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In the modern world, pollution of industrial wastewater by oil and petroleum products is one of the most acute environmental problems. These pollutants have a significant negative impact on ecosystems and water quality. In this regard, there is a need to develop effective and environmentally safe methods of wastewater treatment. The aim of the study is to develop and evaluate the efficiency of using carbonate sludge as an adsorbent for removing oil and petroleum products from wastewater. The scientific and practical significance of the work lies in the proposal of an environmentally friendly treatment method that can not only improve the quality of wastewater, but also ensure the disposal of industrial waste. The use of carbonate sludge, a by-product of industry, makes the method cost-effective and reduces the environmental burden. The main results of the study showed that carbonate sludge has a high sorption capacity for petroleum products. The adsorption isotherm belongs to type I according to the Brunauer, Deming, Deming and Teller classification, which indicates the presence of monolayer adsorption on the sludge surface. It was found that the sludge is able to remove up to 95% of pollutants from wastewater. The value of the study lies in demonstrating that carbonate sludge is an effective and affordable material for solving environmental problems associated with water pollution by petroleum products. This research contributes to the development of industrial waste recycling technologies by offering a new application for carbonate sludge. The practical significance of this work lies in the possibility of introducing this method at industrial enterprises for wastewater treatment, which can lead to a reduction in waste disposal costs and an improvement in the environmental situation. The results of the study can be useful for enterprises of the petrochemical industry and wastewater treatment plants. [ABSTRACT FROM AUTHOR]

Проведены исследования как физико-химических (адсорбционная способность; рН), так и фармацевтических (кислотность; щелочность; растворимость; содержание сульфидов; потеря в массе при высушивании; содержание золы, флуоресцирующих веществ и веществ, растворимых в 96 % спирте; наличие неорганических катионов (медь, свинец, цинк) и анионов (цианиды, хлориды, сульфаты)) свойств новых видов углей, полученных путем термохимического синтеза из целлюлозо- и лигнинсодержащего сырья. Дана оценка соответствия их характеристик требованиям Государственной фармакопеи Республики Беларусь, а также государственных фармакопей других стран.

Метод адсорбции является одним из способов доочистки базовых масел с целью улучшения их показателей качества и цвета. Цель работы – изучение изменения свойств активной глины в процессе адсорбционной очистки гидрокрекингового масла и после проведения окислительной регенерации отработанной глины. Изучение свойств исходной, отработанной и регенерированной глины проводилось при помощи анализатора площади поверхности и распределения пор BELSORP MAX. Определены истинная плотность образцов глины и изотермы адсорбции / де- сорбции ими азота при 77 К. Представлены результаты анализа изотерм адсорбции азота образ- цами глины с использованием моделей адсорбции Ленгмюра и ВЕТ. Анализ распределения пор по размерам в исследуемых образцах глины проводился с применением метода INNES. Установлено, что в ходе адсорбционной доочистки гидрокрекингового масла наблюдается уменьшение объема пор и удельной поверхности активной глины. При этом снижается прочность связи молекул адсорбируемых веществ с поверхностью глины и уменьшается ее поверхность. Показано, что эффективность адсорбента, используемого в процессе адсорбционной доочистки гидрокрекингового масла, определяется главным образом полярностью его поверхности. Чем выше полярность поверхности адсорбента, тем больше ее сорбционной емкости по отношению к удаляемым из очищаемого масла смолам.

In the study, changes in the mass of concrete filled with polyacrylamide/Fe3O4 nanoparticles in an amount of 1–2% of the cement mass in sea and formation water were studied. Besides, by performing IR and X-ray characterization of the prepared samples, the chemical state of the polyacrylamide (PAA) and the nanoparticles in the structure was also determined. Changes in mass of concrete samples containing PAA/Fe3O4 nanoparticles in highly mineralized seawater were shown to be highly dependent on the amount of nanoparticles compared to PAA. It revealed that at 2% PAA-Fe3O4/concrete, the ion penetration was limited and there was a lower weight gain as compared to the control concrete. IR spectroscopic analyses proved that the polymer was in a coordination band with cement and magnetite nanoparticles. X-ray diffraction studies showed a slight increase in the crystallinity of the concrete filled with up to 2% PAA/Fe3O4 magnetite nanoparticles. [ABSTRACT FROM AUTHOR]

Background. Wood processing produces waste, which is a valuable raw material for various industries. Purpose. Studying the possibility of obtaining import-substituting coal adsorbents from wood waste, the characteristics of the adsorption of organic substances and the thermodynamics of adsorption on their surface. Methodology. Adsorption isotherms of benzene vapor and sorption-structural parameters on new coal adsorbents were studied using a high-vacuum calorimetric installation. Originality. Based on the adsorption of benzene vapor, the structural and sorption properties of coal adsorbents obtained by activating waste maple trunks with potassium alkali were determined. Findings. According to the adsorption isotherms of Coal + KOH (1:5), the adsorption of benzene in the studied systems: 3.8 times more than Coal-500, 2.2 times more than Coal + KOH (1:1), Coal turned out to be 1,8 times higher. than +KOH (1:2), 1.5 times higher than Coal+KOH (1:3) and 1.2 times higher than Coal+KOH (1:4). [ABSTRACT FROM AUTHOR]

Background. The use of catalysts and adsorbents in the processing of oil and gas raw materials requires in-depth research into potential import-substituting analogues. Purpose. Study of isotherms and calculation of differential entropy of ammonia adsorption in synthetic zeolite CaA (M-22). Methodology. The studies were carried out on a universal high-vacuum installation, which allows dosing of the adsorbate using both gas-volume and volume-liquid methods with an accuracy of 0.1%. Originality. For the first time, the energy characteristics of ammonia adsorption in CaA (M-22) zeolite were determined, the differential values of free energy and entropy of adsorption were calculated, a correlation was found between the adsorption-energy characteristics and the crystallochemical structure of the adsorbent, the mechanism of formation of ion-molecular clusters of ammonia with cations in the zeolite in the region filling the pore space of the adsorbent. Findings. The stepwise nature of the entropy of ammonia adsorption was revealed. The entropy region correlates with the number of sodium and calcium cations in the zeolite structure. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Almaty Technological University is the property of Almaty Technological University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background. Adsorbents are used in wastewater treatment technologies. Among the nontraditional "green", effective adsorbents, starch and its derivatives stand out. Purpose. Synthesis of sodium salt of carboxymethyl starch (CMS) using local corn starch and sodium salt of monochloroacetic acid, determination of optimal conditions for its production. Methodology. The carboxymethylation reaction of corn starch was carried out using the solid-phase method, and the resulting product was analyzed using physicochemical methods. The absorption of copper ions was determined by the spectrophotometric method. Originality. In the synthesis of CMC, an increase in humidity by 15-20% was established, with the addition of isopropanol in water as a wetting agent, it increases the efficiency of the reaction, and its optimal conditions were identified. Findings. Carboxymethyl starch was synthesized using local corn starch and sodium monochloroacetic acid as an esterifying agent, sodium hydroxide as a catalyst and isopropyl alcohol as a wetting agent. The optimal conditions for obtaining a product with a high degree of exchange of 0.92 using an economical method for the synthesis of KMC-Na were determined. It has been established that humidity increases by 15-20% with the addition of isopropanol. as a wetting agent in the synthesis of CMC, it increases the efficiency of the reaction. When the concentration of copper ions in the simulated water sample was 25 mg/l, the dose of CMC was 2 g/l, the degree of removal of copper ions reached 95.0%, and the adsorption capacity of CMC was 15.24 mg/g. [ABSTRACT FROM AUTHOR]

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents the results of the development of new composite materials obtained from rice husk ash (ZRH). Composite materials are bound by 2 wt.% silver nanoparticles and characterized using methods for determining their structural characteristics, namely: X-ray fluorescence analysis (XRF), scanning electron microscopy with elements of semi-quantitative analysis (SEM-EDS), low-temperature nitrogen adsorption (according to the theory of Brunauer-Emmett-Teller (BET) and X-ray phase analysis (XRD). According to the results of the elemental semi-quantitative analysis, the zeolite was successfully modified with silver nanoparticles, which at co-deposition amounted to 1.44%. Mineralogical phases were determined in an X-ray diffractometer (XRD) and the pronounced crystal structure of synthetic zeolite of the form "analcim" and silver nanoparticles was confirmed. A structural modification of synthetic zeolite "analcime" based on ZRH was carried out in order to quickly bind zeolite with mercury. The BET results showed the formation of mesopores and micropores, while the surface area of synthetic zeolite and modified silver nanoparticles (AgNPs) was 48.94 m2/g and 0.75 m2/g, respectively. Preliminary results showed that the removal of mercury ions from the solution was from 20 to 50% of the initial concentration. [ABSTRACT FROM AUTHOR]

The results of study of the change in the sorption index by chemical, thermal and mechanical treatment of bentonite clay have been obtained. They showed that during the complex processing of samples with mechanical pressure, temperature and cationic solutions, there is a general tendency to an increase in the sorption index. It was found that the greatest effect on the activation of sorption properties is exerted by vertical pressure, heat treatment of samples at 200 оС and saturation with a cationic solution of ferric chloride, which allows us to consider this processing of samples as the most effective for the samples of this study.

The paper gives a brief analysis of experimental work on the production of sorbents from various biological wastes in one process. The obtained sorbents are used without additional activation. In connection with such experimental material, the theoretical aspects of various processes in the channels and on the surface of the sorbent are considered. The processes of solvation of metal particles in an aqueous medium are considered in the framework of the quantum theory of inhomogeneous condensed media with a redistribution of the electron density of the system. The processes of adsorption on the walls and in the channels of the sorbent are considered taking into account the effects of spatial dispersion of the system. [ABSTRACT FROM AUTHOR]

Разработан материал на основе системы трепел – мел, обладающий адсорбционными свойствами по извлечению фосфатов из сточных вод. Показано, что степень адсорбции фосфатов из сточных вод достигает 99,8%, и зависит от параметров синтеза адсорбента и технологического режима обработки сточных вод. Установлен фазовый (CaO, SiO2, CaO · SiO2, CaO · Al2O3 · 2SiO2) и химический (54% SiO2, 33% CaO, 6% Al2O3 и др.) состав сорбционного материала. Величина удельной поверхности и удельного объема пор сорбционного материала равна 88 м2/г и 0,126 см3/г соответственно. Максимальная сорбционная емкость по фосфатам в пересчете на фосфор составляет 79,6 мг P/г. Полученный сорбент сохраняет степень адсорбции выше 90% в течение 5 циклов обработки сточной воды. В отработанном адсорбенте установлено наличие фосфата кальция, гидроксиапатита и брушита. Влажность отработанного адсорбента составляет 89%. Содержание фосфатов в пересчете на фосфор в сухом веществе отработанного адсорбента составляет 3 мас. %.

The article examines the sorption capabilities of sorbents for water-soluble petroleum products, as well as the mechanism of adsorption in the practical use of sorbents in water purification processes. The process of adsorption of petroleum products and some ions with inorganic sorbents is considered. The study revealed: 1 gram of sorbent absorbs 15-18 grams of oil, which contributes to the effective fight against oil spills in the aquatic environment. It is recommended to use rice husk as an effective sorbent.

Copyright of Journal of Mathematics, Mechanics & Computer Science is the property of Al-Farabi Kazakh National University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Eurasian Journal of Ecology is the property of Al-Farabi Kazakh National University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The current scientific research investigates the sorption characteristics of flour mixtures enriched with apple pomace with different percentage ratios between the basic wheat flour (type 500) and the functional additive, as follows 50/50, 75/25 and 90/10. The results obtained for the adsorption and desorption processes were reported under the selected conditions: temperature 25°C and relative humidity in the range of 11% to 84%, maintained using saturated solutions of 8 different salts. The equilibrium moisture content of the 50/50 mixture for the adsorption process ranges from 5.13% to 22.71%, and for the desorption process - from 6.69% to 26.12%, respectively the data obtained for the 75/25 mixture are from 5.39% to 20.62% and from 4.81% to 18.76%, and for mixture 90/10 are from 5.32% to 19.49% and from 6.18% to 19.34%. The graphical analysis of the sorption isotherms in all three types of functionally enriched mixtures has the characteristic for most types of food products – S-type, according to Brunauer’s classification. By linearization of the Brunauer-Emmett- Teller (BET) model, the values for monolayer moisture content were calculated, ensuring maximum preservation of the quality characteristics of the studied mixtures. For the 50/50 mixture, the values for adsorption and desorption are 6.76% and 7.22%, for 75/25 - 6.31% and 6.11%, and for 90/10 are 6.60% and 5.85%. The two-parameter models of Oswin, Henderson, Chung-Pfost, and Halsey were used to describe the obtained sorption isotherms, and the criteria for selecting the most suitable model were mean relative error (P,%) and standard error (SEM). [ABSTRACT FROM AUTHOR]

Copyright of News of Kazakhstan Science / Novosti nauki Kazahstana is the property of NCSTE (JSC National Center for State Scientific and Technical Evaluations) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article provides data on the use of crosslinked with hexamethylenediamine alt-maleic anhydride-styrene copolymer, as a sorbent for the remove of the Rhodamine 6G dye from aqueous solution. The effect of the pH, sorbent amount, contact time, temperature and dye concentration on sorption was studied. The obtained data were processed in the coordinates of the Langmuir, Freundlich and D-R models equations and the values of the equilibrium sorption capacity and mean sorption energy were determined. The found value of the mean sorption energy from D–R equation ED=4.556<8.0 kJ mol–1, indicated that the sorption of Rh6G by synthesized polymer-sorbent has physical character. Also, thermodynamic parameters, like standard Gibbs free energy (∆G˚), standart enthalpy change (∆H˚) and standart entropy change (∆S˚) were determined. The positive values of ΔG° confirm the nonspontaneous of adsorption process, and the positive value of ΔH° (12.464 kJ mol–1) suggested that the adsorption was endothermic in nature. The positive value of ΔS° (0.0271 kJ mol–1 K–1) shows the increasing randomness during adsorption process. [ABSTRACT FROM AUTHOR]

Aim. Determination of the characteristics of regenerated keratin obtained from human hair, development of keratin-based films, and studing their surface morphology and adsorption capacity. Methods. Keratins were extracted by sulfitolysis. The structure of regenerated keratin was studied by IR spectroscopy, thermogravimetry, and electrophoresis. Keratin-based films were made by casting. Their biocompatibility was analyzed in the adsorption test by incubation in human serum. Scanning electron microscopy was used to evaluate the surface morphology of the films. Results. The regenerated keratin is represented mainly by proteins of intermediate filaments and is characterized by better thermal properties than the native one. The keratinbased films had a pronounced relief structure. The adsorption test shows the ability of the films to adsorb albumin from human serum on their surface. Conclusions. The mild extraction of keratins by sulfitolysis ensures the preservation of their native properties and the ability of keratin-based films to form bonds with blood proteins. [ABSTRACT FROM AUTHOR]

This paper describes an optimization procedure for the adsorption of arsenite ions from wastewater using the Adaptive Neuro-Fuzzy Inference System (ANFIS). The adsorbent is based on hydroxy apatite, a natural material obtained from carp (Cyprinus carpio) scales. The input parameters were the influence of pH, the temperature, the initial concentration and reaction time of arsenite adsorption while the adsorption capacity and the arsenite removal percentage were studied as the output parameters. / В данной статье описана процедура оптимизации адсорбции ионов арсенита из сточных вод с использованием адаптивной нейронечеткой логической системы (ANFIS). В основе адсорбента лежит природный гидроксиапатитный материал, полученный из чешуи карпа (Cyprinus carpio). В качестве параметров ввода использовались влияние pH, температуры, начальной концентрации и времени реакции на адсорбцию арсенита, а в качестве выходных параметров были исследованы адсорбционная емкость и процент удаления арсенита. / U radu se opisuje postupak optimizacije adsorpcije arsenitnih jona iz otpadnih voda korišćenjem adaptivnog neuro-fazi sistema (ANFIS). U osnovi adsorbenta nalazi se prirodni hidroksi-apatitni materijal dobijen iz krljušti šarana (Cyprinus carpio). Kao ulazni parametri korišćeni su uticaj pH, temperature, početne koncentracije i vremena adsorpcije arsenita, a kao izlazni parametri ispitivani su adsorpcioni kapacitet i procenat uklanjanja arsenita.

Perspectives of carbon nanotubes arrays in chemical sensors with acoustic information-carrying signal are discussed. The arrays are regarded as nanostructured disperse medium with intertube molecular interaction modulated by molecules adsorbed in the space among the tubes and changing elastic properties of the array. Adsorptive properties of the arrays are described. The possibility of their non-covalent functional modification is proved. Chemical sensitivity of such systems and ways of its selectivity rising are discussed.

Introduction. Formed in a nuclear reactor, tritium is mainly discharged into the hydrosphere. A significant part of tritium also enters the environment during the reprocessing of spent nuclear fuel. Currently, the problem is the development of effective, simple, affordable, inexpensive and low-energy methods for extracting tritium from large volumes of low- and intermediate-level aqueous solutions. Review of previous publications. At nuclear power plants, it is widely used for the purification of small volumes of highly active process waters by isotopic exchange in the "hydrogen-water" system [patents RU 2380144, RU 2060801, RU 2525423, RU 2148426]. There are methods for isotopic fractionation of НTO by low-temperature rectification, which either requires significant energy consumption or occurs with a very insignificant isotopic effect at the level of 1.1 [patents UA 57558, RU 2010772, RU 2091336]. In world practice, mineral adsorbents are widely used, but there are no developments designed to purify aqueous solutions from tritium. Our previous studies have clarified the possibility of using layered silicates and zeolite for the extraction of tritium from aqueous solutions (patents UA 103033, UA 103050, UA 113348). The ability of other minerals to adsorb tritium from aqueous solutions remains unresolved. In order to solve this problem, we involved in experimental research minerals from the classes of hydroxides, sulfates and chain silicates. Purpose. The aim of the work is to determine the influence of the structural features of mineral adsorbents on the removal of tritium from proto-tritium water ("НTO") and the possibility of using a more expanded spectrum of minerals as such adsorbents. Results. Up to 39% of tritium extracted from tritiated water is retained in hibsite in surface adsorbed form. In the boundary layer, heavier НTO molecules are retained with a greater advantage than H2O molecules (α = 1.14). Gypsum: due to the substitution of OH groups of the gypsum crystal lattice by OT groups in the mineral structure, up to 36% of the absorbed tritium solution with partial isotope-hydrogen fractionation is fixed. Due to the presence of tangled fibrous microtexture in wollastonite, a significant part of tritium absorbed during the experiment from a solution of tritiated water is fixed in a surface adsorbed form (61.3%, fractionation coefficient α = 1.03). The reaction of hydroxylation of CaO when it interacts with tritiated water is accompanied by a predominant binding to calcium of OT groups formed by the dissociation of НTO molecules because heavy hydrogen isotopes form a stronger covalent bond with oxygen than with protium (α = 1.23). Conclusions. The highest total ability to extract tritium from aqueous solution was observed in hibsite (38.7%), and the lowest - in wollastonite (34.5%). The obtained new scientific results with the involvement of the results of our previous studies provide an opportunity for more effective development of methods for detritalization of aqueous solutions. [ABSTRACT FROM AUTHOR]

Copyright of Eurasian Journal of Ecology is the property of Al-Farabi Kazakh National University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cases of a particle in a one-dimensional square well – infinitely deep and with finite depth – are also analyzed in detail. As an example, the adsorption of a hydrogen atom on a metal surface by a qualitative and accurate solution of the problem is considered. [ABSTRACT FROM AUTHOR]

В связи c бурным развитием нанотехнологий и микроэлектроники много внимания уделяется изучению различных адсорбционных процессов. Как правило, адсорбция наблюдается на поверхности кристалла или жидкости, но иногда имеет место и одномерная адсорбция. В частности, особый интерес вызывает вопрос о распределении фаз при адсорбции на атомных цепочках. В статье рассматривается адсорбция атомов одного сорта на цепочке конечного размера при температуре абсолютного нуля в рамках обобщенной модели Изинга с учетом взаимодействия первых и вторых соседей и внешнего поля. В качестве граничных условий выбраны «оборванные концы», что позволяет моделировать процессы на реальной цепочке со свободными концами. Построены диаграммы основных состояний — диаграммы стабильности фаз в координатной плоскости энергетических параметров при температуре абсолютного нуля: по вертикали откладывается энергия взаимодействия ближайших или вторых соседей; по горизонтали — внешнее поле. Расчет диаграмм основных состояний позволяет определить возможные адсорбционные превращения и новые фазы при достаточно низких температурах, а также построить изотерму одномерной адсорбции. Некоторые из рассмотренных фаз уже обнаружены экспериментально. DOI 10.14258/izvasu(2018)4-08

Copyright of Scientific Bulletin of National Mining University is the property of National Mining University, State Higher Educational Institution and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Studying interaction of zinc (II) with silica and alumina-silica surfaces is important for several reasons. From a practical point of view, it is carried out in the framework of the creation of a medicinal product, the ingredients of which are, in particular, silica(alumina)containing sorbent and zinc compound; from a theoretical point of view, it is a search for the adsorption patterns on the mentioned surfaces in a series of d-elements with a close electronic structure (zinc, copper, nickel, cadmium, etc.). In addition, it is advisable to supplement the experimental adsorption data with the results of quantum chemical simulation of the structure and formation energy of zinc (II) complexes with active surface centers. Adsorption of Zn2+ ions from a neutral aqueous solution on silica and alumina-silica materials was studied by means of the method of adsorption isotherm. The specific surface of the materials was determined by method of thermal desorption of argon. Quantum chemical analysis of the structure and energy of formation of the hydrated zinc sulfate ion pair on silica and alumina-silica surfaces was performed by means of Hartree-Fock-Roothaan method with extended basis set 6-31++G(d,p). According to the magnitude of adsorption (A) of zinc, the test materials are divided into three groups: 1) enterosgel, kaolin, nanosilica A-300 and polymethylsiloxane, for which Аmax is from 0.15 to 0.3 mg/g; 2) Syloid® 244 FP, KG-60 and KG-40, aminopropylaerosil, smectite (Аmax from 1.2 to 12.0 mg/g); 3) zeolites NaA-TK-1173 and NaX (Аmax more than 30 mg/g). It is concluded that the high adsorption activity of zinc(II) is primarily due to the presence of developed porous structure. The most probable places of interaction between hydrated zinc ions and hydroxyl group of silica and alumina-silica surfaces are determined by means of quantum chemical simulation. The pKMe values have been calculated of ion exchange of silica surface when interacting with Zn2+ cations. [ABSTRACT FROM AUTHOR]

Copyright of Metallophysics & Advanced Technologies / Metallofizika i Novejsie Tehnologii is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The problem of the formation of asphalt-resin-paraffin deposits (ARPD) in oil fields within the "well -- bottom-hole formation zone" system is still relevant. To prevent the formation of ARPD in the "bottom-hole formation zone -- well" system, the ARPD inhibitors must have high adsorption and low desorption properties concerning the rock. The composition of inhibitors often includes surfactants. Nonionic surfactants, namely, polyesters, are widely used to prevent the formation of ARPD. However, currently, little is known about inhibitors with a combined effect, for example, possessing depressor-dispersing properties for ARPD. This work aimed to develop a combined inhibitor possessing not only depressor-dispersing properties but also having good adsorption and desorption properties to the rock to prevent the formation of ARPD. The paper presents the research results on the development of an ARPD inhibitor, as well as the effects of determination of its depressor dispersing, inhibiting, and corrosive properties; the temperature of oil saturation with paraffin is determined as well. The studies of the ARPD inhibitor adsorption were carried out by the static and dynamic methods. In contrast, the process of the inhibitor desorption was studied by oil filtering through a saturated sample of the rock using a bulk model and core material. The impact of the fluid flow rate on the inhibitor desorption rate was studied. The technological parameters of the ARPD inhibitor solution injection into the bottom-hole formation zone of production wells were calculated. The developed composition has high inhibiting properties concerning the ARPD, depressordispersing properties, low corrosive activity for a metal surface, and is capable of lowering the temperature of oil saturation with paraffin. [ABSTRACT FROM AUTHOR]

The paper discusses the problems of environmental pollution with harmful chemicals and their adverse effects on ecosystem components. The main sources of harmful chemicals discharged into the atmosphere air, soil and water basins are specified. Potential threats of toxic organic compounds, heavy metals, radionuclides, as well as exhaust gases to both the natural environment and living organisms are examined. In addition, the results of the author’s researches in the fields of environmental pollution in the territories exposed to various anthropogenic sources and effective methods to prevent their negative environmental impact are presented. [ABSTRACT FROM AUTHOR]

Introduction shows the important of this scientific direction. 60Co with half-life of 5.3 years is one of the few anthropogenic, gamma-emitting radionuclides, that can be detected in aquatic environments affected by liquid effluent discharged from nuclear facilities. The need for control of the content of 60Co in the environment, determines the search for new adsorption materials with high adsorption capacity and chemical, thermal, and radiation resistance. The aim of present work is to investigate the adsorption of Co2+ and 60Co by mesoporous TiO2 from aqueous solutions. Experimental techniques describes the adsorption studies in detail. The mesoporous TiO2 with the initial pore size ratio (Smeso/S = 58 %; Vmeso/V = 64 %) was selected as adsorbent. Synthesis of adsorbents was carried out by the method of liquid phase hydrolysis of aqua complex of TiCl4. The dependence of adsorption value on agitation time, solutions acidity, and equilibrium concentration of Co2+ was investigated in butch mode. The presence of cobalt on the surface of mesoporous TiO2 was confirmed using XRF-analysis. The initial and residual concentration of cobalt was controlled by complexonometric titration with xylenol orange as indicator. Four simplified kinetic models: pseudo-first order and pseudo-second order equations, firstly applied by Lagergren, intraparticle diffusion and Elovich (Roginsky-Zeldovich) kinetic models were applied to experimental data. Langmuir and Dubinin-Radushkevich adsorption theory applied for experimental equilibrium data of adsorption of cobalt cations by mesoporous TiO2. The adsorption energy was measured using Dubinin-Radushkevich equation. The results obtained have shown that the experimental data on the adsorption kinetics of Co2+ by mesoporous TiO2 fit well by Lagergren pseudo-second kinetic model. Applying of Elovich kinetic model gives also high correlation’s coefficients, close to unit (R2 > 0.9). The equilibrium adsorption data are well approximated by Langmuir adsorption theory. Maximal adsorption value obtained experimentally (49±4 mg/g) is in good agreement with calculated by Langmuir adsorption theory (63.81 mg/g). The adsorption energy calculated using Dubinin-Radushkevich equation is 8.104±0.361 kJ/mol, which correspond to physical adsorption mechanism. However, for each values of Polanyi’s potential (ε) (which correspond to certain equilibrium concentration Ce, mg/L) adsorption energy is different. It smooth decreases with increasing concentration of adsorbate in the solution. Although the experimental results are well describing by the Langmuir model, the adsorption energy of Co2+ ions by mesoporous TiO2 depends on the degree of surface filling, which means that the adsorption centers of this sample are not independent. At the low equilibrium concentration of Co2+ (38 mg/L), the adsorption energy is much higher than the corresponding value for adsorption by the physical mechanism. To our opinion, that is why applying of Elovich kinetic model to experimental dada gives high R2. The adsorption of Co2+ by mesoporous TiO2 strongly depends on solutions acidity. To simulate conditions close to real, the adsorption of 60Co by mesoporous TiO2 was investigated. The percentage of 60Co, adsorbed onto TiO2 is more than 90 %. The main conclusion is that mesoporous TiO2 could be useful as an adsorbent for water purification from Co2+ and in decontaminating of radioactive waste containing 60Co. [ABSTRACT FROM AUTHOR]

A number of multifunctional composite adsorbents based on hydrated zirconium dioxide has been synthesized. The inorganic ion exchanger contained nanosheets of oxidized graphene (GO), the modifier amount was 0.5–7 mass. %. The composites were investigated with methods of transmission electron microscopy and nitrogen adsorption-desorption, macropores were determined using water as a working liquid. It has been found that increasing of GO content depresses microporosity, but meso- and macroporosity grow. Crushing strength reduces exponentially with increase of total pore volume from 0.49 to 0.62 cm3 g–1. Removal of phenol from water containing also inorganic ions was investigated. Adsorption capacity reaches 0.15–0.85 (phenol), 0.5–0.85 (Ca2+ and Mg2+), 0.005–0.045 (SO42–) mmol g–1. When the GO content in the composites is 0.5–2 %, this carbon addition improves adsorption of cations and organic molecules comparing with hydrated zirconium dioxide. Further increase in GO amount causes no sufficient effect on adsorption due to decline of specific surface area of the composites. It has been suggested that the optimal content of the modifier, which provides the maximal growth of adsorption capacity, is 2 %. This composite is obtained in a form of large granules (0.3–0.5 mm), their crushing strength is 9 bar. The material was applied to removal of pesticides (acetomipride, carboxine, epoxyconazole and thiamethoxam) from aqueous multicomponent solution under batch conditions. The residual content of carboxine and epoxyconazole, molecules of which contain benzene rings, is lower than the maximal allowable concentration. No deterioration of pesticide uptake has been found after five cycles of adsorption-regeneration. [ABSTRACT FROM AUTHOR]

The adsorption of cationic hexadecylpyridinium bromide and non-ionic oxyethylated octylphenols (TХ-45, TX-100, ТХ-305) surfactants from their mixed solutions at non-porous hydrophobic carbon sorbent such as thermal graphitized carbon black has been studied. The molar fraction of oxyethylated octylphenols in the mixtures was 0.2, 0.4, 0.6, and 0.8. The results have shown that the adsorption values of hexadecylpyridinium bromide depend on the total concentration of the surfactant and the composition of mixtures. It has been found that the molar fraction of nonionic surfactants in the mixed adsorption layers at carbon black surface decreases in the series: ТХ-45 > ТХ-100 > ТХ-305. The regularities of the change in the surface activity of the surfactant mixtures at the solution-solid sorbent interface with an increase in the total surfactant concentration in the solution correlate with those for the solution-air system, but are more pronounced. The areas per hexadecylpyridinium bromide and the oxyethylated octylphenols molecules in the adsorption layer while adsorbing from their binary solutions are lesser than ones for the surfactants adsorption from their individual solutions, and smaller than the corresponding areas at the solution-air interface. These findings indicate the consolidation of the adsorption layer at the solid surface and confirm that the surfactants adsorb at carbon black surface as associates. [ABSTRACT FROM AUTHOR]

Copyright of Chemistry, Physics & Technology of Surface / Khimiya, Fizyka ta Tekhnologiya Poverhni is the property of National Academy of Sciences of Ukraine, Chuiko Institute of Surface Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Military Technical Courier / Vojnotehnicki Glasnik is the property of Military Technical Courier / Vojnotehnicki Glasnik and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It was presented the data on the thicknesses of the adsorbed polymer layer, which were obtained for copper phthalocyanine (CuPc) pigment dispersions under ultrasonic processing conditions. The thicker adsorption layers, which are observed in ultrasound systems, confirm the fact that the activation of the surface of the pigment occurs under the action of ultrasonic energy. The course and efficiency of adsorption of the polymer onto the pigment surface were quantified by electrokinetic measurements of the amplitude of sound (EIAZ). It became possible to obtain a more detailed picture of the pigment-polymer interactions and the adsorption mechanism of the copolymer based on the data on the dynamic mobility, obtained as a result of electrokinetic measurements of the amplitude of the sound. For aqueous dispersions of CuPc, stabilized with a copolymer of poly (acrylic acid) -poly (isobornyl acrylate) (PiBA-PAA), it was established the saturation concentrations of polymeric surfactant. Thus, the ultrasonic treatment allows to obtain stable, highly dispersed pigment suspensions with a modified pigment surface, which opens up new prospects for a more effective change in the surface of the pigment. [ABSTRACT FROM AUTHOR]

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bacgraund. The explosiveness of ammonium nitrate (AN) is more serious shortfall than its caking. In Russia, Cherepovets Nitrogen OJSC organized the production of complex nitrogen-phosphate fertilizer (NPF containing 32% N and 5% P2O5) by introducing into the NH4NO3 melt a liquid complex fertilizer of 11% N, 37% P2O5 from superphosphoric acid. In Uzbekistan, NAVOIYAZOT JSC introduced phosphatized AN (NPF - nitrogen-phosphate fertilizer with a content of 22-28% N, 2-6% P2O5), by adding phosphate flour (17-18% P2O5) to NH4NO3 melt. And the production of lime-ammonium nitrate (LAN) is established in European countries and in Russia, with the addition of limestone or chalk in the melt NH4NO3. Uzbekistan also has huge reserves of limestone and dolomite, which open up the possibility of creating an LAN production. In this regard, the development of scientific principles and technology for producing an explosion-safe AN with the addition of local carbonate minerals is an urgent task. Purpose. Studying the process of obtaining granulated LAN based on NH4NO3 melt and limestone from the Forish deposit (Jizzax region). Methodology. The introduction of crushed limestone in the melt NH4NO3 followed by granulation of nitrate-carbonate melts using the prilling method as well as determining the composition and properties of the finished products. Originality. It was revealed that the use of the CaCO3 additive in the NH4NO3 melt at a mass ratio of from 100: 5 to 100: 80, allows to increase the strength of the nitrate granules by 2.3-5.9 times and reduce the time of their dissolution by 2 times. Findings. For the granulation of nitrate-carbonate melt the prilling method is applied using a granulation tower. Studied the composition and properties of new types of fertilizers. It is shown that with the ratio NH4NO3: CaCO3 = 100: 25 the product contains 27.91% N, 11.06% CaO and has a granule strength of 4.55 MPa, which is much higher than the strength of pure NH4NO3 granules (1.32 MPa). Porosity and absorption of pure AN granules is 22.0% and 4.82 g. With an increase in the proportion of limestone to the NH4NO3: CaCO3 = 100: 25 ratio, the porosity and absorbency of the LAN granules is 8.15% and 3.22g, respectively. [ABSTRACT FROM AUTHOR]

The inhibition activities of 2-hydroxy-5-methylacetophenone thiosemicarbazone (1), (Z)-2-(((E)-1-(2-hydroxy-5-methylphenyl)ethylidene)hydrazono)thiazolidin-4-one (2), (E)-3-(2-hydroxy-5-((E)-phenyldiazenyl)phenyl)-1-phenylprop-2-en-1-one (3), (E)-1-(4-bromophenyl)-3-(2-hydroxy-5-((E)-phenyldiazenyl)phenyl)prop-2-en-1-one (4), (E)-5-(2-hydroxy-5-(phenyldiazenyl)phenyl)-3-phenyl-4,5-dihydro-1H-pyrazole-1-carbothioamide (5), (E)-3-(4-bromophenyl)-5-(2-hydroxy-5-(phenyldiazenyl)phenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide (6), 2,2'-((1E,1'E)-(ethane-1,2-diylbis(azanylylidene))bis(methanylylidene))bis(4-((E)-phenyldiazenyl)phenol (7) and 2-((Z)-2-hydroxy-5-((E)-phenyldiazenyl)benzylidene)hydrazine-1-carbothioamide (8) were explored by means of weight loss measurements for mild St-3 specimen in brine-kerosene solution. The corrosion rates of the St-3 drops as the inhibitor concentration increases together with increase of inhibition efficiencies. Thermodynamic parameters of adsorption on the St-3 surface at different concentrations were calculated. [ABSTRACT FROM AUTHOR]

Copyright of News of Kazakhstan Science / Novosti nauki Kazahstana is the property of NCSTE (JSC National Center for State Scientific and Technical Evaluations) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)