Optimization, Kinetic and Thermodynamic Studies on Biosorption and Bio-reduction of Chromium Hexavalent by Myrtus communis Leaves

Aims: The efficiency of Myrtus communis leaves to eliminate Cr(VI) from aqueous solutions has been investigated. Background: Optimization, kinetic and thermodynamic studies on bio-sorption and bioreduction of Cr(VI) by Myrtus communis leaves. Objective: To eliminate Cr(VI) from aqueous solutions. Method: Batch mode studies, kinetic and thermodynamic studies. Result: The maximum bio-removal was obtained at an initial Cr(VI) concentration of 100 mg/L, biomass of 0.150 g, pH 2, and a temperature of 25°C. The modeling study has shown that the bio-removal kinetics obeyed the pseudo-second-order model along with an R2= 0.9947. Conclusion: A total removal of Cr(VI) after 60 minutes has been noticed. Also, the kinetic studies have indicated that the bioreduction of Cr (VI) to Cr (III) coupled with biosorption was produced on biomass sites. Based on the determined thermodynamic parameters (Gibbs energy (ΔG0), enthalpy (ΔH0), and entropy (ΔS0)), the bio-removal process was found to be endothermic and spontaneous in nature. Other: Myrtus communis leaves powder was characterized by spectroscopy (FTIR) and scanning electron microscope analysis (SEM-EDX).