Mechanism of Norfloxacin Adsorption on Fe-BTC Derived from Acid Mine Drainage Sludge: Adsorption Experiments and Density Functional Theory Analysis

Acid mine drainage sludge (AMDS) can be utilized as a raw material to synthesize an efficient adsorbent through a more environmentally friendly approach for the removal of pollutants from water. In this study, iron ions were extracted from AMDS and then reacted with trimesic acid (BTC) under ambient conditions to synthesize Fe-BTC-n, iron-based metal-organic frameworks. These materials demonstrate an exceptionally high specific surface area and excellent chemical stability. Norfloxacin was applied as a model pollutant to assess the adsorption performance of the synthesized materials. Results indicated a maximum adsorption capacity of 280.84 mg/g at 298 K, an initial solution pH of 10, and an adsorbent dosage of 0.1 g/L. Characterization techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), N2 adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR), along with density functional theory (DFT) calculations, were employed to study the adsorption mechanisms of norfloxacin on the Fe-BTC surface. The adsorption mechanism was found to involve pore filling, electrostatic interactions, π-π stacking, and coordination interactions. Additionally, the adsorbent exhibited an excellent regeneration and desorption performance. This study offers a promising approach for converting AMDS into effective adsorbents for the treatment of antibiotic-contaminated wastewater, contributing to sustainable environmental development and remediation efforts.

A facile route for the recovery of the ligand of zeolitic imidazolate framework ZIF-94/SIM-1

A facile route for the recycling of the organic ligand from ZIF-94/SIM-1 is reported with a recovery yield of 92.5 ± 2.8%. The recycled ligand was used for a new ZIF-94 synthesis compared to the one using fresh ligand. ZIF-94 was embedded in Pebax® 1657 mixed matrix membranes for gas separation of CO₂/N₂ and CO₂/CH₄ mixtures.