Activated graphene oxide-calcium alginate beads for adsorption of methylene blue and pharmaceuticals

Burcu Gunes, Yannick Jaquet, Laura Sánchez, Rebecca Pumarino, Declan McGlade, Brid Quilty, Anne Morrissey, Zahra Gholamvand, Kieran Nolan, Jenny Lawler

Research output: Contribution to journalArticlepeer-review


The remarkable adsorption capacity of graphene-derived materials has prompted their examination in composite materials suitable for deployment in treatment of contaminated waters. In this study, crosslinked calcium alginate–graphene oxide beads were prepared and activated by exposure to pH 4 by using 0.1M HCl. The activated beads were investigated as novel adsorbents for the removal of organic pollutants (methylene blue dye and the pharmaceuticals famotidine and diclofenac) with a range of physicochemical properties. The effects of initial pollutant concentration, temperature, pH, and adsorbent dose were investigated, and kinetic models were examined for fit to the data. The maximum adsorption capacities qmax obtained were 1334, 35.50 and 36.35 mg g−1 for the uptake of methylene blue, famotidine and diclofenac, respectively. The equilibrium adsorption had an alignment with Langmuir isotherms, while the kinetics were most accurately modelled using pseudo-first-order and second order models according to the regression analysis. Thermodynamic parameters such as ∆G, ∆H and ∆S were calculated and the adsorption process was determined to be exothermic and spontaneous.

Original languageEnglish (US)
Article number6343
Issue number21
StatePublished - Nov 1 2021
Externally publishedYes


  • Adsorption
  • Graphene oxide
  • Isotherms and thermodynamics
  • Kinetics
  • Methylene blue
  • Pharmaceuticals

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics


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