KAOLIN–CHITOSAN BIOSORBENT AK-Xz: PHASE COMPOSITION AND MESOPOROUS STRUCTURE
Authors
Berdikulov Bakhtiyor, Gulnora Ikhtiyarova
Share
Annotation
The crystalline phase composition and porous structure of a kaolin–chitosan composite biosorbent (AK-Xz), prepared from Angren kaolin and chitosan isolated from Apis mellifera waste, were studied by powder X-ray diffraction (PXRD) and N₂ adsorption at 77 K (BET, BJH, t-plot). Raw kaolin, kaolin treated with 0.1 N HCl and activated at 450 °C (AK-450), and the composite were compared. The raw material is a polymineral mixture of quartz, mica/illite, kaolinite, chlorite, calcite, feldspar and halite. The HCl treatment removed halite and reduced calcite, and the mica and chlorite structures survived heating at 450 °C. In AK-Xz, calcite was no longer detected, the mica and chlorite reflections were weaker and broader, and the amorphous contribution at 18–24° 2θ increased, whereas the mica d(001) spacing remained unchanged (9.95–9.98 Å), so no evidence for intercalation of chitosan was found. AK-Xz has a BET surface area of 25.6 m²/g, a total pore volume of 0.031 cm³/g and a mean pore diameter of about 4.8 nm. The material is mesoporous, with no detectable micropores.
Keywords
Authors
Berdikulov Bakhtiyor, Gulnora Ikhtiyarova
Share
References:
Crini G. Recent developments in polysaccharide-based materials used as adsorbents in wastewater treatment. Prog. Polym. Sci. 2005, 30, 38–70.
da Silva Alves D.C., Healy B., de Almeida Pinto L.A., Cadaval T.R.S. Jr., Breslin C.B. Recent developments in chitosan-based adsorbents for the removal of pollutants from aqueous environments. Molecules 2021, 26, 594. https://doi.org/10.3390/molecules26030594
Rinaudo M. Chitin and chitosan: Properties and applications. Prog. Polym. Sci. 2006, 31, 603–632.
Wan Ngah W.S., Teong L.C., Hanafiah M.A.K.M. Adsorption of dyes and heavy metal ions by chitosan composites: A review. Carbohydr. Polym. 2011, 83, 1446–1456.
Yang C., Wu X., Mao J. Preparation of a tetraethylenepentamine grafted magnetic chitosan bead for adsorption of Re(VII) from aqueous solutions. RSC Adv. 2024, 14, 38944–38951. https://doi.org/10.1039/D4RA05927A
Abou Alsoaud M.M., Taher M.A., Hamed A.M., Elnouby M.S., Omer A.M. Reusable kaolin impregnated aminated chitosan composite beads for efficient removal of Congo red dye: isotherms, kinetics and thermodynamics studies. Sci. Rep. 2022, 12. https://doi.org/10.1038/s41598-022-17305-w
Majigsuren E., Byambasuren U., Bat-Amgalan M., Mendsaikhan E., Kano N., Kim H.J., Yunden G. Adsorption of chromium (III) and chromium (VI) ions from aqueous solution using chitosan–clay composite materials. Polymers 2024, 16(10), 1399. https://doi.org/10.3390/polym16101399
Murray H.H. Applied Clay Mineralogy; Elsevier: Amsterdam, 2007.
Brindley G.W., Brown G. Crystal Structures of Clay Minerals and Their X-ray Identification; Mineralogical Society: London, 1980.
Moore D.M., Reynolds R.C. X-ray Diffraction and the Identification and Analysis of Clay Minerals, 2nd ed.; Oxford University Press: Oxford, 1997.
Brunauer S., Emmett P.H., Teller E. Adsorption of gases in multimolecular layers. J. Am. Chem. Soc. 1938, 60, 309–319.
Barrett E.P., Joyner L.G., Halenda P.P. The determination of pore volume and area distributions in porous substances. J. Am. Chem. Soc. 1951, 73, 373–380.
Lippens B.C., de Boer J.H. Studies on pore systems in catalysts V. The t method. J. Catal. 1965, 4, 319–323.
Rouquerol J., Llewellyn P., Rouquerol F. Is the BET equation applicable to microporous adsorbents? Stud. Surf. Sci. Catal. 2007, 160, 49–56.
Thommes M. et al. Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report). Pure Appl. Chem. 2015, 87, 1051–1069.
Liu T., Li X., Wang H., Li M., Yang H., Liao Y., Tang W., Li Y., Liu F. Reconstructing kaolinite compounds for remarkably enhanced adsorption of Congo red. Molecules 2024, 29(9), 2121. https://doi.org/10.3390/molecules29092121
Berdikulov B., Ikhtiyarova G. Recovery of rhenium and molybdenum from industrial wastewater using the kaolin-chitosan composite biosorbent: sorption kinetics and elemental analysis. Austrian Journal of Technical and Natural Sciences 2026, No. 7–8, 18–24. https://doi.org/10.29013/AJT-26-7.8-18-24
Other articles of the issue
