A Comparative Analysis of Pollutants Adsorption and Photocatalysis on Composite Materials Synthesized from Fly Ash

The composite materials were obtained from fly ash, collected from the electro filters of the Central Heat Power Plant from Brasov, Romania. This fly ash doesn’t aggregate in water and can form a new composite together with TiO2 and Al2Si2O7.2H2O. The raw ash combined with titanium oxide and silicate was modified by hydrothermal treatment under alkaline conditions. The new composites were characterized in terms of crystallinity (XRD), surface properties such as: morphology (SEM, AFM), wettability (contact angle measurements) and specific surface (BET). Simultaneous removal of heavy metals (Cd2+, Cu2+), dye (methylene blue - MB) and surfactant (sodium dodecylbenzene sulfonate - SDBS) pollutants was investigated by adsorption and photodegradation ontwo composites (FUS-DAl1 and FUS-DAl2). The adsorption parameters (contact time and amount of substrate) were optimized for obtaining a maximum efficiency and were further used in kinetic studies, comparatively discussed with the photocatalysis optimized operating parameters. The UV-photocatalytic properties of the obtained materials were evaluated in pollutant systems containing three (Cd2++MB+SDBS, Cu2++MB+SDBS) and four pollutants (Cd2++Cu2++MB+SDBS).