FLY ASH BASED GEOPOLYMERS AS POTENTIAL ADSORBENT FOR COPPER REMOVAL FROM AQUATIC SOLUTIONS

Fly ash is recognized as by-product material from coal fired power station. Production of large quantity of fly ash impose the finding the solution of fly ash utilization. Currently, especial attention is given to the possibility of fly ash utilization through geopolymerization process into the construction materials. Moreover, fly ash is currently being investigated as an adsorbent for the wastewater treatment. Heavy metals are often present in the wastewaters and currently available methods for its cleanup generate a quantity of toxic sludge. In this paper we have investigated possibility of fly ash based geopolymers as potential adsorbent for copper removal from water solutions. Two methods have been used for synthesis of fly ash based geopolymes: (1) fusion method with NaOH synthesis and (2) mixing of fly ash with alkali solution prepared by mixing of sodium silicate solution (sodium water glass) and NaOH solution. Change of Cu2+ adsorption efficiency in a function of time was investigated. The results have shown that higher efficiency of Cu2+ removal was achieved using the fly ash based geopolymer prepared by fusion methods.