Abstract
In this research, polymer gels sodium alginate/bentonite clay adsorbent beads (SA/Ben) were prepared via encapsulating natural bentonite (Bn) in sodium alginate (SA). The ratio of Polymer Gels SA/Bn was used during preparation bead to yield beads (1/1 w/w), SA-Bn2 (1/2 w/w), and SA-Bn3 (1/3 w/w), respectively. These adsorbents were characterized via different characterisation FESEM, TEM, XRD and EDX to give high confidence of the prepared surface. The adsorption of Clonazepam drug (CLZ) from aqueous solution on the SA/Bn beads was investigated as a function of different factors, including the initial concentration of CLZ, the weight of SA/Bn beads gel, pH solution, temperature of solution and equilibrium time. Adsorption models of Langmuir and Freundlich isotherms were applied and were found to be well described via the isotherm of Freundlich model. The results showed that among the three types of prepared surfaces SA/Bn beads, SA-Bn1 presented the greatest CLZ adsorption capacity. Thermodynamic parameters were calculated including change free of Gibbs energy (ΔG), change entropy (ΔS), and change enthalpy. The change enthalpy of CLZ drug adsorption was found to be positive for the SA/Bn bead and the reaction of adsorption spontaneous and exothermic. After the adsorption proses the SA/Bn beads can easily be regenerated via water and re-used within four cycles.
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