Modified Perfluorinated Alumina with High Adsorption Capacity for Removal of Organic Pollutants from Water

Perfluorinated alumina such as perfluorooctyl alumina, which is prepared by reacting prfluorinaed organic acids with alumina, can be used for adsorption of organic pollutants from aqueous medium. In this work attempts were made to modify perfluorooctyl alumina and increase its adsorption capacity. Aluminum hydroxide was used as a precursor for the preparation of alumina supports. The best results obtained by heat treatment of Al(OH)3 at the temperature range of 350400°C. In this way the specific surface areas obtained are about 176-237 m lg. It is worthwhile to note that the specific surface areas of y-alumina is about 130 m/g. The surface coverage of the alumina by perfluorinated chains may be increased by using the hydrated form of the alumina. For this purpose we treated the alumina support in water for about 10 hours to increase the OH groups on the surface as possible. The results obtained showed that the surface coverage was increased about 39% for the case of y-alumina as the support. The adsorption experiments conducted for the adsorption of MTBE from aqueous medium showed considerable increase of adsorption capacities. The increase of adsorption capacities are in well agreement with perfluorooctyl content of the prepared adsorbents. For example the adsorption capacity of the ads using y-alumina as the support was increased about 35% compared to our previous results.