thorium(IV), sorbent, sorption, desorption, clay

The article considers the danger of thorium due to its radioactive toxicity. There has been proved the diversity of thorium compounds and the influence of thorium on a human body and the environment. A polymer chelating sorbent containing fragments of 4-amino - thiouracil has been investigated. An isotherm of thorium sorption with the sorbent is constructed and the optimal concentration conditions are determined: pH = 4; = 6 • 10–3 mol/l; Vob = 25 ml; msorb = 0.03 g; sorptive capacity (CE) = 1 163 mg/g. The degree of extraction of thorium(IV) ions under optimal conditions exceeds 95%. The developed technique was applied to extract thorium from clay. Studying sorption was carried out under static conditions using special equipment.

Sorption of 90Sr and 137Cs on clays used to build safety barriers in radioactive waste storage facilities

The purpose of the work was to investigate the sorptive capacity of natural clay samples with respect to 90Sr and 137Cs to assess the possibility of using these as components of protective barriers at radioactive waste isolation facilities. Bentonite clays of the Zyryanskoye and Desyaty Khutor deposits and high-melting clay of the Kampanovskoye deposit were selected for the investigation. The capacity of clays for sorption through ionic exchange is characterized by the value of the cation exchange capacity (CEC). In the process of sorption experiments, all of the test clays displayed a high rate of extracting strontium and cesium radionuclides from aqueous solutions. It was shown that the sorption of 90Sr is affected by the content of montmorillonite in the samples: bentonite clays absorb up to 98–99% of the initial radionuclide content in the solution, while about 80% of strontium is sorbed by high-melting clay. Cesium is practically fully sorbed by the tested samples and the degree of sorption amounts to over 99%, the highest value of the distribution coefficient having been recorded for the Kampanovskoye sample (Kd = 5.0×103 cm3/g). The method of sorbed radionuclides fixation on the clay samples were identified by selective desorption using the modified Tessier methodology. It was shown that strontium ions are more mobile than ions of cesium up to 97% of which is retained by clays.

Designing Oxide Aerogels With Enhanced Sorptive and Degradative Activity for Acute Chemical Threats

Oxide aerogels are pore–solid networks notable for their low density, large pore volume, and high surface area. This three-dimensional arrangement of pore and solid provides critical properties: the high surface area required to maximize the number of active sites and a through-connected porosity that plumbs reactants to the active interior. In decontamination applications where reactivity beyond adsorption is desired to degrade deleterious molecules, oxide aerogels offer multiple avenues to add oxidative power to this unique arrangement of pore and solid. For protection against chemical warfare agents or toxic industrial chemicals, metal-oxide aerogels with their oxide/hydroxide surfaces afford stability under ambient conditions against competing sorbents such as water and oxygen. In this review, strategies to maximize sorptive capacity and degradation rate by modifying surface functionality, compositing with dissimilar oxides, or adding metallic nanoparticles and the subsequent impact on decontamination performance will be summarized and expected directions for future research will be discussed based on the observed trends.

AB0078 LIPID IMMOBILIZATION AS A METHOD TO OBTAIN ANTIGENIC NANO-OBJECTS

Objectives:Objective of the study is to research the effect of emulsion polymerization on active sites of cardiolipin antigen determinant in antiphospholipid syndrome (APS) in patients with systemic lupus erythematosus (SLE).Methods:Having integrated antigen nanoobjects we developed immobilized magnetocontrollable antigen nanosystems and put them to an evaluation test. The nanosystems are polyacrylamide granules with a built in antigen. To obtain stable immobilized multi–use biopharmaceuticals with targeted properties (shape, particle diameter, pore size, density) we used a modified version of emulsion polymerization method using polyacrylamide carrier gel. This method permitted a greater sorptive capacity, preserving the antigen in maximum native state, and opened up the possibility of controllable modification of nanoobjects. Cardiolipin was used as the antigen in question.Results:Following the method described above we performed sorption of anticardiolipin antibodies from blood plasma of SLE patients who showed clinical presentations of antiphospholipid syndrome. Blood serum from 10 apparently healthy individuals served as control. The level of cardiolipin antibodies was determined before and after sorption by indirect solid phase immunoenzyme method. In the eluate we estimated total protein by Lowry method. In vitro testing showed that the obtained antigen nanosystems based on immobilized cardiolipin could effectively remove cardiolipin antibodies from whole blood of SLE patients with clinical presentations of APS to achieve the values of healthy individuals (before sorption cardiolipin antibodies 0.328 ± 0.028; after sorption 0.059 ± 0.017; p<0.001; sorption capacity 8.00 ± 0.390 mg/ml).Conclusion:The method of emulsion polymerization with consideration to hydrophobic and hydrophilic properties of lipid molecules permits obtaining and modifying biomolecules with certain properties, in a controlled fashion.Disclosure of Interests:None declared

Long-term effect of crops and fertilization on soil eco-chemical state

The study on long-term effects of various crops and fertilization practices on soil eco-chemical state was performed in the complex of Planosols at the Warsaw University of Life Sciences – SGGW experimental station in Skierniewice. The study covered three experiments – Ex-1 (established in 1923; no organic fertilization, cereals as a crop), Ex-2 (established in 1992; farmyard manure application every 4 years, cereals as a crop) and Ex-3 (established in 1975; no organic fertilization, blueberries as a crop). Additionally, each experiment covered three mineral fertilization options, including no fertilization, NPK and CaNPK. Soil samples were taken from A-horizons in 2017 and analysed using standard procedures. The results demonstrate considerable influence of crops and fertilization practices on soil eco-chemical state. Both mineral and organic fertilizers positively affected sorptive capacity as compared to control and modified ionic composition of soil sorption complex. Lower exchangeable acidity and higher sum of exchangeable basis and base saturation were noted in fertilized soils and cereals as a crop as compared to controls. Under blueberries there was observed strong acidification of the soil, in particular in combination with NPK fertilizers, as evidenced by the highest exchangeable acidity, hydrolytic acidity, and the lowest base saturation. Liming partially neutralized acidifying effect of blueberries. Fertilization and crops also strongly influenced buffering capacity of the soils. Extremely low ability to neutralize acidic ions was noted in unfertilized soils, whereas the highest at plots fertilized with Ca. The highest ability to neutralize alkaline ions was typical for NPK fertilized soils under blueberries.

Organic-Inorganic Composite for Extraction of Platinum(IV)

A new composite adsorbent was obtained by hydrolytic polycondensation of N,N'-bis (3-triethoxysilyl propyl) thiocarbamide in the presence of poly-2-methyl-5-vinylpyridine. The sorption activity of the composite toward platinum (IV) ions was studied in hydrochloric acid solutions. The maximum extraction efficiency of Pt (IV) and the maximum values of sorptive capacity (218 mg g–1), and a coefficient of interphase distribution (7090 cm3 g–1) of the studied adsorbent in 1 М solution of HCl were found at 338 K. The Langmuir, Freundlich, and Dubinin–Radushkevich models were used to describe adsorption nature.

Influence of Streambed Heterogeneity on Hyporheic Flow and Sorptive Solute Transport

The subsurface region where river water and groundwater actively mix (the hyporheic zone) plays an important role in conservative and reactive solute transport along rivers. Deposits of high-conductivity (K) sediments along rivers can strongly control hyporheic processes by channeling flow along preferential flow paths wherever they intersect the channel boundary. Our goal is to understand how sediment heterogeneity influences conservative and sorptive solute transport within hyporheic zones containing high- and low-K sediment facies types. The sedimentary architecture of high-K facies is modeled using commonly observed characteristics (e.g., volume proportion and mean length), and their spatial connectivity is quantified to evaluate its effect on hyporheic mixing dynamics. Numerical simulations incorporate physical and chemical heterogeneity by representing spatial variability in both K and in the sediment sorption distribution coefficient ( K d ). Sediment heterogeneity significantly enhances hyporheic exchange and skews solute breakthrough behavior, while in homogeneous sediments, interfacial flux and solute transport are instead controlled by geomorphology and local-scale riverbed topographies. The hyporheic zone is compressed in sediments with high sorptive capacity, which limits solute interactions to only a small portion of the sedimentary architecture and thus increases retention. Our results have practical implications for groundwater quality, including remediation strategies for contaminants of emerging concern.

TECHNIQUES OF MODIFYING LIPID ANTIGENS FOR SYNTHESIS OF DIAGNOSTIC AND THERPAEUTIC PREPARATIONS IN RHEUMATOLOGY

The objective of the study is to enhance sorption capacity of diagnostic agents by using cardiolipin antigens for antiphospholipid syndrome in patients with systemic lupus erythematosus (SLE). A technique of emulsion polimerization was used. Having integrated antigen nanoobjects we developed immobilized magnetocontrollable antigen nanosystems and put them to an evaluation test. The nanosystems are polyacrylamide granules with a built in antigen. To obtain stable immobilized multi-use biopharmaceuticals with targeted properties (shape, particle diameter, pore size, density) we used a modified version of emulsion polymerization method using polyacrylamide carrier gel. This method permitted a greater sorptive capacity, preserving the antigen in maximum native state, and opened up the possibility of controllable modification of nanoobjects. Cardiolipin was used as the antigen in question. Following the method described above we performed sorption of anticardiolipin antibodies from blood plasma of SLE patients who showed clinical presentations of antiphospholipid syndrome. All SLE patoents with signs of antiphospholipid syndrome showed reliably higher levels of cardiolipin antibodies compared with SLE patients without antiphospholipid syndrome signs; the antibody level was 0.365 ± 0.026 and 0.075 ± 0.003 on average, correspondingly (p < 0.001). Blood serum from 10 apparently healthy individuals served as control. The level of cardiolipin antibodies was determined before and after sorption by indirect solid phase immunoenzyme method. In the eluate we estimated total protein by Lowry method. In vitro testing showed that the obtained antigen nanosystems based on immobilized cardiolipin could effectively remove cardiolipin antibodies from whole blood of SLE patients with clinical presentations of APS to achieve the values of healthy individuals (before sorption cardiolipin antibodies 0.328 ± 0.0289; after sorption 0.059 ± 0.0170; p<0,001; sorption capacity 8.00 ± 0.390 mg/ml). The method of emulsion polymerization with consideration to hydrophobic and hydrophilic properties of lipid molecules permits obtaining and modifying biomolecules with certain properties, in a controlled fashion.

Synthesis Features of Iron Oxide Nanopowders with High Magnetic and Sorption Properties

The magnetic particles of iron oxides are promising materials for the purification of water from ions of heavy metals and radionuclides. Their advantage compared to other sorbents is the ability to extract by applied magnetic field, which greatly simplifies the task of extraction, separation and processing in cleaning technologies. The aim of this work is investigation of temperature and concentration of iron in the solution effect on the phase composition, nanoparticle size and their magnetization. Phase magnetite in the sample increases with increasing temperature and the magnetization decreases slightly with increasing the initial concentration of iron in solution. We found that regardless of the conditions of deposition formed spherical particles whose average size ranges from 7 to 15 nm. The sorptive capacity of the particles is virtually independent of the phase composition and for cobalt is about 18 mg/g. For sorption-based material magnetic particles Fe3O4 recommended to carry out the deposition process at a temperature not lower than 80°C. The concentration of iron in solution must be within 0,15–0,3M. The particles obtained contain in their composition at least 90 wt.% of magnetite phase and are characterized by a magnetization in the range of 65–70 A·m2/kg. Also in the paper is comparing efficiency of extraction and sorption capacity for cobalt particles by different phase of magnetite and hematite.

Production of Zeolite Sorbents from Burning and Co-burning Biomass with Coal

The limited resources of natural zeolites make it necessary to search for and use synthetic products. This paper presents a method of producing zeolite sorbents resulting from hydrothermal synthesis in an autoclave. The raw materials used in the syntheses were fluidized-bed fly ashes derived from the burning of forest biomass and sunflower hulls and two fly ashes derived from biomass combustion. The raw materials and zeolite sorbents were characterised using the analysis methods of phase composition and textural properties of the samples. The sorptive capacity of the raw materials and zeolite sorbents was determined by means of cation and anion exchange capacity. The analyses and research have shown that as a result of the synthesis process it is possible to obtain the following zeolite phases: sodalite, faujasite, chabazite. The determined value of the cation and anion exchange capacity for synthetic zeolite sorbents are greater than those which characterise natural zeolites.