Biosorption of Cr(VI) Ions onto Walnut Flowers: Application of Isotherm Models

Biosorption of Cr(VI) ions onto Walnut Flowers (WF) is studied in a batch system in relation to the physical parameters. The efficiency approaches ۱۰۰% with ۵ g WF/L at pH~۱.۵  for a Cr(VI) concentration of ۱۰۰ mg/L in less than ۱ h. The experimental data are analyzed using two-parameter models (Langmuir, Freundlich, and Temkin), and three-parameter models (Redlich–Peterson, Sips, and Toth). In order to determine the best isotherm, two error analysis methods are used to evaluate the correlation coefficient and chi-square test. The error analysis demonstrates that the three-parameter models better describe the Cr(VI) biosorption data. The Sips equation provides the best fitting. The possible interaction between the Cr(VI) and the biosorbent surface was evaluated by FT-IR analyses. Overall, the proposed biosorbent material was successfully used for the removal of a Cr(VI) from contaminated solutions.

کلیدواژه ها:

Biosorption ، Cr(VI) ، Isotherm ، Models ، Walnut flower