removal of heavy metals from aqueous solution by mordenite nanocrystals

this study examined the ability of the synthetic mordenite nanocrystal to remove tl(iii) and as(iii) from an aqueous solution. the determination of the concentration changes of h+ and oh- quantities in the acidic (ph 3) and alkali (ph 9) treated mordenite nanocrystals were done by the potentiometric titration curves. the maximum uptake capacities (qmax) of these metal ions using the mordenite in the separate batch reactors from 278 to 323 k were obtained about 0.627-0.836 and 0.563-0.742 mmol/g, for tl(iii) and as(iii), respectively. in order to remove these metal ions, the enthalpy change (δh) was 11.236 and 9.856 kj/mol and the entropy change (δs) was 38.1 and 42.9 j/mol k, respectively. mordenite nanocrystal removed these heavy metals corresponding to pseudo-second-order kinetic model.