Perchlorate adsorption by granular activated carbon modified with cetyltrimethyl ammonium chloride

To improve the adsorption of perchlorate (clo 4 ) in contaminated water,granular activated carbon (gac) was modified with cetyltrimethyl ammonium chloride (ctac). to investigate the adsorption mechanism of perchlorate the structure of gac-ctac was characterized by scanning electron microscopy (sem) and ftir spectroscopy. then the gac-ctac was used for the adsorption of perchlorate in water. the effects of the adsorption time,ph,initial clo 4 - concentration,and co-existed anions on perchlorate adsorbed by gac-ctac were studied. the results show that the gac-ctac could absorb perchlorate better in water. the adsorption capacity of perchlorate on gac-ctac decreases in the alkaline solution,and increases with increasing the initial concentration. the competitive adsorption exists between co-existed anions and clo 4 - on gac-ctac. in addition,adsorption of clo 4 - on gac-ctac fits the langmuir,freundlich and tempkin isothermal models in the range of the experimental concentration. the adsorption process follows pseudo-second order kinetics.