Fe-Substituted Isoreticular Metal–Organic Framework for Efficient and Rapid Removal of Phosphate

Abstract

Excessive phosphate can cause water eutrophication. Adsorption can remove excessive phosphate in water to alleviate eutrophication effectively. Herein, an isoreticular metal–organic framework (Fe-IRMOF-3-10) with bimetallic center and double ligand was successfully synthesized from a single metal center and single ligand isoreticular metal–organic framework (IRMOF-3) to remove phosphate in water effectively. In the four IRMOFs, Fe-IRMOF-3-10 shows higher adsorption capacity (177.0 mg g–1 at 25 °C) and faster adsorption kinetics (5 min) for phosphate. The adsorption capacity and removal efficiency remain stable in the range of pH 4–11. The adsorption capacity of Fe-IRMOF-3-10 for phosphate is not only not affected by a large number of coexisting anions (Cl–, F–, NO3 –, and SO4 2–) but also not affected by the ionic strength. The adsorption mechanism study illustrated that the removal of phosphate by Fe-IRMOF-3-10 not only included the affinity of amine group and Fe3+ for phosphate but also involved the ion exchange between hydroxyl group and phosphate. The adsorption efficiency of Fe-IRMOF-3-10 for phosphate from actual water samples indicated the potential of Fe-IRMOF-3-10 for the removal of phosphate from natural water samples.

Trifluoromethyl-Modified Hierarchical Nanoporous Metal–Organic Framework Nanoparticles for Adsorption of Fluorine-Containing Pesticides

“…The adsorption isotherm can reflect the interaction between HP-Fe-CF 3 -B and FCPs and the surface characteristics of the HP-Fe-CF 3 -B. It is generally verified and evaluated by Langmuir (eq ) and Freundlich (eq ) models Among them, C e (mg/L) and q e (mg/g) represent the concentration and adsorption capacity when HP-Fe-CF 3 -B adsorbs FCPs at equilibrium, respectively, q m (mg/g) represents the maximum adsorption capacity for FCPs, b and K F represent Langmuir and Freundlich constants, respectively, and 1/ n represents heterogeneity.…”

“…To better explore the adsorption mechanism, the adsorption thermodynamics of HP-Fe-CF 3 -B on the adsorption of FCPs has been studied (eqs ). Among them, Δ G (kJ/mol), Δ H (kJ/mol), and Δ S (J/(mol K)) respectively represent Gibbs free energy, enthalpy change, and entropy change, K is the thermodynamic equilibrium constant, R is the ideal gas constant which is 8.314 J/(mol K), and T (K) is the temperature in Kelvin.…”

“…All experiments were repeated at least in triplicate. The calculation formula (eq ) for the adsorption capacity of the adsorbent on FCPs is as follows Among them, q t (mg/g) is the adsorption capacity of FCPs at t (min), C 0 and C t (mg/L) are the initial concentration of FCPs, and the remaining concentration at t (min), V (mL), and m (g) are the volume of FCPs and the mass of HP-Fe-CF 3 -B, respectively.…”

Synthesis of MgAl-LDH@ZIF-8 composites by in situ growth method for highly efficient phosphate removal

“…The effect of CO 3 2À on phosphate adsorption is relatively large compared to other anions, which may be due to the decrease in adsorption capacity due to the alkaline nature of the solution caused by CO 3 2À . 53 It was found that the pH = 10.95 for the solution after the addition of CO 3…”

A New Era of Metal–Organic Framework Nanomaterials and Applications

“…Therefore, MOFs and their derivatives have been intensively employed in these fields. In addition to conventional gas capture and separation including CO 2 uptake, hydrogen gas attraction, ammonia capture, and efficient separation between CO 2 and methane, , MOFs have been developed to remove arsenic and phosphate species from water. MOF-based nanosheets also exhibited interesting gate-opening gas adsorption .…”