Browsing by Subject "Equilibrium adsorption"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Comparative adsorption of Ni(II) and Cd(II) ions on epichlorohydrin crosslinked chitosan-clay composite beads in aqueous solution
    (2012) Tirtom V.N.; Dinçer A.; Becerik S.; Aydemir T.; Çelik A.
    Removal of Ni(II) and Cd(II) by adsorption on epichlorohydrin crosslinked chitosan-clay composite beads was examined in solutions representative of contaminated solutions containing heavy metals. Several important parameters influencing the adsorption of Ni(II) and Cd(II) ions such as contact time, pH, temperature and effect of metal concentration were investigated systematically by batch experiments. Langmuir and Freundlich adsorption models were used to describe adsorption isotherms and constants. The obtained results showed that the equilibrium adsorption behavior of Ni (II) and Cd (II) on epichlorohydrin crosslinked chitosan-clay composite beads could be applied to Langmuir and Freundlich models respectively. Maximum adsorption capacities for Ni(II) and Cd(II) ions were found as 32.36mgg-1 and 72.31mgg-1 respectively. The recovery of the metal ions after adsorption and the regeneration of the adsorbent was carried out by treatment of the loaded beads with either 0.1M HNO3, or 0.01M EDTA. The adsorbents were characterized by FTIR, SEM and TGA analysis. © 2012 Elsevier B.V.
  • No Thumbnail Available
    Item
    Determination of adsorption capacities of NaX Nano-particles against heavy metals and dyestuff; [NaX Nano-taneciklerin ağır metal ve boyar maddelere karşı adsorpsiyon kapasitelerinin belirlenmesi]
    (Gazi Universitesi Muhendislik-Mimarlik, 2019) Yürekli Y.
    Adsorption is an effective method for the removing of heavy metals in the industrial waste water. Improvement of the efficiencies of the adsorbents can be possible by reduction of the particle size into nano scale. Therefore, in this study, zeolite nano-particles were synthesized by classical and microwave heating methods and then determined their adsorption capacities for the lead and nickel cations during batch adsorption processes carried out at 25C with different adsorbent loading and initial metal concentrations. Results obtained from X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis revealed that the synthesized zeolite nanoparticles was pure NaX with ultrafine and uniform particle sizes around 170 nm and Si/Al ratio of 1.24. Batch adsorption studies at 25C revealed that, NaX nanoparticles have high affinities against lead, nickel and methylene blue dye. As the initial metal and dye concentrations were increased, sorption capacity of the NaX was increased and reached the maximum value of 0.99, 1.33, 2.11, 1.89 and 0.15 mmol /g for the lead, nickel, copper, silver and methylene blue cations respectively. Sips model equation successfully described the equilibrium adsorption data of all adsorbates. Adsorption experiments of NaX for heavy metals from a real wastewater indicates that although the solution contains calcium and potassium ions in huge concentrations, the adsorbent is capable to adsorb lead and nickel even if they are low in concentrations. © 2019 Gazi Universitesi Muhendislik-Mimarlik. All rights reserved.