Fractal-like kinetics for adsorption of Pb (II) on graphene oxide/hydrous zirconium oxide/crosslinked starch bio-composite: Application of Taguchi approach for optimization Articles uri icon

authors

  • RAHMAN, NAFISUR
  • RAHEEM, ABDUR
  • AL-KAHTANI, ABDULLAH A.
  • PANDIT, BIDHAN
  • UBAIDULLAH, MOHD

publication date

  • July 2023

start page

  • 1

end page

  • 10

issue

  • 5,102712

volume

  • 35

International Standard Serial Number (ISSN)

  • 1018-3647

Electronic International Standard Serial Number (EISSN)

  • 2213-686X

abstract

  • This study deals with the decontamination of Pb (II) from aqueous environment using graphene oxide/hydrous zirconium oxide/crosslinked starch bio-composite (GZS-BC). Various instrumental techniques were used to characterize the GZS-BC. The main factors of Pb (II) sorption were optimized by Taguchi method. Under optimum conditions, (adsorbent dose: 40 mg, contact time: 180 min and initial Pb (II) concentration: 50 mg/L) maximum removal efficiency (98.50%) was achieved at pH 6. Various isotherm models were tested to fit the adsorption data and Freundlich isotherm model was the best fit model with high R2 values (0.9977-0.9983) and low values of x2 (0.01-0.02) and APE (0.90-1.14). The kinetic data were investigated using classical and fractal-like kinetic equations. The fractal-like mixed 1,2-order kinetic model was the best fit model which pointed towards heterogeneous surface of GZS-BC with more than one type of sorption sites. Thermodynamic study shows that Pb (II) sorption onto GZS-BC was spontaneous and endothermic in nature. The values of DG° indicated that physisorption together with chemisorption was responsible for uptake of Pb (II).

subjects

  • Chemistry
  • Industrial Engineering
  • Materials science and engineering

keywords

  • classical and fractal kinetics; graphene oxide/hydrous zirconium oxide/crosslinked starch bio-composite (gzs-bc); pb (ii); sorption; taguchi approach; thermodynamics