Biochar is a well-known material for pollutant removal owing to its low cost and rich surface functionality. A kind of highly active substance, called environmentally persistent free radicals(EPFRs), can be produced i...Biochar is a well-known material for pollutant removal owing to its low cost and rich surface functionality. A kind of highly active substance, called environmentally persistent free radicals(EPFRs), can be produced in the preparation process of biochar, playing an important role in the removal of pollutants.In this study, sludge-derived biochars(SBC_(120) and SBC_(270)) were prepared by the hydrothermal carbonization under two temperatures(120℃ and 270℃) to investigate their removal abilities of Cr(Ⅵ). The maximum removal amounts of Cr(Ⅵ) by SBC_(120) and SBC_(270) were 16.58 and 22.93 mg·g^(-1), respectively. It was further revealed that the appearance of Cr(Ⅲ), as a result of EPFRs on sludge-derived biochar(SBC) transferred electrons to Cr(Ⅵ) in neutral solutions. That is to say, oxygen-centered(O-centered) EPFRs on SBC_(120) and carbon-centered(C-centered) EPFRs on SBC_(270) all could be used as electron donors to Cr(Ⅵ) to make it become Cr(Ⅲ). This study not only provides a theoretical basis for the mechanism of pollutants removal by sludge-derived biochar but also offers a new perspective on the direct effect of EPFRs on pollutants.展开更多
Background,aim,and scope Environmentally persistent free radicals(EPFRs)have received significant attention due to their longer lifetime and stable existence in various environments.The strong environmental migration ...Background,aim,and scope Environmentally persistent free radicals(EPFRs)have received significant attention due to their longer lifetime and stable existence in various environments.The strong environmental migration ability of particulate matter allows EPFRs to migrate over long-distance transport,thereby impacting the quality of the local atmospheric environment.Additionally,EPFRs can also adhere to atmospheric particles and interact with typical gaseous pollutants to affect atmospheric chemical reactions.EPFRs can produce some reactive organic species,promoting oxidative stress in the human body,damaging biological macromolecules and ultimately affecting the organism health.EPFRs are considered as a novel type of pollutant that affects human health.Despite their significance,there are few literatures available on the characteristics and fate behaviors of EPFRs up to date.Therefore,supplemental reviews are crucial for providing comprehensive understanding of EPFRs.Materials and methods This review summarizes the characteristics of EPFRs in particulate matter,outlines the generation mechanism and influencing factors of EPFRs,and the impacts of EPFRs on environmental quality and organism health.Results The content of EPFRs in particulate matter ranges from 1017 to 1020 spins∙g−1.Due to the strong mobility of atmospheric particulate matter,the long-term exposure to high levels of EPFRs may aggravate the impact of particulate matter on human health.The interaction between EPFRs and typical gaseous pollutants can alter their fate and influence atmospheric chemical reactions.EPFRs are mainly produced by transition metal elements and substituted aromatic hydrocarbons through electron transfer.Additionally,the chemical bond rupture of organic substances through heat treatment or ultraviolet radiation can also produce EPFRs,and heterogeneous reactions are capable producing them as well.The production of EPFRs is not only influenced by transition metal elements and precursors,but also by various environmental factors such as oxygen,temperature,light radiation,and relative humidity.Discussion EPFRs in atmospheric particulates matters are usually rich in fine particulates with obvious seasonal and regional variations.They can easily enter the human respiratory tract and lungs with inhalable particulates,thereby increasing the risk of exposure.Additionally,EPFRs in atmospheric particulates can interact with some typical gaseous pollutants,impacting the life and fate of EPFRs in the atmosphere,and alter atmospheric chemical reactions.Traditionally,EPFRs are generated by transition metal elements and substituted aromatic hydrocarbons undergoing electron transfer in the post-flame and cool-zone regions of combustion systems and other thermal processes to remove HCl,H_(2)O or CO groups,ultimately produce semiquinones,phenoxyls,and cyclopentadienyls.Recent studies have indicated that EPFRs can also be generated under the conditions of without transition metal elemental.Organics can also produce EPFRs through chemical bond rupture during heat treatment or light radiation conditions,as well as through some heterogeneous reactions and photochemical secondary generation of EPFRs.The presence or absence of oxygen has different effects on the type and yield of EPFRs.The concentration,type,and crystal type of transition metal elements will affect the type,content,and atmospheric lifetime of EPFRs.It is generally believed that the impact of transition metal element types on EPFRs is related to the oxidation-reduction potential.The combustion temperature or heat treatment process significantly affects the type and amount of EPFRs.Factors such as precursor loading content,pH conditions,light radiation and relative humidity also influence the generation of EPFRs.EPFRs can interact with pollutants in the environment during their migration and transformation process in environmental medium.This process accelerates the degradation of pollutants and plays a crucial role in the migration and transformation of organic pollutants in environmental media.The reaction process of EPFRs may lead to the production of reactive oxygen species(ROS)such as∙OH,which can induce oxidative stress,inflammation and immune response to biological lung cells and tissues,leading to chronic respiratory and cardiopulmonary dysfunction,cardiovascular damage and neurotoxic effects,ultimately impacting the health of organisms.Conclusions The interaction mechanism between EPFRs in particulate matter and gaseous pollutants remains unclear.Furthermore,research on the generation mechanism of EPFRs without the participation of transition metals is not comprehensive,and the detection of EPFRs is limited to simple qualitative categories and lack accurate qualitative analysis.Recommendations and perspectives Further research should be conducted on the generation mechanism,measurement techniques,migration pathways,and transformation process of EPFRs.It is also important to explore the interaction between EPFRs in atmospheric particulate matter and typical gaseous pollutants.展开更多
Among the numerous health conditions environmental pollutants can cause, chronic exposure to pollutants including persistent organic pollutants（POPs） and heavy metals has been shown to disturb a specific biological ...Among the numerous health conditions environmental pollutants can cause, chronic exposure to pollutants including persistent organic pollutants（POPs） and heavy metals has been shown to disturb a specific biological homeostatic process, the iron metabolism in human body. Disorders of iron metabolism are among the common diseases of humans and encompass a broad spectrum of diseases with different clinical manifestations, ranging from anemia to iron overload, and possibly to neurodegenerative diseases and cancer.Hepcidin–ferroportin（FPN） signaling is one of the key mechanisms responsible for iron supply, utilization, recycling, and storage, and recent studies demonstrated that exposure to environmental pollutants including POPs and heavy metals could lead to disruption of the hepcidin–FPN axis along with disordered systemic iron homeostasis and diseases. This article introduces and highlights the accompanying review article by Drs. Xu and Liu in this journal, which elaborates in detail the adverse effects of environmental pollutants on iron metabolism, and the mechanisms responsible for these toxicological outcomes. It also points out the knowledge gaps still existing in this subject matter. Research that will fill these gaps will improve our understanding of the issue and provide useful information to prevent or treat diseases induced by environmental pollutants.展开更多
Environmentally persistent free radicals(EPFRs)in humic substances play an essential role in soil geochemical processes.Light is known to induce EPFRs formation for dissolved organic matter in aquatic environments;how...Environmentally persistent free radicals(EPFRs)in humic substances play an essential role in soil geochemical processes.Light is known to induce EPFRs formation for dissolved organic matter in aquatic environments;however,the impacts of light irradiation on the variation of EPFRs in soil humic substances remain unclear.In this study,humic acid,fulvic acid,and humin were extracted from peat soil and then in situ irradiated using simulated sunlight.Electron paramagnetic resonance spectroscopy results showed that with the increasing irradiation time,the spin densities and g-factors of humic substances rapidly increased during the initial 20 min and then gradually reached a plateau.After irradiation for 2h,the maximum spin density levels were up to 1.63×10^17,2.06×10^17,and 1.77×10^×10^17 spins/g for the humic acid,fulvic acid,and humin,respectively.And the superoxide radicals increased to 1.05×10^l4-1.46×10^14spins/g while the alkyl radicals increased to 0.47×10^14-1.76×10^14 spins/g.The light-induced EPFRs were relatively unstable and readily returned back to their original state under dark and oxic conditions.Significant positive correlations were observed between the concentrations of EPFRs and reactive radical species(R2=0.65-0.98,/?<0.05),which suggested that the newly produced EPFRs contributed to the formation of reactive radical species.Our findings indicate that under the irradiation humic substances are likely to be more toxic and reactive in soil due to the formation of EPFRs.展开更多
Environmentally persistent free radicals(EPFRs)are a new class of pollutants that are long-lived in fine particles(PM_(2.5)),i.e.,their 1/e lifetime ranges from days to months(or even infinite).They are capable of pro...Environmentally persistent free radicals(EPFRs)are a new class of pollutants that are long-lived in fine particles(PM_(2.5)),i.e.,their 1/e lifetime ranges from days to months(or even infinite).They are capable of producing harmful reactive oxygen species such as hydroxyl radicals.The redox cycling of EPFRs is considered as an important pathway for PM_(2.5) to induce oxidative stress inside the humans,causing adverse health effects such as respiratory and cardiovascular diseases.Conse-quently,research regarding their toxicity,formation and environmental occurrences in PM_(2.5) has attracted increasing atten-tions globally during the past two decades.However,literature data in this field remain quite limited and discrete.Hence,an extensive review is urgently needed to summarize the current understanding of this topic.In this work,we systematically reviewed the analytical methods and environmental occurrences,e.g.,types,concentrations,and decay behaviors,as well as possible sources of EPFRs in PM_(2.5).The types of pretreatment methods,g-values of common EPFRs and categories of decay processes were discussed in detail.Moreover,great efforts were made to revisit the original data of the published works of EPFRs in airborne particulate matter and provided additional useful information for comparison where possible,e.g.,their mean and standard deviation of g-values,line widths(ΔHp-p),and concentrations.Finally,possible research opportunities were highlighted to further advance our knowledge of this emerging issue.展开更多
Emerging environmental persistent free radicals(EPFRs),can generate reactive oxygen species(ROS),posing potential exposure risks to human health.Incomplete coal combustion is a major source of EPFRs.Organic carbonaceo...Emerging environmental persistent free radicals(EPFRs),can generate reactive oxygen species(ROS),posing potential exposure risks to human health.Incomplete coal combustion is a major source of EPFRs.Organic carbonaceous fractions are essential and important players in the formation of EPFRs during coal combustion.However,relationship between individual organic carbonaceous and non-carbon fractions with EPFRs in such emissions are not well known.This paper investigated the characteristics of EPFRs discharged from simulated coal combustion.Our results showed that the concentration of EPFRs was major concentrated on PM 1.1(51.66e81.85%),and more easily oxidized by oxygen resulting in producing more oxygen-centered radicals(semiquinone-type)in PM 1.1.The mean of line width(DHp-p)was 5.87±0.41G higher than that of biomass combustion,indicating more free radical species were emitted from coal combustion.Humic-like substances-carbon(HULIS-C)was the major contributor of the for-mation of EPFRs and facilitate the generated of EPFRs.Secondary processes have also contributed to the formation of EPFRs during the coal combustion.Our result also noted that there was no relationship between transition metals and EPFRs,may be due to the variability and complexity of the chemical properties and composition of PM.This is critical for the prediction of geochemical behavior and risk assessment of EPFRs,which can provide basic data to support policy development to address rural air pollutant emissions.展开更多
Emerging pollutants,characterized by high environmental persistence,strong bioaccumulation,and significant biotoxicity,have posed serious threats to humans as well as the environment,and thus attracted global attentio...Emerging pollutants,characterized by high environmental persistence,strong bioaccumulation,and significant biotoxicity,have posed serious threats to humans as well as the environment,and thus attracted global attention.Their rapid identification and precise detection are of critical significance for the risk control of emerging pollutants.展开更多
Per-and polyfluoroalkyl substances(PFAS)are a diverse group of synthetic chemicals.Their nu-merous applications in industrial manufacturing and consumer products have resulted in widespread human exposure.Known as“fo...Per-and polyfluoroalkyl substances(PFAS)are a diverse group of synthetic chemicals.Their nu-merous applications in industrial manufacturing and consumer products have resulted in widespread human exposure.Known as“forever chemicals”due to their persistence in the environment,PFAs have been linked to adverse health effects,including increased risks of certain cancers,reduced antibody responses to vaccines,and elevated cholesterol levels,as noted in literature reviews by the us Environmental Protection Agency(EPA).展开更多
Aerosol-bound organic radicals,including environmentally persistent free radicals(EPFRs),are key components that affect climate,air quality,and human health.While putative structures have been proposed,the molecular c...Aerosol-bound organic radicals,including environmentally persistent free radicals(EPFRs),are key components that affect climate,air quality,and human health.While putative structures have been proposed,the molecular characteristics of EPFRs remain unknown.Here,we report a surrogate method to characterize EPFRs in real ambient samples using mass spectrometry.The method identifies chemically relevant oxygenated polycyclic aromatic hydrocarbons(OxPAH)that interconvert with oxygen-centered EPFR(OC-EPFR).We found OxPAH compounds most relevant to OC-EPFRs are structurally rich and diverse quinones,whose diversity is strongly associated with OC-EPFR levels.Both atmospheric oxidation and combustion contributed to OC-EPFR formation.Redundancy analysis and photochemical aging model show pyrolytic sources generated more oxidized OC-EPFRs than photolytic sources.Our study reveals the detailed molecular characteristics of OC-EPFRs and shows that oxidation states can be used to identify the origins of OC-EPFRs,offering a way to track the development and evolution of aerosol particles in the environment.展开更多
To reveal the influence of the diversity of precursors on the formation of environmental persistent free radicals(EPFRs),pomelo peel(PP)and its physically divided portion,pomelo cuticle(PC),and white fiber(WF)were use...To reveal the influence of the diversity of precursors on the formation of environmental persistent free radicals(EPFRs),pomelo peel(PP)and its physically divided portion,pomelo cuticle(PC),and white fiber(WF)were used as precursors to prepare six hydrochars:PPH-Fe,PCH-Fe,WFH-Fe,PPH,PCH,and WFH with and without Fe(III)addition during hydrothermal carbonization(HTC).PPH-Fe and WFH-Fe had higher EPFRs content(9.11×10^(18)and 8.25×10^(18)spins·g^(−1))compared to PPH and WFH(3.33×10^(18)and 2.96×10^(18)spins·g^(−1)),indicating that iron-doping favored EPFRs formation.However,PCH-Fe had lower EPFRs content(2.78×10^(18)spins·g^(−1))than PCH(7.95×10^(18)spins·g^(−1)),possibly due to excessive iron leading to the consumption of the generated EPFRs.For another reason,the required Fe(III)amount for EPFRs formation might vary among different precursors.PC has a lower concentration of phenolic compounds but 68-97%fatty acids,while WF and PP are rich in cellulose and lignin.In the Fenton-like reaction,oxygen-centered radicals of hydrochar played a significant role in activating H_(2)O_(2)and efficiently degrading bisphenol A(BPA).Mechanisms of reactive oxygen species(ROS)generation in hydrochar/H_(2)O_(2)system were proposed.EPFRs on hydrochar activate H_(2)O_(2)via electron transfer,creating·OH and 1O2,leading to BPA degradation.More importantly,the embedded EPFRs on the hydrochar’s inner surface contributed to the prolonged Fenton-like reactivity of PPH-Fe stored for 45 days.This study demonstrates that by optimizing precursor selection and iron doping,hydrochars can be engineered to maximize their EPFRs content and reactivity,providing a cost-effective solution for the degradation of hazardous pollutants.展开更多
基金supported by the Beijing Municipal Natural Science Foundation (8202007)the National Natural Science Foundation of China (52170148)。
文摘Biochar is a well-known material for pollutant removal owing to its low cost and rich surface functionality. A kind of highly active substance, called environmentally persistent free radicals(EPFRs), can be produced in the preparation process of biochar, playing an important role in the removal of pollutants.In this study, sludge-derived biochars(SBC_(120) and SBC_(270)) were prepared by the hydrothermal carbonization under two temperatures(120℃ and 270℃) to investigate their removal abilities of Cr(Ⅵ). The maximum removal amounts of Cr(Ⅵ) by SBC_(120) and SBC_(270) were 16.58 and 22.93 mg·g^(-1), respectively. It was further revealed that the appearance of Cr(Ⅲ), as a result of EPFRs on sludge-derived biochar(SBC) transferred electrons to Cr(Ⅵ) in neutral solutions. That is to say, oxygen-centered(O-centered) EPFRs on SBC_(120) and carbon-centered(C-centered) EPFRs on SBC_(270) all could be used as electron donors to Cr(Ⅵ) to make it become Cr(Ⅲ). This study not only provides a theoretical basis for the mechanism of pollutants removal by sludge-derived biochar but also offers a new perspective on the direct effect of EPFRs on pollutants.
文摘Background,aim,and scope Environmentally persistent free radicals(EPFRs)have received significant attention due to their longer lifetime and stable existence in various environments.The strong environmental migration ability of particulate matter allows EPFRs to migrate over long-distance transport,thereby impacting the quality of the local atmospheric environment.Additionally,EPFRs can also adhere to atmospheric particles and interact with typical gaseous pollutants to affect atmospheric chemical reactions.EPFRs can produce some reactive organic species,promoting oxidative stress in the human body,damaging biological macromolecules and ultimately affecting the organism health.EPFRs are considered as a novel type of pollutant that affects human health.Despite their significance,there are few literatures available on the characteristics and fate behaviors of EPFRs up to date.Therefore,supplemental reviews are crucial for providing comprehensive understanding of EPFRs.Materials and methods This review summarizes the characteristics of EPFRs in particulate matter,outlines the generation mechanism and influencing factors of EPFRs,and the impacts of EPFRs on environmental quality and organism health.Results The content of EPFRs in particulate matter ranges from 1017 to 1020 spins∙g−1.Due to the strong mobility of atmospheric particulate matter,the long-term exposure to high levels of EPFRs may aggravate the impact of particulate matter on human health.The interaction between EPFRs and typical gaseous pollutants can alter their fate and influence atmospheric chemical reactions.EPFRs are mainly produced by transition metal elements and substituted aromatic hydrocarbons through electron transfer.Additionally,the chemical bond rupture of organic substances through heat treatment or ultraviolet radiation can also produce EPFRs,and heterogeneous reactions are capable producing them as well.The production of EPFRs is not only influenced by transition metal elements and precursors,but also by various environmental factors such as oxygen,temperature,light radiation,and relative humidity.Discussion EPFRs in atmospheric particulates matters are usually rich in fine particulates with obvious seasonal and regional variations.They can easily enter the human respiratory tract and lungs with inhalable particulates,thereby increasing the risk of exposure.Additionally,EPFRs in atmospheric particulates can interact with some typical gaseous pollutants,impacting the life and fate of EPFRs in the atmosphere,and alter atmospheric chemical reactions.Traditionally,EPFRs are generated by transition metal elements and substituted aromatic hydrocarbons undergoing electron transfer in the post-flame and cool-zone regions of combustion systems and other thermal processes to remove HCl,H_(2)O or CO groups,ultimately produce semiquinones,phenoxyls,and cyclopentadienyls.Recent studies have indicated that EPFRs can also be generated under the conditions of without transition metal elemental.Organics can also produce EPFRs through chemical bond rupture during heat treatment or light radiation conditions,as well as through some heterogeneous reactions and photochemical secondary generation of EPFRs.The presence or absence of oxygen has different effects on the type and yield of EPFRs.The concentration,type,and crystal type of transition metal elements will affect the type,content,and atmospheric lifetime of EPFRs.It is generally believed that the impact of transition metal element types on EPFRs is related to the oxidation-reduction potential.The combustion temperature or heat treatment process significantly affects the type and amount of EPFRs.Factors such as precursor loading content,pH conditions,light radiation and relative humidity also influence the generation of EPFRs.EPFRs can interact with pollutants in the environment during their migration and transformation process in environmental medium.This process accelerates the degradation of pollutants and plays a crucial role in the migration and transformation of organic pollutants in environmental media.The reaction process of EPFRs may lead to the production of reactive oxygen species(ROS)such as∙OH,which can induce oxidative stress,inflammation and immune response to biological lung cells and tissues,leading to chronic respiratory and cardiopulmonary dysfunction,cardiovascular damage and neurotoxic effects,ultimately impacting the health of organisms.Conclusions The interaction mechanism between EPFRs in particulate matter and gaseous pollutants remains unclear.Furthermore,research on the generation mechanism of EPFRs without the participation of transition metals is not comprehensive,and the detection of EPFRs is limited to simple qualitative categories and lack accurate qualitative analysis.Recommendations and perspectives Further research should be conducted on the generation mechanism,measurement techniques,migration pathways,and transformation process of EPFRs.It is also important to explore the interaction between EPFRs in atmospheric particulate matter and typical gaseous pollutants.
文摘Among the numerous health conditions environmental pollutants can cause, chronic exposure to pollutants including persistent organic pollutants（POPs） and heavy metals has been shown to disturb a specific biological homeostatic process, the iron metabolism in human body. Disorders of iron metabolism are among the common diseases of humans and encompass a broad spectrum of diseases with different clinical manifestations, ranging from anemia to iron overload, and possibly to neurodegenerative diseases and cancer.Hepcidin–ferroportin（FPN） signaling is one of the key mechanisms responsible for iron supply, utilization, recycling, and storage, and recent studies demonstrated that exposure to environmental pollutants including POPs and heavy metals could lead to disruption of the hepcidin–FPN axis along with disordered systemic iron homeostasis and diseases. This article introduces and highlights the accompanying review article by Drs. Xu and Liu in this journal, which elaborates in detail the adverse effects of environmental pollutants on iron metabolism, and the mechanisms responsible for these toxicological outcomes. It also points out the knowledge gaps still existing in this subject matter. Research that will fill these gaps will improve our understanding of the issue and provide useful information to prevent or treat diseases induced by environmental pollutants.
基金This work was supported by the National Natural Science Foundation of China(Grant No.41877126)National Key R&D Program of China(Grant No.2018YFC1802004)+2 种基金China Postdoctoral Science Foundation funded project(No.2019M650278)Shaanxi Key R&D Program of China(No.2019ZDLNY01-02-01)Shaanxi Science Fund for Distinguished Young Scholars(Grant No.2019JC-18).
文摘Environmentally persistent free radicals(EPFRs)in humic substances play an essential role in soil geochemical processes.Light is known to induce EPFRs formation for dissolved organic matter in aquatic environments;however,the impacts of light irradiation on the variation of EPFRs in soil humic substances remain unclear.In this study,humic acid,fulvic acid,and humin were extracted from peat soil and then in situ irradiated using simulated sunlight.Electron paramagnetic resonance spectroscopy results showed that with the increasing irradiation time,the spin densities and g-factors of humic substances rapidly increased during the initial 20 min and then gradually reached a plateau.After irradiation for 2h,the maximum spin density levels were up to 1.63×10^17,2.06×10^17,and 1.77×10^×10^17 spins/g for the humic acid,fulvic acid,and humin,respectively.And the superoxide radicals increased to 1.05×10^l4-1.46×10^14spins/g while the alkyl radicals increased to 0.47×10^14-1.76×10^14 spins/g.The light-induced EPFRs were relatively unstable and readily returned back to their original state under dark and oxic conditions.Significant positive correlations were observed between the concentrations of EPFRs and reactive radical species(R2=0.65-0.98,/?<0.05),which suggested that the newly produced EPFRs contributed to the formation of reactive radical species.Our findings indicate that under the irradiation humic substances are likely to be more toxic and reactive in soil due to the formation of EPFRs.
基金the Ningbo Natural Science Foundation(Grant no.2018A610208)the National This work was supported by the Ningbo Natural Science Foundation(Grant no.2018A610208)the National Institute of Environmental Health Sciences(NIEHS)(Grant no.2P42ES013648)。
文摘Environmentally persistent free radicals(EPFRs)are a new class of pollutants that are long-lived in fine particles(PM_(2.5)),i.e.,their 1/e lifetime ranges from days to months(or even infinite).They are capable of producing harmful reactive oxygen species such as hydroxyl radicals.The redox cycling of EPFRs is considered as an important pathway for PM_(2.5) to induce oxidative stress inside the humans,causing adverse health effects such as respiratory and cardiovascular diseases.Conse-quently,research regarding their toxicity,formation and environmental occurrences in PM_(2.5) has attracted increasing atten-tions globally during the past two decades.However,literature data in this field remain quite limited and discrete.Hence,an extensive review is urgently needed to summarize the current understanding of this topic.In this work,we systematically reviewed the analytical methods and environmental occurrences,e.g.,types,concentrations,and decay behaviors,as well as possible sources of EPFRs in PM_(2.5).The types of pretreatment methods,g-values of common EPFRs and categories of decay processes were discussed in detail.Moreover,great efforts were made to revisit the original data of the published works of EPFRs in airborne particulate matter and provided additional useful information for comparison where possible,e.g.,their mean and standard deviation of g-values,line widths(ΔHp-p),and concentrations.Finally,possible research opportunities were highlighted to further advance our knowledge of this emerging issue.
基金supported by the National Natural Youth Science Foundation of China(42307465).
文摘Emerging environmental persistent free radicals(EPFRs),can generate reactive oxygen species(ROS),posing potential exposure risks to human health.Incomplete coal combustion is a major source of EPFRs.Organic carbonaceous fractions are essential and important players in the formation of EPFRs during coal combustion.However,relationship between individual organic carbonaceous and non-carbon fractions with EPFRs in such emissions are not well known.This paper investigated the characteristics of EPFRs discharged from simulated coal combustion.Our results showed that the concentration of EPFRs was major concentrated on PM 1.1(51.66e81.85%),and more easily oxidized by oxygen resulting in producing more oxygen-centered radicals(semiquinone-type)in PM 1.1.The mean of line width(DHp-p)was 5.87±0.41G higher than that of biomass combustion,indicating more free radical species were emitted from coal combustion.Humic-like substances-carbon(HULIS-C)was the major contributor of the for-mation of EPFRs and facilitate the generated of EPFRs.Secondary processes have also contributed to the formation of EPFRs during the coal combustion.Our result also noted that there was no relationship between transition metals and EPFRs,may be due to the variability and complexity of the chemical properties and composition of PM.This is critical for the prediction of geochemical behavior and risk assessment of EPFRs,which can provide basic data to support policy development to address rural air pollutant emissions.
文摘Emerging pollutants,characterized by high environmental persistence,strong bioaccumulation,and significant biotoxicity,have posed serious threats to humans as well as the environment,and thus attracted global attention.Their rapid identification and precise detection are of critical significance for the risk control of emerging pollutants.
基金supported by the National Natural Science Foundation of China(42222710).
文摘Per-and polyfluoroalkyl substances(PFAS)are a diverse group of synthetic chemicals.Their nu-merous applications in industrial manufacturing and consumer products have resulted in widespread human exposure.Known as“forever chemicals”due to their persistence in the environment,PFAs have been linked to adverse health effects,including increased risks of certain cancers,reduced antibody responses to vaccines,and elevated cholesterol levels,as noted in literature reviews by the us Environmental Protection Agency(EPA).
基金supported by the National Natural Science Foundation of China(92143301 and 91843301)the National Key Research and Development Program of China(2020YFF01014504)the Chinese Academy Sciences Youth Innovation Promotion Association projects。
文摘Aerosol-bound organic radicals,including environmentally persistent free radicals(EPFRs),are key components that affect climate,air quality,and human health.While putative structures have been proposed,the molecular characteristics of EPFRs remain unknown.Here,we report a surrogate method to characterize EPFRs in real ambient samples using mass spectrometry.The method identifies chemically relevant oxygenated polycyclic aromatic hydrocarbons(OxPAH)that interconvert with oxygen-centered EPFR(OC-EPFR).We found OxPAH compounds most relevant to OC-EPFRs are structurally rich and diverse quinones,whose diversity is strongly associated with OC-EPFR levels.Both atmospheric oxidation and combustion contributed to OC-EPFR formation.Redundancy analysis and photochemical aging model show pyrolytic sources generated more oxidized OC-EPFRs than photolytic sources.Our study reveals the detailed molecular characteristics of OC-EPFRs and shows that oxidation states can be used to identify the origins of OC-EPFRs,offering a way to track the development and evolution of aerosol particles in the environment.
基金supported by the National Key Research and Development Program of China(No.2020YFC1808103)Science&Technology Commission of Shanghai Municipality(No.22002400500)+1 种基金National Natural Science Foundation of China(20907029 and 21577085)Natural Science Fund Projects of Shanghai Municipal Science and Technology Commission(No.14ZR1415600).
文摘To reveal the influence of the diversity of precursors on the formation of environmental persistent free radicals(EPFRs),pomelo peel(PP)and its physically divided portion,pomelo cuticle(PC),and white fiber(WF)were used as precursors to prepare six hydrochars:PPH-Fe,PCH-Fe,WFH-Fe,PPH,PCH,and WFH with and without Fe(III)addition during hydrothermal carbonization(HTC).PPH-Fe and WFH-Fe had higher EPFRs content(9.11×10^(18)and 8.25×10^(18)spins·g^(−1))compared to PPH and WFH(3.33×10^(18)and 2.96×10^(18)spins·g^(−1)),indicating that iron-doping favored EPFRs formation.However,PCH-Fe had lower EPFRs content(2.78×10^(18)spins·g^(−1))than PCH(7.95×10^(18)spins·g^(−1)),possibly due to excessive iron leading to the consumption of the generated EPFRs.For another reason,the required Fe(III)amount for EPFRs formation might vary among different precursors.PC has a lower concentration of phenolic compounds but 68-97%fatty acids,while WF and PP are rich in cellulose and lignin.In the Fenton-like reaction,oxygen-centered radicals of hydrochar played a significant role in activating H_(2)O_(2)and efficiently degrading bisphenol A(BPA).Mechanisms of reactive oxygen species(ROS)generation in hydrochar/H_(2)O_(2)system were proposed.EPFRs on hydrochar activate H_(2)O_(2)via electron transfer,creating·OH and 1O2,leading to BPA degradation.More importantly,the embedded EPFRs on the hydrochar’s inner surface contributed to the prolonged Fenton-like reactivity of PPH-Fe stored for 45 days.This study demonstrates that by optimizing precursor selection and iron doping,hydrochars can be engineered to maximize their EPFRs content and reactivity,providing a cost-effective solution for the degradation of hazardous pollutants.
