Synthesis of superparamagnetic MnFe 2 O 4 /mSiO 2 nanomaterial for degradation of perfluorooctanoic acid by activated persulfate.
Pengfei JiFeng ZhuJiamin ZhouJintao MaHongyong WangGang XuPublished in: Environmental science and pollution research international (2022)
In this paper, magnetic MnFe 2 O 4 /mSiO 2 nanocomposites were successfully synthesized, and the activation performance of the materials for persulfate was evaluated by the degradation efficiency of perfluorooctanoic acid. The structure of the catalyst was proved to be a core-shell structure by several characterization methods. The mesoporous silicon coating can effectively avoid the agglomeration of MnFe 2 O 4 and at the same time increase the contact area with the reactants. A comparison of different catalyst addition conditions demonstrates that MnFe 2 O 4 /mSiO 2 can effectively activate the persulfate. The optimal reaction conditions were investigated by several key influencing factors. It was experimentally demonstrated that about 90% of PFOA (10 mg·L -1 ) could be decomposed under the conditions of 0.4 g·L -1 MnFe 2 O 4 /mSiO 2 and PS, pH 5.68, and 25 °C within 4 h; the defluorination rate reached 58.33%. In addition, the cyclability and stability tests demonstrated that MnFe 2 O 4 /mSiO 2 is a stable material that can be recycled. Furthermore, XPS characterization and radical scavenging experiments demonstrated that sulfate radicals (SO 4 · - ) and hydroxyl radicals (OH) play a major role in the reaction of MnFe 2 O 4 /mSiO 2 activated PS. Subsequently, the degradation products were detected by high-performance liquid chromatography tandem triple quadrupole mass spectrometry, indicating that the degradation of PFOA is a gradual process of defluorination and decarbonization in the presence of free radicals. Finally, the metal leaching rate is tested to prove that the material meets environmental requirements while reacting efficiently. In conclusion, this study shows that MnFe 2 O 4 /mSiO 2 is an easily recoverable and highly efficient and stable material that has great potential for PS activation to treat organic pollutants in water.
Keyphrases
- highly efficient
- high performance liquid chromatography
- mass spectrometry
- tandem mass spectrometry
- liquid chromatography
- simultaneous determination
- ionic liquid
- high resolution
- solid phase extraction
- heavy metals
- room temperature
- metal organic framework
- capillary electrophoresis
- gold nanoparticles
- carbon dioxide
- risk assessment
- human health
- visible light
- carbon nanotubes