Base-functionalized metal-organic frameworks for highly efficient removal of organic acid pollutants from water

Organic acid contaminated wastewater has been of great concerns for water recovery. Base-functionalized metal-organic framework DETA-UiO-66 by grafting diethylenetriamine onto UiO-66 achieved remarkable H-2-FA capacity with large adsorption rate compared with parent UiO-66 and sulfonate-functionalized SO3H-UiO-66. According to the adsorption behavior at various pHs, an adsorption mechanism was proposed involving the acid-base interaction and weak electrostatic interaction. Further investigation including adsorption kinetics, isotherms, thermodynamics, demonstrated that the H-2-FA adsorption process on DETA-UiO-66 was a sponta-neous exothermic process with a theoretical adsorption capacity reaching up to 561.8 mg g(-1) at 10 degrees C. In addition, DETA-UiO-66 can be recovered through simple ethanol washing and reused for at least three times, remaining high adsorption capacity and adsorption rate. Meanwhile, DETA-UiO-66 showed high adsorption capacities for citric acid and sorbic acid, indicating DETA-UiO-66's wide potentials in capturing various organic acid pollutants.