The study of thermodynamics and kinetics methyl orange and malachite green by SWCNTs, SWCNT-COOH and SWCNT-NH2 as adsorbents from aqueous solution

The effective removal of dyes from aqueous wastes is among the most important issues for many industrialized countries. Removal of methyl orange (MO) and malachite green (MG) from aqueous solutions were studied using single-walled carbon nanotubes (SWCNTs), carboxylate functionalized single-walled carbon nanotubes (SWCNT-COOH) and amide functionalized single-walled carbon nanotubes (SWCNT-NH2). The adsorption process was found to be controlled by temperature, ionic strength, initial concentration, adsorbent dosage and contact time. The microstructure of carbon nanotubes was characterized using SEM and FTIR. The adsorbents studied exhibits high efficiency for MO and MG adsorption and the equilibrium states could be achieved in 20, 20, 15 (min) for SWCNTs, SWCNT-COOH, SWCNT-NH2, respectively. Adsorption capacity of each adsorbent increased with increasing active groups on the surface of carbon nanotube, where SWCNT-NH2 was the most effectively adsorbent.