Document Type : Research Paper


1 Ministry of Environment, Baghdad, Iraq.

2 Civil Engineering Department,University of Technology-Iraq, Alsina’a street, 10066 Baghdad, Iraq.

3 Kut Technical Institute, Middle Technical University, Iraq.


This work is an attempt to remove cadmium (II) from wastewater by adsorption on multi-walled carbon nanotubes (MWCNTs) and functional group of carbon nanotubes (fMWCNTs) by using the batch process system and continuous reactor. In the batch reactor, the main variables that govern process efficiency such as the initial Cd (II) concentration, MWCNTs dose, contact time, stirring speed, and pH were studied. The experiments revealed that the amount of cadmium absorption (II) was higher on the increasing fMWCNTs dose and stirring speed. In addition, it decreased significantly with a decrease in the initial concentration of cadmium. The optimum values for the ratio of the acidic function in solution 5.5, the absorbent dose (fMWCNTs) 1 g in 100 ml of Cd (II) solution, and the contact time was 30 minutes, in addition to C0 of 125 mg per liter of the cadmium ion with mixing speed (stirring) 100 rpm, these are the optimum values by which the cadmium ion removal efficiency was obtained for no more than 99%. Equilibrium data were better explained by the Freundlich isotherm model which was converted inside what was achieved with 30 minutes of Cd + 2.


  • Functionalized MWCNTs show better dispersibility in water.
  • In addition to its far lower with decreasing of the initial concentration of the cadmium. The optimum pH values was 5.5 ,the dose of adsorbent was 1g functionalized  Multi Wall carbon Nanotubes(f-MWCNTs) /100 ml of Cd+2.
  • The Freundlich isotherms model is fitted for Cd(II).
  • The exhaustion time and breakthrough are decreased as initial heavy metal ion molecules concentration increase.


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