Improved Magnetite Nanoparticle Immobilization on a Carbon Felt Cathode in the Heterogeneous Electro-Fenton Degradation of Aspirin in Wastewater

Abstract

Toward the improvement of the application of heterogeneous electro-Fenton in water treatment, we report a new strategy of enhancing the immobilization of a magnetite nanoparticle catalyst on a carbon felt cathode. Exploiting the intrinsic ferrimagnetic properties of magnetite nanoparticles, magnet bars were used to attach the magnetite into the void spaces of the porous carbon felt (CF) cathode. The magnetite nanoparticles were prepared by coprecipitation with variations in the molar ratios of Fe 2+ /Fe 3+ . The magnetite was characterized, attached onto the CF electrode with magnetic bars, and used in the heterogeneous electro-Fenton (EF) degradation of aspirin. The effects of the following on the degradation were studied: Fe 2+ /Fe 3+ , pH, catalyst loading concentration, and voltage. The heterogeneous EF degradation of aspirin in wastewater improved by 23% when magnetic bars were used to enhance the immobilization of the magnetite catalysts. The 1:4 Fe 2+ /Fe 3+ ratio resulted in the highest hetero-EF catalytic degradation of aspirin with complete degradation (100%) achieved after 140 min. For a mixture of pharmaceuticals, degradation percentages of 94.3% (aspirin), 88% (ciprofloxacin), and 80% (paracetamol) in 3 h were obtained. The magnetized magnetite on the cathode was reusable for 10 cycles. Thus, the use of magnets shows a promising strategy to avoid the leaching of ferrimagnetic nanoparticle catalysts embedded in the cathode for heterogeneous EF processes.

Impregnation of Modified Magnetic Nanoparticles on Low-Cost Agro-Waste-Derived Biochar for Enhanced Removal of Pharmaceutically Active Compounds: Performance Evaluation and Optimization Using Response Surface Methodology

“…∆G θ = −RTlnK (12) where R depicts the universal gas constant (8.314 J mol −1 K −1 ), the equilibrium constant is K, and T represents the absolute temperature, as shown in Figure 8. In the temperature range of 303 K to 343 K, the calculated ∆G θ value for ASA adsorption was found to be −0.44 to −1.06, and for CBZ, it was −0.04 to −5.14 kJ/mol.…”

“…Both of these drugs have been reported to have adverse impacts on exposed organisms, even at very low concentrations. For instance, ASA exposure leads to gastrointestinal ulcers, tinnitus, DNA damage, induces oxidative stress, and has an inhibitory effect on blood platelets [12,13]. Similarly, CBZ exposure results in endocrine disruption, hepatic injuries, acute pneumonia, and lethal cardiovascular diseases and bears neurotoxicity and developmental toxicity [14,15].…”

Electrofenton with Reticular Vitreous Carbon and Iron Oxide Nanoparticles for Dye Removal: A Preliminary Study

“…In these cases, after the process, the magnetite should be separated by magnetic harvest. To solve this fact, the magnetite nanoparticles can be integrated in the cathode electrode [17][18][19]. These nanoparticles are used as Fe 2+ source, activating the hydrogen peroxide to produce OH • radicals through the Reaction (4).…”