As antibiotic pollutants cannot be incompletely removed by conventional wastewater treatment plants,ultraviolet(UV)based advanced oxidation processes(AOPs)such as UV/persulfate(UV/PS)and UV/chlorine are increasingly c...As antibiotic pollutants cannot be incompletely removed by conventional wastewater treatment plants,ultraviolet(UV)based advanced oxidation processes(AOPs)such as UV/persulfate(UV/PS)and UV/chlorine are increasingly concerned for the effective removal of antibiotics from wastewaters.However,the specific mechanisms involving degradation kinetics and transformation mechanisms are not well elucidated.Here we report a detailed examination of SO_(4)•−/Cl•-mediated degradation kinetics,products,and toxicities of sulfathiazole(ST),sarafloxacin(SAR),and lomefloxacin(LOM)in the two processes.Both SO_(4)•−/Cl•-mediated transformation kinetics were found to be dependent on pH(P<0.05),which was attributed to the disparate reactivities of their individual dissociated forms.Based on competition kinetic experiments and matrix calculations,the cationic forms(H_(2)ST^(+),H_(2)SAR^(+),and H_(2)LOM^(+))were more highly reactive towards SO_(4)•−in most cases,while the neutral forms(e.g.,HSAR^(0)and HLOM^(0))reacted the fastest with Cl•for the most of the antibiotics tested.Based on the identification of 31 key intermediates using tandem mass spectrometry,these reactions generated different products,of which the majority still retained the core chemical structure of the parent compounds.The corresponding diverse transformation pathways were proposed,involving S−N breaking,hydroxylation,defluorination,and chlorination reactions.Furthermore,the toxicity changes of their reaction solutions as well as the toxicity of each intermediate were evaluated by the vibrio fischeri and ECOSAR model,respectively.Many primary by-products were proven to be more toxic than the parent chemicals,raising the wider issue of extended potency for these compounds with regards to their ecotoxicity.These results have implications for assessing the degradative fate and risk of these chemicals during the AOPs.展开更多
Acid-base dissociable antibiotic-metal complexes are known to be emerging contaminants in the aquatic environments.However,little information is available on the photochemical properties and toxicity of these complex ...Acid-base dissociable antibiotic-metal complexes are known to be emerging contaminants in the aquatic environments.However,little information is available on the photochemical properties and toxicity of these complex forms.This study investigated the spectral properties of three fluoroquinolones(FQs)with and without metal ions Fe(III),Cu(II),and Al(III)in solutions under different pH conditions,as well as evaluated the changes in toxicity due to the complex with thesemetal ions using luminescent bacteria(vibrio fischeri).FQs showed a higher tendency to coordinate metal ions under alkaline conditions compared to neutral and acidic conditions,and the formation of complexes weakened the ultravioletabsorbing ability of FQs.At pH=7.0,Cu(II)quenched the fluorescence intensity of FQs.Moreover,their Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy were explored,revealing that the coordination sites of Cu(II)in three FQs were situated in a bidentate manner through the oxygen atom of the deprotonated carboxyl group and cyclic carbonyl oxygen atom.This conclusion was further verified by the theory of molecular surface electrostatic potential.In addition,except for complexes of ciprofloxacin-metals,enhanced toxicity of FQs upon coordination with Fe(III)was observed,while reduced toxicity was found for coordination with Cu(II)and Al(III).These results are important for accurately evaluating the photochemical behavior and risk of these antibiotics in aquatic environments contaminated with metal ions.展开更多
Obtaining the sulfonamides(SAs)concentrations in the water body and sediment bulk was a prerequisite to reveal their transport and partitioning behavior in sediment-water environments and accurately assess their ecolo...Obtaining the sulfonamides(SAs)concentrations in the water body and sediment bulk was a prerequisite to reveal their transport and partitioning behavior in sediment-water environments and accurately assess their ecological risk.In the present study,the influences of multifactor interactions on the performance of o-DGTs with XAD-18 binding gels were analyzed by central combination experiments and response surfaces analysis,in which the target compounds were 9 SAs.The results indicated that dissolved organic matter(DOM),pH,and suspended particulate matter(SS)had significant effects on the o-DGT sampling,whereas this o-DGT was independent of the ionic strength(IS).Concentning the composite influence of the four factors,the interaction between DOM and SS posed the most significant effect on all 9 SAs compounds.Subsequently,an o-DGT and DIFSmodel was applied to explore the SAs migration between the water-sediments interface.The difference between desorption rate(k_(b))and adsorption rates(k_(f))values suggested that the kinetics of SAs was dominated by adsorption.Moreover,the short-term sediment-water partitioning of SAs was clarified on the basis of distribution coefficient(K_(dl))for the labile SAs,among which the sulfadiazine(SDZ)had the largest labile pool.The ability of sediments to release SAs to the liquid phase as a sink was determined by response time(T_(c)).Among the 9 SAs,the longterm release of soseulfamethoxypyridazine(SMP)from the solid phase of sediments would have a potential risk to the aquatic environment,to which more attention should be paid in the future.展开更多
Polycyclic aromatic hydrocarbons （PAHs） investigation in different matrices has been reported largely,whereas reports on snow samples were limited.Snow,as the main matrix in the polar region,has an important study m...Polycyclic aromatic hydrocarbons （PAHs） investigation in different matrices has been reported largely,whereas reports on snow samples were limited.Snow,as the main matrix in the polar region,has an important study meaning.PAHs in snow samples were analyzed to investigate the distribution and contamination status of them in the Antarctic,as well as to provide some references for global migration of PAHs.Snow samples collected in Fildes Peninsula were enriched and separated by solid-phase membrane disks and eluted by methylene dichloride,then quantified by gas chromatography/mass spectrometry.All types of PAHs were detected except for Benzo（a）pyrene.Principal component analysis method was applied to characterize them.Three factors （Naphthalene,Fluorene and Phenanthrene） accounted for 60.57%,21.61% and 9.80%,respectively.The results showed that the major PAHs sources maybe the atmospheric transportation,and the combustion of fuel in Fildes Peninsula.The comparison of concentration and types of PAHs between accumulated snow and fresh snow showed that the main compound concentrations in accumulated snow samples were higher than those in fresh ones.The risk assessment indicated that the amount of PAHs in the snow samples would not lead to ecological risk.展开更多
The photochemical behavior of organic pollutants in ice is poorly studied in comparison to aqueous photochemistry.Here we report a detailed comparison of ice and aqueous photodegradation of two representative OH-PAHs,...The photochemical behavior of organic pollutants in ice is poorly studied in comparison to aqueous photochemistry.Here we report a detailed comparison of ice and aqueous photodegradation of two representative OH-PAHs,2-hydroxyfluorene(2-OHFL)and 9-hydroxyfluorene(9-OHFL),which are newly recognized contaminants in the wider environment including colder regions.Interestingly,their photodegradation kinetics were clearly influenced by whether they reside in ice or water.Under the same simulated solar irradiation(λ>290 nm),OHFLs photodegraded faster in ice than in equivalent aqueous solutions and this was attributed to the specific concentration effect caused by freezing.Furthermore,the presence of dissolved constituents in ice also influenced photodegradation with 2-OHFL phototransforming the fastest in‘seawater’ice(k=(11.4±1.0)×10^(−2) min^(−1))followed by‘pure-water’ice((8.7±0.4)×10^(−2) min^(−1))and‘freshwater’ice((8.0±0.7)×10^(−2) min^(−1)).The presence of dissolved constituents(specifically Cl^(−),NO_(3)^(−),Fe(Ⅲ)and humic acid)influences the phototransformation kinetics,either enhancing or suppressing phototransformation,but this is based on the quantity of the constituent present in the matrixes,the specific OHFL isomer and the matrix type(e.g.,ice or aqueous solution).Careful derivation of key photointermediates was undertaken in both ice and water samples using tandem mass spectrometry.Ice phototransformation exhibited fewer by-products and‘simpler’pathways giving rise to a range of hydroxylated fluorenes and hydroxylated fluorenones in ice.These results are of importance when considering the fate of PAHs and OH-PAHs in cold regions and their persistence in sunlit ice.展开更多
In recent years, Dechloranes have been widely detected in the environment around the world.However, understanding and knowledge of Dechloranes in remote regions, such as the Arctic,remain lacking. Therefore, the conce...In recent years, Dechloranes have been widely detected in the environment around the world.However, understanding and knowledge of Dechloranes in remote regions, such as the Arctic,remain lacking. Therefore, the concentrations of 5 Dechloranes in surface seawater, sediment,soil, moss, and dung collected from Ny-lesund in the Arctic were measured with the concentrations 93 pg/L, 342, 325, 1.4, and 258 pg/g, respectively, which were much lower than those in Asian and European regions. The mean ratios of anti-Dechlorane Plus（DP） to total DP（fanti） in seawater, sediment, soil, moss, dung, and atmospheric samples were 0.36, 0.21, 0.18,0.27, 0.66, and 0.43, respectively. Results suggested that the main source of DP in seawater,sediment, soil, and moss was long-range atmospheric transport. However, the ratio identified in dung was different, for which the migration behavior of the organism is probably the main source of DP.展开更多
Kongsfjorden is known for its characteristic multi-layer water mass formed by the convergence of freshwaters from nearby glaciers and rivers and saline water from the Atlantic and Arctic.The distribution of polycyclic...Kongsfjorden is known for its characteristic multi-layer water mass formed by the convergence of freshwaters from nearby glaciers and rivers and saline water from the Atlantic and Arctic.The distribution of polycyclic aromatic hydrocarbons(PAHs)in the water column of Kongsfjorden was investigated and their potential sources were analyzed.The total concentrations of 16 PAHs in the surface seawater and river water were in the range of 33.4-79.8 ng/L(mean 48.5 ng/L)and 2.3-201.4 ng/L(mean 126.1 ng/L),respectively.Horizontally,PAHs were mainly concentrated around river estuaries and the glacier front in the dissolved phase.Vertically,the PAHs in the particulate phase followed surface-enrichment and depth-depletion patterns in most stations,with the maximum concentration found at 50 m depth in the central area of Kongsfjorden.The compositions of PAHs in seawater and rivers were similar,with two-ring and tricyclic PAHs comprising the majority of the dissolved and particulate phases.PAHs found in Kongsfjorden waters appeared to be derived from multiple sources such as petroleum and coal combustion.PAHs in the bay mouth of Kongsfjorden were mainly introduced by the West Spitsbergen Current and the Arctic waters,while in the inner bay,atmospheric deposition and local sources were the major contributors.The distribution of PAHs was mainly attributed to the suspended particulate distribution.展开更多
The presence of antibiotics as emerging micropollutants in the aquatic environment has been raising health concerns for a number of years.Macrolides(MLs)are a large class of widely-used antibiotics,but there is a lack...The presence of antibiotics as emerging micropollutants in the aquatic environment has been raising health concerns for a number of years.Macrolides(MLs)are a large class of widely-used antibiotics,but there is a lack of information on their distribution and risks in surface waters across the central and western regions of China.To clearly describe the pollution characteristics and risks of MLs in Weihe River(the largest tributary of the Yellow River),analysis of 5 typical MLs was conducted using a newly developed LC-MS/MS method for 50 water samples collected over three seasons during 2021-2022.The results revealed that the area showed comparable ML concentrations with other regions worldwide.However,the ML concentrations were much lower than those in the river during 2016 from a previous study.Furthermore,concentrations exhibited significant seasonal variation,with highest concentrations in the winter.Along the main stream of the Weihe River,the sampling sites close to the wastewater treatment plants(WWTPs)and livestock farms exhibited higher concentrations of MLs,indicating the significant contribution from WWTPs and animal husbandry to the emission of MLs.The risk quotients(RQs)suggested that the ecological risks associated with MLs were most pronounced in winter among the three seasons,with erythromycin posing a high or medium risk to algae at all sampling sites.The results of this study will be of importance towards the goal of understanding the presence of these emerging contaminants in surface waters and any required risk reduction measures.展开更多
Most antibiotics contain ionizable groups that undergo acid-base dissociation giving rise to diverse dissociated forms in aquatic systems depending on the pH of the system.In sunlit surface waters,photochemical transf...Most antibiotics contain ionizable groups that undergo acid-base dissociation giving rise to diverse dissociated forms in aquatic systems depending on the pH of the system.In sunlit surface waters,photochemical transformation plays a crucial role in determining the fate of antibiotics.This study presents a comprehensive examination of the photo-transformation degradation kinetics,pathways and photoinduced toxicity of three widely detected tetracyclines(TCs):tetracycline(TC),oxytetracycline(OTC),and chlortetracycline(CTC).Under simulated sunlight(λ>290 nm),their apparent photolysis followed pseudo-first-order kinetics,with rate constants significantly increasing from H_(2)TCs^(0)to TCs^(2–).Through competition kinetic experiments and matrix calculations,it was found that the anions HTCs–or TCs^(2–)(pH~8–10)were more reactive toward hydroxyl radicals(•OH),while TCs^(2–)(pH~10)reacted the fastest with singlet oxygen(^(1)O_(2)).Considering the dissociated species,the total environmental photo-transformation half-lives of TCs were determined,revealing a strong dependence on the water pH and seasonal variation in sunlight.Generally,apparent photolysis was the dominant photochemical process,followed by^(1)O_(2)and•OH oxidation.Different transformation pathways for the three reactions were determined based on the key photoproducts identified using HPLC-MS/MS.Toxicity tests and ECOSAR software calculations confirmed that the intermediates produced by the•OH and 1O_(2)photo-oxidation processes were more toxic than the parent compounds.These findings significantly enhance our understanding of the complex photochemical fate and associated risks of TCs in aqueous environments.展开更多
The photochemistry of organic contaminants present in ice is receiving growing attention,given the wide presence of ice during winter in temperate regions as well as Polar and mountain environments.Differences between...The photochemistry of organic contaminants present in ice is receiving growing attention,given the wide presence of ice during winter in temperate regions as well as Polar and mountain environments.Differences between ice photochemistry and aqueous photochemistry,however,influence the quanti-tative fate and transformation of organic chemicals present in freshwater,marine and ice-cap environ-ments and these differences need to be explored.Here we comparatively studied the ice and aqueous photochemistry of three antibiotics[levofloxacin(LVX),sulfamerazine(SM),and chlortetracycline(CTC)]under the same simulated sunlight(λ>290 nm).Their photodegradation in ice/water followed pseudo-first-order kinetics,whereby the photolytic rates of LVX in ice and water were found to be similar,SM photodegraded faster in ice,while CTC underwent slower photodegradation in ice.Whether individual antibiotics underwent faster photodegradation in ice or not depends on the specific concentration effect and cage effect coexisting in the ice compartment.In most cases,the fastest photodegradation occurred in freshwater ice or in fresh water,and the slowest photolysis occurred in pure-water ice or in pure water.This can be attributed to the effects of key photochemical reactive constituents of Cl^(-),HA,NO_(3)^(-)and Fe(Ⅲ),that exist in natural waters.These constituents at certain levels showed significant effects(P<0.1)on the photolysis,not only in ice but also in water.However,these individual constituents at a given concentration,serve to either enhance or suppress the photoreaction,depending on the specific antibiotic and the matrix type(e.g.,ice or aqueous solution).Furthermore,extrapolation of the laboratory findings to cold environments indicate that pharmaceuticals present in ice will have a different photofate compared to water.These results are of particular relevance for those regions that experience seasonal ice cover in fresh water and coastal marine systems.展开更多
基金supported by the Key Research and Development Program of Shaanxi Province(No.2024SF-YBXM-567)the National Natural Science Foundation of China(Nos.21976045,22076112)the China Scholarship Council(CSC)Scholarship(No.202308610123).
文摘As antibiotic pollutants cannot be incompletely removed by conventional wastewater treatment plants,ultraviolet(UV)based advanced oxidation processes(AOPs)such as UV/persulfate(UV/PS)and UV/chlorine are increasingly concerned for the effective removal of antibiotics from wastewaters.However,the specific mechanisms involving degradation kinetics and transformation mechanisms are not well elucidated.Here we report a detailed examination of SO_(4)•−/Cl•-mediated degradation kinetics,products,and toxicities of sulfathiazole(ST),sarafloxacin(SAR),and lomefloxacin(LOM)in the two processes.Both SO_(4)•−/Cl•-mediated transformation kinetics were found to be dependent on pH(P<0.05),which was attributed to the disparate reactivities of their individual dissociated forms.Based on competition kinetic experiments and matrix calculations,the cationic forms(H_(2)ST^(+),H_(2)SAR^(+),and H_(2)LOM^(+))were more highly reactive towards SO_(4)•−in most cases,while the neutral forms(e.g.,HSAR^(0)and HLOM^(0))reacted the fastest with Cl•for the most of the antibiotics tested.Based on the identification of 31 key intermediates using tandem mass spectrometry,these reactions generated different products,of which the majority still retained the core chemical structure of the parent compounds.The corresponding diverse transformation pathways were proposed,involving S−N breaking,hydroxylation,defluorination,and chlorination reactions.Furthermore,the toxicity changes of their reaction solutions as well as the toxicity of each intermediate were evaluated by the vibrio fischeri and ECOSAR model,respectively.Many primary by-products were proven to be more toxic than the parent chemicals,raising the wider issue of extended potency for these compounds with regards to their ecotoxicity.These results have implications for assessing the degradative fate and risk of these chemicals during the AOPs.
基金supported by the National Natural Science Foundation of China(Nos.21976045 and 22076112)China Scholarship Council(CSC)Scholarship(Nos.202208610125 and 202308610123)+1 种基金Shaanxi Key Laboratory of Environmental Monitoring and Forewarning of Trace Pollutants(No.SHJKFJJ202318)the Key Research and Development Program of Shaanxi Province(No.2024SF-YBXM-567).
文摘Acid-base dissociable antibiotic-metal complexes are known to be emerging contaminants in the aquatic environments.However,little information is available on the photochemical properties and toxicity of these complex forms.This study investigated the spectral properties of three fluoroquinolones(FQs)with and without metal ions Fe(III),Cu(II),and Al(III)in solutions under different pH conditions,as well as evaluated the changes in toxicity due to the complex with thesemetal ions using luminescent bacteria(vibrio fischeri).FQs showed a higher tendency to coordinate metal ions under alkaline conditions compared to neutral and acidic conditions,and the formation of complexes weakened the ultravioletabsorbing ability of FQs.At pH=7.0,Cu(II)quenched the fluorescence intensity of FQs.Moreover,their Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy were explored,revealing that the coordination sites of Cu(II)in three FQs were situated in a bidentate manner through the oxygen atom of the deprotonated carboxyl group and cyclic carbonyl oxygen atom.This conclusion was further verified by the theory of molecular surface electrostatic potential.In addition,except for complexes of ciprofloxacin-metals,enhanced toxicity of FQs upon coordination with Fe(III)was observed,while reduced toxicity was found for coordination with Cu(II)and Al(III).These results are important for accurately evaluating the photochemical behavior and risk of these antibiotics in aquatic environments contaminated with metal ions.
基金supported by the National Natural Science Foundation of China(Nos.21976045 and 22076112)the CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation(No.2020KFJJ03).
文摘Obtaining the sulfonamides(SAs)concentrations in the water body and sediment bulk was a prerequisite to reveal their transport and partitioning behavior in sediment-water environments and accurately assess their ecological risk.In the present study,the influences of multifactor interactions on the performance of o-DGTs with XAD-18 binding gels were analyzed by central combination experiments and response surfaces analysis,in which the target compounds were 9 SAs.The results indicated that dissolved organic matter(DOM),pH,and suspended particulate matter(SS)had significant effects on the o-DGT sampling,whereas this o-DGT was independent of the ionic strength(IS).Concentning the composite influence of the four factors,the interaction between DOM and SS posed the most significant effect on all 9 SAs compounds.Subsequently,an o-DGT and DIFSmodel was applied to explore the SAs migration between the water-sediments interface.The difference between desorption rate(k_(b))and adsorption rates(k_(f))values suggested that the kinetics of SAs was dominated by adsorption.Moreover,the short-term sediment-water partitioning of SAs was clarified on the basis of distribution coefficient(K_(dl))for the labile SAs,among which the sulfadiazine(SDZ)had the largest labile pool.The ability of sediments to release SAs to the liquid phase as a sink was determined by response time(T_(c)).Among the 9 SAs,the longterm release of soseulfamethoxypyridazine(SMP)from the solid phase of sediments would have a potential risk to the aquatic environment,to which more attention should be paid in the future.
基金supported by the State Ocean Administration Young Scientists Research Program of China (No.2009507)the China Marine Public-welfare Program (No.200805095,201105013)
文摘Polycyclic aromatic hydrocarbons （PAHs） investigation in different matrices has been reported largely,whereas reports on snow samples were limited.Snow,as the main matrix in the polar region,has an important study meaning.PAHs in snow samples were analyzed to investigate the distribution and contamination status of them in the Antarctic,as well as to provide some references for global migration of PAHs.Snow samples collected in Fildes Peninsula were enriched and separated by solid-phase membrane disks and eluted by methylene dichloride,then quantified by gas chromatography/mass spectrometry.All types of PAHs were detected except for Benzo（a）pyrene.Principal component analysis method was applied to characterize them.Three factors （Naphthalene,Fluorene and Phenanthrene） accounted for 60.57%,21.61% and 9.80%,respectively.The results showed that the major PAHs sources maybe the atmospheric transportation,and the combustion of fuel in Fildes Peninsula.The comparison of concentration and types of PAHs between accumulated snow and fresh snow showed that the main compound concentrations in accumulated snow samples were higher than those in fresh ones.The risk assessment indicated that the amount of PAHs in the snow samples would not lead to ecological risk.
基金supported by the National Natural Science Foundation of China (Nos. 21976045, 22076112)the CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation (No. 2020KFJJ03)+2 种基金the State Environmental Protection Key Laboratory of Coastal Ecosystem (No. 202102)the China Scholarship Council (CSC) Scholarship (Nos. 201704180014, 201704180009)the Chinese Arctic and Antarctic Administration
文摘The photochemical behavior of organic pollutants in ice is poorly studied in comparison to aqueous photochemistry.Here we report a detailed comparison of ice and aqueous photodegradation of two representative OH-PAHs,2-hydroxyfluorene(2-OHFL)and 9-hydroxyfluorene(9-OHFL),which are newly recognized contaminants in the wider environment including colder regions.Interestingly,their photodegradation kinetics were clearly influenced by whether they reside in ice or water.Under the same simulated solar irradiation(λ>290 nm),OHFLs photodegraded faster in ice than in equivalent aqueous solutions and this was attributed to the specific concentration effect caused by freezing.Furthermore,the presence of dissolved constituents in ice also influenced photodegradation with 2-OHFL phototransforming the fastest in‘seawater’ice(k=(11.4±1.0)×10^(−2) min^(−1))followed by‘pure-water’ice((8.7±0.4)×10^(−2) min^(−1))and‘freshwater’ice((8.0±0.7)×10^(−2) min^(−1)).The presence of dissolved constituents(specifically Cl^(−),NO_(3)^(−),Fe(Ⅲ)and humic acid)influences the phototransformation kinetics,either enhancing or suppressing phototransformation,but this is based on the quantity of the constituent present in the matrixes,the specific OHFL isomer and the matrix type(e.g.,ice or aqueous solution).Careful derivation of key photointermediates was undertaken in both ice and water samples using tandem mass spectrometry.Ice phototransformation exhibited fewer by-products and‘simpler’pathways giving rise to a range of hydroxylated fluorenes and hydroxylated fluorenones in ice.These results are of importance when considering the fate of PAHs and OH-PAHs in cold regions and their persistence in sunlit ice.
基金supported by the National Natural Science Foundation of China (No. 21377032)the Chinese Polar Environment Comprehensive Investigation and Assessment Program (Nos. 2014-02-01, 2014-03-04, 2014-04-01, 2014-04-03)+1 种基金the Marine Public Welfare Scientific Research Projects (No. 201105013)the Foundation of Polar Science Key Laboratory, SOA, China (No. KP201208)
文摘In recent years, Dechloranes have been widely detected in the environment around the world.However, understanding and knowledge of Dechloranes in remote regions, such as the Arctic,remain lacking. Therefore, the concentrations of 5 Dechloranes in surface seawater, sediment,soil, moss, and dung collected from Ny-lesund in the Arctic were measured with the concentrations 93 pg/L, 342, 325, 1.4, and 258 pg/g, respectively, which were much lower than those in Asian and European regions. The mean ratios of anti-Dechlorane Plus（DP） to total DP（fanti） in seawater, sediment, soil, moss, dung, and atmospheric samples were 0.36, 0.21, 0.18,0.27, 0.66, and 0.43, respectively. Results suggested that the main source of DP in seawater,sediment, soil, and moss was long-range atmospheric transport. However, the ratio identified in dung was different, for which the migration behavior of the organism is probably the main source of DP.
基金supported by the National Key R&D Program of China(2019YFD0901104)the National Natural Science Foun-dation of China(Nos.41976222,21377032)+1 种基金the Open Fund for the Key Laboratory of Ocean-Atmospheric Chemistry and Global Change,State Oceanic Administration(No.GCMAC1812)the Open Fund for the State Key Laboratory of Environmental Chemistry and Ecotoxicology(No.KF2018-05)。
文摘Kongsfjorden is known for its characteristic multi-layer water mass formed by the convergence of freshwaters from nearby glaciers and rivers and saline water from the Atlantic and Arctic.The distribution of polycyclic aromatic hydrocarbons(PAHs)in the water column of Kongsfjorden was investigated and their potential sources were analyzed.The total concentrations of 16 PAHs in the surface seawater and river water were in the range of 33.4-79.8 ng/L(mean 48.5 ng/L)and 2.3-201.4 ng/L(mean 126.1 ng/L),respectively.Horizontally,PAHs were mainly concentrated around river estuaries and the glacier front in the dissolved phase.Vertically,the PAHs in the particulate phase followed surface-enrichment and depth-depletion patterns in most stations,with the maximum concentration found at 50 m depth in the central area of Kongsfjorden.The compositions of PAHs in seawater and rivers were similar,with two-ring and tricyclic PAHs comprising the majority of the dissolved and particulate phases.PAHs found in Kongsfjorden waters appeared to be derived from multiple sources such as petroleum and coal combustion.PAHs in the bay mouth of Kongsfjorden were mainly introduced by the West Spitsbergen Current and the Arctic waters,while in the inner bay,atmospheric deposition and local sources were the major contributors.The distribution of PAHs was mainly attributed to the suspended particulate distribution.
基金supported by the National Natural Science Foundation of China(21976045 and 22076112)China Scholarship Council(CSC)Scholarship(202308610123,202208610125)+2 种基金the Key Research and Development Program of Shaanxi Province(2024SF-YBXM-567)Shaanxi Key Laboratory for Environmental Monitoring and Forewarning of Trace Pollutants(SHJKFJJ202318)the Key Laboratory for Ecology and Environment of River Wetlands in Shaanxi Province(SXSD202403).
文摘The presence of antibiotics as emerging micropollutants in the aquatic environment has been raising health concerns for a number of years.Macrolides(MLs)are a large class of widely-used antibiotics,but there is a lack of information on their distribution and risks in surface waters across the central and western regions of China.To clearly describe the pollution characteristics and risks of MLs in Weihe River(the largest tributary of the Yellow River),analysis of 5 typical MLs was conducted using a newly developed LC-MS/MS method for 50 water samples collected over three seasons during 2021-2022.The results revealed that the area showed comparable ML concentrations with other regions worldwide.However,the ML concentrations were much lower than those in the river during 2016 from a previous study.Furthermore,concentrations exhibited significant seasonal variation,with highest concentrations in the winter.Along the main stream of the Weihe River,the sampling sites close to the wastewater treatment plants(WWTPs)and livestock farms exhibited higher concentrations of MLs,indicating the significant contribution from WWTPs and animal husbandry to the emission of MLs.The risk quotients(RQs)suggested that the ecological risks associated with MLs were most pronounced in winter among the three seasons,with erythromycin posing a high or medium risk to algae at all sampling sites.The results of this study will be of importance towards the goal of understanding the presence of these emerging contaminants in surface waters and any required risk reduction measures.
基金supported by the Key Research and Development Program of Shaanxi Province(No.2024SF-YBXM-567)the National Natural Science Foundation of China(Nos.21976045 and 22076112)+1 种基金the China Scholarship Council(CSC)Scholarship(No.202308610123)the Shaanxi Key Laboratory of Environmental Monitoring and Forewarning of Trace Pollutants(No.SHJKFJJ202318).
文摘Most antibiotics contain ionizable groups that undergo acid-base dissociation giving rise to diverse dissociated forms in aquatic systems depending on the pH of the system.In sunlit surface waters,photochemical transformation plays a crucial role in determining the fate of antibiotics.This study presents a comprehensive examination of the photo-transformation degradation kinetics,pathways and photoinduced toxicity of three widely detected tetracyclines(TCs):tetracycline(TC),oxytetracycline(OTC),and chlortetracycline(CTC).Under simulated sunlight(λ>290 nm),their apparent photolysis followed pseudo-first-order kinetics,with rate constants significantly increasing from H_(2)TCs^(0)to TCs^(2–).Through competition kinetic experiments and matrix calculations,it was found that the anions HTCs–or TCs^(2–)(pH~8–10)were more reactive toward hydroxyl radicals(•OH),while TCs^(2–)(pH~10)reacted the fastest with singlet oxygen(^(1)O_(2)).Considering the dissociated species,the total environmental photo-transformation half-lives of TCs were determined,revealing a strong dependence on the water pH and seasonal variation in sunlight.Generally,apparent photolysis was the dominant photochemical process,followed by^(1)O_(2)and•OH oxidation.Different transformation pathways for the three reactions were determined based on the key photoproducts identified using HPLC-MS/MS.Toxicity tests and ECOSAR software calculations confirmed that the intermediates produced by the•OH and 1O_(2)photo-oxidation processes were more toxic than the parent compounds.These findings significantly enhance our understanding of the complex photochemical fate and associated risks of TCs in aqueous environments.
基金supported by the National Natural Science Foundation of China(21976045 and 22076112)China Scholarship Council(CSC)Scholarship(202308610123,202208610125)+1 种基金the Key Research and Development Program of Shaanxi Province(No.2024SF-YBXM-567)the Shaanxi Key Laboratory for Environmental Monitoring and Forewarning of Trace Pollutants(SHJKFJJ202318).
文摘The photochemistry of organic contaminants present in ice is receiving growing attention,given the wide presence of ice during winter in temperate regions as well as Polar and mountain environments.Differences between ice photochemistry and aqueous photochemistry,however,influence the quanti-tative fate and transformation of organic chemicals present in freshwater,marine and ice-cap environ-ments and these differences need to be explored.Here we comparatively studied the ice and aqueous photochemistry of three antibiotics[levofloxacin(LVX),sulfamerazine(SM),and chlortetracycline(CTC)]under the same simulated sunlight(λ>290 nm).Their photodegradation in ice/water followed pseudo-first-order kinetics,whereby the photolytic rates of LVX in ice and water were found to be similar,SM photodegraded faster in ice,while CTC underwent slower photodegradation in ice.Whether individual antibiotics underwent faster photodegradation in ice or not depends on the specific concentration effect and cage effect coexisting in the ice compartment.In most cases,the fastest photodegradation occurred in freshwater ice or in fresh water,and the slowest photolysis occurred in pure-water ice or in pure water.This can be attributed to the effects of key photochemical reactive constituents of Cl^(-),HA,NO_(3)^(-)and Fe(Ⅲ),that exist in natural waters.These constituents at certain levels showed significant effects(P<0.1)on the photolysis,not only in ice but also in water.However,these individual constituents at a given concentration,serve to either enhance or suppress the photoreaction,depending on the specific antibiotic and the matrix type(e.g.,ice or aqueous solution).Furthermore,extrapolation of the laboratory findings to cold environments indicate that pharmaceuticals present in ice will have a different photofate compared to water.These results are of particular relevance for those regions that experience seasonal ice cover in fresh water and coastal marine systems.
