The influence of an electrolyte on the adsorption of 4-chlorophenol onto activated carbon and multi-walled carbon nanotubes

Abstract

The adsorption of 4-chlorophenol from deionized water and electrolyte solutions onto activated carbon and carbon nanotubes has been studied. The kinetics data were fitted well to the pseudo-second order model. It was found that inorganic salts enhanced the adsorption kinetics onto the carbon nanotubes but did not affect the adsorption kinetics onto the activated carbon. The adsorption was also analyzed as a function of the solution concentration at the equilibrium. The experimental data received were found to be well described by the Freundlich isotherm equation. The experimental data indicated that the presence of salts in the solution did not significantly affect the capacity of the adsorption of the MWCNTs. The adsorption capacity of the activated carbon for the 4-chlorophenol was higher in the electrolyte solutions than in the water, and further indicated that the removal of the 4-CP increased with the increase in the ionic strength of the solution.