Abstract
M.Sc.
Safe drinking water is an essential resource for human survival, health, dignity
and development. However, this vital resource has become scarce mainly due
to population growth, economic activity, climate change and pollution.
Treatment of polluted water is expensive and does not always ensure delivery
of safe drinking water to humans. Reports on the detection of pollutants such
as organics, bacteria, inorganics and the occurrence of toxic disinfection byproducts
in treated water in distribution systems have necessitated further
research in improving water treatment methods.
Metal impregnated carbon nanotube incorporated into cyclodextrin
polyurethanes were synthesised by first functionalising carbon nanotubes and
then impregnating them with metal nanoparticles. The resultant product was
confirmed using Transmission electron microscopy (TEM). The metal
nanoparticles were found to have a diameter range of 6 to 35 nm. The metal
impregnated carbon nanotubes were then polymerised to produce cyclodextrin
polyurethanes. The polymers were characterised using various techniques
such as Scanning electron microscopy (SEM), Emission dispersive X-ray
spectrometry (EDX) and Brunauer-Emmet-Teller analysis. The metal
nanoparticles were found to be part of the polymers through EDX and the
polymers’ surface areas were measured to be 0.78 and 0.3383 m2/g for silver
and copper polymers, respectively.
The synthesised polymers were tested for their efficacy at destroying
pathogenic bacteria from water. The polymers were found to inactivate bacteria
by up to 4 logs from spiked water samples. These metal impregnated polymers
when compared to native carbon nanotubes and cyclodextrin polymers had an
enhanced antibacterial property. In environmental samples, metal impregnated
polymers destroyed up to 3 logs of bacteria. There was complete removal of
bacteria from filtered environmental water samples. Factors affecting the
polymers’ efficacy were turbidity, nature of sample and the ratio of bacterial
cells removed per gram of polymer.