Effective Removal of Iron (II) from Aqueous Solution by Adsorption using Zn/Cr Layered Double Hydroxides Intercalated with Keggin Ion
Melantina Oktrianty, Neza Rahayu Palapa, Risfidian Mohadi, Aldes Lesbani
Abstract
Zn/Cr and Zn/Cr layered double hydroxides (LDHs) intercalated with Keggin ion [-SiW 12 O 40 ] 4-were successfully synthesized at room temperature and pH value of 10. The synthesized materials were characterized by means of the XRD, BET, and FT-IR analyses and used as an adsorbent iron(II). The adsorption process was investigated by studying pH, the kinetics, and thermodynamic properties of the adsorption process. The results showed the interlayer Zn/Cr LDHs was 7.53 and increase to 10.26 on Zn/Cr LDHs intercalated with Keggin ion [-SiW 12 O 40 ] 4-. The BET analysis showed that the pore volume of both materials increased from 0.063 cm 3 g -1 to 0.163 cm 3 g -1 . The pH point zero charge measurement for the Zn/Cr LDHs material was 10 while LDHs Zn/Cr intercalated with Keggin ion [-SiW 12 O 40 ] 4-was 8. Zn/Cr LDHs intercalated with Keggin ion [-SiW 12 O 40 ] 4-has higher adsorption capacity than Zn/Cr LDHs without intercalation. Desorption of iron (III) was successfully conducted using HCl as reagent showing the involvement of ion exchange in the adsorption.