Comparative studies on adsorptive removal of heavy metal ions by biosorbent, bio-char and activated carbon obtained from low cost agro-residue


KIRBIYIK Ç., PÜTÜN A. E., Putun E.

WATER SCIENCE AND TECHNOLOGY, cilt.73, sa.2, ss.423-436, 2016 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 73 Sayı: 2
  • Basım Tarihi: 2016
  • Doi Numarası: 10.2166/wst.2015.504
  • Dergi Adı: WATER SCIENCE AND TECHNOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.423-436
  • Anahtar Kelimeler: adsorption, biosorption, heavy metal, isotherm, kinetic, thermodynamic, AQUEOUS-SOLUTION, WASTE-WATER, HEXAVALENT CHROMIUM, AQUATIC PLANT, FE(III) IONS, KINETICS, BIOSORPTION, CR(III), BIOMASS, EQUILIBRIUM
  • Anadolu Üniversitesi Adresli: Evet

Özet

In this study, Fe(III) and Cr(III) metal ion adsorption processes were carried out with three adsorbents in batch experiments and their adsorption performance was compared. These adsorbents were sesame stalk without pretreatment, bio-char derived from thermal decomposition of biomass, and activated carbon which was obtained from chemical activation of biomass. Scanning electron microscopy and Fourier transform-infrared techniques were used for characterization of adsorbents. The optimum conditions for the adsorption process were obtained by observing the influences of solution pH, adsorbent dosage, initial solution concentration, contact time and temperature. The optimum adsorption efficiencies were determined at pH 2.8 and pH 4.0 for Fe(III) and Cr(III) metal ion solutions, respectively. The experimental data were modelled by different isotherm models and the equilibriums were well described by the Langmuir adsorption isotherm model. The pseudo-first-order, pseudo-second-order kinetic, intra-particle diffusion and Elovich models were applied to analyze the kinetic data and to evaluate rate constants. The pseudo-second-order kinetic model gave a better fit than the others. The thermodynamic parameters, such as Gibbs free energy change Delta G degrees, standard enthalpy change Delta H degrees and standard entropy change Delta S degrees were evaluated. The thermodynamic study showed the adsorption was a spontaneous endothermic process.