LAUSR

Fundamental research of inorganic polymers prepared from available aluminosilicate precursors represent an innovative class of materials characterized by low energy consumption for production. This is just one of the reasons why their use is focused in protecting the environment for removing of heavy metals from aqueous solutions. The concentration of hydroxide as activator solution plays an important role in the geopolymerization process. The present study examined the use of geopolymer materials, obtained in reaction of geopolymerizations of metakaolin as precursor activated with NaOH concentration 2.0, 4.0, 6.0 and 8.0 mol/dm 3 for removal of cadmium ions from aqueous solutions. The structure and properties of the obtained geopolymer samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflection infrared spectroscopy (DRIFTS). To investigate the surface charge of geopolymers the zeta potential measurements were performed. Batch adsorption experiments conducted at room temperature (23 ± 1 °C) showed that the adsorption pattern followed the Freundlich isotherm model. The maximum removal of cadmium obtained from batch studies was 84.1% for GP6M at pH ≈ 6.7. The results generally showed that geopolymer samples could be considered as a potential adsorbent for cadmium removal from aqueous solutions.