Removal of Co（Ⅱ） from aqueous solutions by NKC-9 strong acid resin

A strong acidic ion exchange resin（NKC-9）was used as a new adsorbent material for the removal of Co（Ⅱ）from aqueous solutions.The adsorption isotherm follows the Langmuir model.The maximum adsorption capacity of the resin for Co（Ⅱ）is evaluated to be 361.0 mg/g by the Langmuir model.It is found that 0.5 mol/L HCl solution provides effectiveness of the desorption of Co（Ⅱ）from the resin.The adsorption rate constants determined at 288,298 and 308 K are 7.12×10^-5,8.51×10^-5and 9.85×10^-5s^-1, respectively.The apparent activation energy（Ea）is 12.0 kJ/mol and the adsorption parameters of thermodynamic are-H Θ=16.1 kJ/mol,-SΘ=163.4 J/（mol·K）,-G Θ 298 K=-32.6 kJ/mol,respectively.The adsorption of Co（Ⅱ）on the resin is found to be endothermic in nature.Column experiments show that it is possible to remove Co（Ⅱ）ions from aqueous medium dynamically by NKC-9 resin.