Photocatalytic oxidation kinetics of thiophene in n-octane/water extraction system was studied with fluorine and ferric ion codoped nano-TiO_(2)(nano-F^-/Fe^(3+)/TiO_(2))powders used as the photocatalyst.Effects of in...Photocatalytic oxidation kinetics of thiophene in n-octane/water extraction system was studied with fluorine and ferric ion codoped nano-TiO_(2)(nano-F^-/Fe^(3+)/TiO_(2))powders used as the photocatalyst.Effects of initial concentration of thiophene and additional dosage of F^-/Fe^(3+)/TiO_(2)on the reaction rate constant and half-life were investigated.The results showed that the appropriately added dosage of F^-/Fe^(3+)/TiO_(2)was 0.1 g in the 100-mL reaction system and the photooxidative kinetics of thiophene in the presence of F^-/Fe^(3+)/TiO_(2)catalyst was of first-order with a rate constant of 0.6508 h^(-1)and a half-life of 1.0651 h.The desulfurization rate of thiophene was 98.1%in 5 h and the sulfur content could be reduced from 800 ppm to 15 ppm.The reaction rate constant increased with a decreasing initial concentration of thiophene.展开更多
Recent studies have proposed that the high-valent iron species(such as Fe^(Ⅳ)O^(2+))rather than sulfate radical(SO_(4)^(·-))and hydroxyl radical(·OH)are the main reactive oxidant species(ROS)in Fe(Ⅱ)/perox...Recent studies have proposed that the high-valent iron species(such as Fe^(Ⅳ)O^(2+))rather than sulfate radical(SO_(4)^(·-))and hydroxyl radical(·OH)are the main reactive oxidant species(ROS)in Fe(Ⅱ)/peroxydisulfate(PDS)system with the methyl phenyl sulfoxide(PMSO)as the Fe^(Ⅳ)O^(2+)probe.However,many operational factors may interfere with the accuracy of this method,so the contribution of Fe^(Ⅳ)O^(2+)calculated by this method is controversial.In this study,the possible effect of Fe(Ⅱ)concentration,pollutant type,reducing agent,or coexisted anions on Fe^(Ⅳ)O^(2+)production and its corresponding contribution to the removal of target pollutants in the Fe(Ⅱ)/PDS system were investigated in detail,and the intrinsic mechanisms involved were also explored.This study shows that ROS generation is a complex process in the Fe(Ⅱ)/PDS system,and multiple combinatorial approaches are urgently required to deeply explore the contribution of ROS to the elimination of target contaminants.展开更多
Objective The selective loss of dopaminergic neurons in Parkinson＇s disease is suspected to correlate with the increase of cellular iron, which may be involved in the pathogenesis of PD by promotion of oxidative stre...Objective The selective loss of dopaminergic neurons in Parkinson＇s disease is suspected to correlate with the increase of cellular iron, which may be involved in the pathogenesis of PD by promotion of oxidative stress. This research investigated dopamine-induced oxidative stress toxicity contributed by iron and the production of dopamine-derived neurotoxins in dopaminergic SH-SYSY cells. Methods After the SH-SYSY cells were pre-incubated with dopamine and Fe^2＋ for 24 h, the cell viability, hydroxyl radical, melondialdehyde, cell apoptosis, and catechol isoquinolines were measured by lactate dehydrogenase assay, salicylic acid trapping method, thiobarbuteric acid assay, Hoechst 33258 staining and HPLC-electrochemical detection （HPLC-ECD）, respectively. Results （1） Optimal dopamine （150 μmol/L） and Fe^2＋ （40 or 80 μmol/L） significantly increased the concentrations of hydroxy radicals and melondialdehyde in SH-SYSY cells. （2） Induction with dopamine alone or dopamine and Fe^2＋ （dopamine/Fe^2＋） caused cell apoptosis. （3） Compared with untreated cells, the catechol isoquinolines, salsolinol and N-methyl-salsolinol in dopamine/Fe^2＋-induced cells were detected in increasing amounts. Conclusion Due to dopamine/Fe^2＋-induced oxidative stress similar to the state in the parkinsonian substantia nigra neurons, dopamine and Fe^2＋ impaired SH-SYSY cells could be used as the cell oxidative stress model of Parkinson＇s disease. The catechol isoquinolines detected in cells may be involved in the pathogenesis of Parkinson＇s disease as potential neurotoxins.展开更多
In this study a new water treatment system that couples （photo-） electrochemical catalysis （PEC or EC） in a microbial fuel cell （MFC） was configured using a stainless-steel （SS） cathode coated w th Fe / TiO2....In this study a new water treatment system that couples （photo-） electrochemical catalysis （PEC or EC） in a microbial fuel cell （MFC） was configured using a stainless-steel （SS） cathode coated w th Fe / TiO2. We examined the destruction of methylene blue （MB） and tetracycline. Fe^0/TiO2 was prepared using a chemical reduction-deposition method and coated onto an SS wire mesh （500 mesh） using a sol technique. The anode generates electricity using microbes （bio-anode）. Connected via wire and ohmic resistance, the system requires a short reaction time and operates at a low cost by effectively remowng 94% MB （initial concentration 20 mg·L^-1） and 83% TOC/TOCo under visible light illumination （50 W; 1.99 mW·cm^-2 for 120 rain, MFC-PEC）. The removal was similar even without light irradiation （MFC-EC）. The EEo of the MFC-PEC system was approximately 0.675 kWh·m^-3. order-l whereas that of the MFC-EC system was zero. The system was able to remove 70% COD in tetracycline solution （initial tetracycline concentration 100 mg·L^-1） after 120 min of visible light illumination; without light, the removal was 15% lower. The destruction of MB and tetracycline in both traditional photocatalysis and photoelectrocatalysis systems was notably low. The electron spinresonance spectroscopy （ESR） study demonstrated that. OH was formed under visible light, and. 02 was formed without light. The bio-electricity-activated O2 and ROS （reactive oxidizing species） generation by Fe^0/TiO2 effectively degraded the pollutants. This cathodic degradation improved the electricity generation by accepting and consuming more electrons from the bio-anode.展开更多
基金the NationalNatural Science Foundation of China(20806021)the Natu-ral Science Foundation of Hebei Province(B2009000678)the Research Foundation of Hebei Province EducationDepartment(2007440)for the financial support of this work
文摘Photocatalytic oxidation kinetics of thiophene in n-octane/water extraction system was studied with fluorine and ferric ion codoped nano-TiO_(2)(nano-F^-/Fe^(3+)/TiO_(2))powders used as the photocatalyst.Effects of initial concentration of thiophene and additional dosage of F^-/Fe^(3+)/TiO_(2)on the reaction rate constant and half-life were investigated.The results showed that the appropriately added dosage of F^-/Fe^(3+)/TiO_(2)was 0.1 g in the 100-mL reaction system and the photooxidative kinetics of thiophene in the presence of F^-/Fe^(3+)/TiO_(2)catalyst was of first-order with a rate constant of 0.6508 h^(-1)and a half-life of 1.0651 h.The desulfurization rate of thiophene was 98.1%in 5 h and the sulfur content could be reduced from 800 ppm to 15 ppm.The reaction rate constant increased with a decreasing initial concentration of thiophene.
基金financially supported by the National Natural Science Foundation of China(Nos.51779088,51908528)the Fundamental Research Funds for the Central Universities(No.2021CDJQY-014)the Natural Science Foundation of Hunan Province,China(No.2021JJ30126)。
文摘Recent studies have proposed that the high-valent iron species(such as Fe^(Ⅳ)O^(2+))rather than sulfate radical(SO_(4)^(·-))and hydroxyl radical(·OH)are the main reactive oxidant species(ROS)in Fe(Ⅱ)/peroxydisulfate(PDS)system with the methyl phenyl sulfoxide(PMSO)as the Fe^(Ⅳ)O^(2+)probe.However,many operational factors may interfere with the accuracy of this method,so the contribution of Fe^(Ⅳ)O^(2+)calculated by this method is controversial.In this study,the possible effect of Fe(Ⅱ)concentration,pollutant type,reducing agent,or coexisted anions on Fe^(Ⅳ)O^(2+)production and its corresponding contribution to the removal of target pollutants in the Fe(Ⅱ)/PDS system were investigated in detail,and the intrinsic mechanisms involved were also explored.This study shows that ROS generation is a complex process in the Fe(Ⅱ)/PDS system,and multiple combinatorial approaches are urgently required to deeply explore the contribution of ROS to the elimination of target contaminants.
基金This work was supported by the National Natural Science Foundation of China （No. 20435020, No. 20275005, and No. 30670645）.
文摘Objective The selective loss of dopaminergic neurons in Parkinson＇s disease is suspected to correlate with the increase of cellular iron, which may be involved in the pathogenesis of PD by promotion of oxidative stress. This research investigated dopamine-induced oxidative stress toxicity contributed by iron and the production of dopamine-derived neurotoxins in dopaminergic SH-SYSY cells. Methods After the SH-SYSY cells were pre-incubated with dopamine and Fe^2＋ for 24 h, the cell viability, hydroxyl radical, melondialdehyde, cell apoptosis, and catechol isoquinolines were measured by lactate dehydrogenase assay, salicylic acid trapping method, thiobarbuteric acid assay, Hoechst 33258 staining and HPLC-electrochemical detection （HPLC-ECD）, respectively. Results （1） Optimal dopamine （150 μmol/L） and Fe^2＋ （40 or 80 μmol/L） significantly increased the concentrations of hydroxy radicals and melondialdehyde in SH-SYSY cells. （2） Induction with dopamine alone or dopamine and Fe^2＋ （dopamine/Fe^2＋） caused cell apoptosis. （3） Compared with untreated cells, the catechol isoquinolines, salsolinol and N-methyl-salsolinol in dopamine/Fe^2＋-induced cells were detected in increasing amounts. Conclusion Due to dopamine/Fe^2＋-induced oxidative stress similar to the state in the parkinsonian substantia nigra neurons, dopamine and Fe^2＋ impaired SH-SYSY cells could be used as the cell oxidative stress model of Parkinson＇s disease. The catechol isoquinolines detected in cells may be involved in the pathogenesis of Parkinson＇s disease as potential neurotoxins.
文摘In this study a new water treatment system that couples （photo-） electrochemical catalysis （PEC or EC） in a microbial fuel cell （MFC） was configured using a stainless-steel （SS） cathode coated w th Fe / TiO2. We examined the destruction of methylene blue （MB） and tetracycline. Fe^0/TiO2 was prepared using a chemical reduction-deposition method and coated onto an SS wire mesh （500 mesh） using a sol technique. The anode generates electricity using microbes （bio-anode）. Connected via wire and ohmic resistance, the system requires a short reaction time and operates at a low cost by effectively remowng 94% MB （initial concentration 20 mg·L^-1） and 83% TOC/TOCo under visible light illumination （50 W; 1.99 mW·cm^-2 for 120 rain, MFC-PEC）. The removal was similar even without light irradiation （MFC-EC）. The EEo of the MFC-PEC system was approximately 0.675 kWh·m^-3. order-l whereas that of the MFC-EC system was zero. The system was able to remove 70% COD in tetracycline solution （initial tetracycline concentration 100 mg·L^-1） after 120 min of visible light illumination; without light, the removal was 15% lower. The destruction of MB and tetracycline in both traditional photocatalysis and photoelectrocatalysis systems was notably low. The electron spinresonance spectroscopy （ESR） study demonstrated that. OH was formed under visible light, and. 02 was formed without light. The bio-electricity-activated O2 and ROS （reactive oxidizing species） generation by Fe^0/TiO2 effectively degraded the pollutants. This cathodic degradation improved the electricity generation by accepting and consuming more electrons from the bio-anode.
