Studies on the removal of Cobalt(II) from aqueous solutions by adsorption with Ficus benghalensis leaf powder through response surface methodology

Suitability of Ficus benghalensis leaf powder for the adsorptive removal of Cobalt(II) from aqueous solutions is exhaustively studied and is reported in this article. Experimentation based on response surface methodology is conducted to understand the interaction among the variables—metal ion concentration, adsorbent dosage, initial solution pH and temperature that are of significance in the treatment. A 20?mg?L^?1 of Cobalt(II) solution, treated with 25?g?L^?1 of adsorbent at a pH of 5.0 and a temperature of 303?K, yielded 98.73% removal of Cobalt(II). Langmuir isotherm proved to be a better model representation of the equilibrium. Adsorption kinetics is of pseudo second rate form. Maximum sorption capacity of F. benghalensis leaf powder, q_max, is found to be 5.65?mg?g^?1. Adsorption is endothermic and spontaneous in nature. Study on surface morphology is included in the study.