Жарияланымдар / Публикации

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  • Некоторые метрики заблокированы вашими 
    Тип записи:Публикация,
    Structural and Sorption Characteristics of Nano-Structured Polysaccharide Biopolymers Derived from Plants of the Asteraceae Family
    This study investigates the structural and sorption characteristics of nanostructured polysaccharide biopolymers isolated from plants of the Asteraceae family (Dahlia tubers and Helianthus tuberosus) toward Pb2+ ions in model aqueous solutions. The biopolymers were obtained by acid extraction at pH 1.5-2.5 and 80-90 °C, followed by ethanol precipitation, with a yield of 10-14%.Surface morphology examined by scanning electron microscopy revealed a hierarchically organized nano- and micro structured matrix with particle agglomeration and developed interaggregate porosity. The presence of lamellar structures and a porous network promotes diffusion of metal ions to active functional centers.The interaction mechanism between the biopolymer matrix and Pb2+ was studied by FTIR spectroscopy. Shifts and intensity changes of absorption bands corresponding to carboxyl and hydroxyl groups confirmed a coordination-chelate complexation mechanism without destruction of the polysaccharide backbone.Sorption experiments were performed using model Pb2+ solutions prepared from analytical-grade lead (II) acetate. The residual Pb2+ concentration after contact with the biopolymer was determined by atomic absorption spectrometry at 283.3 nm using calibration. Additional control measurements were conducted by complexometric titration in acetate buffer medium (pH 5.5) with 0.01 M Trilon B.Up to 76-77% of Pb2+ was removed within the first 10 min, and sorption equilibrium was reached after 60 min. The maximum removal efficiency reached 87%. The Freundlich model best described the process, indicating heterogeneous surface structure and multilayer adsorption. These results demonstrate the potential of Asteraceae-derived polysaccharide biopolymers as environmentally safe sorbents for heavy metal removal from aqueous media.
  • Некоторые метрики заблокированы вашими 
    Тип записи:Публикация,
    ADSORBENTS BASED ON MODIFIED NANOCELLULOSE: WATER PURIFICATION FROM ORGANIC AND INORGANIC POLLUTANTS
    (Shakarim University, 2026-07-29)
    Zhexenbek Toktarbay
    ;
    Makhabbat Kunarbekova
    ;
    ;
    Kenes Kudaibergenov
    ;
    Dana Ashiraliyeva
    Against the backdrop of rapid industrial growth, water pollution has become a pressing global environmental issue. This review provides a systematic analysis of the efficiency of functionalized nanocellulose- based adsorbents for the removal of organic (synthetic dyes, phenols, antibiotics, pesticides) and inorganic (Pb 2+ , Cd 2+ , Hg 2+ , Cr(VI), Cu 2+ , As) pollutants from water. Key findings: the highest sorption capacities are achieved by TEMPO-oxidized nanocellulose and amine-functionalized composites – up to 2500 mg/g for methylene blue and up to 2270 mg/g for lead ions. Nanocellulose-based molecularly imprinted polymers (MIPs) selectively adsorb phenols with efficiencies of up to 97% even in the presence of structurally similar competitors. Most adsorbents reviewed retain 80+90% of their capacity after 20 regeneration cycles. The paper examines three main types of nanocellulose (CNC, NFC, BNC), their preparation methods (acid hydrolysis, TEMPO-oxidation, mechanical and enzymatic treatment), and surface functionalization strategies (isocyanate-based, amine- and thiol-functionalization). The alignment of nanocellulose production from agricultural waste (rice husks, soybean hulls) with sustainable development principles is emphasized. Key unresolved challenges – scale-up, stability in real wastewater matrices, and cost-effectiveness – and future research directions are also identified.