Catalytic Degradation of Bisphenol A with a Magnetically Recoverable Geopolymer Composite Using Coal Gangue

oleh: Qishun Shi, Danlei Wu, Chunli Guo, Jianchao Ma

Format: Article
Diterbitkan: MDPI AG 2024-08-01

Deskripsi

The widespread presence and use of Bisphenol A (BPA) in aquatic environments has caused significant ecological damage. Coal gangue (CG), a byproduct of coal mining, poses a major environmental concern due to its vast land occupation and potential for pollution. A magnetic recyclable geopolymer (MnFe<sub>2</sub>O<sub>4</sub>-CGP) using coal gangue geopolymer (CGP) as the carrier was successfully synthesized and was evaluated for its ability to Fenton-like degrade BPA. The characterization techniques revealed the successful incorporation of spherical MnFe<sub>2</sub>O<sub>4</sub> onto the CGP surface and that CGP serves as an excellent platform for the immobilization and dispersion of MnFe<sub>2</sub>O<sub>4</sub>. The degradation rate reached 100% within 60 min at pH = 5, 15 mmol/L H<sub>2</sub>O<sub>2</sub>, 0.6 g/L catalyst, and 50 mg/L BPA, significantly higher than MnFe<sub>2</sub>O<sub>4</sub> and CGP alone. It was indicated that the degradation rate of BPA in MnFe<sub>2</sub>O<sub>4</sub>-CGP composites was 0.1121 min<sup>−1</sup>, which was consistent with the first-order kinetic model. The saturation magnetization of MnFe<sub>2</sub>O<sub>4</sub>-CGP was measured to be 10.96 emu/g, enabling convenient recovery. MnFe<sub>2</sub>O<sub>4</sub>-CGP exhibited excellent stability, as the degradation rate of BPA remained above 95% even after five reaction cycles. This efficiency may be due to the MnFe<sub>2</sub>O<sub>4</sub>-CGP induced generation of reactive radicals. Quenching and EPR radical trapping experiments unequivocally confirmed that the reactive radical was hydroxyl radical (•OH). These results indicate that MnFe<sub>2</sub>O<sub>4</sub>-CGP has potential application prospects as a magnetic recyclable geopolymer composite in Fenton-like catalysis.