Adsorption of Ciprofloxacin on Graphene Oxide-Based Adsorbents: Synthesis, Characterization and DFT Calculations

• Published in: Water, air, and soil pollution air, and soil pollution, 2024-07, Vol.235 (7), p.417, Article 417
• Main Authors: Sanchez, Sergio Nicolas Buitrago, Spaolonzi, Marcela Pires, Cesconeto, Laura Piacentini, Souza, Larissa, Virmond, Elaine, Vieira, Melissa Gurgel Adeodato, Watzko, Elise Sommer, Moreira, Regina de Fátima Peralta Muniz
• Format: Article
• Language: English
• Subjects: Adsorbents; Adsorption; Antibiotics; Atmospheric Protection/Air Quality Control/Air Pollution; Ciprofloxacin; Climate Change/Climate Change Impacts; Coal; Coke; Covalent bonds; Earth and Environmental Science; Electron microscopy; Electrostatic properties; Environment; Field emission spectroscopy; Fourier transforms; Geopolymers; Graphene; Heat treatment; Hydrogeology; Infrared spectroscopy; Kinetics; Multilayers; Oxidation; Ozone; Particle size distribution; Phosphates; Raman spectroscopy; Scanning electron microscopy; Size distribution; Soil Science & Conservation; Solid surfaces; Spectrum analysis; Synthesis; Thermogravimetric analysis; Water Quality/Water Pollution; Water treatment; X-ray diffraction; Zeta potential
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-024-07213-2

In this article, the synthesis of graphene oxide from coal or coke and a composite graphene oxide-geopolymer were carried out to produce adsorbents applied to Ciprofloxacin (CIP) removal from water in a laboratory scale. The characterization analyzes of the adsorbent were performed by Thermogravimetric Analysis (TGA), Zeta Potential (ZP), Particle Size Distribution (PSD), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Gun Scanning Electron Microscopy (FEG/EDS), and RAMAN spectroscopy. Multilayer graphene oxide was identified after coal or coke thermal treatment and ultrasound exfoliation followed by ozone oxidation of the solid surface. A composite produced using phosphate mining residues and graphene oxide incorporation (22 wt%) showed the highest adsorption capacity. Affinity tests showed removal rates for CIP ranging from 15% to 55%. Kinetic studies indicated that the equilibrium time varied between 100 min and 120 min for three different initial CIP concentrations. With regard to the kinetic study, the pseudo-first order model better described the kinetics at the concentration of 0.05 mmol L -1 , while the pseudo-second order model better described the kinetics at concentrations of 0.1 mmol L -1 and 0.2 mmol L -1 . The studies on adsorption equilibrium showed that the Langmuir model provided the most accurate fit to the experimental data. The maximum adsorption capacity was found at 45 °C and it was of 0.24 mmol g -1 . The possible mechanisms of adsorption are related to electrostatic interactions and covalent bonds. Graphical abstract