Adsorption properties of modified Saraca asoca bark powder towards Ni(II) ions

Abstract

In this present study, phosphate-modified Saraca asoca bark powder was used to bring out an efficient bioadsorbent for nickel (II) ion uptake from wastewater. The bioadsorbent was characterized using scanning electron microscopy and Fourier transform infrared spectroscopy. The effect of various parameters such as pH, contact time, initial concentration and temperature were examined using the batch experimental process. The adsorption of nickel(II) was found to increase with the increase in concentration. The used bioadsorbent proved to be highly efficient and adsorbed 96% of nickel(II) from the aqueous solution at pH 4-6. The adsorption equilibrium data were described by using various isotherm models i.e. Langmuir, Freundlich, Temkin and Dubinin-Radhuskevic. Langmuir and pseudo-secondorder-kinetic were found to be best-fitted isotherm and kinetic models, respectively. Thermodynamic parameters showed the spontaneous and endothermic nature of the adsorption process. Succesful desorption of Ni(II) confirms the reusability of the bioadsorbent. The samples from real electroplating wastewater were collected to better examine the applicability of phosphate-modified Saraca asoca bark powder towards nickel(II) ions.