Chemical Journal of Kazakhstan

EFFECT OF POLYMER COMPOSITION AND TEMPERATURE ON THE RHEOLOGICAL PROPERTIES OF CHITOSAN-CARBOXYMETHYL CELLULOSE HYDROGELS

Assem Kaliyeva — 2026-09-30

. Introduction. Over the past decade, superabsorbent hydrogels based on natural polymers (cellulose, chitosan) have been widely applied in biomedicine. Despite their high stability and biocompatibility, these hydrogels exhibit several drawbacks associated with insufficient pseudoplasticity and thixotropy. Consequently, the development of hydrogel systems with tailored rheological properties has acquired critical medical relevance. The objective of this study was to develop and comprehensively investigate the rheological properties of hydrogels based on chitosan (CS) and carboxymethylcellulose (CMC) with different component ratios, as well as to evaluate the effects of shear rate and temperature on their rheological characteristics in order to identify promising formulations for topical application. Results and Discussion. Chitosan/carboxymethylcellulose (CS/CMC) hydrogels with different polymer ratios were investigated by rheometry at temperatures of 20, 25, and 35°C over a shear-rate range of 3-120 s⁻¹. The highest apparent viscosity under all investigated conditions was observed for the CS2.0/CMC0.5 formulation, whereas increasing temperature resulted in a consistent decrease in viscosity. To quantitatively evaluate the rheological behavior, the experimental data were fitted using the Power-law, Herschel-Bulkley, and Casson models. Conclusion. CS/CMC hydrogels exhibited pronounced shear-thinning behavior at 20-35°C and shear rates of 3-120 s⁻¹, facilitating their application to the skin. The CS2.0/CMC0.5 formulation showed the highest viscosity and stable rheological behavior (K = 16.90 Pa·sⁿ, n = 0.389, R² = 0.987 at 25°C), making it a promising matrix for topical hydrogel systems.

SILICA FOULING OF ANION-EXCHANGE RESINS IN URANIUM IN-SITU RECOVERY: CURRENT UNDERSTANDING AND REGENERATION APPROACHES

Bagdat Tolbasuly Altaibayev — 2026-09-30

The growing share of in-situ leaching (ISL) in global uranium mining is increasing the demands on the efficiency of ion-exchange processing of pregnant solutions. Strongly basic anion exchange resins that sorb uranyl sulfate or uranyl carbonate complexes are typically used for uranium extraction. Over long periods of operation, their properties deteriorate due to the accumulation of silicon compounds released into the solution during the leaching of silicate rocks. This review examines the mechanisms of silicon fouling of anion exchange resins used in ISL, as well as existing methods for desilication and regeneration. An analysis of scientific publications and technical materials shows that fouling is primarily due to the penetration of silicic acid into the resin pores and its subsequent polymerization. With localized increases in pH, silicate anions can also interact with exchange sites. The formation of oligomeric and polymeric siloxane structures hinders mass transfer, blocks active sites, and reduces the uranium sorption capacity. Alkaline treatment with NaOH and fluoride-containing reagents are used for regeneration. Alkaline solutions are technologically simpler, but less effective against highly polymerized silica phases and, under harsh conditions, can damage the resin. Fluoride systems provide deeper silicon removal but place increased demands on the corrosion resistance of equipment and wastewater treatment. Therefore, the regeneration process must ensure silicon removal without significantly reducing the mechanical strength and sorption properties of the resin.

SYNTHESIS, STRUCTURE, AND MORPHOLOGY OF SmMnO3-LaMnO3 PEROVSKITE COMPOSITE

Сарсенбаева Беркбайкызы — 2026-09-30

This article discusses the synthesis, phase composition, and structural morphology of the LaMnO₃-SmMnO₃ double manganite perovskite composite. The aim of synthesizing a two-phase manganite containing the rare earth elements samarium and lanthanum is to study the structural features and properties of the resulting products compared to classical perovskite manganites and single-phase samarium and lanthanum manganites. The Pechini method, based on sol-gel synthesis, was used to synthesize the product. The purpose of selecting this method was to obtain a product with high fineness and crystallographic purity. The phase composition and crystallographic parameters were analyzed using X-ray diffraction (XRD), Fourier-transform infrared (FTIR), and morphological methods to determine the formation of bonds between Me-O; scanning electron microscopy (SEM-EDS), scanning surface area, and elemental distribution. The synthesis was carried out based on sol-gel formation in the presence of metal nitrate hydrates. Phase analysis of the product showed that SmMnO₃ has the orthorhombic Pbnm (62) structure in accordance with PDF 00-025-0747, while LaMnO₃ corresponds to the rhombohedral space group R-3C (167) in accordance with PDF card No. 01-090-6505. It was established that the intense absorption bands in the FTIR spectrum lie within the range of 750–600 cm⁻¹, indicating the formation of Mn–O bonds. SEM-EDS results show that the average particle size of the powdered product is 0.489 μm, and the product was successfully characterized using the elemental distribution map.

DEVELOPMENT OF AN INNOVATIVE AND IMPROVED TECHNOLOGY FOR PROCESSING OIL WASTE FROM JSC “OZENMUNAYGAZ” INTO USEFUL PRODUCTS

Ersin Adietovich Tusupkaliev — 2026-09-30

Introduction. Oil and gas activities generate oil-contaminated waste, which poses an environmental hazard. The development of effective technologies for its treatment and reuse is an important task. Objective. To develop and evaluate the efficiency of a technology for processing oil-contaminated waste from JSC «Ozenmunaigas» to produce treated soil suitable for road construction and technical land reclamation. Methods. Pilot-scale industrial tests were conducted using a surfactant, a polymer composite, and technical water. The components were mixed for 10–15 minutes, followed by settling for 20–30 minutes. The concentration of petroleum hydrocarbons was determined using the fluorometric method. Results. The concentration of petroleum hydrocarbons decreased from 102,600 to 900 mg/kg, corresponding to a removal efficiency of 99.12%. The resulting treated soil was proposed for use in road construction and technical land reclamation. The developed technology provides effective processing of oil-contaminated waste and reduces the technogenic impact on the environment.

PHYSICOCHEMICAL ASPECTS OF POLYELECTROLYTE INTERACTIONS IN AQUEOUS FILM-FORMER DISPERSIONS

Татьяна Ширина — 2026-09-30

Introduction. Waterborne coating materials offer environmental and technological advantages; however, the coatings they form may exhibit structural heterogeneity and increased porosity. One approach to controlling the properties of such systems is the introduction of functional modifiers. Objective. The aim of this study was to determine the effect of polyethylene polyamine on the surface and bulk properties of aqueous polyurethane and acrylic-polyurethane dispersions, as well as on the porosity of the coatings formed from them. Methodology. At 293 K, surface tension, specific and molar electrical conductivity, pH, and coating porosity were determined in systems containing 0-0.0024 mol/dm³ PEPA. Results and Discussion. In the binary «water-PEPA» system, changes in the character of the concentration dependences of surface tension, molar conductivity, and pH were observed in the region CPEPA = 0.0012 mol/dm³, corresponding to the critical association concentration. In ternary systems, the nature of changes in the investigated parameters depended on the film-former chemistry; the most pronounced decrease in surface tension was observed for the acrylic-polyurethane dispersion, from 39.60 to 35.15 mN/m. With increasing PEPA concentration, the porosity of the polyurethane coating decreased from 73.70 to 40.56%, while that of the acrylic-polyurethane coating decreased from 37.69 to 4.62%. Conclusion. The results demonstrate that PEPA affects the surface and bulk properties of the investigated aqueous dispersions and the structure of the coatings formed. The observed changes are consistent with the possibility of associative interactions between PEPA and the components of the studied systems, with the most pronounced modification effect established for the acrylic-polyurethane composition.

A A REVIEW OF MODERN FLOTATION COLLECTORS FOR TUNGSTEN MINERALS: FROM BIFUNCTIONAL MOLECULES TO DFT-GUIDED DESIGN (REVIEW)

Assel Yuryevna Ten — 2026-09-30

The flotation efficiency of tungsten minerals depends largely on the structure of the collector and the nature of its adsorption on the mineral surface. Traditional fatty acids, hydroxamates, and organophosphorus reagents are well studied; however, their limited selectivity stimulates the development of more complex molecular systems. The purpose of this review is to examine current developments in the collector design for scheelite and wolframite, focusing on the bifunctional, multifunctional, and DFT-guided approaches. A conditional division of the collectors into generations is proposed: from traditional and chelating reagents to bifunctional and multifunctional systems and further to rationally designed collectors, using DFT and molecular modeling. This review examines the collectors containing various combinations of active groups, including amine–hydroxyl, thioether–hydroxamate, bis-hydroxamate, amino–hydroxamate, amidoxime–phosphonate, and hydroxamate–phosphonate systems. Their interactions with the surface Ca, Fe, Mn, and W sites are discussed, as well as the roles of electrostatic attraction, coordination bonding, hydrogen bonding, and hydrophobicity. Particular attention is paid to the increasing application of the density functional theory (DFT), molecular dynamics, electronic structure analysis, and hydrophobicity calculations in the collector design. The current research shows that the computational methods are increasingly being used not only to elucidate the adsorption mechanisms, but also to optimize spacer length, electron donation capacity, hydrophobicity, and ligand combinations prior to or in parallel with the experimental validation. This review focuses on the studies published between 2020 and 2026, with the earlier studies included where necessary to understand the background to the development of the modern approaches to the collector design.

DOCKING AND ADMET EVALUATION OF ASTRAGALUS-DERIVED PHYTOCHEMICALS AGAINST GLYCOGEN SYNTHASE KINASE‑3β

Elmira Yergaliyeva — 2026-09-30

Glycogen synthase kinase-3β (GSK-3β) regulates cellular processes associated with inflammation, apoptosis, and neurodegeneration and is a validated therapeutic target. Interest in natural compounds capable of interacting with the GSK-3β active site is driven by the toxicity and adverse effects associated with many existing kinase inhibitors. This study aimed to evaluate Astragalus phytocomponents as potential GSK-3β ligands in silico using molecular docking and ADMET prediction. The docking methodology was validated by redocking the native ligand FKB501 from the cocrystallized X-ray structure, yielding an RMSD of 1.83 Å. To assess affinity for the GSK-3β active site, a library of 96 Astragalus compounds was screened. Based on binding affinity and ADMET characteristics, six compounds were selected for detailed analysis: soyasapogenol B, soyasapogenol E, chlorogenic acid, neochlorogenic acid, isoliquiritigenin, and echinatin. Their binding energies were comparable to or exceeded, in absolute value, that of FKB501 (-7.546 kcal/mol), with the lowest values observed for soyasapogenol B (-8.523 kcal/mol) and soyasapogenol E (-8.176 kcal/mol). Interaction analysis revealed key active-site residues, including Ile62, Phe67, Val70, Ala83, Lys85, Val135, Gln185, Leu188, Cys199, and Asp200. ADMET prediction indicated that isoliquiritigenin and echinatin had the most balanced pharmacological and toxicological profiles, whereas sapogenins, despite their higher docking affinity, were limited by low solubility and high lipophilicity. The selected Astragalus phytocomponents are therefore promising candidates for further experimental evaluation as potential GSK-3β inhibitors.

EFFECT OF β-CYCLODEXTRIN AND LACTIC ACID-BASED SUPRADES ON ASPHALTENE AGGREGATION PROCESSES

Kanat Sadykov — 2026-09-30

Introduction. Asphaltene precipitation and aggregation complicate petroleum production, transport, and refining. Aim. To evaluate β-cyclodextrin–L-lactic-acid SUPRADES as a modifier of asphaltene aggregation in model oil prepared from Karazhanbas crude oil. Methods. Asphaltenes were isolated according to GOST 11858-66. SUPRADES was prepared at a 1:60 molar ratio and characterized by FT-IR, UV–Vis, thermogravimetry, and ¹H and ¹³C NMR, including COSY, HMQC, and HMBC. Results and discussion. FT-IR indicated a hydrogen-bonded network, TGA revealed multistage decomposition, and NMR confirmed the lactic-acid fragment and its principal correlations. Near 292 nm, absorbance decreased from approximately 0.88 to 0.59 after SUPRADES addition, an apparent decrease of about 33%. Because replicate-level variability was unavailable, the comparison is semiquantitative. Conclusion. The system may modify asphaltene aggregation, but quantitative inhibition must be confirmed at defined concentrations with independent replicates.

RESEARCH ON THE TECHNOLOGY FOR PRODUCING ZINC SULFATE MONOHYDRATE FROM ZINC-CONTAINING WASTE

Svetlana Yermukhanova — 2026-09-30

Zinc sulfate is an important chemical compound widely used in various industries. It is applied in agriculture to increase crop yields, as well as in the production of paints, pharmaceuticals, beer, and other products. The main element, zinc, promotes the active growth and development of plants. A technology for producing zinc sulfate monohydrate was studied and developed. Powders containing 75-99% zinc and 25% sulfuric acid were used as research materials. In order to increase the interaction rate between the components, the powders were preliminarily mixed with water. The amount of concentrated sulfuric acid added was regulated so that, after addition, a sulfuric acid solution with a concentration of 25% was obtained. Hydrogen peroxide was used to remove impurities such as iron, copper, cadmium, and nickel. According to XRD analysis, the obtained product consisted of single-phase zinc sulfate monohydrate. A laboratory-scale procedure for the production of zinc sulfate monohydrate was developed.

SYNTHESIS AND EVALUATION OF OCTADECYL METHACRYLATE-VINYLIMIDAZOLE COPOLYMERS AS COLD-FLOW IMPROVERS FOR DIESEL FUEL

Aknur Galymzhan — 2026-09-30

Introduction. The formation and aggregation of wax crystals at low temperatures impair the flow and filtration properties of diesel fuel. Comb-like copolymers containing long alkyl side chains can modify wax crystallization and improve the low-temperature performance of diesel fuel. This study aimed to synthesize octadecyl methacrylate-vinylimidazole (ODMA-VI) copolymers with different monomer feed ratios and evaluate their effects on the cold filter plugging point (CFPP), cloud point (CP) and pour point (PP) of diesel fuel. Results and Discussion. ODMA-VI copolymers with ODMA:VI monomer feed ratios of 9:1, 6:1 and 4:1 were synthesized by free-radical solution copolymerization and characterized by ¹H NMR, FTIR spectroscopy and gel permeation chromatography. Their effects on the low-temperature properties of diesel fuel were evaluated at dosages ranging from 1000 to 3000 ppm. The observed changes depended on the monomer feed ratio and additive dosage. Among the investigated samples, the copolymer prepared at an ODMA:VI monomer feed ratio of 4:1 resulted in the largest reductions at 3000 ppm, decreasing the CFPP from -7 to -10 °C, the CP from -3 to -8 °C and the PP from -10 to -18 °C. Optical microscopy showed that the copolymer reduced the size and aggregation of wax crystals and promoted their more uniform dispersion in diesel fuel. Conclusion. The results indicate that the ODMA:VI monomer feed ratio influences the depressant performance of the synthesized copolymers. Among the investigated samples, the copolymer prepared at an ODMA:VI monomer feed ratio of 4:1 showed the most pronounced effects on wax-crystal morphology and the measured low-temperature properties of diesel fuel.

STRUCTURAL OPTIMIZATION OF BIOCOMPOSITES USING MULTIVALENT IONS AND MODIFIED MONTMORILLONITE

Bakyt Baimuratovna Tyussyupova — 2026-09-30

In modern biomedicine and pharmacology, one of the central challenges is the development of highly efficient therapeutic systems with controlled drug release. Objective. This study investigates the influence of cation valence and concentration on the degree of crosslinking in polymer networks of alginate hydrogels prepared via ionotropic gelation. Results and Discussion. The structural characteristics of the synthesized materials were examined using physicochemical analysis. A detailed evaluation was conducted on the swelling kinetics and the release profiles of immobilized drugs in physiological saline. Stimuli-responsive (pH-dependent) ionotropic biocomposites capable of adapting to changes in environmental acidity were successfully synthesized. Particular attention was given to the differences in insulin release kinetics from alginate-gelatin biocomposites upon the incorporation of montmorillonite and its magnetized form. It was demonstrated that the inclusion of magnetized montmorillonite nanoparticles not only prolongs the release of the protein drug but also enables prospects for targeted transport under the influence of an external magnetic field. Conclusion. The findings highlight effective strategies for controlling the structure and physicochemical properties of biocomposite hydrogels. These advances represent an important step toward the development of therapeutic systems for controlled and targeted drug delivery.

RESEARCH OF THE TECHNOLOGY FOR PRODUCING A GRANULATED COMPOSITION BASED ON MONOMETHYLOLUREA, COPPER AND ZINC PHYTOCOMPOUNDS, CALCIUM PHOSPHATES OF MONOETHANOLAMINE

Gaukhar Tungushpaevna Omarova — 2026-09-30

Conventional active substances used for cotton and grain seed treatment belong to toxicity classes II–III, negatively affecting soil fertility and agricultural product quality. This study focuses on low-toxic (class IV) preparations. Objective. To study the pilot-scale production technology of a granulated multifunctional composition based on monomethylolurea, copper and zinc phytocompounds, mono- and dicalcium phosphate, and phosphate monoethanolamine. Methods. Experiments were conducted at the pilot plant of LLP “Scientific and Production Association Ana-Zher” using a screw granulator (L = 4.7 m, D = 0.8 m). Results. The optimal solid-to-liquid composition ratio was 0.80:0.20. At a 30-min residence time, the yield of 1–4 mm granules was 83% for MMM and FSCu • MCP (150 kg/h; moisture 0.95%), 85% for MMM and FSZn • DCP (160 kg/h; 0.93%), and 82% for MMM • FMEA (145 kg/h; 0.94%). Conclusion. The selected parameters ensure production of a high-quality granulated preparation with favorable physicochemical and commercial properties.

FORMATION OF A POROUS SILICA-RICH MATRIX FROM CHRYSOTILE-ASBESTOS WASTE FOR POTENTIAL APPLICATION IN SILICON REMOVAL FROM PROCESS SOLUTIONS

Aigerim Khambarkyzy — 2026-09-30

Silicon-containing species in uranium-bearing process solutions can accumulate on ion-exchange materials, impairing mass transfer and sorption efficiency. Inexpensive porous inorganic materials for preliminary silicon removal are therefore of practical interest. This study aimed to evaluate how thermal, chemical and mechanical post-treatment affects the porous structure of a silica-rich product obtained by hydrochloric acid leaching of chrysotile-asbestos waste, in order to select a promising matrix for sorption studies. Raw material underwent magnetic separation followed by HCl leaching. Five products were examined: material calcined at 650 °C; material calcined at 850 °C (1 h) and modified with 5% NiSO₄ and 10% MoO₄; material calcined at 650 °C for 52 h; leached product before attrition; and the same product after attrition. Textural properties were assessed via low-temperature N₂ adsorption using BET, Langmuir, t-plot and BJH methods. The BET specific surface area of the samples varied from 56.55 to 169.02 m²/g. The most favorable textural characteristics were observed for the leaching product without additional grinding: the specific surface area was 169.02 m²/g, the micropore area was 44.72 m²/g, the t-plot micropore volume was 0.0180 cm³/g, and the average pore diameter was 3.89 nm. After attrition, surface area remained high (165.99 m²/g) while total pore volume increased to 0.1951 cm³/g. Calcination at 650 °C and prolonged 52-h calcination reduced surface area to 106.61 and 91.41 m²/g, respectively; combined 850 °C treatment with Ni–Mo modification gave the lowest value (56.55 m²/g). HCl leaching was the key step forming the porous silica matrix. The unattrited leached product was selected as the most promising matrix for silicon removal from uranium solutions.

SYNTHESIS OF AMINOPHTHALIDES BASED ON MORPHOLINE AND CYTISINE ALKALOID

Serik Drakhmetovich Fazylov — 2026-09-30

This work describes the investigation of the reactions between o-formylbenzoic acid and morpholine, as well as the alkaloid cytisine. This study is aimed at the synthesis of new aminophthalide derivatives as compounds of potential interest for biological evaluation. The interactions between the starting reagents were studied, and optimal synthesis conditions were determined to ensure high the amounts of desired compounds obtained. The structures, electronic properties of the initial substances, intermediates, and synthesized compounds were analyzed using quantum-chemical computations are based on density functional theory using a quantum‑chemical research method. The molecular constitution of the obtained products were established based on their Infrared spectral data, one-dimensional ¹H, ¹³C and two-dimensional Nuclear Magnetic Resonance spectroscopy (COSY, HMQC, HMBC), and mass spectrometry. A possible reaction pathway accounting for the formation of aminophthalides is presented, involving the nucleophilic addition of secondary amines to the carbonyl group of o-formylbenzoic acid, followed by intramolecular cyclization. The spectral analysis is fully consistent with the proposed structure of the obtained compounds. The findings reveal the effectiveness of the established procedure for synthesizing aminophthalides based on morpholine and cytisine and provide the basis for further studies of their reactivity, physicochemical characteristics, and potential biological activity.

SYNTHESES AND STRUCTURE OF ALKYL AND DIALKYL ISOPENTYLDITHIOCARBAMATE THIOETHERS

Meruyert Sissenbekovna Mukanova — 2026-09-30

Dithiocarbamates and their derivatives are promising sulfur-containing compounds used as flotation reagents in the flotation enrichment of mineral raw materials. Variations in the structure of the hydrocarbon substituent and the introduction of additional functional fragments make it possible to regulate their surface properties. The aim of this study was to synthesize new alkyl and dialkyl thioethers based on isopentyldithiocarbamates and to establish their structures using IR and NMR spectral methods. Results and discussion. The reaction of isopentylamine with carbon disulfide in an alkaline medium yielded disodium isopentylbis(dithiocarbamate) and sodium isopentyldithiocarbamate in 58% and 30% yields, respectively. The subsequent reaction of the salts with hexyl, heptyl, octyl, nonyl, and decyl bromides allowed the synthesis of a series of alkyl and dialkyl thioethers in 75–98% yields. The composition and structure of the synthesized compounds were confirmed by elemental analysis, IR, ¹H, and ¹³C NMR spectroscopy. Spectral characteristics indicate the presence of a dithiocarbamate fragment, an isopentyl substituent, and alkyl substituents of varying lengths. Conclusion. Synthetic conditions for a series of new isopentyldithiocarbamate thioethers have been developed. The synthesized isopentyldithiocarbamate thioethers with variable alkyl fragment lengths are of interest for further study of their flotation properties and the possibility of using them as flotation reagents.

REGENERATING SOLUTION COMPOSITION FOR SILICON REMOVAL AND ANION-EXCHANGE RESIN RESTORATION IN URANIUM EXTRACTION

Manarbek Kalymovich Kylyshkanov — 2026-09-30

The effect of the composition of regenerating solutions on the removal of silicon-containing and related impurities from anion exchange resins used for sorption extraction of uranium from productive solutions of in-situ leaching was investigated. The objects were technological solutions and regenerated resins from the Akdala and South Inkai deposits. The elemental composition was determined by atomic emission and X-ray fluorescence methods, and the phase composition of solid residues was determined by X-ray phase analysis. Screening of the NaOH–Na₂SO₄, H₂SO₄–NH₄HF₂ and HNO₃–NH₄HF₂ systems showed silicon removal at 90.2–97.9; 93.3–95.0 and 95.7–97.5%, respectively. The HNO₃–NH₄HF₂ system, despite its effectiveness, is excluded due to the high affinity of nitrate ions for the resin; NaOH–Na₂SO₄ and H₂SO₄–NH₄HF₂ were then studied. Increasing the concentrations of NaOH and Na₂SO₄ to 75 and 100 g/l increased silicon removal to 97.5–98.7% but could reduce the strength of the resin. A solution of 25 g/l of NaOH + 25 g/l of Na₂SO₄ removed 93.1% of Si, retained strength of 76.5%, increased hydrodynamic index by 30% and uranium capacity from 10.75 to 13.89 g/l; a solution of 150 g/l H₂SO₄ + 150 g/l NH₄HF₂ increased the capacity to 16.69 g/l. The choice of regenerating solution should consider not only the removal of silicon, but also the degree of purification, strength, hydrodynamic and sorption properties of the resin.

CHEMICAL APPROACHES TO MONITORING AND EVALUATING THE BIOREMEDIATION OF OIL CONTAMINATED DESERT SOILS: A REVIEW OF MODERN METHODS

Roza A. Narmanova — 2026-09-30

Oil spills in deserts and other arid regions, including Kuwait, the Arava Valley in Israel, and Western Kazakhstan, have created extensive areas of chronically contaminated soil whose remediation is constrained by low moisture, nutrient deficiency, salinity, temperature fluctuations, and the ageing of petroleum residues. The purpose of this review is to systematise modern chemical and physicochemical approaches to monitoring and evaluating the bioremediation of oil-contaminated desert soils and to identify indicators suitable for an integrated, risk-based assessment. The review considers the composition of crude oil as a multicomponent contaminant, including total petroleum hydrocarbons, polycyclic aromatic hydrocarbons, BTEX compounds, resins, and asphaltenes, as well as the soil properties that control their mobility, bioavailability, persistence, and toxicity. Natural attenuation, biostimulation, bioaugmentation, biopiling, and phytoremediation are compared with chemically enhanced treatments based on Fenton and persulfate oxidation, nanomaterials, electrokinetic processes, microwave heating, and bioelectrochemical systems. Particular attention is paid to combining chromatographic and spectroscopic determination of petroleum fractions with soil respiration, microbial and functional-gene indicators, ecotoxicological tests, and remote-sensing observations. Hyperspectral data and artificial-intelligence methods are discussed as tools for mapping contamination and tracking spatial changes during remediation. Sorbent materials, including shungite-based compositions relevant to Kazakhstan, are considered for the preliminary containment and removal of oil. The analysis shows that a decrease in total petroleum hydrocarbons alone is insufficient to demonstrate environmental recovery because persistent aromatic fractions and residual toxicity may remain.