Modelling studies for remediation of Cr (VI) from wastewater by activated Mangifera indica bark

Activated bark prepared from Mangifera indica was used for the removal of Cr(VI) from aqueous solution. Activated bark (AB) was characterized by some instrumental techniques such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermal analysis (TGA). The effect of different adsorption parameters such as metal ion concentration, adsorbent dosage, contact time, pH, and the temperature was optimized. Langmuir, Freundlich, and Tempkin’s isotherms were studied for the interpretation of experimental data. Langmuir model was found to be best fitted with a maximum adsorption capacity of 78.96 ​mg/g. The kinetic study was described by pseudo-first-order kinetics and Elovich model. Kinetic study indicates that physio-adsorption play major role in Cr(VI) removal from water system. The thermodynamic parameters such as energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°) were found to be spontaneous, feasible, and endothermic nature.