Share
Wollastonite based ceramics for water purification
- Speaker: Dr. Nina Obradović
- Institution: Institute of Technical Sciences of SASA, Serbia
- Date: 23.01. 2018
- Place: CEITEC Brno University of Technology
Anotation:
The first part of the lecture is going to be about Serbian academy of sciences and arts, Institute of technical sciences of SASA, and research projects that I am working on, regarding electroceramics, titanium-based. The second part will be about the synthesis of porous wollastonite-based ceramics for water purification. Ceramic precursor, methyl hydro cyclosiloxane, together with micro-sized CaCO3, was used as starting material. After 20 min of ultrasound treatment, and calcination at 250 o C for 30 min, yeast as a pore-forming agent was added to the as-obtained powders. Sintering regime was set up based on the results obtained by differential thermal analysis. Prepared mixture was pressed into pellets and sintered at 900 o C for 1 h. After the sintering regime, porous wollastonite based ceramics was obtained. The phase composition of the sintered samples, as well as microstructures, was analyzed by X-ray diffraction method and SEM. In a batch test, the influence of pH, contact time and initial ion concentration on adsorption efficiency of As+5, Cr+6, and phosphate ions on synthesized wollastonite-based ceramics were studied. Time-dependent adsorption was best described by pseudo-second-order kinetic model and Weber-Morris model that predicted intra-particle diffusion as a rate-controlling step of the overall process. High adsorption capacities 39.97, 21.87, and 15.29 mgg–1 were obtained for As+5, Cr+6, and phosphate ions, respectively.