Anaerobic ammonium oxidation(anammox)plays a vital role in the global nitrogen cycle by mitigating reactive nitrogen.In recent years,its ecological importance has drawn increasing attention.Despite its widespread occu...Anaerobic ammonium oxidation(anammox)plays a vital role in the global nitrogen cycle by mitigating reactive nitrogen.In recent years,its ecological importance has drawn increasing attention.Despite its widespread occurrence,the distribution and quantitative contribution of anammox to global nitrogen loss remain unclear.We collected 390 reported anammox activity measurements which were obtained using 15N isotope tracing techniques and analyzed anammox rate and environmental factors including soil/sediment and water property using generalized additive models(GAMs).Moreover,based on the division of the anammox activity region,we estimated anammox-driven nitrogen loss across different ecosystems including wetlands and oxygen minimum zones(OMZs)ecosystems.Our findings revealed that soil moisture content was the most significant predictor of anammox activity in wetlands ecosystems.Paddy fields contributed 51%of anammox-driven nitrogen loss(32.0 Tg N/yr),followed by rivers/lakes(29%)and wetlands(20%).Asia emerged as the dominant region for anammoxdriven nitrogen loss(30.7 Tg N/yr),with paddy fields making a substantial contribution.North America was the second-largest contributor(25.4 Tg N/yr),with rivers/lakes being the main sources of nitrogen loss.In OMZs ecosystems,nitrate and dissolved oxygen were key factors influencing anammox rates.OMZs were hotspots for anammox,with peak activity at 300 m depth and nitrogen loss totaling 68.6 Tg N/yr,mostly between 100 and 500 m depths.This study underscores the critical role of anammox in global nitrogen cycling and offers a basis for environmental nitrogen management through predictive anammox modeling.展开更多
In order to prevent the emission of NO_(x) from diesel engines during the cold-start period,a NO_(x) adsorption selective catalytic reduction(AdSCR)catalyst was prepared by combining a selective catalytic reduction(SC...In order to prevent the emission of NO_(x) from diesel engines during the cold-start period,a NO_(x) adsorption selective catalytic reduction(AdSCR)catalyst was prepared by combining a selective catalytic reduction(SCR)catalyst with an NO_(x) adsorbent.In this study,CeO_(2)/Al_(2)O_(3)(Ce/Al)was employed as the NO_(x) adsorbent,combined with WO_(3)/CeZrO_(x)(W/CZ)as a promising SCR catalyst,to prepare an AdSCR catalyst.The characterization results demonstrate that the synergistic effects of the combined catalyst significantly enhance the activated oxidation of NO_(x) in comparison to the individual catalysts.The addition of Ce/Al enhances the adsorption of NO_(x) on the catalysts,which is then reduced to N_(2) and H_(2)O by NH_(3) under the action of W/CZ catalysts.The results of the NH_(3)-SCR activity test indicate that an excess of Ce/Al results in a reduction in SCR performance,suggesting that there is a balance between the SCR component and the NO_(x) adsorbent.The optimal combination of 20 wt%Ce/Al+W/CZ(20CA-W/CZ)catalyst demonstrates enhanced NO_(x) adsorption-storage performance while maintaining the exceptional NH_(3)-SCR performance.The NO_(x) complete storage time of the 20CA-W/CZ catalyst is 125 s,which is nearly twice as long as that of the Ce/Al and W/CZ catalysts.Furthermore,the NO_(x) conversion of the 20CA-W/CZ catalyst at low temperatures is approximately 10%higher than that of the W/CZ catalyst.The findings of this study offer a promising s trategy for the design of high-performance AdSCR catalysts in the future.展开更多
La-BiO_(2-x)composite photocatalyst was successfully synthesized through a single-step hydrothermal strategy.The introduction of La3+into the BiO_(2-x)lattice replaces the Bi^(3+)in the BiO_(2-x)lattice,resulting in a...La-BiO_(2-x)composite photocatalyst was successfully synthesized through a single-step hydrothermal strategy.The introduction of La3+into the BiO_(2-x)lattice replaces the Bi^(3+)in the BiO_(2-x)lattice,resulting in a new defect level and oxygen vacancies(Vo)generation.The·O_(2)^(−)generated in the surface of Vo,which was converted into singlet oxygen(1O2)with the transformation of Bi^(5+)to Bi^(3+).Upon visible(near-infrared)light irradiation,the removal rates of tetracycline(TC),oxytetracycline(OTC),and levofloxacin(LEV)by trace 5%La-BiO_(2-x)(0.1 g/L)reached 84.18%(55.56%),78.85%and 70.12%,respectively.The Toxicity Estimation Software Tool(T.E.S.T)based on Quantitative Structure-Activity Relationship(QSAR)models illustrated that the biological toxicity of TC intermediates can be eliminated by 5%La-BiO_(2-x).The green bean germination rates in 5%La-BiO_(2-x)treated TC solution was close to that in the tap water(100.0%).The inorganic anion and humic acid(HA)exhibited almost no influence on the degradation of TC in lake water and river water.This study enhances the comprehension of biological toxicity elimination in antibiotics degradation process,providing the possibilities for actual applications of La-BiO_(2-x).展开更多
Perovskite oxides are highly promising catalysts for the combustion removal of volatile organic compounds(VOCs)due to their excellent stability,structural flexibility,and compositional versatility.This study presents ...Perovskite oxides are highly promising catalysts for the combustion removal of volatile organic compounds(VOCs)due to their excellent stability,structural flexibility,and compositional versatility.This study presents a novel perovskite oxide that exhibits enhanced catalytic activity and superior durability for toluene combustion at reduced temperatures.This improvement is achieved by phosphorus doping at the B-site of LaCoO_(3-δ)(LC)perovskite oxide,followed by post-synthesis acid etching for a proper time.The resulting catalyst demonstrates increased specific surface area,higher total pore volume,and enhanced oxygen vacancy concentration both in the bulk and on the surface.Additionally,the activity of surface lattice oxygen species is significantly improved,leading to enhanced catalytic performance in toluene combustion.Notably,the optimized catalyst shows an exceptionally low activation energy(E_(a))of 49.3 kJ mol^(-1),with a T90 reduction of over 214℃compared to the phosphorus doped LC and 190℃compared to pristine LC.Phosphorus doping plays a main role in significantly improving the long-term durability,particularly in the presence of CO_(2)and H_(2)O,while acid etching boosts the catalytic activity.This work introduces a rational and innovative strategy for optimizing VOC oxidation by improving the structure and surface chemical states of perovskite catalysts.展开更多
Fluoroquinolones(FQs)have the propensity to accumulate in sediments once introduction into aquatic envi-ronments,thereby posing potential threats to benthic organisms,yet the ecotoxicity of sediment-associated FQs rem...Fluoroquinolones(FQs)have the propensity to accumulate in sediments once introduction into aquatic envi-ronments,thereby posing potential threats to benthic organisms,yet the ecotoxicity of sediment-associated FQs remains unclear.In this study,the toxicokinetics and responses of multiple biomarkers in Bellamya aeruginosa,exposed to the three commonly used FQs(norfloxacin,NOR;ciprofloxacin,CIP;levofloxacin,LEVO)at envi-ronmentally relevant concentrations were investigated under sediment exposure scenario.The results revealed that FQs were effectively ingested by B.aeruginosa from sediments,CIP showing the highest bioaccumulation(180.59μg/kg),followed by NOR(74.49μg/kg)and LEVO(36.02μg/kg).CIP exhibiting a highest uptake rate constant(Ks)(4.64 g/(g·day))and the lowest elimination rate constant(K_(e))(0.05 g/(g·day)).The descending order of biological half-life is as follows:CIP(13.62 days),LEVO(8.14 days),and NOR(6.83 days).NOR induced the activity of superoxide dismutase,catalase,and glutathione-S-transferase while CIP and LEVO depressed their activities and increased malondialdehyde content,indicating a more pronounced oxidative damage to B.aerug-inosa caused by CIP and LEVO than NOR.Furthermore,all three FQs were found to induce DNA damage and elevate acetylcholinesterase activity,suggesting distinct genotoxic and neurotoxic effects.Interestingly,despite its low bioaccumulation potential,LEVO exhibited high toxicity towards B.aeruginosa.These findings enhance our understanding of the ecotoxicity of FQs in sediments,providing further evidence of their potential ecological risks.展开更多
The escalating pace of industrialization has significantly intensified water pollution challenges,for instance,the persistent organic pollutants like methyl orange(MO).Conventional remediation techniques,such as adsor...The escalating pace of industrialization has significantly intensified water pollution challenges,for instance,the persistent organic pollutants like methyl orange(MO).Conventional remediation techniques,such as adsorption and biological degradation,are often hampered by low efficiency and the risk of secondary pollution.Photocatalysis emerges as a promising sustainable alternative;however,the benchmark material titanium dioxide(TiO_(2))suffers from its intrinsic limitations,notably its wide bandgap energy(≥3.4 eV)restricting its activity to the region of the ultraviolet light and its rapid recombination of photogenerated charge carriers.To overcome these constraints,this research focused on synthesizing novel TiO_(2)/Sn_(3)O_(4) heterojunction composite photocatalysts via a solvothermal approach.Comprehensive characterization techniques confirmed the successful formation of the composite,which revealed that ultrathin Sn3O4 nanosheets uniformly coated TiO_(2) nanospheres.This unique architecture effectively reduced the overall crystallinity and introduced the beneficial oxygen vacancies.Under visible-light irradiation(λ≥420 nm),the optimized TiO_(2)/Sn3O4 composite exhibited the exceptional photocatalytic performance,which achieved 96%degradation of MO within just 60 minutes.The calculated apparent kinetic rate constant(0.103 min^(-1))was remarkably(5.15 times)higher than that of pristine TiO_(2).ESR experiments identified that hydroxyl radicals(·OH)was the predominant active species driving the degradation.Furthermore,cyclic degradation tests demonstrated its excellent material stability,with the composite retaining 85%of its initial efficiency after four consecutive reuse cycles.This work underscored the synergistic effects within the TiO_(2)/Sn_(3)O_(4) heterojunction,which significantly enhanced the visible-light absorption,charge separation,and photocatalytic activity,which provided the valuable insights for designing efficient,stable catalysts for the advanced environmental remediation applications.展开更多
Anammox bacteria in constructed wetlands(CWs)play pivotal role in sustainable nitrogen transformation,yet existing studies lack comprehensive analysis of environmental gradients and microbial interactions,both key fac...Anammox bacteria in constructed wetlands(CWs)play pivotal role in sustainable nitrogen transformation,yet existing studies lack comprehensive analysis of environmental gradients and microbial interactions,both key factors in anammox bacteria enrichment.This study investigated the mechanisms driving anammox bacteria enrichment in lab-scale simulated CWs treating high-nitrogen wastewater,focusing on bacterial community re-sponses across wetland layers with various strategies,including continuous up-flow influent,nitrogen loading increase,effluent recirculation,intermittent influent,and anammox bacteria inoculation.Results showed that total relative and absolute abundances of anammox bacteria ranged from 0.77%to 12.50%and from 0.13 to 6.46×10^(7) copies/g,respectively.Dissolved oxygen and pH had significant positive correlations with the absolute abundance of anammox bacteria,while organic matter and nitrate negatively impacted their relative abundance.Permutational multivariate analysis of variance indicated that spatial heterogeneity explained more variation in anammox bacteria abundance(43.44%)compared to operational strategies(8.58%).In terms of microbial interactions,60 dominant species exhibited potential correlations with anammox bacteria,comprising 170 interactions(105 positive and 65 negative),which suggested that anammox bacteria generally foster cooperative relationships with dominant bacteria.Notably,significant interspecies interactions were observed between Candidatus Kuenenia(dominant anammox bacteria in CWs)and species within the genera Chitinivibrio-nia and Anaerolineaceae,suggesting that microbial interactions primarily manifest as indirect facilitative effects rather than direct mutualistic relationships.Given that the Normalized Stochasticity Ratio in CWs were<50%,this study inferred that environmental gradients have greater influence on anammox bacteria than microbial interactions.展开更多
To explore the adaptive mechanisms of the partial nitritation-anammox(PNA)process under high salinity stress during kitchen wastewater treatment,focusing on their physiological and molecular responses through metageno...To explore the adaptive mechanisms of the partial nitritation-anammox(PNA)process under high salinity stress during kitchen wastewater treatment,focusing on their physiological and molecular responses through metagenomic analysis.An airlift inner-circulation partition bioreactor(AIPBR)was developed,featuring an inner cylinder and a flow guide tube to create distinct oxygen gradients,facilitating the study of microbial adaptation under varying salt conditions.The AIPBR was operated with synthetic wastewater containing ammonium concentrations of 1800±100 mg/L and salinity gradients ranging from 1 to 10 g/L,followed by a fixed salinity period at 6 g/L,with ammonium concentrations approximately 850 mg/L.High-throughput metagenomic analysis revealed shifts in functional genes and metabolic pathways in response to salinity stress.Anammox bacteria adapted by enriching genes involved in the synthesis of osmoprotective compounds and activating energy-producing pathways like the tricarboxylic acid cycle(TCA).These adaptations,along with modifications in membrane composition,were essential for sustaining system stability under elevated salinity.Under prolonged high salinity stress,anaerobic ammonium oxidizing(AnAOB)exhibited improved salt tolerance,maintaining a total nitrogen removal efficiency above 85%and stabilizing after an adaptation phase.The metagenomic data revealed a marked enrichment of genes associated with ion transport,stress response mechanisms,and DNA repair pathways.Changes in microbial community composition favored salt-tolerant species,supporting system stability.These findings highlight the applicability of the developed bioreactor for scaling up the PNA process to handle high-salinity wastewater,providing a promising avenue for sustainable nitrogen removal in challenging environments.展开更多
Microplastics are becoming well-known as chronic pollutants of terrestrial ecosystems,although their sources,dynamics of transportation,reliability of detection and ecological hazard are not evenly described.This revi...Microplastics are becoming well-known as chronic pollutants of terrestrial ecosystems,although their sources,dynamics of transportation,reliability of detection and ecological hazard are not evenly described.This review is a synthesis of the existing information about microplastics in soils,including analytical detection and characterization techniques,the major sources in the terrestrial environment,transport routes within the compartments and between compartments,and reported ecotoxicological consequences on soil biota,plants,and microbial communities.We also critically discuss the strengths and weaknesses of methodologies,making the distinction of sampling design differences,size detection limits,polymer identification methods,and quality assurance procedures on data comparability and uncertainty.An important outcome of this review is the systematic evaluation of the strength of evidence in three interrelated areas:measurement,environmental transport,and biological impacts,hence explaining which findings are strong and in which areas of research significant knowledge gaps still exist.We also suggest a conceptual framework that strongly connects the measurement uncertainty to the exposure estimation,interpretation of risk,and management relevance.This review uses mechanistic insights into transport and ecotoxicology alongside analysis constraints to add to the more comprehensive foundation of terrestrial risk assessment.Lastly,we determine research priorities,such as harmonized methodologies,realistic exposure scenarios,and cross-scale monitoring strategies,in order to assist in the science-based policies and mitigation action.展开更多
Tropospheric ozone(O_(3))is a harmful air pollutant negatively impacting forest health,causing O_(3)-specific visible foliar injury(O_(3)VFI).Ozone monitoring in forests has usually implemented by passive samplers,alt...Tropospheric ozone(O_(3))is a harmful air pollutant negatively impacting forest health,causing O_(3)-specific visible foliar injury(O_(3)VFI).Ozone monitoring in forests has usually implemented by passive samplers,although they cannot detect the diurnal peak when a significant part of stomatal O_(3)uptake occurs.This results into uncertainties for the calculation of stomatal O_(3)uptake.This study compares the stomatal-flux-based POD1(phytotoxic ozone dose above a threshold of 1 nmol m^(-2)s^(-1))for forest trees/shrubs estimated from data collected by either passive samplers or active O_(3)monitors to evaluate O_(3)damage to plants in terms of O_(3)VFI in the Southern Alps.The study was conducted over two years(2018-2019)in a mountainous Alpine area(Valle Stura,Italy).An integrative monitoring station for active O_(3)monitoring,as well as passive O_(3)monitors,were installed in an open field area(OFD).The O_(3)VFI was investigated in woody species in the light exposed sampling Site(LESS—Betula pendula,Fagus sylvatica,Larix decidua,Populus tremula,Salix caprea,Rubus sp.and Vaccinium myrtillus)in late summer according to the international co-operative programme on assessment and monitoring of air pollution effects on forests(ICP Forests)manual.The results confirmed that Fagus sylvatica and Rubus sp.are O_(3)-sensitive species showing relatively high POD1(>20 mmol m-2),while Larix decidua is O_(3)-tolerant.We derived flux-based critical levels(CL)corresponding to the presence of O_(3)VFI(5,25,and 50%of symptomatic plants along the LESS)from flux-effect relationships for forest protection against O_(3)VFI.The results support the hypothesis that passive samplers cannot detect episodic high stomatal O₃fluxes(>1 nmol m^(-2)s^(-1)).According to the active monitoring,the CL for O_(3)VFI occurrence was estimated to be 17.1 mmol m-2 POD1 for 25%presence and 34.3 mmol m-2 POD1 for 50%presence of symptomatic plants,while passive samplers underestimated POD1 values for CL calculations by 17%on average,with underestimation increasing at higher CL thresholds.The findings demonstrate that active monitoring refines CLs towards a proper quantitative assessment of O_(3)impact,particularly in capturing peak flux events that are crucial for evaluating plant damage and emphasizes the importance of active O₃monitoring for reliable forest health assessments.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750400)the National Natural Science Foundation of China(Nos.91851204,42177063,and 52370185)+1 种基金the Special project of eco-environmental technology for peak carbon dioxide emissions and carbon neutrality(No.RCEES-TDZ-2021-20)the State Key Joint Laboratory of Environmental Simulation and Pollution Control(Research Center for Eco-environmental Sciences,Chinese Academy of Sciences)(No.24Z01ESPCR).
文摘Anaerobic ammonium oxidation(anammox)plays a vital role in the global nitrogen cycle by mitigating reactive nitrogen.In recent years,its ecological importance has drawn increasing attention.Despite its widespread occurrence,the distribution and quantitative contribution of anammox to global nitrogen loss remain unclear.We collected 390 reported anammox activity measurements which were obtained using 15N isotope tracing techniques and analyzed anammox rate and environmental factors including soil/sediment and water property using generalized additive models(GAMs).Moreover,based on the division of the anammox activity region,we estimated anammox-driven nitrogen loss across different ecosystems including wetlands and oxygen minimum zones(OMZs)ecosystems.Our findings revealed that soil moisture content was the most significant predictor of anammox activity in wetlands ecosystems.Paddy fields contributed 51%of anammox-driven nitrogen loss(32.0 Tg N/yr),followed by rivers/lakes(29%)and wetlands(20%).Asia emerged as the dominant region for anammoxdriven nitrogen loss(30.7 Tg N/yr),with paddy fields making a substantial contribution.North America was the second-largest contributor(25.4 Tg N/yr),with rivers/lakes being the main sources of nitrogen loss.In OMZs ecosystems,nitrate and dissolved oxygen were key factors influencing anammox rates.OMZs were hotspots for anammox,with peak activity at 300 m depth and nitrogen loss totaling 68.6 Tg N/yr,mostly between 100 and 500 m depths.This study underscores the critical role of anammox in global nitrogen cycling and offers a basis for environmental nitrogen management through predictive anammox modeling.
基金Project supported by the National Natural Science Foundation of China(22072098)the Sichuan Science and Technology Program(2022ZHCG0125)。
文摘In order to prevent the emission of NO_(x) from diesel engines during the cold-start period,a NO_(x) adsorption selective catalytic reduction(AdSCR)catalyst was prepared by combining a selective catalytic reduction(SCR)catalyst with an NO_(x) adsorbent.In this study,CeO_(2)/Al_(2)O_(3)(Ce/Al)was employed as the NO_(x) adsorbent,combined with WO_(3)/CeZrO_(x)(W/CZ)as a promising SCR catalyst,to prepare an AdSCR catalyst.The characterization results demonstrate that the synergistic effects of the combined catalyst significantly enhance the activated oxidation of NO_(x) in comparison to the individual catalysts.The addition of Ce/Al enhances the adsorption of NO_(x) on the catalysts,which is then reduced to N_(2) and H_(2)O by NH_(3) under the action of W/CZ catalysts.The results of the NH_(3)-SCR activity test indicate that an excess of Ce/Al results in a reduction in SCR performance,suggesting that there is a balance between the SCR component and the NO_(x) adsorbent.The optimal combination of 20 wt%Ce/Al+W/CZ(20CA-W/CZ)catalyst demonstrates enhanced NO_(x) adsorption-storage performance while maintaining the exceptional NH_(3)-SCR performance.The NO_(x) complete storage time of the 20CA-W/CZ catalyst is 125 s,which is nearly twice as long as that of the Ce/Al and W/CZ catalysts.Furthermore,the NO_(x) conversion of the 20CA-W/CZ catalyst at low temperatures is approximately 10%higher than that of the W/CZ catalyst.The findings of this study offer a promising s trategy for the design of high-performance AdSCR catalysts in the future.
基金supported by Hunan Provincial Natural Science Foundation of China(Nos.2022JJ40505 and 2024JJ8069)the National Natural Science Foundation of China(No.21671026)The authors would like to extend their appreciation to Researchers Supporting Project number(RSP-2025-R20),King Saud University,Riyadh,Saudi Arabia.
文摘La-BiO_(2-x)composite photocatalyst was successfully synthesized through a single-step hydrothermal strategy.The introduction of La3+into the BiO_(2-x)lattice replaces the Bi^(3+)in the BiO_(2-x)lattice,resulting in a new defect level and oxygen vacancies(Vo)generation.The·O_(2)^(−)generated in the surface of Vo,which was converted into singlet oxygen(1O2)with the transformation of Bi^(5+)to Bi^(3+).Upon visible(near-infrared)light irradiation,the removal rates of tetracycline(TC),oxytetracycline(OTC),and levofloxacin(LEV)by trace 5%La-BiO_(2-x)(0.1 g/L)reached 84.18%(55.56%),78.85%and 70.12%,respectively.The Toxicity Estimation Software Tool(T.E.S.T)based on Quantitative Structure-Activity Relationship(QSAR)models illustrated that the biological toxicity of TC intermediates can be eliminated by 5%La-BiO_(2-x).The green bean germination rates in 5%La-BiO_(2-x)treated TC solution was close to that in the tap water(100.0%).The inorganic anion and humic acid(HA)exhibited almost no influence on the degradation of TC in lake water and river water.This study enhances the comprehension of biological toxicity elimination in antibiotics degradation process,providing the possibilities for actual applications of La-BiO_(2-x).
基金support from the National Key Research and Development Program of China(Project No.2018YFB1502903).
文摘Perovskite oxides are highly promising catalysts for the combustion removal of volatile organic compounds(VOCs)due to their excellent stability,structural flexibility,and compositional versatility.This study presents a novel perovskite oxide that exhibits enhanced catalytic activity and superior durability for toluene combustion at reduced temperatures.This improvement is achieved by phosphorus doping at the B-site of LaCoO_(3-δ)(LC)perovskite oxide,followed by post-synthesis acid etching for a proper time.The resulting catalyst demonstrates increased specific surface area,higher total pore volume,and enhanced oxygen vacancy concentration both in the bulk and on the surface.Additionally,the activity of surface lattice oxygen species is significantly improved,leading to enhanced catalytic performance in toluene combustion.Notably,the optimized catalyst shows an exceptionally low activation energy(E_(a))of 49.3 kJ mol^(-1),with a T90 reduction of over 214℃compared to the phosphorus doped LC and 190℃compared to pristine LC.Phosphorus doping plays a main role in significantly improving the long-term durability,particularly in the presence of CO_(2)and H_(2)O,while acid etching boosts the catalytic activity.This work introduces a rational and innovative strategy for optimizing VOC oxidation by improving the structure and surface chemical states of perovskite catalysts.
基金supported by the Hunan Provincial Natural Science Foundation of China(Nos.2023JJ40518 and 2023JJ30490)the Scientific Research Foundation of Hunan Provincial Education Department(Nos.21B0511 and 22A0384)the Research Funding Project of Jishou University for talent introduction.
文摘Fluoroquinolones(FQs)have the propensity to accumulate in sediments once introduction into aquatic envi-ronments,thereby posing potential threats to benthic organisms,yet the ecotoxicity of sediment-associated FQs remains unclear.In this study,the toxicokinetics and responses of multiple biomarkers in Bellamya aeruginosa,exposed to the three commonly used FQs(norfloxacin,NOR;ciprofloxacin,CIP;levofloxacin,LEVO)at envi-ronmentally relevant concentrations were investigated under sediment exposure scenario.The results revealed that FQs were effectively ingested by B.aeruginosa from sediments,CIP showing the highest bioaccumulation(180.59μg/kg),followed by NOR(74.49μg/kg)and LEVO(36.02μg/kg).CIP exhibiting a highest uptake rate constant(Ks)(4.64 g/(g·day))and the lowest elimination rate constant(K_(e))(0.05 g/(g·day)).The descending order of biological half-life is as follows:CIP(13.62 days),LEVO(8.14 days),and NOR(6.83 days).NOR induced the activity of superoxide dismutase,catalase,and glutathione-S-transferase while CIP and LEVO depressed their activities and increased malondialdehyde content,indicating a more pronounced oxidative damage to B.aerug-inosa caused by CIP and LEVO than NOR.Furthermore,all three FQs were found to induce DNA damage and elevate acetylcholinesterase activity,suggesting distinct genotoxic and neurotoxic effects.Interestingly,despite its low bioaccumulation potential,LEVO exhibited high toxicity towards B.aeruginosa.These findings enhance our understanding of the ecotoxicity of FQs in sediments,providing further evidence of their potential ecological risks.
文摘The escalating pace of industrialization has significantly intensified water pollution challenges,for instance,the persistent organic pollutants like methyl orange(MO).Conventional remediation techniques,such as adsorption and biological degradation,are often hampered by low efficiency and the risk of secondary pollution.Photocatalysis emerges as a promising sustainable alternative;however,the benchmark material titanium dioxide(TiO_(2))suffers from its intrinsic limitations,notably its wide bandgap energy(≥3.4 eV)restricting its activity to the region of the ultraviolet light and its rapid recombination of photogenerated charge carriers.To overcome these constraints,this research focused on synthesizing novel TiO_(2)/Sn_(3)O_(4) heterojunction composite photocatalysts via a solvothermal approach.Comprehensive characterization techniques confirmed the successful formation of the composite,which revealed that ultrathin Sn3O4 nanosheets uniformly coated TiO_(2) nanospheres.This unique architecture effectively reduced the overall crystallinity and introduced the beneficial oxygen vacancies.Under visible-light irradiation(λ≥420 nm),the optimized TiO_(2)/Sn3O4 composite exhibited the exceptional photocatalytic performance,which achieved 96%degradation of MO within just 60 minutes.The calculated apparent kinetic rate constant(0.103 min^(-1))was remarkably(5.15 times)higher than that of pristine TiO_(2).ESR experiments identified that hydroxyl radicals(·OH)was the predominant active species driving the degradation.Furthermore,cyclic degradation tests demonstrated its excellent material stability,with the composite retaining 85%of its initial efficiency after four consecutive reuse cycles.This work underscored the synergistic effects within the TiO_(2)/Sn_(3)O_(4) heterojunction,which significantly enhanced the visible-light absorption,charge separation,and photocatalytic activity,which provided the valuable insights for designing efficient,stable catalysts for the advanced environmental remediation applications.
基金supported by Natural Science Foundation of Xiamen,China(No.3502Z20227232)the STS Project of Fujian-CAS(No.2023T3018)Bureau of International Cooperation,Chinese Academy of Sciences(No.322GJHZ2022035MI).
文摘Anammox bacteria in constructed wetlands(CWs)play pivotal role in sustainable nitrogen transformation,yet existing studies lack comprehensive analysis of environmental gradients and microbial interactions,both key factors in anammox bacteria enrichment.This study investigated the mechanisms driving anammox bacteria enrichment in lab-scale simulated CWs treating high-nitrogen wastewater,focusing on bacterial community re-sponses across wetland layers with various strategies,including continuous up-flow influent,nitrogen loading increase,effluent recirculation,intermittent influent,and anammox bacteria inoculation.Results showed that total relative and absolute abundances of anammox bacteria ranged from 0.77%to 12.50%and from 0.13 to 6.46×10^(7) copies/g,respectively.Dissolved oxygen and pH had significant positive correlations with the absolute abundance of anammox bacteria,while organic matter and nitrate negatively impacted their relative abundance.Permutational multivariate analysis of variance indicated that spatial heterogeneity explained more variation in anammox bacteria abundance(43.44%)compared to operational strategies(8.58%).In terms of microbial interactions,60 dominant species exhibited potential correlations with anammox bacteria,comprising 170 interactions(105 positive and 65 negative),which suggested that anammox bacteria generally foster cooperative relationships with dominant bacteria.Notably,significant interspecies interactions were observed between Candidatus Kuenenia(dominant anammox bacteria in CWs)and species within the genera Chitinivibrio-nia and Anaerolineaceae,suggesting that microbial interactions primarily manifest as indirect facilitative effects rather than direct mutualistic relationships.Given that the Normalized Stochasticity Ratio in CWs were<50%,this study inferred that environmental gradients have greater influence on anammox bacteria than microbial interactions.
基金supported by China Hunan Provincial Science&Technology Department(No.2023NK2031)the Natural Science Foundation of Hunan Province(No.2023JJ40031)the Ministry of Human Resources and Social Security(No.H20240365).
文摘To explore the adaptive mechanisms of the partial nitritation-anammox(PNA)process under high salinity stress during kitchen wastewater treatment,focusing on their physiological and molecular responses through metagenomic analysis.An airlift inner-circulation partition bioreactor(AIPBR)was developed,featuring an inner cylinder and a flow guide tube to create distinct oxygen gradients,facilitating the study of microbial adaptation under varying salt conditions.The AIPBR was operated with synthetic wastewater containing ammonium concentrations of 1800±100 mg/L and salinity gradients ranging from 1 to 10 g/L,followed by a fixed salinity period at 6 g/L,with ammonium concentrations approximately 850 mg/L.High-throughput metagenomic analysis revealed shifts in functional genes and metabolic pathways in response to salinity stress.Anammox bacteria adapted by enriching genes involved in the synthesis of osmoprotective compounds and activating energy-producing pathways like the tricarboxylic acid cycle(TCA).These adaptations,along with modifications in membrane composition,were essential for sustaining system stability under elevated salinity.Under prolonged high salinity stress,anaerobic ammonium oxidizing(AnAOB)exhibited improved salt tolerance,maintaining a total nitrogen removal efficiency above 85%and stabilizing after an adaptation phase.The metagenomic data revealed a marked enrichment of genes associated with ion transport,stress response mechanisms,and DNA repair pathways.Changes in microbial community composition favored salt-tolerant species,supporting system stability.These findings highlight the applicability of the developed bioreactor for scaling up the PNA process to handle high-salinity wastewater,providing a promising avenue for sustainable nitrogen removal in challenging environments.
文摘Microplastics are becoming well-known as chronic pollutants of terrestrial ecosystems,although their sources,dynamics of transportation,reliability of detection and ecological hazard are not evenly described.This review is a synthesis of the existing information about microplastics in soils,including analytical detection and characterization techniques,the major sources in the terrestrial environment,transport routes within the compartments and between compartments,and reported ecotoxicological consequences on soil biota,plants,and microbial communities.We also critically discuss the strengths and weaknesses of methodologies,making the distinction of sampling design differences,size detection limits,polymer identification methods,and quality assurance procedures on data comparability and uncertainty.An important outcome of this review is the systematic evaluation of the strength of evidence in three interrelated areas:measurement,environmental transport,and biological impacts,hence explaining which findings are strong and in which areas of research significant knowledge gaps still exist.We also suggest a conceptual framework that strongly connects the measurement uncertainty to the exposure estimation,interpretation of risk,and management relevance.This review uses mechanistic insights into transport and ecotoxicology alongside analysis constraints to add to the more comprehensive foundation of terrestrial risk assessment.Lastly,we determine research priorities,such as harmonized methodologies,realistic exposure scenarios,and cross-scale monitoring strategies,in order to assist in the science-based policies and mitigation action.
基金supported by the INTERREG ALCOTRA project MITIMPACT,PNRR for Mission 4(Component 2,Notice 3264/2021,IR0000032)-ITINERIS-Italian Integrated Environmental Research Infrastructure System CUP B53C22002150006Project funded under the National Recovery and Resilience Plan(NRRP),Mission 4 Component 2 Investment 1.4-Call for tender No.3138 of December 16,2021,rectified by Decree n.3175 of December 18,2021 of Italian Ministry of University and Research funded by the European Union-NextGenerationEU,Award Number:Project code CN_00000033,Concession Decree No.1034 of June 17,2022 adopted by the Italian Ministry of University and Research,CUP,H43C22000530001 Project title“National Biodiversity Future Center-NBFC”(Spoke 3 and 5)AP and IP were supported by the FOR-CLIMSOC Programme,Project ID PN23090101,financed by the Ministry of Research,Innovation,and Digitization in Romania.
文摘Tropospheric ozone(O_(3))is a harmful air pollutant negatively impacting forest health,causing O_(3)-specific visible foliar injury(O_(3)VFI).Ozone monitoring in forests has usually implemented by passive samplers,although they cannot detect the diurnal peak when a significant part of stomatal O_(3)uptake occurs.This results into uncertainties for the calculation of stomatal O_(3)uptake.This study compares the stomatal-flux-based POD1(phytotoxic ozone dose above a threshold of 1 nmol m^(-2)s^(-1))for forest trees/shrubs estimated from data collected by either passive samplers or active O_(3)monitors to evaluate O_(3)damage to plants in terms of O_(3)VFI in the Southern Alps.The study was conducted over two years(2018-2019)in a mountainous Alpine area(Valle Stura,Italy).An integrative monitoring station for active O_(3)monitoring,as well as passive O_(3)monitors,were installed in an open field area(OFD).The O_(3)VFI was investigated in woody species in the light exposed sampling Site(LESS—Betula pendula,Fagus sylvatica,Larix decidua,Populus tremula,Salix caprea,Rubus sp.and Vaccinium myrtillus)in late summer according to the international co-operative programme on assessment and monitoring of air pollution effects on forests(ICP Forests)manual.The results confirmed that Fagus sylvatica and Rubus sp.are O_(3)-sensitive species showing relatively high POD1(>20 mmol m-2),while Larix decidua is O_(3)-tolerant.We derived flux-based critical levels(CL)corresponding to the presence of O_(3)VFI(5,25,and 50%of symptomatic plants along the LESS)from flux-effect relationships for forest protection against O_(3)VFI.The results support the hypothesis that passive samplers cannot detect episodic high stomatal O₃fluxes(>1 nmol m^(-2)s^(-1)).According to the active monitoring,the CL for O_(3)VFI occurrence was estimated to be 17.1 mmol m-2 POD1 for 25%presence and 34.3 mmol m-2 POD1 for 50%presence of symptomatic plants,while passive samplers underestimated POD1 values for CL calculations by 17%on average,with underestimation increasing at higher CL thresholds.The findings demonstrate that active monitoring refines CLs towards a proper quantitative assessment of O_(3)impact,particularly in capturing peak flux events that are crucial for evaluating plant damage and emphasizes the importance of active O₃monitoring for reliable forest health assessments.
