This study investigates the removal of arsenic from leaching solutions obtained during the processing of Dashkesan cobalt ore using the electrocoagulation method. Electrocoagulation (EC) is a promising technology for the effective removal of arsenic from industrial wastewater. The influence of various process parameters (initial concentration of AsO43⁻ ions, initial and latest pH of the solution, electrolysis time, current density, amount of supporting electrolyte (NaCl), presence of other ions etc.) on the efficiency of arsenate ion removal were studied. During electrocoagulation, hydrolysis of iron ions passing the solution results in the formation of an amorphous precipitate – Fe(OH)3 coagulant. Experiments were conducted at different current and voltage values, pH levels, and time intervals. In the initial stages (U = 5.4 V, I = 0.125 A), the Fe(OH)2 and Fe(OH)3 precipitates were formed after the dissolution and hydrolysis of iron at the anode zone, which were adsorbed AsO4³⁻ ions. The optimal operating time was 20 minutes, with a current density of 10 mA/cm2 and pH = 7–8. As a result of electrocoagulation, the concentration of arsenic in the solution decreased from 0.05 g/l to 0.01 mg/l. In addition, Response Surface Methodology (RSM) was applied to statistically model and optimize the electrocoagulation process. A quadratic model was developed to describe the effects of key parameters (initial arsenic concentration, electrolysis time, and pH) and their interactions on arsenic removal efficiency. Analysis of variance (ANOVA) confirmed the significance of the model (F = 4.42, p = 0.029), with initial arsenic concentration identified as the most influential factor (p = 0.001). The RSM-based optimization predicted maximum arsenic removal efficiency of 96–99.5%, which was in excellent agreement with experimental results, confirming the adequacy of the model for process optimization and scale-up.
A complex combination of Mn(II) acetate with 3-amino-1,2,4-triazole with polymer structure [C3.556H6.222Mn0.444N3.556O1.778] was synthesized. The composition and structure of the synthesized complex were determined using modern physicochemical methods (IR spectroscopy, elemental analysis, thermal analysis, X-ray diffraction analysis, and Hirschfeld surface analysis). Based on derivative analysis, the causes of endo- and exo-effects were determined, and the thermal products were identified. X-ray diffraction analysis showed that in the formation reactions of the 3-amino-1,2,4-triazole complex, the central atom of the triazole forms a polymer structure through monodentate coordination through nitrogen atoms. ring, and the oxygen atom of the acidic ligand with manganese. According to Hirshfeld surface analysis, the most important effects on the crystal structure correspond to the pair of atoms H•••H (51.8%) and H•••O/O•••H (20.6%). interaction between the hydrogens of the methylene and benzene rings
Considering the growing interest in environmentally friendly and economically advantageous materials, this study focuses on developing activated carbons from waste wheat straw and husk and modifying them with transition metal ions, such as Ni2+, Co2+, and Co3+, to enhance their electrochemical properties. Using agricultural waste simultaneously addresses biomass utilisation challenges and produces valuable low-cost functional materials. A comprehensive physicochemical characterisation of the modified activated carbon (AC) was carried out. This included elemental (CHNS), ash, and oxygen content analysis, as well as spectral (FTIR, Raman) and structural (XRD) analysis of ACs, confirming the successful modification and morphological change. Carbon-paste electrodes exhibited high sensitivity and stable responses in electroanalytical assessments, including redox and acid-base potentiometric titrations. These findings suggest that the material holds significant promise as a cost-effective and efficient sensor for analysing aquatic environments and environmental monitoring. The study underscores the potential of utilising secondary biological resources to fabricate functional carbon materials, aligning with principles of sustainable development and the circular economy
Essential oils (EOs) contain natural antioxidants that play a critical role in food preservation by preventing premature spoilage, rancidity, and decay. While data on EO antioxidants is plentiful, there remains a lack of precise methods for evaluating their efficacy. Kinetic analysis, in particular, offers deeper insight into activity constants and reaction mechanisms. This study utilizes the liquid-phase aerobic oxidation of cumene, initiated by benzoyl peroxide (BPO) at 343K, to determine the effective inhibition constants of antioxidants in commercial lemon essential oil (LEO) produced from fruits of Azerbaijan’s Lankaran zone and cold-pressed black seed oil (BSO). Prior to antioxidant analysis, PBO decomposition rate constant (kd) and created rate of initiation [Wi(0)] has been accurately determined at 343K to be 7.5• 10-6 (s-1) and 4•10-8 (Ms-1), respectively. Oxygen uptake was monitored via a gasometric setup. Results indicate that LEO significantly flattens the oxygen consumption curves, reducing the oxidation rate and introducing an induction period. The effective rate constant for LEO hydrogen donors was identified as k7(eff.) = (6.0 ±2.0) M−1s−1, likely due to oxygenated terpenes. However, the overall antioxidant capacity is primarily driven by alkyl radical (R•) scavengers. The total antioxidative activity (A) for LEO and BSO was measured to be 66.5% and 69.1%, respectively, aligning with existing literature
The present work comprises a detailed ecological study on Cynanchum acutum L. growing in two different. Phytogeographical regions, including vegetation analysis of ten stands representing Cynanchum community type at each of the Deltaic Coast and the Isthmic Desert. Synthetic caracters of Cynanchun community was studied in details twenty six associate species belong to 13 families were recarded Cynanchum community type of Deltaic Coast. Atriplex semibaccata, phragmites australis, Pancratium maritimum and Halocnemum strobilaceum were common perennial associates while Mesembryanthemum crystallinum, Richardia tingitana and Senecio glaucus were the common annuals. The floristic components of this community differentiated into 15 perennials 12 annuals. Seven life-forms were recognized and Therophytes, Helophytes, Cryptophytes and Geophytes were the main types. The plant assemblage belongs to 7 chorotypes: Mediterranean, Irano-Turanian, Saharo-Arabian, Euro-Siberian and Pantropical. Phyochemically, the proximate constituents and nutitive values of the two ecotypes of C. acutum of Deltaic Coast and Isthmic Desert as well as the secondary metabolic products including protein amino acids, fatty acids, antioxidant compounds (phenols, flavonoids, anthocyanins and ascorbic acid) and their activities, total carbohydrates, tannins, alkaloids, saponins were quantifid and mineral nutrients were in shoots of the two Cynanchum ecotypes in Deltaic Coast and Isthmic Desert regions. This perennials herbaceous twiner plant prevailing soil laomy textured, non-saline, fertile and slightly alkaline. Nutritive value C. acutum ecotype of Deltaic Coast higher (505.95 kcal/100g) than the Isthmic Desert ecotype (470.18 kcal/100g dry wt.). Seventeen amino acids were detected in aerial parts of the two ecotypes. Also, both the two plant of two habitats showed antioxidant activities
The increasing power and harsh operating conditions of modern gasoline and diesel engines place increasing demands on the quality of modern motor oils. To ensure long-term and reliable operation of vehicles, the purchase and production of high-quality oils is increasing. Modern equipment cannot function without high-quality engine oils. Improving the quality of engine oils with effective additives is one of the most modern and promising methods. Scientific and technical progress in engine production is closely related to the development of high-quality lubricants that meet the requirements of modern and advanced technology. Only base oils with additives with different functional properties can have a wide range of performance characteristics, since base oils, regardless of their production and refining methods, do not meet all requirements. The most commonly used additives are alkylphenolate additives. Alkylphenolate additives have multifunctional properties and are one of the main components of motor oils. Therefore, the synthesis of high-quality alkylphenolate additives, the organization of their production and the creation of high-quality motor oils are among the most pressing problems of the petrochemical industry. In this regard, a new calcium salt of the condensation product of dodecylphenol, formaldehyde and sodium disulfide - AKI-55 additive was obtained. The structure of the additive was confirmed by IR spectroscopy and its physicochemical and functional properties were studied using standard methods. Compared to the production of industrially produced sulfur-containing alkylphenolates TsIATIM-339, VNIINP-714 and OLOA-218A, the method of obtaining the AKI-55 additive is simple and environmentally friendly. It has been shown that the functional properties of the AKI-55 additive are superior to its analogues and as an inhibitor it stops the oxidation chain of cumene
The study of the co-deposition of cadmium with elemental sulfur demonstrated that the quality, composition, and properties of the deposited films are significantly influenced by factors such as the concentration of the primary components, current density, electrolyte temperature, and agitation. These factors, to varying degrees, affect the composition of the deposited films. To investigate the influence of various factors on the composition of the deposited films, they were obtained under galvanostatic conditions in a two-electrode cell, where a nickel plate was used as the cathode and platinum served as the anode. In this work, we present a study on the effects of current density, the concentration of the main alloy components, temperature, and agitation on the composition of CdS thin films. It has been established that an increase in the concentration of one of the main alloy components leads to an increase in its content within the alloy. An increase in current density during the co-deposition process leads to a higher cadmium content and a lower sulfur content in the deposits. When the current density is doubled-from 10 mA/cm² to 20 mA/cm²-the sulfur content in the deposit decreases by 11.3%. Elevating the electrolyte temperature leads to an increase in the sulfur content of the films. The study of the effect of agitation on the co-deposition process of cadmium with sulfur showed that, under identical electrodeposition conditions, agitation increases the sulfur content by an average of 4%.
Based on the results of complex methods of physicochemical analysis: differential thermal analysis (DTA), X-ray diffraction (XRD), microstructural analysis (MSA), as well as microhardness and density, the chemical interaction in the GaSe-SrSe system was studied and its Tx phase diagram was constructed. It has been established that the phase diagram of the system is of a quasi-binary eutectic type and is characterized by the formation of the SrGaSe2 compound. The SrGaSe2 compound is formed at a temperature of 1010°C as a result of the peritectic reaction M+SrSe↔ SrGaSe2. Co-crystallization of SrSe and SrGaSe2 compounds crystallizes at the double eutectic point, composition 15 mol % SrSe, temperature 920°C. In the GaSe-SrSe system at room temperature, 4.5 mol % SrSe based on GaSe, while the solubility based on SrSe compound is 2.5 mol % GaSe. X-ray diffraction analysis of samples containing 4.5; 25, 50 and 80 mol. % SrSe and compared with the diffraction maxima of the main components. As a result, it was found that the diffraction lines in the diffraction pattern of the 4.5 mol % SrSe are similar to the diffraction lines of the GaSe compound; they differ slightly only in the interplanar distances. Based on the results of X-ray diffraction analysis, it was established that the SrGaSe2 compound crystallizes in a tetragonal syngony with lattice parameters: a = 6.85; c=10.01 Å. The dependence of electrical conductivity and thermionic conductivity of solid solutions of (GaSe)1-х(SrSe)х (x=0.02; 0.04) alloys on composition and temperature was studied
