Removal of Heavy Metals from Waste Water by using Carbon Nano Tubes (CNT)

Keywords: Heavy Metals, Waste Water, carbon Nano Tubes

Heavy metals present in waste water such as (Lead, Magnesium, Nickel, Zinc and Cadmium) can be harmful and problematic if present at large quantities. It might lead to cancer and acute or chronic toxicity if the water containing heavy metals was used in irrigation of soil and food crops, also reducing the effectiveness of biosolids fertilizers which are organic materials rich in nutrients that are derived from domestic sewage treatment.

Deferent techniques might be used in the removal of heavy metals from waste water such as membrane separation, chemical precipitation in which the dissolved metals are transformed into an insoluble solid that precipitates and thus easily removed, ion exchange in which the heavy metals ions are exchanged with another ion of the same charge present on the surface of a fixed bed, and adsorption on a solid surface which in the case we are studying by using carbon nanotubes.

The definition of the term nano in a numerical way means that a certain unit is multiplied by 10 -9 .The word itself is derived from the ancient Latin language word dwarf, which in turns indicates an extremely small quantity. And according to the European union the term nanomaterials refers to ‘a natural or synthesized material in which half or more of the particles in the number size distribution, one or more external dimensions should range from 1 nm to 100 nm’.

The carbon nanotubes are defined as an allotropy or manner in which carbon atoms are formed in a cylindrical shape resembling hollow tubes. The diameter is nanometer sized while on the contrary the length is in centimeters with a length/diameter ratio exceeding 107. The deferent nanotubes resemble the shape of ropes that are held together by Vander wall attractive force.

The carbon nanotubes can be used in the removal of heavy metal from waste water due to their adsorption capabilities for both aromatic and aliphatic contaminants in water. And also for their ability to adsorb low molecular weight and polar contaminants.

Finally this paper highlights the potential of using carbon nano tubes in the removal of heavy metals from waste water. By using 250 mg of Multi-walled carbon nano tubes (MWCNTs) at pH 7.0 and 298 0K in 0.01 M KNO3 and after 10 min of adsorption we measuring the amount of heavy metals in waste water and then compare it with the initial amount of heavy metals in waste water. And finally comparing it by the results obtained from adsorption of heavy metals from waste water by using deferent adsorbents to evaluate its efficiency.