INFLUENCE OF THE RATE OF IRON HEXATIANOFERRATE ON ITS SORPTION ABILITY IN RELATION TO SILVER, INDIUM AND GALLIUM CATIONS

The processing of phosphorites into elemental phosphorus is accom-panied by the formation of waste - cotrile "milk", in which indium, gallium, and silver are present. This waste can be considered as a cheap raw material for the production of rare and precious metals. In the scientific literature there are data on the sorption capacity of hexacyano-ferrates of iron, which has a crystal lattice with a channel diameter from 3.0 to 3.5Å. Investigation of the sorption process in the model system "Fe4[Fe(CN)6]3·10H2O - Ag+- In3+- Ga3+ - H2O" depending on the norm of iron hexacyanoferrate (sorbent). The initial concentration of silver, indium and gallium ions and their residual content in solutions were determined using the atomic absorption spectrophotometer "PerkinElmer Analyst 400" (USA). The microstructure of the initial iron hexacyanoferrate and iron hexacyano-ferrate, after sorption, was studied on the CarlZeissFESEM and JEOL brand "JXA-8230" (Japan). With a ratio to T:W equal to 1.75-2.5:100, the degree of sorption of Ag+ with iron hexacyanoferrate is 99.5 and 99.8 %. The highest degree of sorption (96.75%) of In3+ ions can be obtained with a sorbent weighing 3 g per 100 g of solution at 60oC. A high degree of sorption of Ga3+ cations is achieved at low (0.5:100 wt. h.) and high (3:100 wt. h.) consumption of iron hexacyanoferrate. It was revealed that iron hexacyanoferrate exhibits sorption properties simultaneously with respect to mono- and trivalent metals, and the basic laws of their sorption were established.

SELECTIVITY OF INTERPOLYMER SYSTEMS WITH RESPECT TO LANTHANUM IONS

The paper deals with the sorption of lanthanum ions by an interpolymer system consisting of sulfonic cation exchanger KU2-8 and anion exchanger AV-17-8. To predict the sorption activity of the intergel system, the mutual activation of the KU2-8 sulfonic cationite with the AV-17-8 anionite in the aqueous medium was initially studied. Due to the mutual activation of hydrogels in the course of their remote interaction, the polymer macromolecules pass into a highly ionized state, which leads to a significant increase in the degree of extraction of lanthanum ions from polymer hydrogels in intergel vapors as compared to the initial polymers. We calculated the degree of extraction of lanthanum ions by the interpolymer system KU2-8: AV-17-8, the degree of binding of the polymer chain (in relation to lanthanum ions) with the initial ion exchangers and the interpolymer system KU2-8: AV-17-8. Based on the data obtained, a comparative analysis of the sorption of lanthanum ions by individual sorbents and an interpolymer system was carried out within the limits of the ratio KU2-8: AV-17-8 = 5: 1–1: 5. It has been established that the maximum degree of sorption of lanthanum ions by the KU2-8: AV-17-8 interpolymer system is observed within the ratio KU2-8: AV-17-8 = 2: 4 at 48 hours of remote interaction of the interpolymer system and is 54.73 mol. %, at which the degree of binding of the polymer chain is 6.15%

SORPTION OF HEAVY METAL CATIONS FROM A WATER-SALT SYSTEMBY NATURAL MONTMORILLONITE

The sorption properties of natural montmorillonite from the Tagan deposit with respect to heavy metal cations were researched on the model system "Mn2+–Co2+– Ni2+–V4+–H2O–montmorillonite". The influence of temperature, duration of the process and concentration of solutions, as well as the norm of the sorbent on the degree of sorption of cations is considered. The optimal conditions for the sorption process (25о С, 30 min, Т:Ж = 1,5:100) have been determined, at which the degree of solution purification is up to 86.36% cations of Co2+, 85.59% of Ni2+, 82.64% of Mn2+ and 52.29% of V4+. The nature of the sorption curves is determined by the nature of the sorbed cation. According to the absorption efficiency of natural montmorillonite, ions are arranged in the following order: Ni2+≥ Co2+> Mn2+> V4+. The results of the conducted studies indicate the possibility of effective use of bentonite clays of the Tagan field in the purification of wastewater from heavy metal cations

DETERMINATION OF VANADIUM (V) TRACE AMOUNTS IN OIL SLUDGE AFTER PRELIMINARY CONCENTRATION WITH POLYMER SORBENT

A modified sorbent based on copolymer of maleic anhydride with methacrylic acid was proposed for sorption of vanadium (V) concentration. A polymer chelating sorbent with fragments of para-amino salicylic acid was used in the work. Optimal sorption conditions were determined and the dependence of sorption capacity on the acidity of the solution studied. At pH 5, the degree of sorption attains its maximum. The effect of ionic strength on vanadium sorption was studied. Studies have shown that the ionic strength up to 0.6 mol/l does not affect the sorption, after 0.6 mol/l the increase in the ionic strength at the beginning gradually, and then sharply decreases the sorption. The effect of ionic strength on vanadium sorption was studied to show that the ionic strength up to 0.6 mol/l does not affect the sorption, and after 0.6 mol/l the increase in the ionic strength at the beginning gradually, and then sharply decreases the sorption. All further experiments were carried out in the solutions with an ionic strength of 0.6. It was found that as the concentration of vanadium rises in the solution, the amount of sorbed metal increases, and at a concentration of 8.10-3 mol/l it becomes maximum (pH = 5, CV5+ = 8.10-3 mol/l, vtotal = 20 ml, msorb. = 0.03 g, SC = 243 mg/g). The isotherm of vanadium (V) sorption with the synthesized sorbent was constructed. Sorption equilibrium is achieved within 1 hour of contact between the solution and the sorbent. Further growth in the sorption time does not change sorbent’s characteristics. The sorbent extracts vanadium (V) from solutions with a recovery rate of 93%. The effect of different mineral acids (HClO4, H2SO4, HNO3, HCl) of identical concentrations on vanadium (V) desorption from the sorbent was also studied. The results of the analysis showed that the maximum desorption of vanadium (V) occurs in perchlorate acid. The developed method was applied to determine the trace amounts of vanadium in oil sludge with preliminary concentration.

Features of gallium sorption on mechanoactivated titanium dioxide.

The features of sorption of gallium from aqueous solutions on mechanically activated TiO2(rutile) were studied. The dependence of the degree of sorption on the time of mechanical activation is obtained. The experimental sorption isotherms at temperatures from 20 to 50 ºСwere processed by adsorption models of Langmuir, Freindlich, Dubinin —Radushkevich. To achieve sorption equilibrium depending on temperature, 10–30 minutes are required. Dependence of sorption on time is better described by the kinetic model of the pseudo-second order. According to the Arrhenius equation, the activation energy is calculated —9,7 kJ / mol.

Sorption of medical preparations by chitosan

The article provides information about sorption properties of crab chitosan in relation to Analgin, Aspirin, Quamatel, Mydocalm, Paracetamol, Tsifran and Phtalazol. Quantitative determination of medicines’ amount before and after sorption was performed by HPLC-MS method with the preliminary plotting of calibration curves. The sorption capacity of chitosan taken in different concentrations was determined. Sorption isotherms and kinetic curves of medications’ sorption by chitosan were plotted. It has been shown that the maximum degree of sorption in static conditions for all studied medicines was achieved within an hour after the beginning of the sorption process.

Biochar compared with activated granular carbon for landfill leachate treatment

The aim of the research was to compare the effectiveness of sorption of pollutants from landfill leachate on two granulated activated carbons (AG and BA-10) and biochar (BC). The sorption process of wastewater components on activated carbons was carried out under static conditions for 72 hours. The doses of adsorbents used varied from 2–8 g·dm-3. Results of removing of COD were estimated on the base of adsorption capacity and COD removal efficiency. After 72 h of the process at the highest doses (8 g·dm-3), the COD removal rate ranged from 40% (BA-10) to 60% (AG). In the case of biochar, the COD adsorption rate was 53% The state of sorption equilibrium takes a similar character for BC and AG and is determined after 4 h. The degree of sorption of selected metals from landfill leachate using the analyzed range ranged from 84% to 96% depending on its type.

STUDY OF SORPTION OF Cr(III) IONS BY PHOSPHORUS-CONTAINING POLYMER SORBENT

The paper presents the results of a study on the sorption of Cr(III) ions from aqueous solutions using phosphorus-containing sorbent based on butadiene-styrene rubber of the DSKK brand. This sorbent was synthesized by the reaction of oxidative chlorophosphorylation of butadiene-styrene rubber of the DSKK brand using PCl3, CCl4, H2SO4 and O2 under laboratory conditions. The effect of various parameters, such as the pH of the solution, the initial concentration of metal ions, the sorbent mass, the contact time of the phases, and the temperature on the sorption efficiency of Cr(III) ions have been studied. The sorption capacity and the degree of sorption were calculated on the basis of the concentration data obtained from the analysis of samples on the ISP MS 7700e mass spectrometer. A decrease in the degree of sorption of Cr(III) ions in acidic and alkaline media is established, and an acid-poor medium is the optimal condition for sorption. The increase in the temperature and mass of the sorbent positively affects sorption. The degree of sorption decreases with increasing initial concentration of Cr(III) ions. This indicates that the phosphorus-containing sorbent based on butadiene-styrene rubber of the DSSC brand has a limited number of active sites for sorption, and at lower concentrations almost all Cr(III) ions were sorbed. However, an increase in the initial concentration of Cr(III) ions leads to a rapid saturation of the surface of the sorbent. It has also been established that equilibrium is established at room temperature after 40 minutes. Experimental results have shown that a phosphorus-based sorbent based on butadiene-styrene rubber can be successfully used to extract Cr(III) ions from aqueous solutions.

Ozonation of nanofiltration permeate of whey before processing by reverse osmosis

During nanofiltration processing of whey a significant amount of permeate is generated. In some cases this permeate is treated by reverse osmosis to get purified water for technological needs. Dry substances are not used, because they contain practically the same amount of organic and inorganic components. Mineral substances can be used for the mineralization of drinking water purified by reverse osmosis. However, the presence of organic compounds complicates the process of separation, as well as reduces the specific productivity of reverse osmosis membranes at the concentration stage. Therefore, the search for methods of destruction and removal of organic components is grounded. In the presented work, experimental studies of ozonation and sorption of organic compounds by activated carbon were carried. It has been shown that ozonation improves the degree of sorption purification by six times. Sequential treatment with ozone and subsequent filtration through the layer of activated carbon improves the specific productivity of reverse osmosis membranes by 30% at the stage of treatment of the nanofiltration permeate, while their selectivity remains unchanged.