Synthesis of porous metal-organic framework composite adsorbents and pollutant removal from multicomponent systems

Herein, MIL-101 (Fe)/phosphotungstic acid (PA) composites were synthesized and characterized. Materials Institute Lavoisier (MIL-101 (Fe)) composites as metal-organic frameworks (MOFs) with 0, 0.347, 0.694 and 1.042 mmol of PA were synthesized and denoted as MIL, MP-1, MP-2, and MP-3, respectively. The synthesized MOFs were used to remove organic contaminants from binary systems (BB:Basic Blue 41 and MB:Methylene Blue). The synthesized materials were characterized in detail. Pollutant removal obeyed the Langmuir isotherm and pseudo-second-order kinetic. The free energy of adsorption for MP-2 at 298, 308, 318 and 328 K was −15.24,-15.93, −16.63 and −17.32 kJ/mol for BB and −15.04, −15.02, −15.01 and −14.99 kJ/mol for MB, respectively. Adsorption by the synthesized materials was spontaneous and endothermic process. The multicomponent dye removal data indicated that the synthesized MIL-101 (Fe)/phosphotungstic acid (PA) composites could be used as efficient adsorbents for treating colored wastewater. In addition, the synthesized MOFs were recyclable and regenerable adsorbents.