The Kinetics of Cd2+ and Pb2+ Leaching from Fly Ash Geopolymers

This research is aimed to reveal the kinetics of Cd2+ and Pb2+ leaching from fly ash geopolymer as a promising and sustainable method to solve the problems of heavy metals contamination. The geopolymer was made by using fly ash of PT. IMPOMI in East Java, Indonesia and the ratio of SiO2/Al2O3 = 6.5, Solid/Liquid (S/L) = 3.59 and Na2SiO3/NaOH = 2.5. A solution of Cd (NO3)2 or Pb(NO3)2 were added at 1,000, 4,000, 8,000 or 16,000 ppm relative to the weight of fly ash. Compressive strength test of geopolymers was carried out at the end of day 7 after curing the geopolymer mixture at room temperature. Leaching tests for the kinetics and mechanisms studies were carried using TCLP method by immersing the resulted geopolymers into 0.01 M acetic acid solution. The ratio of geopolymer mass to the volume of acetic acid solution was 1:25. ICP-OES was used to measure the leached Cd2+ and Pb2+ while SEM-EDS was used to study the morphology and heavy metal distribution on the polished geopolymer cross section. It was found that the compressive strength of Cd2+ geopolymer was slightly higher than those of Pb2+-geopolymer. The strength of geopolymer decreased at higher concentration of heavy metal cations. The maximum strength (24.4 MPa) was shown by 4,000 ppm Cd2+ geopolymer while SEM-EDX images showed that Cd2+ and Pb2+ were distributed uniformly from the surface to the core of geopolymers. The leaching test reveals that more than 99.5 % of Cd2+ and Pb2+ were retained by geopolymer while in depth kinetics investigation of both Cd2+ and Pb2+ leaching shows that the leaching rate follows the first order rate law with two step leaching processes. The first originates from cations at the surface followed by cations from the bulk of geopolymer.

Определение ионов тяжелых металлов в экстрактах корня элеутерококка колючего

The content of cadmium, mercury, zinc and cuprum ions in extracts of Eleutherococcus prickly root powder was determined by stripping voltammetry. The content of Zn2+ cations in the aqueous extracts of the plant adaptogen was below the detection limit for the analysis method used. The concentration of ions Cd2+, Pb2+ in aqueous extracts it was less than 0.0002 mg/kg. The amount of cuprum ions did not exceed 2.6 mg/kg. Consequently, the concentrations of heavy metal cations are below the MPC level (maximum permissible concentration), which allows us to speak about the toxicological safety of the plant material studied. Increasing the maceration temperature from 23 to 40 °C reduces the efficiency of the process. The possible causes of this phenomenon are discussed. The source of raw materials does not have a significant effect on the content of pollutants. For the extraction of plant materials, along with distilled water, tap water can be used, which in its performance meets the standards for the content of heavy metal ions in all areas of the city of Kazan. The maximum value of the total pollution indicator is 4.5 mg/l. It was found in tap water selected in the Vakhitovsky district of the city of Kazan. However the maximum lead content is characteristic of the water selected in the Soviet district of the city. Distillation of water is expected to reduce pollution by pollutants. However complete purification from heavy metal ions does not occur. The most intense distillation is the purification of water from cuprum ions. The minimum amount of pollutants is found in ethanolic extracts of Eleutherococcus root powder. It is obvious that ethanol, as an extractant of heavy metal cations, is less preferable than water.