Abstract
M.Sc.
Improper disposal of industrial effluents that contain heavy metals such as mercury causes a threat to the environment due to the toxic effects of such matal even at low concentrations. It is also known that sewage waste in water contains bacteria that pose a health hazard to human beings, animals and micro-organisms. One major concern is the transmission of diseases through drinking this water; which destabilizes the water supply. Water for human consumption therefore needs to be of high quality. In this study copper-containing multiwalled carbon nanotubes (Cu/MWCNTs) were investigated for their ability to remove and kill mercury (Hg2+) and Escherichia coli (E. coli), a major species found in the coliform bacteria. These Cu/MWCNTs were synthesized “in situ” by using an electric arc-discharge apparatus and separately via one of two multi-step wet chemical techniques namely; an electroless plating and impregnation method respectively. MWCNTs used for the wet techniques were synthesized by a nebulized spray pyrolysis (NSP) process using ferrocene/toluene under argon flow.
These MWCNTs were purified and functionalized to introduce functional groups that made provision for the nucleation of the copper metal on the surface of MWCNTs. Infrared spectroscopy confirmed the successful introduction of COOH and O-H groups on the surface of MWCNTs. Raman spectroscopy confirmed a relative increase in the intensity the ratio of the D-band after functionalization. Deposition of the copper nanoparticles by electroless plating method in different volumes of 100 ml, 80 ml and 60 ml produced copper nanoparticles of varying sizes and distribution on the surface of MWCNTs. SEM images revealed densely and homogeneously distributed small sized copper nanoparticles that followed the trend; 100 ml> 80 ml > 60 ml. The volume proved to be a critical factor of the electroless plating bath with an increase or decrease of the volume affecting the concentration of the Cu2+ ions and HCHO, which also affected the pH of the plating solution.