Removal of Chromium (VI) from Water by Using Carbon Nanotubes

This study was carried out to evaluate the environmental application of carbon nanotubes through the experiment removal of Chromium (VI) from water. The matrix design has been developed in this experimental runs in order to find the optimal condition of the Cr (VI) removal from water. To achieve the objectives of the study, four independent variables including pH, adsorbent dosage, time contact and its agitation speed were carried out to determine the influence of these parameters on the adsorption capacity of the Chromium (VI). Multi wall carbon nanotubes (MWCNTs) were characterized by filed emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) in order to measure the diameter and the length of the adsorbent. The diameter of the carbon nanotubes were varied from 20-40 nm with average diameter at 24 nm and 10 micrometer in length. Adsorption isotherms were used in order to model the adsorption behavior and to calculate the adsorption capacity of the absorbents. The results showed that, carbon nanotubes (CNTs) at pH 7, 150 rpm, and 2 hours achieved 100 % of Cr (VI) removal. These high removal efficiencies were likely attributed to the strong affinity of Chromium (VI) to the physical and chemical properties of the CNTs. The adsorption isotherms plots were well fitted with experimental data.