Biosorption of hexavalent chromium metal ions from an aqueous solution of leaves and bark of Cinnamomum verum via green route

In present research work Cinnamomum verum leaves (CL) and barks (CB) are exploited to encounter their effectiveness against the concentration of hexavalent chromium (Cr+6 metal ions) through biosorption process. To achieve this goal optimal conditions were set and broken into various parts such as; doses of adsorbents, concentrations of adsorbates, variations in contact and stirring time (5–100 min), temperatures (10 °C to 50 °C) and pHs from acidic to basic range (1 to 12). Thermodynamic parameters were also applied to validate the assay, which shows that the process is endothermic with positive ∆H° values, while negative values of ∆G° proved the spontaneous nature of sorption. Moreover, Lagergren’s kinetic equations were employed, which suggest that the observed reaction process followed the dynamics of pseudo-second order. Equilibrium adsorption isotherms namely Langmuir and Freundlich have been applied to study the adsorbate materials attraction towards Cr+6 metal ions. The determined adsorption capability, i.e. qe was found to be 11.33 and 26.85 mg/g acquired by CL and CB at 30 °C and 40 °C, respectively. FT-IR spectrums of loaded and unloaded metal ions were taken, which confirmed the participated functional groups of herbal plants in biosorption process. EDX analysis revealed the presence of Cr+6 metal ions after biosorption process. Furthermore, irregularities on surface of adsorbent material obtained from SEM images have provided more support to results for validation.