Ion-exchange of synthesized zeolite X pellets
Various ions were introduced into the synthesized zeolite NaX to obtain zeolite M-NaX. Particularly, 25 g zeolite NaX pellets were immersed into 250 mL M(NO3)x (M = Mg2+, Ca2+, Co2+, Ni2+, Cu2+, Zn2+and Ag+) aqueous solution (0.1 mol/L) under vigorous stir at 333 K for 6 h. The ion-exchanged zeolite X samples were washed with deionized water for three times, separated by filtration and dried in a vacuum oven at 373 K overnight.