Preparation and application of fly ash-based geopolymer for heavy metal removal
Aprilina Purbasari, Dessy Ariyanti, Siswo Sumardiono
Abstract
Geopolymer is anorganic polymer which can be used to heavy metal removal through adsorption process. Geopolymer can be produced from raw material containing alumino-silicate oxide such as fly ash which is solid waste from coal combustion. In this study, geopolymer was prepared from fly ash with alkali activation process using mixture of 10 N NaOH solution and Na-Silicate solution. Fly ash-based geopolymer was then applied as adsorbent for different heavy metals removal, i.e. Cu2+, Fe2+, Mn2+, Zn2+, in aqueous solutions. Removal efficiencies were calculated from changes of heavy metal concentration determined by Atomic Absorption Spectroscopy (AAS) analysis. Characterization of fly ash- based geopolymer covered Brunauer-Emmett-Teller (BET) surface area analysis and Scanning Electron Microscope- Energy Dispersive X-Ray (SEM-EDX) analysis. The results showed that fly ash-based geopolymer could adsorb heavy metals with better removal efficiency compared to the raw fly ash.