Abstract:
Carbon nanotubes were used to study the adsorption behavior of arsenic (As) found
in aqueous media and its effect in the adsorption efficiency when they are modified with certain trace
metals onto the multi- walled carbon nanotubes (MCNTs) as adsorbents. Iron, titanium, silver, gold,
copper were made to be impregnated on the CNTs for this study. The effect on the surface functional
group of the carbon nanotubes were further studied on the removal of As. Batch experiments were
performed to study the effect of the As removal in the aqueous media, the independent variables
considered are pH, contact time and agitation speed. The morphology of the CNTs were characterized
by using field emission scanning electron microscopy (FESEM) and transmission electron microscopy
(TEM) which indicates the dimensions of the adsorbents and the impregnation were seen before and
after the adsorbents were made. Results of the study showed that iron and titanium impregnated on
the surface of the CNT has the highest As removal percentage compared to pure CNT and the
functionalized CNT with carboxylic group. Almost 70% of the As was removed from the water that
contained 1 mg/L initial arsenic contamination. The highest removal was at pH 3, contact time of 24
hours and agitation speed of 200 RPM. Part of the study is also dedicated to investigate the effect of
dosage in the removal of arsenic from water.
