The pollution of water resources with chemical and biological pollutants is the serious problem of the present century. So synthesis of new adsorbents which can remove both types of pollutants is necessary. In the present study a novel clay/mesoporous alumina composite has been synthesized in order to remove both cationic and anionic dye pollutants and their binary mixtures from aqueous solutions. Also the clay/mesoporous alumina/Ag nanoparticle composite has been synthesized for the first time by the new combined method and used for both chemical and biological treatment of aqueous solution. The characterization of the prepared nanocomposite has been performed by TEM and EDS techniques. The results show that the synthesized materials are good adsorbents for effective removal of both cationic and anionic dye pollutants. Also the nanocomposite shows very good antibacterial activity against both Gram negative and Gram positive bacteria. (C) 2014 Elsevier B.V. All rights reserved.