Novel ag/kaolin nanocomposite as adsorbent for removal of acid cyanine 5r from aqueous solution

Ag/kaolin nanocomposite was prepared by reduction of ag+ ion with ethanol at alkaline condition on kaolin surface. nanocomposite was characterized by ftir,xrd,tem,and bet methods. results showed the ag/kaolin composite has particle size 50 nm. the surface area was increased from kaolin to ag/kaolin from 1.0215 to 7.409 m2 g-1,respectively. ag/kaolin nanocomposite was used for adsorption of acid cyanine 5r (ac5r) from aqueous solution. the effect of parameters such as contact time,ph,and mass of nano composite has been investigated. the maximum percentage of adsorption of ac5r was found at ph 3 and contact time of 60 min. the higher percentage removal of ac5r by ag/kaolin than kaolin can be attributed to catalytic activity of ag on the surface of kaolin. the experimental data was fitted by pseudo-second-order kinetic model. the adsorption isotherm data could be well interpreted by langmuir isotherm model. from the results of thermodynamic study,the adsorption process of ac5r onto ag/kaolin nanocomposite was spontaneous and endothermic process. the process is clean and safe for purifying of water pollution. © 2013 saeedeh hashemian and mohammad reza shahedi.