P-cresol, indole and indole-3-acetic acid (IAA) are catabolites of amino acids, formed by the gut microbiome. Most of these aromatic hydrocarbon derivatives are excreted by the colon before reentering the body to form "exogenous" protein-bound uremic toxins (PBUTs), which aggravate chronic kidney disease (CKD). Removal efficiencies of these PBUT precursors from model phosphate-buffered saline solutions by three different surface-modified nanoporous carbon adsorbents (PCs) were studied. PCs were produced by physicochemical and/or acid base activation of carbonized rice husk waste. Removal rates achieved values of 32-96% within a 3 h contact time. High micro/mesoporosity and surface chemistry of the N- and P-doped biochars were established by N2 adsorption studies, SEM/EDS analysis, XPS and FT-IR-spectroscopy. The ammoxidized PC-N1 had the highest adsorption capacity (1.97 mmol/g for IAA, 2.43 mmol/g for p-cresol and 2.42 mmol/g for indole), followed by "urea-nitrified" PC-N2, whilst the phosphorylated PC-P demonstrated the lowest adsorption capacity for these solutes. These results do not correlate with the total pore volume values for PC-N2 (0.91 cm3/g) < PC-P (1.56 cm3/g) < PC-N1 (1.84 cm3/g), suggesting that other parameters such as the micropore volume (PC-N1 > PC-N2 > PC-P) and the interaction of surface chemical functional groups with the solutes play key roles in the adsorption mechanism. N-doped PC-N1 and PC-N2 have basic functional groups with higher affinity with acidic IAA and p-cresol. The ion-exchange mechanism of phenolic and indolic compound chemisorption by nanoporous carbon adsorbents, modified with surface N- and P-containing functional groups, has been proposed.

This study evaluates the effectiveness of natural zeolite (Shankhanai deposit, Kazakhstan) as a functional hydroponic substrate compared to a commercial foamed-glass control (GrowPlant). Using the Nutrient Film Technique (NFT), we assessed the growth and metabolic responses of Medicago sativa L. and three cultivars of Lactuca sativa L. Brunauer-Emmett-Teller (BET) analysis confirmed that zeolite (particle size 3.70 ± 1.20 mm) possesses a high specific surface area (21.80 m2/g), significantly exceeding the control (0.49 m2/g). This structure ensured superior moisture retention and cation exchange, even after a moderate decrease in surface area to 16.66 m2/g post-cultivation due to organic pore-filling. In M. sativa experiments, zeolite increased seedling viability and promoted a more branched root system compared to the artificial substrate. Gas chromatography-mass spectrometry (GC-MS) metabolic profiling of L. sativa revealed a significant substrate-driven reprogramming: zeolite increased the relative proportion of fatty acids and their derivatives (up to +51.27% in May King variety roots), suggesting membrane-protective adaptation. Genotype-specific responses were observed, with the Yeralash cultivar showing increased polyol synthesis (+2.93%) for osmoregulation. The results demonstrate that natural zeolite is an efficient, stable substrate for intensive hydroponics, optimizing root development and physiological stability through enhanced nutrient and water management.

Against the backdrop of growing environmental and industrial risks, particularly those associated with toxic CO emissions, the development of highly sensitive gas sensors capable of operating stably at room temperature is of strategic importance. This work investigates composite materials based on polyaniline (PANi) and graphene oxide (GO) as promising sensing elements for carbon monoxide (CO) detection. It was found that pristine PANi exhibits limited gas sensitivity, yielding a response of only 9.7% upon CO exposure. The introduction of GO into the polymer matrix facilitates the formation of conductive pathways, increases the number of active adsorption sites, and accelerates charge transfer processes, resulting in a pronounced synergistic effect. Consequently, the PANi/GO composite achieves a response of 31.5%, which is nearly three times higher than that of pure PANi. A detailed comparative analysis indicates that the carbon nanostructures play a dual role: they enhance the conductivity of the system and activate surface gas-material interactions. Thus, the formation of hierarchical composites based on PANi and GO represents an effective strategy for enhancing the sensitivity and improving the dynamic characteristics of room-temperature CO sensors. The obtained results confirm the high potential of PANi/GO composites for applications in environmental monitoring systems, industrial safety, and next-generation intelligent sensor platforms.

Carbon-based nanomaterials have emerged as a promising strategy for bitumen modification to enhance the mechanical and thermal performance of pavements. This review evaluates the present advancements in the inclusion of coke and carbon nanomaterials (CNMs) such as carbon nanotubes (CNTs) and graphene into bituminous systems. The findings and limitations of recent experiments in synthesis procedures along with dispersion methods are deeply explored to determine their impact on the rheological properties of bitumen as well as aging resistance and durability characteristics. Petroleum coke enhances bitumen softening points by 10–15 °C and causes up to 30% improvement in rutting resistance while simultaneously prolonging material fatigue life and aging resistance. Bitumen modification through petroleum coke faces challenges in addition to mixing difficulties due to its high viscosity. Moreover, the incorporation of CNTs and graphene as CNMs shows significant enhancements in rutting resistance with improved tensile strength, lower additive requirements, and enhanced dispersion. Both the superior mechanical properties of carbon nanomaterials and processing advancements in nano-enhanced bitumen have the capability to solve technical issues including material costs and specialized mixing processes. Combining coke with CNMs to enhance performance is a future research direction, which could result in economic and scalability considerations. This review comprehensively explores insights into physicochemical interactions, performance outcomes, and processing techniques, crucial for the development of sustainable, high-performance bitumen composites tailored for next-generation infrastructure applications.

This study aims to evaluate whether N-doping of activated carbons (ACs) can improve CO2 separation in a real-world post-combustion scenario. A high-surface-area, N-free AC was synthesized and subsequently N-doped by blending it with urea and subjecting it to heat treatment at 623 K in air. The potential of this N-doped AC for environmental gas separation was assessed, focusing on its CO2 capture performance in the presence of increasing relative humidity (RH) levels. High-pressure adsorption isotherms for CO2 and N2 were obtained and fitted, using the Dual-Site Langmuir model to calculate selectivity. The results indicate that the N-doping post-treatment with urea reduces the AC textural properties, particularly affecting larger micropores and mesopores. Despite this, N-doping enhances CO2 selectivity, and dynamic breakthrough simulations for CO2/N2 separation suggest that N-doped AC can perform better than undoped samples under dry conditions due to their increased tap density. However, N-doping also increases water affinity, which may be undesirable for applications involving undried flue gas streams. The pristine AC exhibited a nearly stable CO2 adsorption capacity up to 40% relative humidity (RH), whereas the CO2 capacity of the N-doped AC progressively decreased from 10% RH.

Thorium occupies a unique position in the global energy agenda, being simultaneously considered a promising nuclear fuel and an ecological risk factor. Its fuel cycle (Th-232 → U-233) offers significant advantages over uranium, including reduced waste, improved resistance to burnup, and lower proliferation risks, while molten salt reactor designs demonstrate potential to reduce electricity costs and consume transuranic elements from spent nuclear fuel. At the same time, the geochemical mobility of Th4+ ions, prone to forming soluble and colloidal species, increases the likelihood of their migration into soils and waters, with subsequent accumulation in biota and induction of radiotoxic effects. This study applied a comprehensive review of thorium’s energy potential and environmental risks, analyzing advances in reactor technology alongside mitigation methods such as coagulation, membrane separation, ion exchange, and adsorption with natural and modified sorbents. The findings emphasize that thorium’s strategic role in sustainable nuclear power is inseparable from the development of reliable safeguards to protect ecosystems. We conclude that a dual approach—integrating innovative reactor engineering with effective environmental countermeasures—will be essential for safe deployment of thorium technologies, ensuring their contribution to clean energy generation while minimizing ecological impacts.

After undergoing biological treatment, wastewater still contains substances with endotoxic activity, such as lipopolysaccharide. However, due to the increasing practice of treating wastewater to make it suitable for drinking (potable reuse), the removal of these endotoxic active materials is crucial. These substances can be harmful to human health, leading to a condition called endotoxaemia. Furthermore, environmental endotoxins pose risks to pharmaceutical manufacturing processes and the quality of the final pharmaceutical products. Ultimately, the most significant concern lies with the patient, as exposure to such substances can have adverse effects on their health and well-being. Activated carbon has a proven efficiency for endotoxin removal; rice husk (RH), as a type of natural lignocellulosic agricultural waste, is a unique carbon precursor material in terms of its availability, large-scale world production (over 140 million tons annually), and is characterized by the presence of nanoscale silica phytoliths, which serve as a template to create additional meso/macropore space within the nanoscale range. High surface area RH/lignin-derived honeycomb monoliths were prepared in this study via extrusion, followed by carbonization and physical and chemical activation to develop additional pore space. The nanoporosity of the carbon honeycomb monoliths was established by means of low-temperature nitrogen adsorption studies, using calculations based on QSDFT equilibrium and BJH models, as well as mercury intrusion porosimetry (MIP) and SEM investigations. An alternative method for the elimination of the bacterial lipopolysaccharide (LPS)—a conventional marker—using filtration in flowing recirculation systems and the adsorbent activity of the monoliths towards LPS was investigated. Since LPS expresses strong toxic effects even at very low concentrations, e.g., below 10 EU/mL, its removal even in minute amounts is essential. It was found that monoliths are able to eliminate biologically relevant LPS levels, e.g., adsorption removal within 5, 30, 60, 90, and 120 min of circulation reached the values of 49.8, 74.1, 85.4, 91.3%, and 91.6%, respectively.

Natural clinoptilolite from the Shankhanai deposit (Kazakhstan) was modified via acid and thermal treatments to improve its physicochemical and catalytic properties. The zeolite was activated using 10% nitric acid alone, nitric acid followed by thermal treatment (600 degrees C), and a mixed acid solution (10% HNO3 + 5% CH3COOH) followed by mild thermal treatment (280 degrees C). Structural, textural, and thermal changes were characterized by XRD, FTIR, BET, TGA, SEM, and EDX. Nitric acid treatment increased the BET surface area from 4.95 to 59.9 m2/g but reduced crystallinity, whereas the dual-acid approach enhanced porosity and acidity while preserving framework integrity. Preliminary catalytic testing in thiophene hydrodesulfurization (HDS) revealed improved conversion (up to 20.7%) in the absence of active metals, confirming the potential of modified clinoptilolite as a catalyst support. The dual-acid method presents a promising, eco-friendly pathway for producing thermally stable and catalytically active zeolitic materials, suitable for selective hydrodesulfurization of thiophene.

Thorium has emerged as a promising alternative to uranium in nuclear energy systems due to its higher natural abundance, favorable conversion to fissile 233U, and reduced generation of long-lived transuranic waste. This review provides a comprehensive overview of advanced techniques for thorium recovery from primary ores and secondary resources. The main mineralogical carriers—including monazite, thorianite, thorite, and cheralite as well as industrial by-products such as rare-earth processing tailings—are critically examined with respect to their occurrence and processing potential. Physical enrichment methods (gravity, magnetic, and electrostatic separation) and hydrometallurgical approaches (acidic and alkaline leaching) are analyzed in detail, highlighting their efficiencies, limitations, and environmental implications. Particular emphasis is placed on modern separation strategies such as solvent extraction with organophosphorus reagents, diglycolamides, and ionic liquids, as well as extraction chromatography, nanocomposite sorbents, ion-imprinted polymers, and electrosorption on carbon-based electrodes. These techniques demonstrate significant progress in enhancing selectivity, reducing reagent consumption, and enabling recovery from low-grade and secondary feedstocks. Environmental and radiological aspects, including waste minimization, immobilization, and regulatory frameworks, are discussed as integral components of sustainable thorium management. Finally, perspectives on hybrid technologies, digital process optimization, and economic feasibility are outlined, underscoring the need for interdisciplinary approaches that combine chemistry, materials science, and environmental engineering. Collectively, the analysis highlights the transition from conventional practices to integrated, scalable, and environmentally responsible technologies for thorium recovery.

The thermal decomposition of ammonium perchlorate (AP) proceeds via a well-established stepwise mechanism. However, its catalytic decomposition under combustion conditions is not yet fully understood. This study investigates and clarifies the catalytic decomposition pathway of AP in the presence of Ti3C2Tx, a novel two-dimensional (2D) material with unique structural properties. MXene was chosen for its exceptional conductivity, large surface area, and layered architecture, which provide active sites for redox interactions and enhance the thermal decomposition rate of AP. During combustion of AP-based solid rocket propellants, MXene acts as a catalyst, promoting more complete and rapid oxidation reactions. The combustion products were thoroughly analyzed using X-ray phase analysis, and based on the obtained data, stoichiometric equations for the potential reaction pathways were proposed. These equations highlight the formation of metal oxides and intermediate chlorinated compounds. Furthermore, a schematic model illustrating the catalytic action of Ti3C2Tx was developed, showing the interaction between AP molecules and MXene's surface functional groups. These findings advance understanding of nanocatalyst behavior in energetic materials and offer insights for improving solid-propellant performance via MXene incorporation.

This study presents a comparative analysis of two synthesis approaches for fabricating magnetic sorbents based on activated carbon (AC) incorporated with magnetite (Fe3O4) nanoparticles: hydrothermal synthesis and ultrasonic treatment. The results demonstrate that ultrasonic-assisted synthesis yields a magnetically responsive composite, us-AC/Fe3O4, exhibiting a Pb2+ removal efficiency of 92.84%, which is comparable to that of pristine activated carbon (99.0%). A key advantage of the synthesized composite lies in its facile recovery via magnetic separation following adsorption, rendering it a promising candidate for the remediation of heavy metal-contaminated water. Kinetic modeling suggests a dual adsorption mechanism: initial stages are governed by physisorption, while chemisorption dominates in the later phases. Adsorption isotherm modeling demonstrated that the Langmuir model provided the best description of Pb2+ adsorption on AC and us-AC/Fe3O4, with the highest sorption capacities observed for pristine activated carbon, followed by the ultrasonically modified composite, and comparatively lower values for the hydrothermally treated material. These findings underscore the potential of ultrasonic processing as an effective route for developing magnetically separable sorbents with high performance in aqueous heavy metal removal.

Some drawbacks of aqueous electrolytes, such as freezing at low temperatures and extensive evaporation at high temperatures, restrict their industrial viability. This article introduces a stabilized neutral aqueous choline nitrate electrolyte with a 10 vol.% methanol additive that improves the temperature stability of the electrolyte via enhanced hydrogen bonding with the choline cation and water and maintains the good state of health of the supercapacitor cells under extreme operating conditions. The symmetric carbon/carbon supercapacitor in 5 mol/kg choline nitrate + 10 vol.% methanol (σ = 76 ms/cm at 25°C) exhibits 103 F/g at room temperature during galvanostatic charge/discharge up to 1.5 V, which decreases to 78 F/g at −40°C due to the suppressed Faradaic reactions occurring at the carbon electrode. However, under similar charge/discharge conditions, the capacitance increases to 112 F/g when the supercapacitor operates at 60°C. This capacitance increase at high temperatures is due to the Faradaic reactions related to enhanced hydrogen adsorption and desorption. The most remarkable aspect of the proposed supercapacitor is its ability to maintain capacitance and power performance during high voltage floating at 1.5 V at three tested temperatures (−40°C, 24°C, and 60°C).

The culture of Pseudomonas mendocina H-3 was selected as the microorganism for oil destruction, and its effect on oil-contaminated soil from the Zhanazhol deposit in West Kazakhstan was studied. After conducting model laboratory experiments, field experiments were carried out. Six and twelve months after the treatment of the oil-contaminated field with microorganisms, the amount of oil fractions in the soil decreased noticeably, while the content of asphaltenes remained constant. Analyses show that the composition of the oil fraction changes—the concentration of paraffin-naphthenic—polycycloaromatic components decreases, whereas the relative amount of mono- and bicycloaromatic hydrocarbons increases. The results of the efficiency assessment showed that the use of Pseudomonas mendocina H-3 cell suspension in natural conditions leads to a decrease in the content of hydrocarbons in the soil from 55 to 70%. The lower efficiency of bioremediation with cell cultures in field experiments (on average, 61%) compared with laboratory model studies (reduction of oil content to 79%) is apparently associated with climatic conditions.

Water and soil resources are one of the most important natural resources of a country, from which all the food needs of humans and animals are provided, but unfortunately, they are constantly exposed to encroachment and changes by human and non-human factors. Biochar is one of the solutions recently considered in international scientific forums for soil and water protection. In this study, carbon adsorbents' performance has been investigated to remove heavy metal pollutants. Carbon adsorbents, unlike resins that only deal with ion exchange, work in different environments, including in the presence of carboxyl, imidazole, sulfhydryl, amine, sulfate, phosphate, thioether, phenol, carbonyl, amide, and hydroxyl bases. In this study, the absorption rate of heavy trace elements with carbon adsorption and their efficiency has been investigated, and the results of pH and optimal concentration for carbon adsorption have been presented. A study has been done on the carbon absorbents used to separate heavy metals. Bio-carbon adsorbents are a cheaper and more effective alternative to separate metals and metal elements, especially in the separation of heavy metals in soil treatment. In this study, the amount of absorption in bio-absorbents, according to the cell structure and their types, has been investigated. The results show that the subsequent adsorption of bio-carbon adsorbent can be a suitable method for purifying soil from heavy metal ions.

Choline bromide (ChBr) has been less explored as an electrolyte material. This work demonstrates the promising potential of ChBr as a novel aqueous electrolyte for hybrid supercapacitors. At its optimized concentration of 3.5 M, ChBr solution exhibits a maximum conductivity of 79.56 mS cm−1 at room temperature, along with a viscosity of 3.15 mPas and a density of 1.14 g cm−3. A reduction in water activity of the optimized ChBr electrolyte concentration extends the electrochemical stability window (ESW), enabling operation up to 1.9 V for two-electrode cells. When the current densities increase from 0.5 to 5 A g−1, the hybrid supercapacitor based on ChBr electrolyte with the optimized mass ratio of electrodes composed of commercial microporous carbon (Maxsorb) demonstrates impressive specific energy and capacitance retention from 41 to 36 Wh kg−1 and from 330 to 300 F g−1 (per mass of one electrode), respectively. The experimental results obtained from this work demonstrate possibilities for further development and applications of ChBr-based hybrid systems in energy storage devices.

The catalytic decomposition of a Ti3C2–ammonium perchlorate composite was investigated. The elemental and structural properties of the MXene were determined using the scanning electron microscopy, and its catalytic activity in the combustion of the ammonium perchlorate was estimated on the basis of the DTA and TGA data. It was established that the MXene exhibits an excellent reactivity and substantially influences the temperature of the ammonium perchlorate in the first and second exothermic periods of its decomposition and, consequently, the kinetic parameters of this decomposition.

In recent years, the interest of researchers in developing materials that can solve the problems of energy scarcity and environmental pollution has led to a special focus on nanocellulose and carbon nanotube-based composites. Nanocellulose has outstanding characteristics that promote highly ordered structures that are renewable and biodegradable. Carbon nanotubes, in turn, have high surface area, strength and electrical functionality. Their combined use holds promise for the development of composites with unique properties applicable in a variety of applications. However, despite the research conducted, questions remain unresolved regarding the technological aspects of production and specific applications of nanocellulose and carbon nanotubes. This review presents recent advances in the field of multifunctional hybrid nanocellulose and carbon nanotube-based nanocomposites, with a focus on their role in addressing environmental and energy challenges. The paper discusses the characteristics and advantages of the components of the composites, methods for their synthesis, as well as potential problems and possible directions for further research. Particular emphasis is placed on improving the interactions between the components, reducing the cost of production, and extending the scope of applications by integrating additional nanomaterials.

This study performs a comprehensive investigation to objectively analyze the effects of various carbon nanomaterials using as conductive additives (5 wt%) in activated carbon (AC) based electrodes for electrical double-layer capacitors (EDLCs). A variety of carbon nanomaterials including carbon black (CB), single-walled carbon nanotubes (SWCNT), graphene nanoplatelets (GNP), fullerenes (C60), and activated carbon nanofibers (ACNF) are considered in this work as they provide a diverse combination of intrinsic properties such as specific surface area, conductivity, micro-mesoporous structures, and geometry of nanomaterials. These additives are incorporated into freestanding carbon electrodes, and their EDLC performance in a neutral aqueous electrolyte is investigated by means of electrochemical measurements. The findings from this work provide useful insight into how the properties of various carbon nanomaterials influence EDLC performance in different aspects such as capacitive behavior, resistivity, performance at different current densities, charge propagation properties, and stability over long-term cycling. The results show that each carbon additive has its own strengths and limitations for different performance parameters considered. The unfavorable material properties of C60 cause a significant decrease in capacitance at high current density, leading to the lowest device performance incorporated with C60 as additives. While GNP and SWCNT show high crystallinity, low ID/IG ratios, the EDLCs still exhibit decreased specific capacitance and moderate energy densities due to their relatively limited specific surface area and high resistivity of the resultant composite electrodes compared to the pristine AC. The CB additives-based samples demonstrate the highest conductivity of dry electrodes and low equivalent series resistance (ESR) in EDLCs. On the other hand, a reduction in capacitance at high current densities and material degradation during long-term cycling are observed for CB samples, which could be attributed to the high dispersibility of CB causing limited interparticle voids and thus increasing diffusion resistance. In contrast, the use of ACNFs significantly reduces the diffusion resistance and improves the cyclic stability compared with CB based samples due to the advantages of larger specific surface area and superior micro-mesoporous structures of ACNFs. In particular, EDLCs with ACNFs demonstrate an increase in specific capacitance and energy density by 99 % and 76 %, respectively compared to CB based EDLCs at a current density of 20 A/g. This work elucidates the complex interplay between carbon nanomaterials using as additives and corresponding EDLC performance. These results provide important information to the community for future development of new energy conversion and storage devices.

Gas sensors are essential for safety and quality of life, with broad applications in industry, healthcare, and environmental monitoring. As urbanization and industrial activities intensify, the need for advanced air quality monitoring becomes critical, driving the demand for more sensitive, selective, and reliable sensors. Recent advances in nanotechnology, particularly 1D nanostructures like nanofibers and nanowires, have garnered significant interest due to their high surface area and improved charge transfer properties. Electrospinning stands out as a promising technique for fabricating these nanomaterials, enabling precise control over their morphology and leading to sensors with exceptional attributes, including high sensitivity, rapid response, and excellent stability in harsh conditions. This review examines the current research on chemoresistive gas sensors based on 1D nanostructures produced by electrospinning. It focuses on how the morphology and composition of these nanomaterials influence key sensor characteristics—sensitivity, selectivity, and stability. The review highlights recent advancements in sensors incorporating metal oxides, carbon nanomaterials, and conducting polymers, along with their modifications to enhance performance. It also explores the use of fiber-based composite materials for detecting oxidizing, reducing, and volatile organic compounds. These composites leverage the properties of various materials to achieve high sensitivity and selectivity, allowing for the detection of a wide range of gases in diverse conditions. The review further addresses challenges in scaling up production and suggests future research directions to overcome technological limitations and improve sensor performance for both industrial and domestic air quality monitoring applications.