A Study of Cadmium, Nickel and Copper Adsorption Using Multi-walled Nanotubes

Water contaminated with heavy metals has harmful effects not only to human being but
the environment as well. Their non-biodegradable characteristic may possess possible
accretion in living organism and may accumulate to toxic concentration and causes
ecological damage under certain environmental condition. This dissertation promotes the
adsorption process of heavy metal ions by adopting Multi-walled Carbon Nanotubes
(MWNTs) as an adsorbent. MWNTs have been identified as promising materials for use
in a wide range of applications. In combination with the large surface area, they have
also strapped up with d-spacing more compatible with most heavy metal ions and
endowed with exceptionally high material properties such as electrical and thermal
conductivity, strength, stiffness, and toughness. Theoptimum contact time, effect of pH
and the effect of concentration were investigated. Experiments were done in a batch
process mode using water bath shaker at shaking speed of 200 rpm. The highest removal
efficiencyachieved at 99.8% for copper followed by 99.7%and 94.6% for cadmium and
nickel respectively. The affinity order was determined to be Cu (U) > Cd(H) > Ni(II).