Kinetics, thermodynamics and regeneration of molybdenum adsorption in aqueous solutions with NaOCl-oxidized multiwalled carbon nanotubes

Multiwalled carbon nanotubes (MWCNTs) were modified by NaOCl solution and employed as adsorbents to study kinetics, thermodynamics and regeneration of molybdenum (Mo) adsorption from aqueous solutions. The amount of Mo adsorbed onto MWCNT(NaOCl) increased with increasing solution temperature indicating an endothermic reaction while the kinetics of Mo adsorption follows the pseudo- second-order rate law. The Mo ions could be efficiently desorbed from the surface of MWCNT(NaOCl) by 3.6 wt% NaOCl solution for 4 h. A comparative study on the cyclic Mo adsorption between MWCNT(NaOCl) and granular activated carbon (GAC) revealed that the MWCNT(NaOCl) possess higher capacity and less attrition of Mo adsorption through 10 cycles of adsorption and desorption. This suggests that the MWCNT(NaOCl) have good potential for Mo removal in wastewater treatment.