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Jingyun Fang - One of the best experts on this subject based on the ideXlab platform.
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The Multiple Role of Bromide Ion in PPCPs Degradation under UV/Chlorine Treatment.
Environmental science & technology, 2018Co-Authors: Shuangshuang Cheng, Chii Shang, Jingyun Fang, Xinran Zhang, Xin Yang, Weihua Song, Yanheng PanAbstract:This study investigated the role of bromide ions in the degradation of nine pharmaceuticals and personal care products (PPCPs) during the UV/chlorine treatment of simulated drinking water containing 2.5 mgC L−1 natural organic matter (NOM). The kinetics of contributions from UV irradiation and from oxidation by free chlorine, free Bromine, hydroxyl radical and reactive halogen species were evaluated. The observed loss rate constants of PPCPs in the presence of 10 μM bromide were 1.6–23 times of those observed in the absence of bromide (except for iopromide and ibuprofen). Bromide was shown to play multiple roles in PPCP degradation. It reacts rapidly with free chlorine to produce a trace amount of free Bromine, which then contributes to up to 55% of the degradation of some PPCPs during 15 min of UV/chlorine treatment. Bromide was also shown to reduce the level of HO• and to change the reactive chlorine species to Bromine-containing species, which resulted in decreases in ibuprofen degradation and enhancem...
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Bromate formation from the oxidation of bromide in the UV/chlorine process with low pressure and medium pressure UV lamps
Chemosphere, 2017Co-Authors: Jingyun Fang, Chihhao Fan, Chii Shang, Yun Fu, Quan Zhao, Xiangru ZhangAbstract:When a bromide-containing water is treated by the ultraviolet (UV)/chlorine process, hydroxyl radicals (HO[rad]) and halogen radicals such as Cl[rad] or Br[rad] are formed due to the UV photolysis of free halogens. These reactive species may induce the formation of bromate, which is a probable human carcinogen. Bromate formation in the UV/chlorine process using low pressure (LP) and medium pressure (MP) lamps in the presence of bromide was investigated in the present study. The UV/chlorine process significantly enhanced bromate formation as compared to dark chlorination. The bromate formation was elevated with increasing UV fluence, bromide concentration, and pH values under both LP and MP UV irradiations. It was significantly enhanced at pH 9 compared to those at pH 6 and 7 with MP UV irradiation, while it was slightly enhanced at pH 9 with LP UV. The formation by UV/chlorine process started with the formation of free Bromine (HOBr/OBr−) through the reaction of chlorine and bromide, followed by a subsequent oxidation of free Bromine and formation of BrO[rad] and bromate by reacting with radicals.
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Bromate Formation from Bromide Oxidation by the UV/Persulfate Process
2016Co-Authors: Jingyun Fang, Chii ShangAbstract:Bromate formation from bromide oxidation by the UV/persulfate process was investigated, along with changes in pH, persulfate dosages, and bromide concentrations in ultrapure water and in bromide-spiked real water. In general, the bromate formation increased with increasing persulfate dosage and bromide concentration. The bromate formation was initiated and primarily driven by sulfate radicals (SO4•–) and involved the formation of hypobromous acid/hypobromite (HOBr/OBr–) as an intermediate and bromate as the final product. Under the test conditions, the rate of the first step driven by SO4•– is slower than that of the second step. Direct UV photolysis of HOBr/OBr– to form bromate and the photolysis of bromate are insignificant. The bromate formation was similar for pH 4–7 but decreased over 90% with increasing pH from 7 to above 9. Less bromate was formed in the real water sample than in ultrapure water, which was primarily attributable to the presence of natural organic matter that reacts with Bromine atoms, HOBr/OBr– and SO4•–. The extent of bromate formation and degradation of micropollutants are nevertheless coupled processes unless intermediate Bromine species are consumed by NOM in real water
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bromate formation in bromide containing water through the cobalt mediated activation of peroxymonosulfate
Water Research, 2015Co-Authors: Zhi Chen, Chii Shang, Jingyun Fang, Yingying Xiang, Li Ling, Dionysios D DionysiouAbstract:Abstract Bromate formation in bromide-containing water through the cobalt (Co)-mediated activation of peroxymonosulfate (PMS) was investigated. Increasing the PMS dosage and the cobalt dosage increased the formation of bromate and bromate yields of up to 100% were recorded under the test conditions. The bromate yield increased to a maximum as the pH rose from 2.7 to 6 before decreasing by over 90% as the pH rose further from 6 to above 9. The bromate formation is a two-step process involving free Bromine as a key intermediate and bromate as the final product. In the first step, apart from the known oxidation of bromide to free Bromine and of free Bromine to bromate by sulfate radicals (SO4 −), Co(III) produced from the oxidation of Co(II) by PMS and SO4 − also oxidizes bromide to free Bromine. The contribution of Co(III) to the bromate formation was verified with the addition of methanol and EDTA, a radical scavenger and a Co(III) ligand, respectively. In the presence of methanol, free Bromine formation increased with increasing Co(II) dosage but no bromate was detected, indicating that Co(III) oxidized bromide to form free Bromine but not bromate. In the presence of both EDTA and methanol, no free Bromine or bromate was detected, as Co(III) was stabilized by EDTA to form the CoIIIEDTA– complex, which could not oxidize bromide. Mathematical simulation further suggested that Co(III) outweighed SO4 − to oxidize bromide to free Bromine. On the other hand, SO4 − is essential for the oxidation of free Bromine to bromate in the second step. In real water, the presence of NOM significantly decreased the bromate formation but caused the brominated organic DBP formation with high quantity. This is the first study to demonstrate the significant bromate formation in the Co/PMS system and the substantial contribution of Co(III) to the formation.
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bromate formation from bromide oxidation by the uv persulfate process
Environmental Science & Technology, 2012Co-Authors: Jingyun Fang, Chii ShangAbstract:Bromate formation from bromide oxidation by the UV/persulfate process was investigated, along with changes in pH, persulfate dosages, and bromide concentrations in ultrapure water and in bromide-spiked real water. In general, the bromate formation increased with increasing persulfate dosage and bromide concentration. The bromate formation was initiated and primarily driven by sulfate radicals (SO4•–) and involved the formation of hypobromous acid/hypobromite (HOBr/OBr–) as an intermediate and bromate as the final product. Under the test conditions, the rate of the first step driven by SO4•– is slower than that of the second step. Direct UV photolysis of HOBr/OBr– to form bromate and the photolysis of bromate are insignificant. The bromate formation was similar for pH 4–7 but decreased over 90% with increasing pH from 7 to above 9. Less bromate was formed in the real water sample than in ultrapure water, which was primarily attributable to the presence of natural organic matter that reacts with Bromine ato...
Chii Shang - One of the best experts on this subject based on the ideXlab platform.
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The Multiple Role of Bromide Ion in PPCPs Degradation under UV/Chlorine Treatment.
Environmental science & technology, 2018Co-Authors: Shuangshuang Cheng, Chii Shang, Jingyun Fang, Xinran Zhang, Xin Yang, Weihua Song, Yanheng PanAbstract:This study investigated the role of bromide ions in the degradation of nine pharmaceuticals and personal care products (PPCPs) during the UV/chlorine treatment of simulated drinking water containing 2.5 mgC L−1 natural organic matter (NOM). The kinetics of contributions from UV irradiation and from oxidation by free chlorine, free Bromine, hydroxyl radical and reactive halogen species were evaluated. The observed loss rate constants of PPCPs in the presence of 10 μM bromide were 1.6–23 times of those observed in the absence of bromide (except for iopromide and ibuprofen). Bromide was shown to play multiple roles in PPCP degradation. It reacts rapidly with free chlorine to produce a trace amount of free Bromine, which then contributes to up to 55% of the degradation of some PPCPs during 15 min of UV/chlorine treatment. Bromide was also shown to reduce the level of HO• and to change the reactive chlorine species to Bromine-containing species, which resulted in decreases in ibuprofen degradation and enhancem...
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Bromate formation from the oxidation of bromide in the UV/chlorine process with low pressure and medium pressure UV lamps
Chemosphere, 2017Co-Authors: Jingyun Fang, Chihhao Fan, Chii Shang, Yun Fu, Quan Zhao, Xiangru ZhangAbstract:When a bromide-containing water is treated by the ultraviolet (UV)/chlorine process, hydroxyl radicals (HO[rad]) and halogen radicals such as Cl[rad] or Br[rad] are formed due to the UV photolysis of free halogens. These reactive species may induce the formation of bromate, which is a probable human carcinogen. Bromate formation in the UV/chlorine process using low pressure (LP) and medium pressure (MP) lamps in the presence of bromide was investigated in the present study. The UV/chlorine process significantly enhanced bromate formation as compared to dark chlorination. The bromate formation was elevated with increasing UV fluence, bromide concentration, and pH values under both LP and MP UV irradiations. It was significantly enhanced at pH 9 compared to those at pH 6 and 7 with MP UV irradiation, while it was slightly enhanced at pH 9 with LP UV. The formation by UV/chlorine process started with the formation of free Bromine (HOBr/OBr−) through the reaction of chlorine and bromide, followed by a subsequent oxidation of free Bromine and formation of BrO[rad] and bromate by reacting with radicals.
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Bromate Formation from Bromide Oxidation by the UV/Persulfate Process
2016Co-Authors: Jingyun Fang, Chii ShangAbstract:Bromate formation from bromide oxidation by the UV/persulfate process was investigated, along with changes in pH, persulfate dosages, and bromide concentrations in ultrapure water and in bromide-spiked real water. In general, the bromate formation increased with increasing persulfate dosage and bromide concentration. The bromate formation was initiated and primarily driven by sulfate radicals (SO4•–) and involved the formation of hypobromous acid/hypobromite (HOBr/OBr–) as an intermediate and bromate as the final product. Under the test conditions, the rate of the first step driven by SO4•– is slower than that of the second step. Direct UV photolysis of HOBr/OBr– to form bromate and the photolysis of bromate are insignificant. The bromate formation was similar for pH 4–7 but decreased over 90% with increasing pH from 7 to above 9. Less bromate was formed in the real water sample than in ultrapure water, which was primarily attributable to the presence of natural organic matter that reacts with Bromine atoms, HOBr/OBr– and SO4•–. The extent of bromate formation and degradation of micropollutants are nevertheless coupled processes unless intermediate Bromine species are consumed by NOM in real water
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bromate formation in bromide containing water through the cobalt mediated activation of peroxymonosulfate
Water Research, 2015Co-Authors: Zhi Chen, Chii Shang, Jingyun Fang, Yingying Xiang, Li Ling, Dionysios D DionysiouAbstract:Abstract Bromate formation in bromide-containing water through the cobalt (Co)-mediated activation of peroxymonosulfate (PMS) was investigated. Increasing the PMS dosage and the cobalt dosage increased the formation of bromate and bromate yields of up to 100% were recorded under the test conditions. The bromate yield increased to a maximum as the pH rose from 2.7 to 6 before decreasing by over 90% as the pH rose further from 6 to above 9. The bromate formation is a two-step process involving free Bromine as a key intermediate and bromate as the final product. In the first step, apart from the known oxidation of bromide to free Bromine and of free Bromine to bromate by sulfate radicals (SO4 −), Co(III) produced from the oxidation of Co(II) by PMS and SO4 − also oxidizes bromide to free Bromine. The contribution of Co(III) to the bromate formation was verified with the addition of methanol and EDTA, a radical scavenger and a Co(III) ligand, respectively. In the presence of methanol, free Bromine formation increased with increasing Co(II) dosage but no bromate was detected, indicating that Co(III) oxidized bromide to form free Bromine but not bromate. In the presence of both EDTA and methanol, no free Bromine or bromate was detected, as Co(III) was stabilized by EDTA to form the CoIIIEDTA– complex, which could not oxidize bromide. Mathematical simulation further suggested that Co(III) outweighed SO4 − to oxidize bromide to free Bromine. On the other hand, SO4 − is essential for the oxidation of free Bromine to bromate in the second step. In real water, the presence of NOM significantly decreased the bromate formation but caused the brominated organic DBP formation with high quantity. This is the first study to demonstrate the significant bromate formation in the Co/PMS system and the substantial contribution of Co(III) to the formation.
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bromate formation from bromide oxidation by the uv persulfate process
Environmental Science & Technology, 2012Co-Authors: Jingyun Fang, Chii ShangAbstract:Bromate formation from bromide oxidation by the UV/persulfate process was investigated, along with changes in pH, persulfate dosages, and bromide concentrations in ultrapure water and in bromide-spiked real water. In general, the bromate formation increased with increasing persulfate dosage and bromide concentration. The bromate formation was initiated and primarily driven by sulfate radicals (SO4•–) and involved the formation of hypobromous acid/hypobromite (HOBr/OBr–) as an intermediate and bromate as the final product. Under the test conditions, the rate of the first step driven by SO4•– is slower than that of the second step. Direct UV photolysis of HOBr/OBr– to form bromate and the photolysis of bromate are insignificant. The bromate formation was similar for pH 4–7 but decreased over 90% with increasing pH from 7 to above 9. Less bromate was formed in the real water sample than in ultrapure water, which was primarily attributable to the presence of natural organic matter that reacts with Bromine ato...
Urs Von Gunten - One of the best experts on this subject based on the ideXlab platform.
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oxidative treatment of bromide containing waters formation of Bromine and its reactions with inorganic and organic compounds a critical review
Water Research, 2014Co-Authors: Michele B Heeb, Saskia G Zimmermannsteffens, Justine Criquet, Urs Von GuntenAbstract:Bromide (Br(-)) is present in all water sources at concentrations ranging from ≈ 10 to >1000 μg L(-1) in fresh waters and about 67 mg L(-1) in seawater. During oxidative water treatment bromide is oxidized to hypobromous acid/hypobromite (HOBr/OBr(-)) and other Bromine species. A systematic and critical literature review has been conducted on the reactivity of HOBr/OBr(-) and other Bromine species with inorganic and organic compounds, including micropollutants. The speciation of Bromine in the absence and presence of chloride and chlorine has been calculated and it could be shown that HOBr/OBr(-) are the dominant species in fresh waters. In ocean waters, other Bromine species such as Br2, BrCl, and Br2O gain importance and may have to be considered under certain conditions. HOBr reacts fast with many inorganic compounds such as ammonia, iodide, sulfite, nitrite, cyanide and thiocyanide with apparent second-order rate constants in the order of 10(4)-10(9)M(-1)s(-1) at pH 7. No rate constants for the reactions with Fe(II) and As(III) are available. Mn(II) oxidation by Bromine is controlled by a Mn(III,IV) oxide-catalyzed process involving Br2O and BrCl. Bromine shows a very high reactivity toward phenolic groups (apparent second-order rate constants kapp ≈ 10(3)-10(5)M(-1)s(-1) at pH 7), amines and sulfamides (kapp ≈ 10(5)-10(6)M(-1)s(-1) at pH 7) and S-containing compounds (kapp ≈ 10(5)-10(7)M(-1)s(-1) at pH 7). For phenolic moieties, it is possible to derive second-order rate constants with a Hammett-σ-based QSAR approach with [Formula in text]. A negative slope is typical for electrophilic substitution reactions. In general, kapp of Bromine reactions at pH 7 are up to three orders of magnitude greater than for chlorine. In the case of amines, these rate constants are even higher than for ozone. Model calculations show that depending on the bromide concentration and the pH, the high reactivity of Bromine may outweigh the reactions of chlorine during chlorination of bromide-containing waters.
Urs Von Gunten - One of the best experts on this subject based on the ideXlab platform.
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oxidative treatment of bromide containing waters formation of Bromine and its reactions with inorganic and organic compounds a critical review
Water Research, 2014Co-Authors: Michele B Heeb, Saskia G Zimmermannsteffens, Urs Von Gunten, Justine CriquetAbstract:Bromide (Br-) is present in all water sources at concentrations ranging from similar to 10 to >1000 mu g L-1 in fresh waters and about 67 mg L-1 in seawater. During oxidative water treatment bromide is oxidized to hypobromous acid/hypobromite (HOBr/OBr-) and other Bromine species. A systematic and critical literature review has been conducted on the reactivity of HOBr/OBr- and other Bromine species with inorganic and organic compounds, including micropollutants. The speciation of Bromine in the absence and presence of chloride and chlorine has been calculated and it could be shown that HOBr/OBr- are the dominant species in fresh waters. In ocean waters, other Bromine species such as Br-2, BrCl, and Br2O gain importance and may have to be considered under certain conditions. HOBr reacts fast with many inorganic compounds such as ammonia, iodide, sulfite, nitrite, cyanide and thiocyanide with apparent second-order rate constants in the order of 10(4)-10(9) M-1 s(-1) at pH 7. No rate constants for the reactions with Fe(II) and As(III) are available. Mn(II) oxidation by Bromine is controlled by a Mn(III,IV) oxide-catalyzed process involving Br2O and BrCl. Bromine shows a very high reactivity toward phenolic groups (apparent second-order rate constants k(app) approximate to 10(3)-10(5) M-1 s(-1) at pH 7), amines and sulfamides (k(app) 10(5) -10(6)M(-1) s(-1) at pH 7) and S-containing compounds (k(app) 10(5)-10(7)M(-1) s(-1) at pH 7). For phenolic moieties, it is possible to derive second-order rate constants with a Hammett-sigma-based QSAR approach with log(k((HOBr/PhO-)))= 7.8 - 3.5 Sigma sigma. A negative slope is typical for electrophilic substitution reactions. In general, k(app) of Bromine reactions at pH 7 are up to three orders of magnitude greater than for chlorine. In the case of amines, these rate constants are even higher than for ozone. Model calculations show that depending on the bromide concentration and the pH, the high reactivity of Bromine may outweigh the reactions of chlorine during chlorination of bromide-containing waters. (C) 2013 Elsevier Ltd. All rights reserved.
Justine Criquet - One of the best experts on this subject based on the ideXlab platform.
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oxidative treatment of bromide containing waters formation of Bromine and its reactions with inorganic and organic compounds a critical review
Water Research, 2014Co-Authors: Michele B Heeb, Saskia G Zimmermannsteffens, Urs Von Gunten, Justine CriquetAbstract:Bromide (Br-) is present in all water sources at concentrations ranging from similar to 10 to >1000 mu g L-1 in fresh waters and about 67 mg L-1 in seawater. During oxidative water treatment bromide is oxidized to hypobromous acid/hypobromite (HOBr/OBr-) and other Bromine species. A systematic and critical literature review has been conducted on the reactivity of HOBr/OBr- and other Bromine species with inorganic and organic compounds, including micropollutants. The speciation of Bromine in the absence and presence of chloride and chlorine has been calculated and it could be shown that HOBr/OBr- are the dominant species in fresh waters. In ocean waters, other Bromine species such as Br-2, BrCl, and Br2O gain importance and may have to be considered under certain conditions. HOBr reacts fast with many inorganic compounds such as ammonia, iodide, sulfite, nitrite, cyanide and thiocyanide with apparent second-order rate constants in the order of 10(4)-10(9) M-1 s(-1) at pH 7. No rate constants for the reactions with Fe(II) and As(III) are available. Mn(II) oxidation by Bromine is controlled by a Mn(III,IV) oxide-catalyzed process involving Br2O and BrCl. Bromine shows a very high reactivity toward phenolic groups (apparent second-order rate constants k(app) approximate to 10(3)-10(5) M-1 s(-1) at pH 7), amines and sulfamides (k(app) 10(5) -10(6)M(-1) s(-1) at pH 7) and S-containing compounds (k(app) 10(5)-10(7)M(-1) s(-1) at pH 7). For phenolic moieties, it is possible to derive second-order rate constants with a Hammett-sigma-based QSAR approach with log(k((HOBr/PhO-)))= 7.8 - 3.5 Sigma sigma. A negative slope is typical for electrophilic substitution reactions. In general, k(app) of Bromine reactions at pH 7 are up to three orders of magnitude greater than for chlorine. In the case of amines, these rate constants are even higher than for ozone. Model calculations show that depending on the bromide concentration and the pH, the high reactivity of Bromine may outweigh the reactions of chlorine during chlorination of bromide-containing waters. (C) 2013 Elsevier Ltd. All rights reserved.
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oxidative treatment of bromide containing waters formation of Bromine and its reactions with inorganic and organic compounds a critical review
Water Research, 2014Co-Authors: Michele B Heeb, Saskia G Zimmermannsteffens, Justine Criquet, Urs Von GuntenAbstract:Bromide (Br(-)) is present in all water sources at concentrations ranging from ≈ 10 to >1000 μg L(-1) in fresh waters and about 67 mg L(-1) in seawater. During oxidative water treatment bromide is oxidized to hypobromous acid/hypobromite (HOBr/OBr(-)) and other Bromine species. A systematic and critical literature review has been conducted on the reactivity of HOBr/OBr(-) and other Bromine species with inorganic and organic compounds, including micropollutants. The speciation of Bromine in the absence and presence of chloride and chlorine has been calculated and it could be shown that HOBr/OBr(-) are the dominant species in fresh waters. In ocean waters, other Bromine species such as Br2, BrCl, and Br2O gain importance and may have to be considered under certain conditions. HOBr reacts fast with many inorganic compounds such as ammonia, iodide, sulfite, nitrite, cyanide and thiocyanide with apparent second-order rate constants in the order of 10(4)-10(9)M(-1)s(-1) at pH 7. No rate constants for the reactions with Fe(II) and As(III) are available. Mn(II) oxidation by Bromine is controlled by a Mn(III,IV) oxide-catalyzed process involving Br2O and BrCl. Bromine shows a very high reactivity toward phenolic groups (apparent second-order rate constants kapp ≈ 10(3)-10(5)M(-1)s(-1) at pH 7), amines and sulfamides (kapp ≈ 10(5)-10(6)M(-1)s(-1) at pH 7) and S-containing compounds (kapp ≈ 10(5)-10(7)M(-1)s(-1) at pH 7). For phenolic moieties, it is possible to derive second-order rate constants with a Hammett-σ-based QSAR approach with [Formula in text]. A negative slope is typical for electrophilic substitution reactions. In general, kapp of Bromine reactions at pH 7 are up to three orders of magnitude greater than for chlorine. In the case of amines, these rate constants are even higher than for ozone. Model calculations show that depending on the bromide concentration and the pH, the high reactivity of Bromine may outweigh the reactions of chlorine during chlorination of bromide-containing waters.
