In the present study, walnut shell powder (NIWSP) was explored as potential adsorbent for removal of Brilliant Blue FCF (BBF); a toxic triphenylmethane dye from aqueous solution using batch process. The parameters, such as, initial dye concentration, adsorbent dosage, temperature and pH, influencing the process of biosorption were studied. Kinetic studies were performed using pseudo first-order and pseudo second-order equations. The absorption parameters were determined using Langmuir and Freundlich isotherm models. The latter gave good fitting to the experimental data. The thermodynamic parameters, like, change in enthalpy (∆H°), entropy (∆S°) and Gibbs free energy (∆G°) of adsorption system were also determined and evaluated. Scanning electron microscopy and Fourier transform infrared spectroscopy were used for the surface characterization of the adsorbent.
