Key Engineering Materials Vol. 743

Abstract: In the present article, the experimental research of electrochemical cleaning of oil-contaminated soil is provided. The decrease of oil concentration in the soil from 1100 mg/kg down to 250 mg/kg at the current density in the range from 22 A/m² to 174 A/m² during 90 minutes is shown. It has been established that there is the limit amount of charge required for effective cleaning, which amounted to 0.96·10⁷ coulombs per kilogram of oil. The electrodes placement variant for the proposed method realization in real conditions is described. It is shown that at a voltage between the electrodes about 18 V and the cleaning efficiency of 77% the energy consumption will be 173 MJ/kg of oil.

Abstract: We propose to evaluate the level of eutrophication of surface water in the middle reaches of the river Belaya in the vicinity of the town of Sterlitamak using "eutrophication factor", as the main indicator used by the average length of seedling cress in undiluted samples. We selected a few water samples in eight gauges above, below and within the city. We consider the seasonal dynamics of the level of eutrophication of the variability in different years (2011-2016). Statistical analysis of the data revealed positive and negative dependence. Studies show high nutrient content in this water body. Thus, our proposed method can be used to determine the level of eutrophication of different water bodies.

Abstract: Water plays a crucial role in the growth and development of species on Earth. Changes in the physicochemical properties of water have a large effect on the human activities. Researchers have researched and evaluated effects of electric current frequency on the physicochemical properties of distilled water samples. The effect of electric fields on the physicochemical properties of water allows it to identify the optimal treatment regimes that promote the intensification of various processes taking place in an aqueous medium or in the presence of water.

Abstract: Red mud is a by-product of alumina industry which is currently almost completely stored in landfill sites without further use. It contains considerable amounts of valuable components such as iron, aluminum, titanium and rare-earth metals. The reduction smelting of red mud was carried out in laboratory scale to recover iron and obtain slag suitable for use in the construction industry. It has been shown that it is expedient to obtain pig iron and slag from the unprocessed red mud. Those two are suitable for the subsequent leaching of aluminum, titanium and rare-earth metals. It is practical to process dealkalized red mud, with composition adjustment by CaO and Al₂O₃ addition, in order to obtain pig iron and slag in the form of aluminous clinker.

Abstract: In order to maintain the volume of oil and gas supplies, the number of oil and gas wells increases every year, drilling platforms are built, which proportionally increases the amount of sludge and drilling waste mud, which must be recycled. The research gives light to the danger of introducing chemical substances into various natural environments from industrial and anthropogenic sources on an example of drill cuttings from oil fields of Tomsk region.

Abstract: This scientific paper deals with the waste recycling process of soda ash production which comprised processing the still waste liquid with obtaining calcium hydroxide, sodium hydroxide and hydrochloric acid. Still waste liquid was treated with sodium hydroxide to transform calcium as fully as possible into insoluble form of calcium hydroxide. After detachment of precipitate, the filtrate consisting mainly of sodium chloride was treated by a three-compartment membrane cell. Authors have examined the main regularities of still waste liquid recycling on the basis of the specified method. It has been shown that the process can be organized without the use of chemicals.

Abstract: By now there is no effective treatment for a number of socially significant bacterial and fungal diseases. β-(1→3)-glucans are the principal components of the cell wall of fungi, including Candida albicans, Aspergillus fumigatus and other. At the same time, β-(1→3)-glucans are absent in mammals and man, that makes them promising components of carbohydrate-protein conjugated vaccines for the prevention and treatment of fungal infections. Alginic acid, constructed of β-(1→ 4)-linked mannuronic acid are extracellular polysaccharides produced by Pseudomonas aeruginosa. The protein CRM197 is a non toxic derivative of diphtheria toxin, which is widely used as a safe carrier in conjugated vaccines. The purpose of this study was to investigate the antigenic activity of experimental samples of the conjugated vaccines based on synthetic oligosaccharide ligands and CRM197 carrier protein in the competitive enzyme-linked immunosorbent assay. Two-time immunization Balb/c mice with experimental samples of the conjugated vaccines induced the formation of high titers of specific antibodies. High antibody’s avidity to their oligosaccharide ligands was shown in competitive ELISA. These data suggest the relevance of further preclinical trials of the conjugated antifungal vaccine against Candida and Aspergillus and antibacterial vaccine against Pseudomonas.

Abstract: [bnmim]HSO₄ and [bnpy]HSO₄ are active and environmentally friendly catalysts for the acetylation of camphene with acetic acid. The reaction provides isobornyl acetate with 100% selectivity and 72-86% yield. The effect of temperature, molar ratio camphene/acetic acid, and catalyst loading were investigated. The catalyst can be reused four times without loss of activity. Isobornyl acetate is an important fine chemical and has been used in the field of fragrance, medicine, organic synthesis and cosmetics [1]. It is an intermediary in the synthesis of camphor [2]. Usually it is prepared by an acid-catalized reaction of camphene with acetic acid or acetic anhydride. But this process has serious drawbacks such as the corrosion of equipment, non-recyclability of the catalyst and serious environmental pollution. In the face of increasing environmental requirements, the use of such catalysts becomes unacceptable. Therefore many studies have recently focused on the development of "clean" (green) processes for the production of terpene derivatives with high selectivity. For this purpose, heteropolyacids [3, 4], zeolites [5, 6], solid acid catalysts [7, 8], ion-exchange resin [9-11] were used as catalysts for synthesizing terpene esters. However, these catalysts have drawbacks such as a large ratio of catalyst/substrate, fast deactivation and a selectivity that leaves much to be desired. In the recent years ionic liquids (IL) have been investigated by many researchers as catalysts for different reactions. Due to its low volatility, negligible vapor pressure, reasonable thermal stability, outstanding recyclability and reusability, ionic liquids may be a viable alternative to widely applicable catalysts in the processes of modern synthetic chemistry, the green chemistry [12]. The improvement of the versatility of ionic liquids was achieved by creating acidic functionalized ionic liquids and combining the properties of a reagent and solvent [13]. A number of such ionic liquids were synthesized and successfully applied in the esterification reaction [14-17]. Received that the structure of the IL cation determines the direction of the rearrangement of terpene, whereas the nature of the anion affects the selectivity of the reaction [18, 19]. In the present work, we report the acetylation of camphene with acetic acid catalyzed by imidazolium and pyridinium ionic liquids (Scheme 1). The influence of various reaction parameters, such as the temperature, the molar ratio of camphene/acetic acid and catalyst loading, on the activity of the most active catalyst is also studied.

Abstract: This work reviews the issues of modeling of the operating modes for a blast furnace and identification of areas of unimprovable solutions on a set of indicators of cast iron output, coke consumption, and thermal state. These areas define the boundaries of potential opportunities for achieving high values of quality of the blast-furnace processes on a set of real-life operating modes of a blast furnace. They also indicate the reserves of coke consumption reduction and output enhancement, which might be implemented by optimal choice of a blast furnace operating mode and which enable the reasonable choice of the operating mode of a blast furnace based on the potential opportunities for increasing the output, minimizing coke consumption for the specified coke quality and the specified requirements to the furnace thermal state.

Abstract: Numerical modelling of the molten metal flow in a crucible under the action of stirred disk agitator is carried out. The influence of the agitator rotational speed on the molten metal flow field is investigated. Dependences of the turbulent diffusivity and the power number on the agitator rotational speed are obtained. The effect of the interaction between the molten metal-air interface and agitator elements on the flow field in a crucible is shown.