Beata Tryba

Application of TiO2-mounted activated carbon to the removal of phenol from water

Abstract TiO 2 -mounted activated carbon was prepared through hydrolytic precipitation of TiO 2 from teraisopropyl orthotitanate and following heat treatment at 650–900xa0°C for 1xa0h under a flow of nitrogen. The removal of phenol from its aqueous solution under UV irradiation was measured on TiO 2 -mounted activated carbons thus prepared. Although BET surface area of TiO 2 -mounted activated carbons decreased drastically in comparison with the original activated carbon, the efficiency of phenol removal under UV irradiation was high. The sample heated at 900xa0°C, which consisted mainly of rutile phase, showed the highest total removal of phenol. Efficiency of phenol degradation is reduced because of phenol adsorption on the catalyst.

A new route for preparation of TiO2-mounted activated carbon

Abstract TiO 2 -mounted activated carbon was prepared by the precipitation of TiO 2 from tetraisopropyl orthotitanate on the surface of poly(vinyl butyral) (PVB) and subsequent carbonization to different final temperatures from 700 to 900xa0°C under a flow of carbon dioxide. Photoactivity of the prepared TiO 2 /carbon composities was checked by decomposition of phenol in aqueous solution under UV irradiation. Adsorption of phenol on these catalysts was found to be very small (0–4%) without UV irradiation. Almost complete removal of phenol after 12xa0h under UV irradiation was observed for the sample heated to 700xa0°C that consisted of a single phase of anatase with 2.5% carbon. Carbon suppressed transformation of anatase onto rutile during heat treatment process. It has some benefits such as improving the crystalline structure of TiO 2 catalyst by using higher temperature of heat treatment and selection of the proper carbon precursor for carbonisation. Prepared TiO 2 mounted on carbon could be easily separated from the solution and it can be used repeatedly for phenol removal with preservation of its photoactivity.

Exfoliated Graphite as a New Sorbent for Removal of Engine Oils from Wastewater

Abstract A commercial exfoliated graphite was used for checking its sorption capabilities for removing engine oil and dyes from wastewater. Slight oxidation of exfoliated graphite in the air at 400 °C was found to be effective to improve adsorption capacity for dyes, methylene blue and methyl orange. However, its treatment in HNO3 reduced all capacities for engine oil and dyes. A possibility for simultaneous removal of oil and dyes dispersed in wasted water was revealed.

Studies of Exfoliated Graphite (EG) for Heavy Oil Sorption

Abstract Electrochemically intercalated graphite with H2SO4 was thermally expanded at 1000°C. Exfoliated samples of GIC-H2SO4 with different times of expansion revealed different expansion volumes. Both the surface area and the chemical character of samples also depend on the exfoliation time. A low density of the exfoliated graphite is demanded for the oil sorption. The oil sorption is restricted by the surface area and the bulk density.

Adsorption of carbon dioxide on phenolic resin-based carbon spheres

Abstract Two sorts of spherical carbons were prepared by a carbonization of phenolic resin-based spheres in both, N2 and CO2 atmospheres. Values of N2-BET specific surface area of the samples were very different. CO2 adsorption tests were performed for the obtained carbons. Total amount of CO2 adsorbed on the carbon spheres prepared in CO2 atmosphere was found as bigger than on the carbon obtained with use of N2. In the case of the spheres prepared in N2 atmosphere their area covered by adsorbed CO2 molecules was bigger than the surface area of the spheres estimated from N2 adsorption isotherms. In spite of different gases used for the preparations, tested samples did not show significant differences in their surface chemistry.