Thermodynamics and Kinetics Studies of Pentachlorophenol Adsorption from Aqueous Solutions by Multi-Walled Carbon Nanotubes

The adsorption of pentachlorophenol (PCP) from aqueous solutions using pristine multi-walled carbon nanotubes (MWCNTs) was studied kinetically and thermodynamically. The results showed that MWCNTs are good adsorbents for the elimination of PCP from aqueous solutions in a very short time compared with activated charcoal. The kinetics study showed that the adsorption of PCP is mainly due to the diffusion of PCP from the aqueous phase to the solid phase beside intra-particle diffusion. This intra-particle diffusion was more significant for activated charcoal compared with MWCNTs. The equilibrium adsorption of PCP at different temperatures was studied, and the adsorption isotherms were well described using different adsorption models. Thermodynamics study showed that the adsorption process was product-favored (enhanced) as the temperature decreased.