REMOVAL PERFORMANCE OF Cd2 + USING NANOSCALE ZERO-VALENT IRON EMBEDDED BY β-CYCLODEXTRIN

To improve the stability of nano-Fe0 in the air，embedded nanoscale Fe0 was synthesized using a cross-linked polymer ( β-cyclodextrin and epichlorohydrin) ． Effect of alkalinity，cross-linker dosage on cross-linking degree was evaluated． The encapsulated Fe0 nanoparticles obtained in 40% NaOH medium was compared to that synthesized in 30% NaOH by Cd2 + removal efficiency． The embedded material was characterized with scanning electron microscope ( SEM) and thermogravimetric analysis ( TGA) ． Higher reactivity was observed with the embedded nano-Fe0 synthesized in 40% NaOH medium． A Cd2 + removal rate of 98. 8% ( 100 mg /L) was achieved with 3. 0 g of the encapsulated nano-Fe0 after reacting for 150 min． And the as-prepared nano-Fe0 can still remove 90. 5% of the Cd2 + after being exposed to air for oven 1 month，indicating its excellent ambient air stability．