The Experts below are selected from a list of 4533 Experts worldwide ranked by ideXlab platform
Guoguang Liu - One of the best experts on this subject based on the ideXlab platform.
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Thermo-activated Peroxydisulfate oxidation of indomethacin: Kinetics study and influences of co-existing substances.
Chemosphere, 2018Co-Authors: Meixuan Cai, Haijin Liu, Guoguang LiuAbstract:Abstract The widespread occurrence of non-steroidal anti-inflammatory drugs (NSAIDs) (e.g., Indomethacin) in the ambient environment has attracted growing concerns due to their potential threats to ecosystems and human health. Herein, we investigated the degradation of indomethacin (IM) by thermo-activated Peroxydisulfate (PDS). The pseudo first-order rate constant (kobs) of degradation of IM was increased significantly with higher temperatures and PDS doses. Moreover, when the initial pH value was raised from 5 to 9 the IM degradation was initially decreased and then increased. Basic conditions were favorable for the removal of IM in the thermo-activated Peroxydisulfate system. A response surface methodology based on the Box-Behnken design (BBD) was successfully employed for the optimization of the thermo-activated Peroxydisulfate (PDS) system. The presence of chlorine ions manifested a dual effect on the degradation of IM, while bicarbonate and SRFA (as a NOM model) reduced it. Radical scavenging tests and electron spin resonance (ESR) revealed that the dominant oxidizing species were SO4 − and OH at pH 9. Furthermore, the TOC removal efficiency attained 28.8% and the release of Cl−was 38.5% at 60 °C within 24min, while the mineralization rate of IM were 85.5% with the PDS concentration up to 20 mM at 2 h oxidation. To summarize, thermo-activated PDS oxidation is a promising technique for the remediation of IM-contaminated water.
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a sulfate radical based ferrous Peroxydisulfate oxidative system for indomethacin degradation in aqueous solutions
RSC Advances, 2017Co-Authors: Jing Kong, Haijin Liu, Ping Chen, Guoguang LiuAbstract:The degradation of indomethacin (IM) by ferrous ion-activated potassium Peroxydisulfate (Fe2+/PDS) was investigated. We aimed to determine the optimal conditions for the removal of IM under different concentrations of Fe2+and PDS, evaluate the effects of operational parameters (solution pH, humic acid (HA), N2 bubbling and persulfate species), and propose the degradation mechanism of IM by the Fe2+/PDS system. The sequential addition of Fe2+ led to an improvement in the IM degradation and TOC removal efficiency. When the molar ratio of IM/PDS/Fe2+ was 1 : 1.5 : 2, the IM was almost completely degraded. Restrictions to the degradation efficiency of IM were caused by increasing the solution pH, bubbling with nitrogen, or through the addition of HA. A low concentration of Cl− had no effect on the reaction, while a high concentration led to a dramatic inhibitory effect. In addition, quenching experiments revealed that SO4˙− was the major active radical for the degradation of IM by ferrous ion-activated Peroxydisulfate. Based on the identification of transformation products by liquid chromatography-mass spectrometry (LC-MS/MS), the pathways of the ferrous–Peroxydisulfate oxidative system for the degradation of IM were tentatively proposed.
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A sulfate radical based ferrous–Peroxydisulfate oxidative system for indomethacin degradation in aqueous solutions
RSC Advances, 2017Co-Authors: Jing Kong, Haijin Liu, Ping Chen, Guoguang LiuAbstract:The degradation of indomethacin (IM) by ferrous ion-activated potassium Peroxydisulfate (Fe2+/PDS) was investigated. We aimed to determine the optimal conditions for the removal of IM under different concentrations of Fe2+and PDS, evaluate the effects of operational parameters (solution pH, humic acid (HA), N2 bubbling and persulfate species), and propose the degradation mechanism of IM by the Fe2+/PDS system. The sequential addition of Fe2+ led to an improvement in the IM degradation and TOC removal efficiency. When the molar ratio of IM/PDS/Fe2+ was 1 : 1.5 : 2, the IM was almost completely degraded. Restrictions to the degradation efficiency of IM were caused by increasing the solution pH, bubbling with nitrogen, or through the addition of HA. A low concentration of Cl− had no effect on the reaction, while a high concentration led to a dramatic inhibitory effect. In addition, quenching experiments revealed that SO4˙− was the major active radical for the degradation of IM by ferrous ion-activated Peroxydisulfate. Based on the identification of transformation products by liquid chromatography-mass spectrometry (LC-MS/MS), the pathways of the ferrous–Peroxydisulfate oxidative system for the degradation of IM were tentatively proposed.
Yong Hae Kim - One of the best experts on this subject based on the ideXlab platform.
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Highly efficient synthesis of 1,2,4-thiadiazoles from thioamides utilizing tetra(n-butyl)ammonium Peroxydisulfate
Synthetic Communications, 2020Co-Authors: Kieseung Lee, Richard S. Lee, Yong Hae KimAbstract:A new synthetic approach to 1,2,4-thiadiazoles using tetra(n-butyl)ammonium Peroxydisulfate via oxidative dimerization of thioamides is described. This new oxidative protocol is simple, highly effi...
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A Simple and Selective Oxidation of Sulfides to Sulfoxides Using Tetrabutylammonium Peroxydisulfate: A Rebuttal
Synthetic Communications, 2004Co-Authors: Min Young Park, Vidyadhar K. Jadhav, Yong Hae KimAbstract:Abstract The report that oxidation of sulfides to sulfoxides using tetrabutylammonium Peroxydisulfate (2) in methylene chloride was found to be erroneous. We repeated the procedure described in the paper and found that oxidation of sulfide to sulfoxide could not be achieved with the method.
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A practical iodination of aromatic compounds using tetrabutylammonium Peroxydisulfate and iodine
Tetrahedron Letters, 1999Co-Authors: Seung Gak Yang, Yong Hae KimAbstract:Abstract A variety of aromatic compounds substituted with an electron donating group such as methoxy, hydroxy, or amino group, were regioselectively iodinated with iodine in the presence of tetrabutylammonium Peroxydisulfate under mild conditions in excellent yields.
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Practical Epoxidation of α,β-Unsaturated Ketones with Tetra-n-butylammonium Peroxydisulfate
Tetrahedron Letters, 1997Co-Authors: Yong Hae Kim, Je Pil Hwang, Seung Gak YangAbstract:Abstract α,β- Unsaturated ketones reacted with tetra-n-butylammonium Peroxydisulfate in the presence of hydrogen peroxide and base in acetonitrile at 25 °C to give the corresponding epoxides in excellent yields. © 1997 Elsevier Science Ltd.
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Novel α-iodination of functionalized ketones with iodinemediated by bis(tetra-n-butylammonium) Peroxydisulfate
Chemical Communications, 1997Co-Authors: Je Pil Whang, Seung Gak Yang, Yong Hae KimAbstract:α,β-Unsaturated ketones, β-keto esters and uracil derivatives react with iodine in the presence of bis(tetra-n-butylammonium) Peroxydisulfate under mild conditions in MeCN at 25 °C to give the corresponding α-iodinated products in good yields.
Jing Kong - One of the best experts on this subject based on the ideXlab platform.
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a sulfate radical based ferrous Peroxydisulfate oxidative system for indomethacin degradation in aqueous solutions
RSC Advances, 2017Co-Authors: Jing Kong, Haijin Liu, Ping Chen, Guoguang LiuAbstract:The degradation of indomethacin (IM) by ferrous ion-activated potassium Peroxydisulfate (Fe2+/PDS) was investigated. We aimed to determine the optimal conditions for the removal of IM under different concentrations of Fe2+and PDS, evaluate the effects of operational parameters (solution pH, humic acid (HA), N2 bubbling and persulfate species), and propose the degradation mechanism of IM by the Fe2+/PDS system. The sequential addition of Fe2+ led to an improvement in the IM degradation and TOC removal efficiency. When the molar ratio of IM/PDS/Fe2+ was 1 : 1.5 : 2, the IM was almost completely degraded. Restrictions to the degradation efficiency of IM were caused by increasing the solution pH, bubbling with nitrogen, or through the addition of HA. A low concentration of Cl− had no effect on the reaction, while a high concentration led to a dramatic inhibitory effect. In addition, quenching experiments revealed that SO4˙− was the major active radical for the degradation of IM by ferrous ion-activated Peroxydisulfate. Based on the identification of transformation products by liquid chromatography-mass spectrometry (LC-MS/MS), the pathways of the ferrous–Peroxydisulfate oxidative system for the degradation of IM were tentatively proposed.
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A sulfate radical based ferrous–Peroxydisulfate oxidative system for indomethacin degradation in aqueous solutions
RSC Advances, 2017Co-Authors: Jing Kong, Haijin Liu, Ping Chen, Guoguang LiuAbstract:The degradation of indomethacin (IM) by ferrous ion-activated potassium Peroxydisulfate (Fe2+/PDS) was investigated. We aimed to determine the optimal conditions for the removal of IM under different concentrations of Fe2+and PDS, evaluate the effects of operational parameters (solution pH, humic acid (HA), N2 bubbling and persulfate species), and propose the degradation mechanism of IM by the Fe2+/PDS system. The sequential addition of Fe2+ led to an improvement in the IM degradation and TOC removal efficiency. When the molar ratio of IM/PDS/Fe2+ was 1 : 1.5 : 2, the IM was almost completely degraded. Restrictions to the degradation efficiency of IM were caused by increasing the solution pH, bubbling with nitrogen, or through the addition of HA. A low concentration of Cl− had no effect on the reaction, while a high concentration led to a dramatic inhibitory effect. In addition, quenching experiments revealed that SO4˙− was the major active radical for the degradation of IM by ferrous ion-activated Peroxydisulfate. Based on the identification of transformation products by liquid chromatography-mass spectrometry (LC-MS/MS), the pathways of the ferrous–Peroxydisulfate oxidative system for the degradation of IM were tentatively proposed.
Haijin Liu - One of the best experts on this subject based on the ideXlab platform.
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Thermo-activated Peroxydisulfate oxidation of indomethacin: Kinetics study and influences of co-existing substances.
Chemosphere, 2018Co-Authors: Meixuan Cai, Haijin Liu, Guoguang LiuAbstract:Abstract The widespread occurrence of non-steroidal anti-inflammatory drugs (NSAIDs) (e.g., Indomethacin) in the ambient environment has attracted growing concerns due to their potential threats to ecosystems and human health. Herein, we investigated the degradation of indomethacin (IM) by thermo-activated Peroxydisulfate (PDS). The pseudo first-order rate constant (kobs) of degradation of IM was increased significantly with higher temperatures and PDS doses. Moreover, when the initial pH value was raised from 5 to 9 the IM degradation was initially decreased and then increased. Basic conditions were favorable for the removal of IM in the thermo-activated Peroxydisulfate system. A response surface methodology based on the Box-Behnken design (BBD) was successfully employed for the optimization of the thermo-activated Peroxydisulfate (PDS) system. The presence of chlorine ions manifested a dual effect on the degradation of IM, while bicarbonate and SRFA (as a NOM model) reduced it. Radical scavenging tests and electron spin resonance (ESR) revealed that the dominant oxidizing species were SO4 − and OH at pH 9. Furthermore, the TOC removal efficiency attained 28.8% and the release of Cl−was 38.5% at 60 °C within 24min, while the mineralization rate of IM were 85.5% with the PDS concentration up to 20 mM at 2 h oxidation. To summarize, thermo-activated PDS oxidation is a promising technique for the remediation of IM-contaminated water.
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a sulfate radical based ferrous Peroxydisulfate oxidative system for indomethacin degradation in aqueous solutions
RSC Advances, 2017Co-Authors: Jing Kong, Haijin Liu, Ping Chen, Guoguang LiuAbstract:The degradation of indomethacin (IM) by ferrous ion-activated potassium Peroxydisulfate (Fe2+/PDS) was investigated. We aimed to determine the optimal conditions for the removal of IM under different concentrations of Fe2+and PDS, evaluate the effects of operational parameters (solution pH, humic acid (HA), N2 bubbling and persulfate species), and propose the degradation mechanism of IM by the Fe2+/PDS system. The sequential addition of Fe2+ led to an improvement in the IM degradation and TOC removal efficiency. When the molar ratio of IM/PDS/Fe2+ was 1 : 1.5 : 2, the IM was almost completely degraded. Restrictions to the degradation efficiency of IM were caused by increasing the solution pH, bubbling with nitrogen, or through the addition of HA. A low concentration of Cl− had no effect on the reaction, while a high concentration led to a dramatic inhibitory effect. In addition, quenching experiments revealed that SO4˙− was the major active radical for the degradation of IM by ferrous ion-activated Peroxydisulfate. Based on the identification of transformation products by liquid chromatography-mass spectrometry (LC-MS/MS), the pathways of the ferrous–Peroxydisulfate oxidative system for the degradation of IM were tentatively proposed.
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A sulfate radical based ferrous–Peroxydisulfate oxidative system for indomethacin degradation in aqueous solutions
RSC Advances, 2017Co-Authors: Jing Kong, Haijin Liu, Ping Chen, Guoguang LiuAbstract:The degradation of indomethacin (IM) by ferrous ion-activated potassium Peroxydisulfate (Fe2+/PDS) was investigated. We aimed to determine the optimal conditions for the removal of IM under different concentrations of Fe2+and PDS, evaluate the effects of operational parameters (solution pH, humic acid (HA), N2 bubbling and persulfate species), and propose the degradation mechanism of IM by the Fe2+/PDS system. The sequential addition of Fe2+ led to an improvement in the IM degradation and TOC removal efficiency. When the molar ratio of IM/PDS/Fe2+ was 1 : 1.5 : 2, the IM was almost completely degraded. Restrictions to the degradation efficiency of IM were caused by increasing the solution pH, bubbling with nitrogen, or through the addition of HA. A low concentration of Cl− had no effect on the reaction, while a high concentration led to a dramatic inhibitory effect. In addition, quenching experiments revealed that SO4˙− was the major active radical for the degradation of IM by ferrous ion-activated Peroxydisulfate. Based on the identification of transformation products by liquid chromatography-mass spectrometry (LC-MS/MS), the pathways of the ferrous–Peroxydisulfate oxidative system for the degradation of IM were tentatively proposed.
Ping Chen - One of the best experts on this subject based on the ideXlab platform.
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a sulfate radical based ferrous Peroxydisulfate oxidative system for indomethacin degradation in aqueous solutions
RSC Advances, 2017Co-Authors: Jing Kong, Haijin Liu, Ping Chen, Guoguang LiuAbstract:The degradation of indomethacin (IM) by ferrous ion-activated potassium Peroxydisulfate (Fe2+/PDS) was investigated. We aimed to determine the optimal conditions for the removal of IM under different concentrations of Fe2+and PDS, evaluate the effects of operational parameters (solution pH, humic acid (HA), N2 bubbling and persulfate species), and propose the degradation mechanism of IM by the Fe2+/PDS system. The sequential addition of Fe2+ led to an improvement in the IM degradation and TOC removal efficiency. When the molar ratio of IM/PDS/Fe2+ was 1 : 1.5 : 2, the IM was almost completely degraded. Restrictions to the degradation efficiency of IM were caused by increasing the solution pH, bubbling with nitrogen, or through the addition of HA. A low concentration of Cl− had no effect on the reaction, while a high concentration led to a dramatic inhibitory effect. In addition, quenching experiments revealed that SO4˙− was the major active radical for the degradation of IM by ferrous ion-activated Peroxydisulfate. Based on the identification of transformation products by liquid chromatography-mass spectrometry (LC-MS/MS), the pathways of the ferrous–Peroxydisulfate oxidative system for the degradation of IM were tentatively proposed.
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A sulfate radical based ferrous–Peroxydisulfate oxidative system for indomethacin degradation in aqueous solutions
RSC Advances, 2017Co-Authors: Jing Kong, Haijin Liu, Ping Chen, Guoguang LiuAbstract:The degradation of indomethacin (IM) by ferrous ion-activated potassium Peroxydisulfate (Fe2+/PDS) was investigated. We aimed to determine the optimal conditions for the removal of IM under different concentrations of Fe2+and PDS, evaluate the effects of operational parameters (solution pH, humic acid (HA), N2 bubbling and persulfate species), and propose the degradation mechanism of IM by the Fe2+/PDS system. The sequential addition of Fe2+ led to an improvement in the IM degradation and TOC removal efficiency. When the molar ratio of IM/PDS/Fe2+ was 1 : 1.5 : 2, the IM was almost completely degraded. Restrictions to the degradation efficiency of IM were caused by increasing the solution pH, bubbling with nitrogen, or through the addition of HA. A low concentration of Cl− had no effect on the reaction, while a high concentration led to a dramatic inhibitory effect. In addition, quenching experiments revealed that SO4˙− was the major active radical for the degradation of IM by ferrous ion-activated Peroxydisulfate. Based on the identification of transformation products by liquid chromatography-mass spectrometry (LC-MS/MS), the pathways of the ferrous–Peroxydisulfate oxidative system for the degradation of IM were tentatively proposed.
