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The globally increasing contents of microplastics (MP) in ecosystems have become a serious environmental problem with far-reaching and at present unpredictable consequences for both aquatic life and human well-being. Until recently, most research on MP focused on marine ecosystems. Research on the occurrence of MP has lately started to focus on freshwater environments. This comprehensive and critical review examines the multifaceted problem of MP pollution in freshwater ecosystems, delving into its diverse sources, transport mechanisms, environmental impacts, detection methods, and mitigation strategies. The environmental impacts of MP pollution span a spectrum of impacts on aquatic life, food webs, and biodiversity in general. In addition, human health concerns have arisen due to potential exposures resulting from the consumption of contaminated freshwater and biological resources. The review summarizes analytical methods and technologies used to detect and quantify MP in freshwater samples, while recognizing the challenges and new innovations in this area. Mitigation and management strategies are explored, ranging from waste management and recycling initiatives to engineering solutions such as wastewater treatment and stormwater management. Legislative measures aimed at curbing MP pollution are also reviewed. Reviewed case studies highlight regional differences, and the unique challenges faced by different freshwater ecosystems. The review concludes by highlighting the urgent need for global awareness, further research, and coordinated action to address the growing problem of MP pollution in freshwater. As humanity faces this complex environmental challenge, interdisciplinary approaches, and international collaboration are essential for sustainable solutions and protection of freshwater ecosystems and health of the planet.

A wide range of propellants, and propulsion systems in space exploration by aircrafts or space vehicles was studied, developed, investigated, and commercialized. Liquid, solid, or hybrid propellants have been used for rocket’s launches. In this review, a consistent definition of space propulsion systems, including solid, liquid and hybrid has been given with up-to-date state of developments. A comparison of their performances was made by theoretical and experimental specific impulses. On the other hand, ammonium perchlorate and hydrazine were used as propellants for rocket’s launches and for satellite’s maneuverings; respectively. However, their high toxicity and their storage problem pushed researchers and scientists to investigate and develop other eco-friendly, propellant systems, so called “green propellants”, for launch or reaction control systems of satellites.

Drinking water samples from eight districts of Almaty, Kazakhstan was collected and physical and chemical analysis of the samples was carried out. Quality indicators of drinking water, such as organoleptic characteristics of water (smell, taste, color, and turbidity), general characteristics (pH, total hardness, permanganate demand, and dry residue), inorganic substances (cations and anions) and contaminants (heavy metals and total petroleum hydrocarbons) were determined, except pesticide residues which will be analyzed for further analysis with a wide range of pollutants. According to all indicators obtained for all districts of Almaty, the anthropogenic impact on drinking water in Almaty districts is assessed as low, not exceeding the permissible maximum allowable concentrations (MAC) values, and drinking water in Almaty corresponds to the approved standards and rules for drinking water of Kazakhstan. Despite of the fact that studied pollutants are below their MAC values, they still pose threat to public health due to their accumulative properties. The study of drinking water in the districts of Almaty made it possible to assess the ecological state in the studied districts of Almaty, as well as to propose recommendations for improving the quality of drinking water in areas where water quality indicators are closer to their MAC values.

Hydrogenated vegetable oils contain high contents of trans-fatty acids. Because of the increased health concern about trans-fatty acids, new hydrogenations have been studied to seek ways for substantial reduction of the trans-fatty acids in the hydrogenated products. In this research, activated diatomite has distinctive properties as a support for hydrogenation catalysts. Investigation of textural properties of raw and purified diatomite samples reveals that during acid activation surface area increases significantly. Although, acid activation of diatomite is a commonly chemical modification to enhance its adsorption capacity. We are preparing adsorption method to synthesize low percentage 0.2% of Pd/Diatomite catalyst. The activated diatomite and the obtained catalyst was characterized by using thermogravimetric analysis (TGA), Brunauer-Emmett-Teller surface area analysis (BET), scanning electron microscopy (SEM-EDAX), transmission electron microscopy (TEM). It was utilized for hydrogenation of sunflower oil using the Parr reactor in laboratory testing a variety of temperature (70, 90, 110 ºC) and canola oil in industrial testing, at temperature 90 ºC and 0.5 MPa pressure and compared to commercial nickel catalyst (Pricat-9910) at 150 ºC, 0.5 MPa pressure agitation of 800 rpm for 160 min. The changes in iodine value, fatty acid composition, trans-fatty acids, melting point and solid fat content were investigated on partial hydrogenated sunflower oil and canola oil. The experimentally obtained results show that the palladium catalyst is the most active compared to the commercial catalyst. Lower hydrogenation temperature used 0.2% Pd/Diatomite catalyst, significant reducing the formation of trans-content by 13% in fat.

Sulfur is a nonmetallic element necessary for life. Sulfur nanopartieles display unique physical and chemical feature because of effects such as the quantum size effect, mini size effect, surface effect and macro-quantum tunnel effect. So sulfur nanoparticles would present higher efficacies such as removal of heavy metals, radical-scavenging, antimicrobial activity, antioxidant and antitumor activities. It is used as a fungicide product in agriculture, also used in medicine, to obtain sulfur fertilizers and cosmetics industries, as well as in obtaining nanocomposite lithium batteries. In synthesis of sulfur nanowires with carbon to from hybrid materials with useful properties for gas sensor and catalytic applications. This work presents the results of obtaining the sulfur nanoparticles, which can be used in agriculture as a fungicide treatment. Sulfur nanoparticles were obtained by modifying the surface of sulfur by various surfactants including cetyltriammoniumbromide (CTABr), Sulfanol, Sodium Ligninsulfonate (CMN), Sodium salt of polynaphthalene sulphonic acid (NNO), water soluble polymer sodium carboxymethylcellulose (NaCMC), mineral mixtures and their compositions. The size and the structure of sulfur nanoparticles were determined by methods as LSA, XRD, SEM. Been studied the value of adsorption at the interface of solid/gas. It is shown that the nanoparticles have a sulfur monoclinic B-form, and their average size is in the range 500-1000 nm. The received products can be considered as perspective forms of application in agriculture.

Infant mortality in Kazakhstan is six times higher compared with the EU. There are several reasons for this, but a partial reason might be that less than 30% of Kazakhstan's population has access to safe water and sanitation and more than 57% uses polluted groundwater from wells that do not comply with international standards. For example, nitrate pollution in surface and groundwater continues to increase due to intensified agriculture and the discharge of untreated wastewater, causing concerns regarding environmental and human health. For this reason, drinking water samples were collected from the water supply distribution network in eight districts of Almaty, Kazakhstan, and water quality constituents, including nitrate, were analyzed. In several districts, the nitrate concentration was above the WHO and Kazakhstan's maximum permissible limits for drinking water. The spatial distribution of high nitrate concentration in drinking water was shown to be strongly correlated with areas that are supplied with groundwater, whereas areas with lower nitrate levels are supplied with surface water sources. Based on source identification, it was shown that groundwater is likely polluted by mainly domestic wastewater. The health risk for infants, children, teenagers, and adults was assessed based on chronic daily intake, and the hazard quotient (HQ) of nitrate intake from drinking water was determined. The non-carcinogenic risks increased in the following manner: adult < teenager < child < infant. For infants and children, the HQ was greater than the acceptable level and higher than that of other age groups, thus pointing to infants and children as the most vulnerable age group due to drinking water intake in the study area. Different water management options are suggested to improve the health situation of the population now drinking nitrate-polluted groundwater.

Context: The main challenge of large-scale biofuel production is related to the extraction of its undesired impurities including glycerol, water, methanol, soap/catalyst, free fatty acids, glycerides, and others. There are many ways to remove glycerol, and herein, the one alternative is the extraction of glycerol from biodiesel by deep eutectic solvents. In this regard, the mixture of a choline chloride (ChCl) and urea, methyltriphenylphosphonium chloride (MTPPCl), and ethylene glycol (EGL), as a deep eutectic solvent (DES), is effective in removing glycerol from biofuel., Methods: In this work, we have investigated the formation mechanism of ChCl and urea, and then MTPPCl and EGL, as a DES, and then extraction of glycerol from biofuel via DES implementing density functional theory (DFT) by Gaussian09 software, B3LYP basis set, and classical all-atom molecular dynamics (MD) simulations by Gromacs software, GROMOS force field. DFT approximation demonstrates that Cl ion plays an important binding role in the formation of complexes ChCl/urea-based DES + biofuel and in MTPPCl/EGL-based DES + biofuel. We have also considered the formation and change of hydrogen bonds upon the formation of these systems using the DFT method. Large HOMO-LUMO gaps in ChCl/urea-based DES + biofuel and in MTPPCl/urea-based DES + biofuel demonstrate the stability of the complexes. The results of MD work have stated that the chloride ion formed bonding with the choline/ethylene glycol EGL, while still weakly intermolecular interacting with the urea/methyltriphenylphosphonium in ChCl/urea- and MTPPCl/EGL-based DESs. Further results of MD simulations stated that the DESs had a higher intermolecular interaction with glycerol in comparison with biofuel, thereby favoring the extraction process of glycerol from model biofuel., Highlights: • Intermolecular interactions of choline chloride and urea, methyl triphenyl phosphonium chloride, and ethylene glycol-based DESs and their applications in the extraction of glycerol from biofuel studied by DFT calculations and classical all-atom molecular dynamics simulations. • Calculated outputs of DFT calculations and classical all-atom molecular dynamics simulations for DESs and their applications in the extraction of glycerol from biofuel were discussed in detail. • The molecular formation mechanism of choline and methyl triphenyl phosphonium-based DESs and their application in the extraction process of glycerol from biofuel were summarized., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The liquid waste is the major source of waste, which usually generated from academic laboratories and industry during the extraction, separation, chemical synthesis, and pretreatment processes. These chemical and engineering processes require more solvents. In this regard, there is a need to develop more environmentally friendly, cheaper, non-toxic solvents that are harmless to humans and the environment. In this regard, deep eutectic solvents (DES) and their derivatives so-called natural deep eutectic solvents (NADES) are a new field in the search for green alternative solvents. In our work, the formation of choline chloride-based NADESs using density functional theory (DFT) calculations, and classical all-atom molecular dynamics (MD) simulation was studied in detail using Gaussian09 and Gromacs software's. Next, the ground state geometry optimizations were performed in the gas phase using DFT B3LYP 6-31 + G(d) level of theory. Moreover, classical all-atom MD simulations were implemented using Gromos force field. After the modeling and simulations, the DFT calculation results revealed the formation of NADESs via formation (creation) of binding between chlorine and choline, and chlorine and glucose. At the same time, the results of classical all-atom MD simulations, based on the time average of the equilibrated production run of MD simulations, stated that the nitrogen atom of choline ion and chloride ion has greater interactions, while chloride ion has also greater interaction with glucose during formation of NADES. The outcomes of both DFT and classical all-atom MD simulations are in good agreements., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Hydrogel copolymers based on N , N -dimethyl acrylamide (DMA) and acrylic acid (AAc) were synthesized using a solution polymerization technique with different monomer ratios and ammonium persulfate as an initiator. This paper investigates the thermal stability, physical and chemical properties of the hydrogel copolymer. Testing includes Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and elemental analysis (CHNS). The copolymer composition was determined by elemental analysis, and the reactivity ratios of monomers were calculated through linearization methods such as Fineman-Ross (FR), inverted Fineman-Ross (IFR), Kelen-Tudos (KT) and Mayo-Lewis (ML). Good agreement was observed between the results of all four methods. The ratio of r 1 and r 2 were 0.38 (r 1 ) and 1.45 (r 2 ) (FR), 0.38 (r 1 ) and 1.46 (r 2 ) (IFR), 0.38 (r 1 ) and 1.43 (r 2 ) (KT), and 0.38 (r 1 ) and 1.45 (r 2 ) (ML). Hydrogel copolymers exhibited good thermal stability, and SEM showed three-dimensional porous structures. Antibiotic-free and antibiotic-loaded hydrogels demonstrated antimicrobial properties against both Gram-positive and Gram-negative bacteria. As the ratio of DMA in hydrogel copolymer increased, the activity of copolymer against bacteria enhanced. The results indicated that these hydrogels have the potential to be used as antibacterial materials.