Extraction of Zn (II) ions in an polypropylene glycol 425 - sodium chloride - water aqueous two-phase system

Liquid-liquid extraction is one of the most used separation methods in chemical technology for recovery and separation of metal ions, other inorganic and organic substances. It is known that for extraction of Zn(II) the most frequently used extractants are D2EHPA, Aliquat 336, etc., diluted in an organic solvent. The use of these reagents does not meet the principles of “green” chemistry. Thus, in the present work, the extraction system based on polypropylene glycol 425 and sodium chloride for the extraction of Zn(II) ions from aqueous solutions is proposed. Equilibrium values of the distribution coefficient in the proposed aqueous two-phase system have been determined. Dependence of metal distribution coefficient on time of phase contact is obtained, time to reach equilibrium was 10 minutes. The isotherm of Zn(II) extraction obtained in the proposed system is a straight line, which indicates the independence of the distribution coefficient from the initial concentration of metal in the solution. The received experimental data can be used at the creation of “green” schemes of processing of Ni-MH batteries.

QUALITATIVE CONTENT AND SOME PHYSICAL AND CHEMICAL PROPERTIES OF POLYSACCHARIDES FROM ONOPORDUM ACANTHIUM L. HERB

Natural polymers are interesting as independent pharmaceutical substances also as complex drugs including herbal drugs. The aim of this work was determination of the main features of water-soluble polysaccharides (WSPS) and pectinic substances (PS) isolated from Onopordum acanthium L. herb for using as pharmaceutical substances. The following tasks were set to achieve this aim: determination of qualitative content of monosaccharides after previous acidic hydrolysis of fractions by paper chromatography, determination of molecular weight, isoelectric point, distribution coefficient, superficial activity these fractions by physical and chemical methods. It was found that WSPS consist of xylose and rhamnose, PS – galacturonic acid. WSPS have molecular weighs 783.96 g/mol, PS – 17351.37 g/mol. Molecules WSPS are neutralize in buffer solution with pH 5.2 and PS – pH 4.7. Also WSPS and PS have similar distribution activity with distribution coefficient 2.97 and 2.59, respectively. But WSPS and PS are superficially inactive substances. Determinate features including well distribution activity may be used for development complex herbal drugs containing herb of Onopordum acanthium L. Also sorption activity should be detected in the future.

Optimisation of conditions for deacetylation of chitin-containing raw materials

The paper describes the differences between chitosan and chitin, and reviews works by foreign scientists on obtaining chitosan from various raw materials. Methods of modifying chitosan and obtaining combined sorbents have been analysed. It has been studied whether chitosan is applicable in the technology of wines and alcoholic beverages as a sorbent. The purpose of the study was determining the optimal conditions of the deacetylation stage to obtain chitosan with the best sorption properties from Aspergillus niger biomass. A three-factor experiment has been carried out. It involved obtaining 27 samples of chitosan using sequential four-step acid-base hydrolysis under various conditions of the deacetylation stage. The deacetylation process was optimised under alkaline conditions depending on the alkali concentration, processing temperature, and exposure. For each of the samples obtained, the adsorption activity, specific surface area, and distribution coefficient in the sorbent–sorbate system have been determined. The degrees of deacetylation of all chitosan samples have been determined by potentiometric titration. The study has resulted in determining the optimal conditions for the deacetylation stage: processing temperature 110–130°C, sodium hydroxide concentration 27–36 g/dm3, exposure 45 to 65 minutes. The sample deacetylated at the temperature 120 °C, alkali concentration 30 g/dm3, and exposure 45 minutes has shown the best adsorption activity values: the adsorption activity for methyl orange 347.96 mg/g, the specific surface area of the sorbent samples 0.52·105 m2/g, the distribution coefficient in the sorbent–sorbate system 3.29·10-3 ml/g. This sample had the highest degree of deacetylation, 43.6%. The sample has been analysed using IR spectroscopy, and its main characteristic frequencies have been studied. It has been concluded that the sample obtained was equivalent to the reference chitosan

Assessment of The Dioxins Leaching Potentials In Selected Soils Through Breakthrough Curves (BTCs) Model

The current study was to investigate the leaching and groundwater contamination potential of selected Dioxins, in local soil series. Solute transport was modelled through Breakthrough curve (BTC) plots, based on distribution coefficient (Kd), Retardation factor and Dispersivity, under normal velocity (20 cm day -1) and preferential or steady flow (50 cm day -1). In case of Dibenzo -p- Dioxin (DD), distribution coefficient values were found in order of Charsadda > Peshawar > Sultanpur series, while for 2 Chloro- p- Dioxin (2Cl-DD), the order was Charsadda > Sultanpur > Peshawar. However, the overall sorption was low. Under the normal velocity both of selected Dioxins (DD & 2Cl-DD), BTC plots relatively took longer time to reach the point of saturation as compared to high seepage velocity. However, the overall solute transport was found to be rapid. This behaviour showed that sorption of the Dioxins selected soil series is low and there is potential for leaching and groundwater contamination.

Research on Optimal Torque Control of Turning Energy Consumption for EVs with Motorized Wheels

This paper aims to explore torque optimization control issue in the turning of EV (Electric Vehicles) with motorized wheels for reducing energy consumption in this process. A three-degree-of-freedom (3-DOF) vehicle dynamics model is used to analyze the total longitudinal force of the vehicle and explain the influence of torque vectoring distribution (TVD) on turning resistance. The Genetic Algorithm-Particle Swarm Optimization Hybrid Algorithm (GA-PSO) is used to optimize the torque distribution coefficient offline. Then, a torque optimization control strategy for obtaining minimum turning energy consumption online and a torque distribution coefficient (TDC) table in different cornering conditions are proposed, with the consideration of vehicle stability and possible maximum energy-saving contribution. Furthermore, given the operation points of the in-wheel motors, a more accurate TDC table is developed, which includes motor efficiency in the optimization process. Various simulation results showed that the proposed torque optimization control strategy can reduce the energy consumption in cornering by about 4% for constant motor efficiency ideally and 19% when considering the motor efficiency changes in reality.

A Novel Algorithm for Profit Distribution of Sustainable Development Using E-Commerce Supply Chain

E-commerce supply chain actually deals with the acquisition of the raw materials, their timely processing, and on-time delivery to the right place. It deals with a number of processes such as supply and demand, managing order entry, and inventory tracking. Now profit distribution models are actually stochastic models that are used to optimize the gains and profits in a particular business. They actually generate modern time solutions to the existing problems in a sustainable environment. However, in order to solve the problems existing in the traditional profit distribution algorithm of the e-commerce supply chain, such as low distribution accuracy and large time cost, a profit distribution algorithm of the e-commerce supply chain under the concept of sustainable development was designed. It was supported by the concept of sustainable development, and the coefficient of income distribution is calculated according to the equilibrium bidding strategy of supply chain alliance and its members, net present value of income distribution, total investment, minimum expected rate of return on investment, and other parameters. First, calculate the Shapley value of the profit distribution of the power supply chain, and obtain the correction coefficient through the correction matrix, dimensionless processing, and analytic hierarchy process. Use the correction coefficient to correct the Shapley value and the income distribution coefficient to realize the design of the profit distribution algorithm for the power supply chain. The experimental results show that the algorithm has low relative error rate, high precision, and short time cost of profit distribution coefficient calculation.

Migration Law of Atrazine During Freezing of Water

To explore the migration law of atrazine during the freezing process, an indoor simulated freezing experiment was carried out. The distribution coefficient (K) was used to characterize the migration ability of atrazine and explore the effects of freezing thickness, freezing temperature, and initial concentration on the migration of atrazine between ice and water. The research results showed that the concentration relationship between the ice and water phases was: ice < water before freezing < water under the ice. This indicates that atrazine migrated to the water under the ice during the freezing process in our experiment. The K value decreased as the ice thickness, freezing temperature, and initial concentration increased; thus, the greater the ice thickness, the higher the freezing temperature, the greater the initial atrazine concentration, and the greater the ability of atrazine to migrate to the water under the ice. This study provides a reference for managing natural waterbodies in high-latitude and high-altitude environments during the freezing period.

Theoretical and Experimental Studies of Sulfur and Boron Distribution between the Slag of the CaO-SiO2-B2O3-MgO-Al2O3 System and the Metal

The equilibrium interfacial distribution of sulfur and boron was estimated using the HSC 6.1 Chemistry software package (Outokumpu) and the simplex-lattice planning method. Adequate mathematical models have been constructed in the form of III degree polynomial, which describe the effect of the composition of the studied oxide system on the equilibrium distribution of sulfur and boron between the slag and the metal. Generalization of the results of experimental studies and thermodynamic modeling made it possible to obtain new data on the influence of the basicity and content of B2O3 in the slag of the CaO-SiO2-B2O3-MgO-Al2O3 system on the interphase distribution of sulfur and boron. It was found that in the range of boron oxide concentration of 1.0-10%, an increase in slag basicity from 2 to 5 at 1600°C leads to an increase in the sulfur distribution coefficient from 1 to 20 and, as a consequence, a decrease in the sulfur content in the metal from 0.02 to 0.0014 %, i.e. an increase in slag basicity favorably affects the development of the metal desulfurization process. An increase in the B2O3 content from 2.0 to 10.0% in slags formed in the region of moderate basicity, not exceeding 2-3, is accompanied at 1600°C by a decrease in the boron interphase distribution coefficient from 450 to 150 and an increase in the boron concentration in the metal from 0.006 to 0.021 %, which indicates the progress of boron reduction from slag to metal. The shift of the formed slags to the area of ​​increased basicity up to 5.0 shows a high degree of boron reduction from slag to metal. The results of the laboratory experiment confirmed the results of thermodynamic modeling.