Batch removal of hazardous azo dye Bismark Brown R using waste material hen feather

The adsorption of dye Bismark Brown R has been investigated at 30, 40 and 50 °C temperatures. Various essential factors affecting the extent of adsorption like, adsorbent dosage, dye concentration, pH and contact time have been analyzed. On the basis of Langmuir adsorption isotherms feasibility of the ongoing adsorption has been ascertained and thermodynamic parameters have been calculated. Attempts have also been made to verify Freundlich, Tempkin and D-R adsorption isotherm models. The experimental data has been applied to the various isotherms and their constant parameters have been determined. The mean adsorption energy obtained through the D-R isotherm gave an understanding about the nature of the adsorption occurring in the removal process. Determination of various thermodynamic parameters such as free energy, entropy etc. have been accomplished with the help of Langmuir isothermal data. It has also been established that the ongoing adsorption follows a pseudo second order kinetics at all the temperatures and value of the rate constant have been determined as 3.57, 3.51 and 4.55 g mol−1 s−1 at 30, 40 and 50 °C temperatures, respectively. The mathematical treatment on the kinetic data reveals that at all the temperatures the rate determining step is governed through film diffusion at lower as well as at higher concentration ranges.