Isotherm and kinetic studies on the adsorption of humic acid molecular size fractions onto clay minerals

  • Mohamed E. A. El-SayedEmail author
  • Moustafa M. R. Khalaf
  • James A. Rice
Original Article


Humic acid (HA) can adsorb onto mineral surfaces, modifying the physicochemical properties of the mineral. Therefore, understanding the sorption behavior of HA onto mineral surfaces is of particular interest, since the fate and transport of many organic and inorganic contaminants are highly correlated to HA adsorbed onto clay surfaces. Due to the extreme heterogeneity of HA, the extracted IHSS Leonardite humic acid (LHA) used in this work was fractionated using an ultrafiltration technique (UF) into different molecular size fractions (Fr1, > 0.2 µm; Fr2, 0.2 µm–300,000 daltons; Fr3, 300,000–50,000 daltons; Fr4, 50,000–10,000 daltons; Fr5, 10,000–1000 daltons). Equilibrium and the kinetics of LHA and fraction adsorption onto kaolinite and montmorillonite were investigated. The results demonstrated that the maximum adsorption capacity of LHA, Fr1, Fr2, Fr3, Fr4, and Fr5 was 5.99, 13.69, 10.29, 7.02, 5.98, and 5.09 on kaolinite while it was 8.29, 22.62, 13.17, 8.91, 8.62, and 5.69 on montmorillonite, respectively. The adsorption equilibrium data showed that the adsorption behavior of LHA and its fractions could be described more practically by the Langmuir model than the Freundlich model. The rate of humic acid fraction adsorption onto clays increased with decreasing molecular size fraction and increasing carboxylic group content. Pseudo-first- and second-order models were used to assess the kinetic data and the rate constants. The results explained that LHA and its fractions adsorption on clay minerals conformed more to pseudo-second-order.


Kaolinite Montmorillonite Leonardite humic acid Humic acid fractions Kinetics Equilibrium 



This work was funded by a Fulbright Visiting Scholar fellowship to Mohamed El-sayed and performed at South Dakota State University.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


  1. Al-Essa K, Khalili F (2018) Adsorption of humic acid onto Jordanian kaolinite clay: effects of humic acid concentration, pH, and temperature. Sci J Chem 6(1):1–10CrossRefGoogle Scholar
  2. Asfaram A, Ghaedi M, Agarwal Sh, Tyagib I, Gupta VK (2015) Removal of basic dye Auramine-O by ZnS: Cu nanoparticles loaded on activated carbon optimization of parameters using response surface methodology with central composite design. RSC Adv 5:18438–18450CrossRefGoogle Scholar
  3. Bhattacharyya G, Gupta SS (2008) Kaolinite and montmorillonite as adsorbents for Fe(III), Co(II) and Ni(II) in aqueous medium. Appl Clay Sci 41:1–9CrossRefGoogle Scholar
  4. Chang MY, Juang RS (2005) Equilibrium and kinetic studies on the adsorption of surfactant, organic acids and dyes from water onto natural biopolymers. Colloid Surf A Physicochem Eng Asp 269:35–46CrossRefGoogle Scholar
  5. Derakhshani E, Naghizadeh A (2018) Optimization of humic acid removal by adsorption onto bentonite and montmorillonite nanoparticles. J Mol Liq 259:76–81CrossRefGoogle Scholar
  6. Dunnivant FM, Jardine PM, Taylor DL, McCarthy JF (1992) Transport of naturally occurring dissolved organic carbon in laboratory columns containing aquifer material. Soil Sci Soc Am J 56:437CrossRefGoogle Scholar
  7. El-sayed MEA, Khalaf MMR, gibson D, Rice JA (2019) Assessment of clay mineral selectivity for adsorption of aliphatic/aromatic humic acid fraction. Chem Geol 511:21–27CrossRefGoogle Scholar
  8. Feng X, Simpson JA, Simpson JM (2005) Chemical and mineralogical controls on humic acid sorption to clay mineral surfaces. Org Geochem 36:1553–1566CrossRefGoogle Scholar
  9. Freundlich HMF (1906) Over the adsorption in solution. Phys Chem 57(1):385–470Google Scholar
  10. Ghaedi M, Hajjati S, Mahmudi Z, Tyagi I, Agarwal Sh, Maity A, Gupta VK (2015) Modeling of competitive ultrasonic assisted removal of the dyes—methylene blue and Safranin-O using Fe3O4 nanoparticles. Chem Eng J 268:28–37CrossRefGoogle Scholar
  11. Helal AA, Murad GA, Helal AA (2011) Characterization of different humic materials by various analytical techniques. Arab J Chem 4:51–54CrossRefGoogle Scholar
  12. Khalaf M (2003) Effect of the fractionation and immobilization on the sorption properties of humic acid. PhD thesis, Institut für Chemie und Dynamik der Geosphäre Institut IV: Agrosphäre, Jül-4046, ISSN 0944-2952Google Scholar
  13. Khalaf M, Mourad A, Heggy S, El-Sayed M (2009) Influence of pH and ionic strength on the adsorption of humic acid onto montmorillonite and kaolinite. El-Minia Sci Bull 20(1):21–34Google Scholar
  14. Komy ZR, Shaker AM, Heggy SEM, El-Sayed Mohamed EA (2014) Kinetic study for copper adsorption onto soil minerals in the absence and presence of humic acid. Chemosphere 99:117–124CrossRefGoogle Scholar
  15. Langmuir I (1916) The constitution and fundamental properties of solids and liquids. Part I. Solids. J Am Chem Soc 38:2221–2295CrossRefGoogle Scholar
  16. Li L, Zhao Z, Huang W, Peng P, Sheng G, Fu J (2004) Characterization of humic acids fractionated by ultrafiltration. Org Geochem 35:1025–1037CrossRefGoogle Scholar
  17. Maghoodloo Sh, Noroozi B, Haghi AK, Sorial GA (2011) Consequence of chitosan treating on the adsorption of humic acid by granular activated carbon. J Hazard Mater 191:380–387CrossRefGoogle Scholar
  18. Mukasa-Tebandeke IZ, Ssebuwufu PJM, Nyanzi SA, Schumann A, Nyakairu GWA, Ntale M, Lugolobi F (2015) The elemental, mineralogical, IR, DTA and XRD analyses characterized clays and clay minerals of central and eastern Uganda. Adv Mater Phys Chem 5:67–86CrossRefGoogle Scholar
  19. Murphy EM, Zachara JM (1995) The role of sorbed humic substances on the distribution of organic and inorganic contaminants in groundwater. Geoderma 67:103–124CrossRefGoogle Scholar
  20. Nagao S, Aoyama M, Watanabe A, Tanaka T (2009) Complexation of Am with size fractionated soil humic acids. Colloids Surf A 347:239–244CrossRefGoogle Scholar
  21. Noroozi B, Sorial G, Bahrami AH, Arami MJ (2007) Equilibrium and kinetic adsorption study of a cationic dye by a natural adsorbent—Silkworm pupa. Hazard Mater B139:167–174CrossRefGoogle Scholar
  22. Purmalis O, Klavins M (2013) Comparative study of peat humic acids by using UV spectroscopy. In: 1st annual international interdisciplinary conference, AIIC 2013, 24–26 April, Azores, PortugalGoogle Scholar
  23. Shaker AM, Komy ZR, Heggy S, El-sayed Mohamed EA (2012) Kinetic study for adsorption humic acid on soil minerals. J Phys Chem A 116:10889–10896CrossRefGoogle Scholar
  24. Shang Ch, Rice JA, Lin J (2001) Thickness and surface characteristic of colloidal 2:1 aluminosilicates using an indirect Fourier transform of small-angle X-ray scattering data. Clays Clay Miner 49(4):277–285CrossRefGoogle Scholar
  25. Swift RS (1991) In: Wilson WS (ed) Advances in soil organic matter research: the impact on agriculture and the environment. The Royal Society of Chemistry, Cambridge, p 153Google Scholar
  26. Tanaka T (2012) Functional groups and reactivity of size-fractionated Aldrich humic acid. Thermochim Acta 532:60–64CrossRefGoogle Scholar
  27. Tombácz E, Zs Libor, Illés E, Majzik A, Klumpp E (2004) The role of reactive surface sites and complexation of clay mineral and iron oxide particles. Org Geochem 35:257–267CrossRefGoogle Scholar
  28. Wu FC, Tseng RL, Huang SC, Juang RS (2009) Characteristics of pseudo-second-order kinetic model for liquid-phase adsorption: a mini-review. Chem Eng J 151:1–9CrossRefGoogle Scholar
  29. Zaouri N (2013) The adsorption of different fractions of organic matter on the surface of metal oxide. MSc thesis, King Abdullah University of Science and Technology, Kingdom of Saudi ArabiaGoogle Scholar
  30. Zhang L, Luo L, Zhang Sh (2012) Integrated investigations on the adsorption mechanisms of fulvic and humic acids on three clay minerals. Colloids Surf A Physicochem Eng Asp 406:84–90CrossRefGoogle Scholar

Copyright information

© Science Press and Institute of Geochemistry, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Mohamed E. A. El-Sayed
    • 1
    • 2
    Email author
  • Moustafa M. R. Khalaf
    • 1
    • 3
  • James A. Rice
    • 1
  1. 1.Department of Chemistry and BiochemistrySouth Dakota State UniversityBrookingsUSA
  2. 2.Soils, Water, and Environmental Research InstituteAgriculture Research CenterEl-GizaEgypt
  3. 3.Chemistry Department, Faculty of ScienceMinia UniversityEl-MiniaEgypt

Personalised recommendations