Adsorption of Cu (II) on ceramic structures made from Greek fly ash.

Fly ash is produced as an important by-product of coal combustion in power plants. The annual production of fly ash in Greece reaches 9 million tones. In the present study the potential of utilizing fly ash as a means of heavy metals removal from industrial effluents has been examined. Ceramic structures in the form of pellets have been produced in a laboratory scale pelletizing machine. The fly ash examined, is derived from Megalopolis power plant in southern Greece. The material before shaping was pulverized under 90 mu m. Surface area as well as physical and chemical characterization of fly ash as raw material was performed by means of SEM, XRD and AAS. The physicochemical characterization of fly ash shows that it is a material rich in silicon and aluminum. The parameters studied on pellets include abrasion resistance, porosity and size distribution. Due to the pozollanic properties of fly ash the pellets developed adequate mechanical strength after curing under wet conditions. These structures have been tested as sorbents of Cu (II) ions from aqueous solutions. The results show good adsorption capacity and low desorption. Furthermore there is evidence of potential adsorption of other heavy metals cations i.e. Pb (II), Cd (II) and Zn (II) on these structures. This indicates that ceramic structures from coal fly ash have the capacity for fixation of heavy metals thus rendering the possibility of their utilization as purifying agents for industrial effluents.