The adsorption of Cd(II) from aqueous solution by synthesized zeolite NaX from coal gangue was investigated in a batch adsorption system. The studies include both equilibrium adsorption isotherms and kinetics. Different isotherm models were examined and the adsorption isotherm could be best represented with Langmuir. The adsorption kinetic experimental data were found to be better fitted with the pseudo-second-order kinetic model. An intra-particle diffusion model was employed to investigate the adsorption mechanism. The results showed that the intra-particle diffusion step was not the only rate limiting step. According to the Langmuir equation, the maximum adsorption capacity was 38.61 mg/g, suggesting that zeolite NaX synthesized from coal gangue can be used as a potential green alternative for the removal of Cd(II) from aqueous solution.
- coal gangue
- zeolite NaX
- First received 3 August 2016.
- Accepted in revised form 23 September 2016.
- © IWA Publishing 2016