Browsing by Subject "Freundlich isotherm model"

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    Adsorption of thorium (IV) by amorphous silica; response surface modelling and optimization
    (Springer Netherlands, 2018) Kaynar U.H.; Şabikoğlu İ.
    The amorphous SiO2 (200–300 nm) was synthesized as an absorbent and thorium adsorption of SiO2 was investigated using experimental and RSM method. The SiO2 particles were made for the adsorption of thorium from aqueous solutions, and characterized by particle size measurement, XRD and SEM. The adsorption of thorium process was optimized with RSM method. The correlation between four variables was modeled and studied. Under optimum conditions, the adsorption capacity of SiO2 particles was found to be 134.4 mg/g, the correlation coefficient (R2) and the F value was obtained 0.96 and 1.98 × 10−6, respectively. In addition, the adsorption isotherms were examined. © 2018, Akadémiai Kiadó, Budapest, Hungary.
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    Removal of lead from aqueous solutions by low cost and waste biosorbents (lemon, bean and artichoke shells)
    (IWA Publishing, 2020) Ergüvenerler F.; Targan Ş.; Tirtom V.N.
    Simple, fast, effective, low cost and waste biosorbents, lemon, bean and artichoke shells, were used to remove lead (II) ions from aqueous solution. The influence of pH, contact time, temperature and lead (II) concentration of the removal process was investigated. The sufficient contact time was deemed 10 minutes for bean and artichoke shells and 60 minutes for lemon shells for Pb(II) ions. The thermodynamic parameters, such as standard free energy (AG), standard enthalpy (AH), and standard entropy (AS) of the adsorption process were calculated as -5.6786, -5.5758, -3.1488 kJmol- 1 for AG, -7.2791, -20.285, -9.5561 kJ mol-1 for AH, -0.00545, -0.05017, -0.02185 kJ mol-1 K-1 for AS, respectively, for lemon, artichoke and bean shells. Maximum adsorption capacities of lead (II) were observed as 61.30 m g g - 1, 88.5 mgg- 1 and 62.81 m g g - 1, respectively, for lemon, bean and artichoke shells according to the Freundlich isotherm model at 20 °C. Scanning electron microscope (SEM) and energy-dispersive X-ray detector (EDX) were used to characterize the surface morphology of the adsorbents. Consequently, Pb(II) removal using lemon, bean and artichoke shells would be an effective method for the economic treatment of wastewater. © IWA Publishing 2020 Water Science & Technology