MgAl Layered Double Hydroxides Intercalated with EDTA: Cu(II) Recovery and Mechanism

In water treatment, it is a valid way to remove Cu(II) efficiently via layered double hydroxides (LDHs) intercalated with chelate, but the desorption and its mechanism remain an unsolved difficult problem. To solve this problem, MgAl LDHs intercalated with EDTA (MgAl-EDTA-LDHs) was synthesized by one-step co-precipitation method, and applied to recover Cu2+. The characterizations of SEM, XRD, XPS, EA and AAS were employed, and the results showed that MgAl-EDTA-LDHs exhibited a typical lamellar structure, the adsorption capacity of MgAl-EDTA-LDHs on Cu(2+)could reach 79.69 mg/g, which was attributed to the chelation of EDTA and chemical bonding of hydroxyl (-OH) on the surface of LDHs layers. In addition, the adsorption capacity could achieve 45.75 mg/g after eluting by Na(2)CO(3)solution, which was relevant to the ion exchange by CO32-. Herein, the adsorption and desorption mechanism of MgAl-EDTA-LDHs on Cu(2+)was expounded, which may pave a new way to recover the heavy metal and provide a theoretical guidance for future research.