Efficient Removal of Pb(II) and Cd(II) Using NH2-Functionalized Zr-MOFs via Rapid Microwave-Promoted Synthesis

Heavy metal ions of Pb(II) and Cd(II) have become the global health and environmental concerns. NH2functionalized Zr-MOFs were prepared via a rapid microwave promoted synthesis and first used in the adsorptive removal of both Pb(II) and Cd(II). The nanosized (<100 nm) Zr-MOFs had an XRD pattern of UiO-66-NH2. Effects of adsorption time, temperature, pH, and initial ions concentration were studied on the adsorption of Pb(II) and Cd(II) onto the ZrMOFs. The absorption results showed that the removal of Pb(II) was 99.95% after 120 min at temperature of 30 C and pH of 6 with an initial concentration of 10 mg.L-1. And the adsorption capacity of Cd(II) achieved 177.35 mg.g(-1) at an initial concentration of 40 mg.L-1. The adsorption fit the pseudo second-order kinetic model well and the mechanism was confirmed mainly as a coordination interaction between the amino group (-NH2) and Pb(II) or Cd(II). The NH2-functionalized Zr-MOFs have been proven to show good performance in the removal of heavy metal ions as an efficient adsorbent.