Porous Fe-Porphyrin as an Efficient Adsorbent for the Removal of Ciprofloxacin from Water

Antibiotics are widely used in medicine, but they are not fully metabolized in the body and can end up in wastewater. Conventional wastewater treatment methods fail to completely remove antibiotic residues, which can then enter rivers and streams. Adsorption is a promising technique for removing antibiotics from wastewater, even at low concentrations. The successful one-pot synthesis of an adsorbent, iron-containing porphyrin-based porous organic polymer (Fe-POP), was achieved through the reaction of pyrrole groups and terephthalaldehyde in the presence of FeCl3. Characterized by a substantial BET surface area of 597 m2 g-1, Fe-POP was systematically investigated for its adsorption potential in the removal of the antibiotic Ciprofloxacin (CIP) from aqueous solutions. By systematic variation of key parameters, including pH, adsorbent loading, and CIP concentration, the adsorption conditions were optimized. Under the optimal conditions at pH = 3, CIP concentration of 5 ppm, and 25 mg of Fe-POP, the maximum adsorption capacity reached an impressive 263 mg g-1. The robust adsorption behavior was elucidated through the fitting of experimental data to the Langmuir adsorption isotherm (R2 = 0.962) and the pseudo-second-order kinetic model (R2 = 0.999) with lower error values. These models suggested that the adsorption process predominantly involved chemical interactions between CIP molecules and the Fe-POP surface. Fe-POP exhibited a robust structure with a high adsorption capacity, showcasing its efficacy in removing CIP contaminants from water. Therefore, Fe-POP can be considered a valuable adsorbent for water treatment applications, specifically for antibiotic removal.

Optimization of Visible-Light-Driven Ciprofloxacin Degradation Using a Z-Scheme Semiconductor MgFe2O4/UiO-67

A heterogeneous photocatalyst, MgFe2O4/UiO-67 (MU-x), was successfully synthesized by doping magnetic magnesium ferrite nanoparticles (MgFe2O4) with the UiO-67 metal-organic framework at various weight ratios (MgFe2O4: UiO-67 at 30, 50, 70, and 90 wt %). Various techniques, including X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR) , Brunauer-Emmett-Teller (BET), photoluminescence (PL), vibrating sample magnetometry (VSM), electrochemical impedance spectroscopy (EIS), and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), were used to characterize the prepared photocatalysts. The photocatalytic performance of MU-x in the degradation of ciprofloxacin (CIP) under visible light was assessed. The CIP degradation efficiency was found to increase as the amount of MgFe2O4 in the composite was increased up to 70 wt %. Experimental conditions were optimized using response surface methodology (RSM) based on central composite design (CCD) with three factors: initial pH, catalyst loading, and CIP concentration. Using the obtained model, the optimal conditions were determined as follows: initial pH of 8.025, catalyst loading of 33.8 wt %, and CIP concentration of 10.8 mg/L. Under these optimal conditions, a notable improvement was achieved, with 99.62% of CIP removal achieved within 90 min, surpassing the performance of previously reported photocatalysts. Total organic carbon (TOC) analysis revealed a high degree of mineralization, at 81.25%. The degradation pathway of CIP was investigated based on liquid chromatography-mass spectrometry (LC-MS) analysis. Finally, the values of ECB and EVB of the photocatalyst were determined and the possible degradation mechanism of CIP was investigated based on Mott-Schottky and the applied scavengers. The hydroxyl radical (•OH) was identified as the dominant species in the removal of CIP through a trapping experiment. The photocatalyst with 70 wt % of MgFe2O4 (MU-70) exhibited excellent stability and recoverability with an external magnet, demonstrating 86.33% CIP removal after four cycles. According to the obtained results, MU-70 is a promising visible-light-active photocatalyst with great potential for water treatment applications and convenient recovery.

Fabrication of a biological metal-organic framework based superhydrophobic textile fabric for efficient oil/water separation

In response to the industry's difficulty in properly separating oily wastewater discharge, researchers are investigating enhanced oil/water separation materials. In this work, a cost-effective and environmentally friendly superhydrophobic textile fabric was fabricated for effective oil-water mixture and emulsion separation. A biological metal-organic framework consisting of copper as a core metal and aspartic acid as a linker (Cu-Asp MOF) was used to improve the surface roughness of the pristine textile fabric, and stearic acid was used to lower its surface energy. The thermal gravimetric analysis investigated the prepared Cu-Asp MOF's thermal stability. X-ray spectroscopy and Fourier-transform infrared spectroscopy studied the crystal orientation and chemical composition of the Cu-Asp MOF, Cu-Asp MOF@SA, pristine textile fabric, and superhydrophobic textile fabric, respectively. The surface morphology of the pristine and modified textile fabric was studied by scanning electron microscope. The wettability results showed that the prepared superhydrophobic textile fabric has a water contact angle of 158° ± 1.3 and water sliding angle of 2° ± 0.2°. The prepared superhydrophobic textile fabric showed excellent oil-water mixture and emulsion separation performance, oil absorption capacity, chemical stability, mechanical abrasion resistance, and a high flux rate. These outstanding characteristics of the prepared superhydrophobic textile fabric greatly increase the possibility for practical applications.