Preparation and characterisation of nZnO/fly ash composite

Abstract

Composite material involving fly ash and nZnO was prepared by dispersion technique. The nature, morphology and the properties of the precursors and the composite were determined and compared by scanning electron microscopy, surface area determination by BET, and x-ray diffraction. The ash and carbon contents, particle size, pH and point of zero charge of the materials were also investigated. Experimental results showed that the surfaces of fly ash and nZnO are positively charged and will be favourable to the sorption of anionic complexes and heavy metals while the surface of nZnO/fly ash is negatively charged and will be suitable for the sorption of cationic complexes. Results also showed that the composition of fly ash and nZnO contributed to the development of intergranular voids and crevices which improved the surface and micropore areas of nZnO/fly ash composite. This resulted in higher sorption capacity of nZnO/fly ash composite material. Due to the presence of nano oxides in the composite material, it is also expected that the remediation mechanism by nZnO/fly ash composite will combine the synergistic effect of adsorption and oxidation when it is used for the remediation of environmental pollutants from wastewaters and not adsorption alone