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
As a novel advanced oxidation process (AOP), electro-Fenton process is powerful for degrading most organic compounds including toxic and non-biodegradable ones, and so has attracted great attention. This paper reviews...As a novel advanced oxidation process (AOP), electro-Fenton process is powerful for degrading most organic compounds including toxic and non-biodegradable ones, and so has attracted great attention. This paper reviews this process in detail including the mechanism, electrolytic bath, electrode materials, aerations and operation parameters. The application of electro-Fenton method in wastewater treatment is evaluated and summarized. Future work in this field is suggested, and three main directions of new electrode exploitation, development of assisted technologies and mechanistic study should be strengthened.展开更多
The present study aims to fabricate heterogeneous electro-Fenton(HEF)cathode catalysts for the in-situ generation of H2O2 and the degradation of organic pollutants in water.To achieve this,preparation of Fe and N co-d...The present study aims to fabricate heterogeneous electro-Fenton(HEF)cathode catalysts for the in-situ generation of H2O2 and the degradation of organic pollutants in water.To achieve this,preparation of Fe and N co-doped MXene composites(FeCN/MXene-x,where x represents the loading content of FeCN)and construction of the HEF system for the degradation of sulfathiazole(STZ)were carried out.The characterization results showed that Fe,C and N mainly existed in the form of Fe3C and Fe3N in the FeCN/MXene catalysts,which were favorable for promoting the ORR reaction in the HEF system.Among them,FeCN/MXene-2 exhibited the highest redox electron transfer rate and H2O2 selectivity(86%).The catalytic oxidation mechanism of the FeCN/MXene-2/HEF system was investigated by free radical quenching,electron paramagnetic resonance and frontier orbital theory studies.These studies demonstrated that the main active substances for the degradation of STZ were·OH and 1O2.In addition,the excellent stability and practical performance of the prepared cathodic catalysts were demonstrated by cycling experiments and real water sample tests.展开更多
A combined treatment technology （DEF-BIO） using the direct electro-Fenton （DEF） process and bioremediation （BIO） was established in this study. The performance of the DEF-BIO process on the remediation of a pyre...A combined treatment technology （DEF-BIO） using the direct electro-Fenton （DEF） process and bioremediation （BIO） was established in this study. The performance of the DEF-BIO process on the remediation of a pyrene （PYR）-contaminated soil was evaluated in a slurry reactor. The appropriate order of application was to conduct the DEF process followed by BIO, evaluated through analysis of the degradation characteristics of each process individually. In addition, the application time of the DEF process affected the efficiency of the combined process. The optimum time to apply the DEF process was determined through an analysis of the induced changes in PYR intermediates, pH, soil organic matter （SOM） and bacteria. The optimum application time of the DEF process was 6 h. All the induced changes were beneficial for the BIO phase. The removal of PYR was 91.02% for DEF- BIO after 72h, and the efficiency was almost 50% increased, compared with the individual DEF and BIO treatments. Therefore, the combined process of DEF-BIO process may be an efficient and promising method for the remediation.展开更多
Traditional Fenton oxidation is an effective method for reducing pollutants that are difficult to degrade.Owing to the large amounts of Fe(II),acids,and alkalis added in the reaction,large amounts of Fenton sludge are...Traditional Fenton oxidation is an effective method for reducing pollutants that are difficult to degrade.Owing to the large amounts of Fe(II),acids,and alkalis added in the reaction,large amounts of Fenton sludge are produced,increasing treatment costs and restricting the method’s application.In this study,we developed a three-dimensional electro-Fenton system by adding iron-carbon filler and investigated the effects of different electrolytic cell structure arrangements,particle electrode dosages,sponge iron(SI)to granular activated carbon(GAC)dosage ratios,current densities,H_(2)O_(2)dosages,and cathodic aeration on nitrobenzene(NB)wastewater treatment.The optimal system conditions were a particle electrode dosage of 100 g/L,SI:GAC mass ratio of 3:1,current density of 30 mA/cm^(2),H_(2)O_(2)dosage of 50 mmol/L,cathodic aeration of 0.8 L/min,and hydraulic retention time of 120 min.The average NB removal rate and chemical oxygen demand reached 67.38%±1.05%and 70.60%±1.15%,respectively,for which the increase in Fenton sludge was 891.8 mg/L.Different from the traditional Fenton process,additional Fe(II)was not required in the process used herein,reducing iron sludge accumulation and lowering the operating costs of using Fenton sludge as a hazardous waste treatment.In addition,the process applied in this study was able to reduce the chemical amounts used and increase the treatment efficiency.The reductions in sludge treatment costs and secondary pollutants make the proposed process an efficient and sustainable alternative for treating NB wastewater.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.
基金Project supported by the National Natural Science Foundation of China (No. 50478049)the Natural Science Foundation of Guangdong Province (No. 04011215), China
文摘As a novel advanced oxidation process (AOP), electro-Fenton process is powerful for degrading most organic compounds including toxic and non-biodegradable ones, and so has attracted great attention. This paper reviews this process in detail including the mechanism, electrolytic bath, electrode materials, aerations and operation parameters. The application of electro-Fenton method in wastewater treatment is evaluated and summarized. Future work in this field is suggested, and three main directions of new electrode exploitation, development of assisted technologies and mechanistic study should be strengthened.
基金supported by the National Key R&D Program of China(No.2019YFC0408500)the Key Science and Technology Projects of Anhui Province(No.202003a07020004)the Open Foundation of the Key Lab(Center)of Anhui Institute of Ecological Civilization(No.W2023JSKF0152).
文摘The present study aims to fabricate heterogeneous electro-Fenton(HEF)cathode catalysts for the in-situ generation of H2O2 and the degradation of organic pollutants in water.To achieve this,preparation of Fe and N co-doped MXene composites(FeCN/MXene-x,where x represents the loading content of FeCN)and construction of the HEF system for the degradation of sulfathiazole(STZ)were carried out.The characterization results showed that Fe,C and N mainly existed in the form of Fe3C and Fe3N in the FeCN/MXene catalysts,which were favorable for promoting the ORR reaction in the HEF system.Among them,FeCN/MXene-2 exhibited the highest redox electron transfer rate and H2O2 selectivity(86%).The catalytic oxidation mechanism of the FeCN/MXene-2/HEF system was investigated by free radical quenching,electron paramagnetic resonance and frontier orbital theory studies.These studies demonstrated that the main active substances for the degradation of STZ were·OH and 1O2.In addition,the excellent stability and practical performance of the prepared cathodic catalysts were demonstrated by cycling experiments and real water sample tests.
文摘A combined treatment technology （DEF-BIO） using the direct electro-Fenton （DEF） process and bioremediation （BIO） was established in this study. The performance of the DEF-BIO process on the remediation of a pyrene （PYR）-contaminated soil was evaluated in a slurry reactor. The appropriate order of application was to conduct the DEF process followed by BIO, evaluated through analysis of the degradation characteristics of each process individually. In addition, the application time of the DEF process affected the efficiency of the combined process. The optimum time to apply the DEF process was determined through an analysis of the induced changes in PYR intermediates, pH, soil organic matter （SOM） and bacteria. The optimum application time of the DEF process was 6 h. All the induced changes were beneficial for the BIO phase. The removal of PYR was 91.02% for DEF- BIO after 72h, and the efficiency was almost 50% increased, compared with the individual DEF and BIO treatments. Therefore, the combined process of DEF-BIO process may be an efficient and promising method for the remediation.
基金supported by the National Natural Science Foundation of China(Grant No.52360009)the Lanzhou Science and Technology Plan(China)(2023-3-86).
文摘Traditional Fenton oxidation is an effective method for reducing pollutants that are difficult to degrade.Owing to the large amounts of Fe(II),acids,and alkalis added in the reaction,large amounts of Fenton sludge are produced,increasing treatment costs and restricting the method’s application.In this study,we developed a three-dimensional electro-Fenton system by adding iron-carbon filler and investigated the effects of different electrolytic cell structure arrangements,particle electrode dosages,sponge iron(SI)to granular activated carbon(GAC)dosage ratios,current densities,H_(2)O_(2)dosages,and cathodic aeration on nitrobenzene(NB)wastewater treatment.The optimal system conditions were a particle electrode dosage of 100 g/L,SI:GAC mass ratio of 3:1,current density of 30 mA/cm^(2),H_(2)O_(2)dosage of 50 mmol/L,cathodic aeration of 0.8 L/min,and hydraulic retention time of 120 min.The average NB removal rate and chemical oxygen demand reached 67.38%±1.05%and 70.60%±1.15%,respectively,for which the increase in Fenton sludge was 891.8 mg/L.Different from the traditional Fenton process,additional Fe(II)was not required in the process used herein,reducing iron sludge accumulation and lowering the operating costs of using Fenton sludge as a hazardous waste treatment.In addition,the process applied in this study was able to reduce the chemical amounts used and increase the treatment efficiency.The reductions in sludge treatment costs and secondary pollutants make the proposed process an efficient and sustainable alternative for treating NB wastewater.
