UPTAKE OF HEAVY METAL IONS FROM AQUEOUS SOLUTION BY Mg-Al LAYERED DOUBLE HYDROXIDES INTERCALATED WITH ORGANIC ACID ANIONS, AND ITS KINETICS

摘要

Mg-Al layered double hydroxide (Mg-Al LDH) has anion-exchange capability. In this study, Mg-Al LDH was modified with organic acid anions using a coprecipitation technique, and the uptake of heavy metal ions from aqueous solution by the Mg-Al LDH was studied [1]. Citrate? Mg-Al LDH, malate?Mg-Al LDH, or tartrate?Mg-Al LDH, which had citrate~(3-)(C_6H_5O_7~(3-)), malate~(2-) (C_4H_4O_5~(2-)), or tartrate~(2-) (C_4H_4O_6~(2-)) anions intercalated in the interlayer, was prepared by dropwise addition of a mixed aqueous solution of Mg(NO_3)_2 and AI(NO_3)_3 to a citrate, malate, or tartrate solution at a constant pH of 10.5.