Soil quality assessment plays a critical role in promoting sustainable land management, particularly in fragile steppe ecosystems. This study provides a comprehensive geoecological evaluation of heavy metal contamination (Pb, Cd, Zn, Cu, Co, Ni, Fe, and Mn) in soils across five districts of the Akmola region, Kazakhstan. The assessment incorporates multiple integrated pollution indices, including the geochemical pollution index (Igeo), pollution coefficient (CF), ecological risk index (Er), pollution load index (PLI), and integrated pollution index (Zc). Spatial analysis combined with multivariate statistical techniques (PCA and clustering analysis) was used to identify pollutant distribution patterns and differentiate areas by risk levels. The findings reveal generally low to moderate contamination, with cadmium (Cd) posing the highest environmental risk due to its elevated toxic response coefficient, despite its low concentration. The study also explores the connection between current soil conditions and historical land-use changes, particularly those associated with the Virgin Lands Campaign of the mid-20th century. The highest PLI values were recorded in the Yesil and Atbasar districts (7.88 and 7.54, respectively), likely driven by intensive agricultural activity and lithological factors. PCA and cluster analysis revealed distinct spatial groupings, reflecting heterogeneity in both the sources and distribution of soil pollutants.

In this paper, the possibility of adsorption treatment of oil refineries industrial wastewater from phenols by production waste was considered. Phenols are toxic substances for the human body and belong to the II hazard class. Legally approved sanitary and hygienic standards establish maximum permissible concentrations (M PC) of phenols: M PC in the air of the working area of industrial promises is 1 mg/m(3), M PC in water is 0.001 mg/dm(3). It is proposed to use carbonate sludge for chemical water treatment of natural water for wastewater treatment, as one of the most accessible materials, which is a large-tonnage waste of energy. In the work, carbonate sludge of Aktobe TPP JSC formed during liming and coagulation at the stage of preliminary purification of incoming water. The adsorption isotherm, the kinetic, curve of phenol adsorption, the output curve of phenol adsorption under dynamic conditions have been constructed, and the dynamic sorption material "GrSM-1" is determined. On the basis of carbonate sludge, a granular hydrophobic sorption material of waste from the power industry "GrSM -1", modified with a water repellent and liquid sodium glass, has been developed. After heat treatment, granules with a particle diameter of 0.5 2.5 mm are formed by rolling. A technological scheme for the purification of industrial wastewater from phenols is proposed, the calculation of the fictitious and true flow rate, adsorbent density, adsorbent specific surface area, Reynolds number, friction coefficient, adsorbent mass in an adsorption filter with carbonate sludge loading in the scheme of wastewater treatment from phenols of Aklobe Oil Refining LLP was performed.

This work presents a detailed study of the coordination of Eu(III) with tartrate and oxalate ligands in aqueous solutions. The following techniques were employed: potentiometric titrations, 1D ¹H, ¹³C multinuclear NMR spectroscopy, 2D NMR experiments (COSY, HMQC, HMBC), and UV-Vis spectroscopy. Overall (cumulative) formation constants (logβ) were determined at ionic strengths of 0.1, 0.5, and 1.0, M KNO₃ over the temperature range 298–318 K. At 298 K, the oxalate complexes are significantly more stable (logβ = 7.63→15.70 as the ionic strength increases from 0.1 to 1.0 M) than the corresponding tartrate species (logβ = 5.11→8.87). Analysis of the temperature dependence of logβ shows that the Gibbs free energy change comprises both temperature-dependent terms and an approximately temperature-independent covalent contribution, the latter becoming strongly negative values in the tartrate system. The NMR data support a bidentate coordination mode involving deprotonated hydroxyl and carboxylate groups, whereas ¹⁷O NMR monitors the mechanism of water exchange within the Eu(III) hydration sphere. In the UV-Vis domain, a distinct blue shift in the absorption band is observed at 0.1 M KNO₃, while at 1.0 M KNO₃, the band shows a pronounced decrease in intensity, a hypochromic effect. This behavior can be attributed to increased structural distortion and a partial loss of coplanarity within the tartrate coordination environment. By contrast, the oxalate system behaves differently: the spectra, together with the thermodynamic data, support a more covalent Eu–O interaction, consistent with stabilization of Eu(III) by two dicarboxylate ligands adopting distinct coordination modes.

This study experimentally demonstrates that a bentonite–vermiculite composite (1:2 mass ratio) is the most effective formulation for the treatment of crude oil–contaminated wastewater. The sorbents were characterized using XRD, SEM/EDS, ζ-potential, DLS, and TGA/DSC to evaluate their structural, surface, and adsorption-related properties. Kinetic analysis showed that the adsorption process followed the pseudo-second-order (PSO) model (R² = 0.96–0.99), suggesting that surface interactions and intraparticle diffusion within the layered composite governed the overall adsorption rate. Thermodynamic analysis revealed negative Gibbs free energy values (ΔG < 0) and a moderately positive enthalpy change (ΔH ≈ 26 kJ·mol⁻¹), confirming that adsorption is spontaneous and endothermic, with contributions from physical interactions, ion exchange, and hydrophobic effects. After adsorption, the ζ-potential shifted toward less negative values, indicating partial surface charge neutralization by hydrocarbon species. TGA/DSC data further confirmed strong oil retention and preserved structural stability of the sorbents, while the DSC-derived enthalpy increased from 2.0 kJ·g⁻¹ to 141.6 kJ·g⁻¹ after hydrocarbon uptake, indicating pronounced energetic effects associated with sorbate incorporation. Techno-economic evaluation under industrially relevant conditions (Q = 120,000 L·h⁻¹; C₀ = 392 mg·L⁻¹) showed effective oil removal to residual concentrations below regulatory discharge limits at a low treatment cost.

The article examines the potential for the secondary use of industrial waste from the energy sector, specifically chemical water treatment (CWT) sludge generated at thermal power plants (TPPs), as an efficient and economically viable adsorbent for the treatment of wastewater contaminated with oil and petroleum products. A detailed analysis of the physicochemical characteristics of the sludge was conducted, including its elemental composition, specific surface area, porosity, and particle size, which determine its high sorption activity. It was found that the presence of magnesium and calcium promotes effective hydrocarbon capture due to ionic interactions and the alkaline nature of the surface, while silicon dioxide ensures structural stability and mechanical strength. The sludge was compared with widely used commercial adsorbents based on key parameters such as chemical composition, mechanical strength, environmental safety, regeneration capability, and effectiveness against various pollutants. The results indicate that carbonate sludge is a promising, cost-effective, and environmentally friendly material for use in the treatment of oil-contaminated wastewater, as well as within the framework of sustainable industrial waste management strategies. The necessity for further research is emphasized to explore the regeneration potential of the adsorbent and its performance in treating different types of contaminants.

This study investigates the potential for using XShP-02 chromium spinel sludge (rich fraction) from the Aktobe Ferroalloy Plant as a sorbent for the removal of phenol from the effluent of oil refineries. The sludge was subjected to alkaline modification with 1 M NaOH at 70°C, followed by calcination at 450 °C. The physicochemical properties were characterised using XRF, SEM, IR spectroscopy and TGA/DSC. The Langmuir and Redlich–Peterson models provide the best description of the adsorption equilibrium (R² = 1.000). The maximum adsorption capacity is 36.00 mg/g; an optimal dose of 0.30 g/100 ml ensures the removal of 96 % of phenol. ΔG° = - 5.97 kJ/mol confirms the spontaneous physical nature of the adsorption and the possibility of sorbent regeneration.