Assel A. Kurtebayeva

Қазіргітаңда қоршаған ортаның ластануы, әсіресе тазарту құрылыстарынан шығатын сарқынды сулар құрамындағы қауіпті ластағыштардың көбеюі өзекті мәселелердің бірі болып табылады. Бұл зерттеуде ауыл шаруашылығы-өнеркәсіптік қалдығынан (жүгері собығынан) химиялық белсендіру әдісі арқылы жүгері биокөмірі (CB600C) алынды. СЭМ, ТГА, БЭТ, FT-IR, бөлшектердің өлшемін талдағыш анализы, элементтік көміртек анализы сияқты әдістермен жүргізілген толық сипаттаматұрақты органикалық ластағыштарды, соның ішінде микропластикті суда тиімді ұстай алатын материалға айналдыратынын растады.Алынған CB600C материалының тиімділігі адсорбция процесінде поливинилхлорид (ПВХ) ластағышын жоюда жүгері биокөмірін қолдана отырып бағаланды. Алынған нәтижелер ауыл шаруашылығы-өнеркәсіптік қалдықтан алынған CB600C материалының экологиялық қауіпсіз, оңай катализатор ретінде ластанған ағынды суларды терең тазартуда қолдану әлеуеті жоғары екенін көрсетеді.

Fe-modified activated carbons were prepared from corn-cob-derived activated carbon by wet impregnation with ferric nitrate, followed by thermal treatment under nitrogen. The obtained materials, denoted MAC1, MAC2.5, and MAC5 according to their nominal iron loadings, were evaluated for the aqueous-phase removal of paracetamol (PCM) and sulfamethoxazole (SMX) by adsorption and oxidant-assisted treatment using hydrogen peroxide and sodium persulfate (SPS). The experiments were conducted with an initial pollutant concentration of 50 mg L-¹, a material dose of 2.5 g L-¹, pH 3.5, and 60 °C for up to 24 h. Hydrogen peroxide and SPS were each used at an initial mass concentration of 44.3 mg L-¹, corresponding to 1.30 mmol L-¹ H₂O₂ and 0.186 mmol L-¹ Na₂S₂O₈. The residual oxidant concentration was monitored during treatment, and samples were chemically quenched before HPLC analysis. Under the tested model-water conditions, the highest experimental adsorption uptake was 17.08 mg g-¹ for PCM on MAC5 and 7.52 mg g-¹ for SMX on MAC2.5. The SPS-assisted systems produced a greater decrease in the aqueous concentration of the parent compounds than the hydrogen-peroxide-assisted systems, with PCM removal above 98% and SMX removal up to 74% after 24 h. These values represent aqueous-phase removal and do not by themselves distinguish adsorption from chemical transformation. The results indicate that iron loading, porous structure, pollutant speciation, and oxidant consumption jointly influence the observed performance.

This work is devoted to the synthesis and comprehensive study of activated carbons (ACs) obtained from agricultural wastes—specifically corn cob (C) and onion (O)—for the effective removal of paracetamol (PCM) and sulfamethoxazole (SMX) from aqueous media. The synthesis was carried out by chemical activation using H₃PO₄, HNO₃, and NaOH as activating agents, which made it possible to obtain materials with a clearly defined microporous structure (microporous fraction V_micro/V_total = 0.75–0.81) and specific surface chemistry. Particular attention was paid to studying the kinetics and equilibrium of adsorption in both single-component and binary (two-pollutant) systems. It was established that the equilibrium time is 8 h, and the experimental data are best described by a pseudo-second-order kinetic model. During binary adsorption tests, the competitive behavior was observed for certain materials, such as the corn-derived carbon activated with HNO₃ (AC-CN) and the onion-derived carbon activated with HNO₃ (AC-ON), where molecules compete for active sites. Conversely, synergistic effects were identified in other systems, controlled by specific surface-functional groups and hydration effects. The maximum adsorption capacity was found to be 29.4 mg∙g⁻¹ for PCM on the AC-CN sample. Adsorption mechanisms, including multilayer isotherm profiles and the competition between pollutant and water molecules, were interpreted using quantum chemical calculations within the framework of Density Functional Theory (DFT). These calculations revealed that partial deprotonation and intense solvation of SMX molecules at natural pH reduce their adsorption capacity. In contrast, the PCM structure favors π-π interactions and the formation of strong hydrogen bonds with oxygen-containing groups on the carbon surface. These results demonstrate the high potential of using agro-industrial waste to create a new generation of selective adsorbents with tailored surface properties.

The removal of contaminants of emerging concern (CECs) from wastewater remains one of the key challenges in water treatment, especially in countries with limited water resources and partially outdated infrastructure, including Kazakhstan. This study investigates polymeric membranes based on polyvinylidene fluoride (PVDF) modified with activated carbon of plant origin (AC-CN) to assess their structural characteristics and potential for further use in the removal of organic pollutants. AC-CN activated carbon was characterized by BET, SEM and FT-IR methods, which showed a developed microporous structure (SBET ≈462 м2∙g-1) and the presence of oxygen-containing functional groups. The membranes were formed by phase inversion using distilled water and a 70/30 ratio of distilled water and isopropanol, respectively, as a coagulation bath. Under continuous-flow conditions (C₀ = 10 mg/L, flow 0.5 mL/min, pH ≈6.8), PVDF membranes loaded with AC-CN showed markedly different performance depending on the coagulation bath: the water-coagulated AC-CN_membrane removed ≈13.8% of paracetamol and ≈40.9% of 4-nitrophenol, whereas the H2O/IPA (70:30)-coagulated AC-CN-IPA membrane achieved substantially higher paracetamol removal (≈60–64% at 60 min) and an initial 4-nitrophenol removal of ≈37.7% with sustained retention of ≈33.0 → 21.7% over 20–60 min. These findings indicate that coagulation bath composition critically controls membrane morphology and access to AC-CN sorption sites, supporting further optimization of these materials for sustainable wastewater treatment.

Pharmaceutical residues, particularly paracetamol, have emerged as persistent pollutants in aquatic environments due to their widespread use and incomplete removal by conventional wastewater treatment processes. This study investigates the potential of twolow-cost and sustainable adsorbents–natural Kokshetau clay and activated carbon derived from peanut shells–for the removal of paracetamol from aqueous solutions. The adsorbents were characterized using XRD, and SEM, TEM, Elemental analyses to determine their surface properties and structural features. Batch adsorption experiments were conducted to evaluate the effects of pH, contact time, and initial concentration, while fixed-bed column studies were used to simulate continuous treatment conditions. The adsorption data were fitted to isotherm and kinetic models, with the Langmuir and pseudo-second-order models providing the best fit, respectively. Column performance was evaluated using the Thomas and Yoon-Nelson models. Results demonstrate that both materials exhibit high removal efficiency for paracetamol, with activated carbon showing superior performance. The findings highlight the potential of these materials as eco-friendly and effective adsorbents for pharmaceutical removal in water treatment applications.Keywords: paracetamol,Kokshetau clay,activated carbon,peanut shell,pharmaceutical,adsorption, water treatment

This review aims to increase attention on present water quality issues on Central Asia, finding gaps in the literature on ways to address treatment needs, and help ensure future use of Central Asia surface waters and groundwater for all beneficial uses. Central Asia is a landlocked region known for its harsh climatic conditions and scarce water resources, despite being home to some of the world’s largest internal drainage basins. The available literature suggests that increasing salinity has rendered water unsuitable for irrigation and consumption; hazardous trace elements are found throughout Central Asia, most often associated with mining and industrial sources; and that legacy pesticides influence water quality, particularly in agriculturally influenced basins. This study also focuses on the effects of municipal and industrial wastewater discharge. Additionally, the impact of inadequately treated wastewater on water resources is analyzed through a review of available data and reports regarding surface and groundwater quantity and quality. Given the challenges of water scarcity and accessibility, the reuse of treated wastewater is becoming increasingly important, offering a valuable alternative that necessitates careful oversight to ensure public health, environmental sustainability, and water security. However, due to insufficient financial and technical resources, along with underdeveloped regulatory frameworks, many urban areas lack adequate wastewater treatment facilities, significantly constraining their safe and sustainable reuse. Proper management of wastewater effluent is critical, as it directly influences the quality of both surface and groundwater, which serve as key sources for drinking water and irrigation. Due to their persistent and biologically active nature even at trace levels, we discuss contaminants of emerging concern such as antibiotics, pharmaceuticals, and modern agrochemicals. This review thus highlights gaps in the literature reporting on impacts of wastewater inputs to water quality in Central Asia. It is recommended that future research and efforts should focus on exploring sustainable solutions for water quality management and pollution control to assure environmental sustainability and public health.

Rapid industrialization, expanding urbanization, and unrestrained use of natural resources contribute to environmental issues, particularly the contamination of water bodies by a variety of chemical compounds due to inadequate wastewater treatment. These contaminants, referred to as contaminants of emerging concern (CECs), pose global challenges due to their widespread occurrence, persistence, and bioaccumulation, stemming from anthropogenic activities. Notable examples of CECs include pharmaceuticals like paracetamol and synthetic chemicals such as perfluorooctanoic acid (PFOA), underscoring the imperative for effective wastewater treatment. Furthermore, phenolic species originating from pharmaceutical and dye industries endure in wastewater, posing threats to human health and ecosystems. To address these challenges, permeable reactive barriers (PRBs) have been developed to treat polluted waters, utilizing various materials. However, concerns about their manufacturing complexity processes have prompted the exploration of simpler and eco-friendly alternatives. Promising options include geopolymers, activated carbons derived from waste, and carbon nanotubes sourced from plastic solid waste. Integrating these materials into permeable barriers and adopting the concept of PRBs, with a focus on circular economy principles, presents a sustainable approach to mitigate population exposure to contaminated water. This innovative strategy not only addresses the environmental and health risks associated with water pollution but also aligns with the broader purpose of this work, which is to produce environmentally friendly permeable barriers for application in systems post wastewater treatment plants.

Treatment of wastewater by adsorption is one of the most environmentally friendly methods, along with high efficiency. The main criteria when choosing materials for wastewater treatment by adsorption are its adsorption properties, porous structure and cost-effectiveness. Heavy metal ions are the main pollutants present in wastewater from machine-building, non-ferrous metallurgy and instrument-making enterprises, its removal being mandatory employing processes such as adsorption. This work deals with the development of materials based on natural clays and on pillared clays and further application in the the adsorption of Ni (II), used as model pollutant, from aqueous solution. The starting natural clay (montmorillonite) was obtained in a deposit of Kazakhstan (Asa), and two additional samples were prepared by treatment of the natural clay with acid and by pillarization with Fe2+ and Zn2+. Batch adsorption experiments were carried out to explore the effect of pH, adsorbent load, contact time and the initial ion concentrations of Ni (II) in the adsorption of the heavy metal from aqueous solution with the three adsorbent samples. A maximum removal of Ni (II) of 98.9% was achieved at pH 10 with a dose of adsorbent of 2 g/L, a contact time of 120 min and an initial concentration of metal ions of 50 mg/L, when considering the Asa natural clay.