Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes （Fe^2＋/H2O2, UV/Fe^2＋/H2O2, and electrolysis/Fe^2＋/H2O2） in this study. Comparison of these techniques in oxidation...Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes （Fe^2＋/H2O2, UV/Fe^2＋/H2O2, and electrolysis/Fe^2＋/H2O2） in this study. Comparison of these techniques in oxidation efficiency was undertaken. It was found that Fenton process could not completely degrade citrate in the presence of hypophosphite since it caused a series inhibition. Therefore, UV light （photo-Fenton） or electron current （electro-Fenton） was applied to improve the degradation efficiency of the Fenton process. Results showed that both photo-Fenton and electro-Fenton processes could overcome the inhibition of hypophosphite, especially the electro-Fenton.展开更多
The current modified electro-Fenton system was designed to develop a more convenient and efficient undivided system for practical wastewater treatment. The system adopted a cathode portion that employed magnetic stirr...The current modified electro-Fenton system was designed to develop a more convenient and efficient undivided system for practical wastewater treatment. The system adopted a cathode portion that employed magnetic stirring instead of common oxygen gas diffusion or gas sparging to supply oxygen gas for the electrolyte solution. Key factors influencing the cathode fabrication and activit） were investigated. The degradation of acid fuchsine with a self-made graphite-polytetrafluorethylene cathode was studied using spectrophotometer. It was found that the cathode generated hydrogen peroxide with high current efficiency and the hydrogen peroxide yield of the cathode did not decay after 10 times reuse. With the Pt anode at a ferrous ion concentration of 0.5 mmol/L, a pH of 3, and using magnetic stirring, dye decolorization could be rapidly accomplished but the destruction of benzene rings and intermediates was fairly difficult. With a Fe anode, dye degradation was more complete.展开更多
A novel Fe-Pd bifunctional catalyst supported on mesh-type γ-Al<sub>2</sub>O<sub>3</sub>/Al was prepared and applied in the degradation of Rhodamine B (RhB). The monolithic mesh-type Fe-Pd/γ-...A novel Fe-Pd bifunctional catalyst supported on mesh-type γ-Al<sub>2</sub>O<sub>3</sub>/Al was prepared and applied in the degradation of Rhodamine B (RhB). The monolithic mesh-type Fe-Pd/γ-Al<sub>2</sub>O<sub>3</sub>/Al bifunctional catalyst could be separated from the solution directly and could synthesize H<sub>2</sub>O<sub>2</sub> in situ. The characterization results showed that Fe could improve the dispersion of Pd<sup>0</sup>, and the electronic interactions between Pd and Fe could increase the Pd<sup>0</sup> contents on the catalyst, which increased the productivity of H<sub>2</sub>O<sub>2</sub>. Furthermore, DFT calculations proved that the addition of Fe could inhibit the dissociation of O<sub>2</sub> and promote the nondissociative hydrogenation of O<sub>2</sub> on the surface of Fe-Pd/γ-Al<sub>2</sub>O<sub>3</sub>/Al, which resulted in the increasement of H<sub>2</sub>O<sub>2</sub> selectivity. Finally, the in-situ synthesized H<sub>2</sub>O<sub>2</sub> by Pd was furtherly decomposed in situ by Fe to generate<span lang="EN-US" style="white-space:normal;font-size:10pt;font-family:;" "=""><span lang="EN-US" style="white-space:normal;font-size:10pt;font-family:;" "=""><span style="white-space:normal;color:#FFFFFF;font-family:Roboto, " background-color:#d46399;"=""><img src="Edit_e6a13073-7151-40b7-b2c3-a59a59d064fc.png" alt="" /></span></span></span>OH radicals to degrade organic pollutants. Therefore, Fe-Pd/ γ-Al<sub>2</sub>O<sub>3</sub>/Al catalysts exhibited excellent catalytic activity in the in-situ synthesis of H<sub>2</sub>O<sub>2</sub> and the degradation of RhB due to the synergistic effects between Pd and Fe on the catalyst. It provided a new idea for the design of bifunctional electro-Fenton catalysts. Ten cycles of experiments showed that the catalytic activity of Fe-Pd/γ-Al<sub>2</sub>O<sub>3</sub>/Al catalyst could be maintained for a long time.展开更多
The Electrochemical advanced oxidation method “Electro-Fenton” has been applied to remove 17β-estradiol (17β)- estra-1,3,5(10)-triéne-3,17-diol) in aqueous-acetonitrile mixture. This endocrine disrupting is a...The Electrochemical advanced oxidation method “Electro-Fenton” has been applied to remove 17β-estradiol (17β)- estra-1,3,5(10)-triéne-3,17-diol) in aqueous-acetonitrile mixture. This endocrine disrupting is a steroid hormone, releases from humans, animals and residual pharmaceuticals into the environmental water and usually causes suspected undesirable effects in aquatic organisms. The degradation of this organic compound by Electro-Fenton process was showed using a carbon felt cathode and platinum anode. The evolution of the concentration during treatment was followed up by high performance liquid chromatography (HPLC). The influence of operating conditions on the degradation of 17β-estradiol by Electro-Fenton step, such as initial concentration and catalyst concentration, has been investi- gated and discussed. We showed that the degradation reaction obeyed apparent first-order reaction kinetics, with absolute rate constant determined as 5.12 × 109 M–1 s–1 by competitive kinetics method taking Benzoic Acid as reference compound. The results confirm the efficiency of the Electro-Fenton process to degrade organic pollutant in aqueous-acetonitrile mixture.展开更多
基金The authors thank the "National" Science Council, Taiwan, China for financially supporting (No. NSC95- 2211-E-006-032).
文摘Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes （Fe^2＋/H2O2, UV/Fe^2＋/H2O2, and electrolysis/Fe^2＋/H2O2） in this study. Comparison of these techniques in oxidation efficiency was undertaken. It was found that Fenton process could not completely degrade citrate in the presence of hypophosphite since it caused a series inhibition. Therefore, UV light （photo-Fenton） or electron current （electro-Fenton） was applied to improve the degradation efficiency of the Fenton process. Results showed that both photo-Fenton and electro-Fenton processes could overcome the inhibition of hypophosphite, especially the electro-Fenton.
文摘The current modified electro-Fenton system was designed to develop a more convenient and efficient undivided system for practical wastewater treatment. The system adopted a cathode portion that employed magnetic stirring instead of common oxygen gas diffusion or gas sparging to supply oxygen gas for the electrolyte solution. Key factors influencing the cathode fabrication and activit） were investigated. The degradation of acid fuchsine with a self-made graphite-polytetrafluorethylene cathode was studied using spectrophotometer. It was found that the cathode generated hydrogen peroxide with high current efficiency and the hydrogen peroxide yield of the cathode did not decay after 10 times reuse. With the Pt anode at a ferrous ion concentration of 0.5 mmol/L, a pH of 3, and using magnetic stirring, dye decolorization could be rapidly accomplished but the destruction of benzene rings and intermediates was fairly difficult. With a Fe anode, dye degradation was more complete.
文摘A novel Fe-Pd bifunctional catalyst supported on mesh-type γ-Al<sub>2</sub>O<sub>3</sub>/Al was prepared and applied in the degradation of Rhodamine B (RhB). The monolithic mesh-type Fe-Pd/γ-Al<sub>2</sub>O<sub>3</sub>/Al bifunctional catalyst could be separated from the solution directly and could synthesize H<sub>2</sub>O<sub>2</sub> in situ. The characterization results showed that Fe could improve the dispersion of Pd<sup>0</sup>, and the electronic interactions between Pd and Fe could increase the Pd<sup>0</sup> contents on the catalyst, which increased the productivity of H<sub>2</sub>O<sub>2</sub>. Furthermore, DFT calculations proved that the addition of Fe could inhibit the dissociation of O<sub>2</sub> and promote the nondissociative hydrogenation of O<sub>2</sub> on the surface of Fe-Pd/γ-Al<sub>2</sub>O<sub>3</sub>/Al, which resulted in the increasement of H<sub>2</sub>O<sub>2</sub> selectivity. Finally, the in-situ synthesized H<sub>2</sub>O<sub>2</sub> by Pd was furtherly decomposed in situ by Fe to generate<span lang="EN-US" style="white-space:normal;font-size:10pt;font-family:;" "=""><span lang="EN-US" style="white-space:normal;font-size:10pt;font-family:;" "=""><span style="white-space:normal;color:#FFFFFF;font-family:Roboto, " background-color:#d46399;"=""><img src="Edit_e6a13073-7151-40b7-b2c3-a59a59d064fc.png" alt="" /></span></span></span>OH radicals to degrade organic pollutants. Therefore, Fe-Pd/ γ-Al<sub>2</sub>O<sub>3</sub>/Al catalysts exhibited excellent catalytic activity in the in-situ synthesis of H<sub>2</sub>O<sub>2</sub> and the degradation of RhB due to the synergistic effects between Pd and Fe on the catalyst. It provided a new idea for the design of bifunctional electro-Fenton catalysts. Ten cycles of experiments showed that the catalytic activity of Fe-Pd/γ-Al<sub>2</sub>O<sub>3</sub>/Al catalyst could be maintained for a long time.
文摘The Electrochemical advanced oxidation method “Electro-Fenton” has been applied to remove 17β-estradiol (17β)- estra-1,3,5(10)-triéne-3,17-diol) in aqueous-acetonitrile mixture. This endocrine disrupting is a steroid hormone, releases from humans, animals and residual pharmaceuticals into the environmental water and usually causes suspected undesirable effects in aquatic organisms. The degradation of this organic compound by Electro-Fenton process was showed using a carbon felt cathode and platinum anode. The evolution of the concentration during treatment was followed up by high performance liquid chromatography (HPLC). The influence of operating conditions on the degradation of 17β-estradiol by Electro-Fenton step, such as initial concentration and catalyst concentration, has been investi- gated and discussed. We showed that the degradation reaction obeyed apparent first-order reaction kinetics, with absolute rate constant determined as 5.12 × 109 M–1 s–1 by competitive kinetics method taking Benzoic Acid as reference compound. The results confirm the efficiency of the Electro-Fenton process to degrade organic pollutant in aqueous-acetonitrile mixture.
