Enhanced Removal of Low Concentrations of Anti-inflammatory Drugs in Water Using Fe-MOF Derived Carbon Treated by Acidic Leaching: Characterization and Performance

In this work, the MIL-101(Fe) derived carbon prepared by direct carbonization under N-2 atmosphere followed by acidic treatment (TC-MIL-101(Fe)) was evaluated as an adsorbent of low concentrations of naproxen (NPX) in an aqueous solution. The adsorption performance of TC-MIL-101(Fe) was compared with its analog without acidic treatment (C-MIL-101(Fe) and pristine MIL-101(Fe). The prepared materials were characterized by X-ray diffraction (XRD), nitrogen physisorption, scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The TC-MIL-101(Fe) improved its textural and physicochemical properties. The increase of specific surface area, broad pore size distribution, and low residual level of Fe particles, and graphitization index turned this material into a potential adsorbent of pharmaceutical compounds. The NPX adsorption experiments onto TC-MIL-101(Fe) showed complete removal in 15 min, and 63.30 mg/g adsorption capacity in equilibrium compared to 22.94, and 22.72 mg/g achieved using pristine MIL-101(Fe) and C-MIL-101(Fe). The NPX adsorption using MIL-101(Fe) and their derived carbon materials was associated with a pseudo-second order (R-2 >= 0.995) and Langmuir (R-2 >= 0.938) models. Moreover, the thermodynamic parameters were calculated, suggesting the spontaneous and exothermic adsorption mechanism. These results evidenced the potential application of TC-MIL-101(Fe) adsorbent associated with its good textural properties and modulable porosity.

Automated summary

This study evaluated the use of acid-treated MIL-101(Fe) derived carbon material as an adsorbent for low concentrations of naproxen in an aqueous solution. The material showed improved textural and physicochemical properties, resulting in enhanced adsorption capacity compared to other materials. The adsorption process followed pseudo-second order and Langmuir models, and the thermodynamic parameters indicated spontaneous and exothermic adsorption. These findings highlight the potential application of acid-treated MIL-101(Fe) adsorbent for pharmaceutical compounds.